Aperture Mechanism

Abstract

The present application provides an aperture mechanism that can reduce the size of the aperture configuration and has a simple configuration. The aperture mechanism includes a rotary drive unit 2 having a rotary ring 21 that rotates around the optical axis and a drive source unit 22 that generates a drive force to rotate the rotary ring 21, and an aperture unit 3 that engages with the rotary ring 21 and has multiple aperture plates 31-31 arranged around the optical axis and is swung as the rotary ring 21 rotates, and can expand and reduce an opening area through which light passes as the multiple aperture plates 31-31 swish. The drive source unit 22 includes a piezoelectric element 1 that deforms when electricity is applied, and a pressing unit that is provided to be interlocked with the piezoelectric element and can abut against the rotary ring 21. The aperture mechanism 1 rotates the rotary ring 21 by deforming the piezoelectric element when electricity is applied, and pressing the pressing unit against the rotary ring 21 with a force having a circumferential component.

Description

[Technical field]

[0001] The present invention relates to an aperture mechanism used in cameras built into smartphones and small cameras. [Background technology]

[0002] As an example of the conventional technology, there is an aperture mechanism described in Japanese Patent Application Laid-Open No. 2011-90028. In this conventional technology, the aperture is operated by a lever, and therefore the configuration is complicated. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of this, an object of the present invention is to provide an aperture mechanism that can reduce the size of the aperture structure and has a simple structure. [Means for solving the problem]

[0004] One form of the present invention is an aperture mechanism comprising: a rotary drive unit having a rotary ring that rotates around the optical axis; and a drive source unit that generates a drive force to rotate the rotary ring; and an aperture unit having a plurality of aperture plates arranged around the optical axis that engage with the rotary ring and are oscillated as the rotary ring rotates, and which can expand and reduce the opening area through which light passes as the plurality of aperture plates oscillate, wherein the drive source unit comprises a piezoelectric element that deforms when electricity is passed through it, and a pressing unit that is arranged in conjunction with the piezoelectric element and can abut against the rotary ring, and which rotates the rotary ring by deforming the piezoelectric element when electricity is passed through it, causing the pressing unit to press against the rotary ring with a force having a circumferential component.

[0005] In addition, each of the multiple throttling plates is supported on a shaft at the center of the oscillation on the radially outer side of the throttling section, and a notch is formed in the edge at the tip side of the oscillation for enlarging and reducing the opening area, and an engagement portion that engages with the rotating ring is provided between the supported part and the notch.

[0006] In addition, the rotational locus of the rotating ring and the swinging locus of each of the multiple diaphragm plates intersect, and engagement by the engagement portion is achieved by a combination of a convex portion provided on one of the diaphragm plate and the rotating ring and a concave portion provided on the other, and the transverse dimension of the concave portion is larger than the transverse dimension of the convex portion.

[0007] The recess may have an elliptical shape when viewed in the optical axis direction.

[0008] The drive source may be provided so as to be able to come into contact with an outer circumferential surface of the rotary ring in a radial direction.

[0009] In addition, the diaphragm section can have an even number of the diaphragm plates, and in the portions that overlap each other during the swinging motion, the diaphragm plates located in the front and rear in the optical axis direction can be arranged adjacent to each other in the circumferential direction.

[0010] Also, a permanent magnet may be provided on the rotating ring, and a magnetic sensor may be provided radially outside the rotating ring.

[0011] Another aspect of the present invention is a camera module including one or more lenses and the aperture mechanism according to any one of the above aspects. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an exploded perspective view showing a schematic structure of an aperture mechanism according to an embodiment of the present invention, with each component disassembled and arranged in the optical axis direction. [Diagram 2]FIG. 2 is a perspective view showing the diaphragm mechanism in an assembled state. [Diagram 3] FIG. 3 is a perspective view showing a rotary drive unit and a diaphragm unit of the diaphragm mechanism, as viewed from the bottom side. [Figure 4] FIG. 4 is a perspective view showing the throttle portion in an open state. [Diagram 5] FIG. 5 is a perspective view showing a state in which the throttle portion is throttled. [Figure 6] FIG. 6 is a plan view showing the drive source of the rotation drive unit (as a throttle mechanism). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An aperture mechanism 1 according to one embodiment of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the terms "optical axis direction," "circumferential direction," "radial direction," "inner diameter," and "outer diameter" refer to directions in the aperture mechanism 1 as a whole. In other words, the direction that rotates around the optical axis direction in the aperture mechanism 1 is the circumferential direction. And the direction perpendicular to the optical axis direction is the radial direction. Also, "forward" refers to the direction facing the subject in the optical axis direction, and "rearward" refers to the direction facing the image sensor of the camera in the optical axis direction.

[0014] FIG. 1 shows an exploded view of the entire camera. The upper side of the figure is the front in the optical axis direction, and the lower side is the rear in the optical axis direction. The part not shown exploded, shown at the lower left of FIG. 1, is the lens drive mechanism X that receives the light beam narrowed down by the aperture mechanism 1. Since the lens drive mechanism X is not directly related to the present invention, detailed description will not be given below except for necessary matters. The aperture mechanism 1 is configured by arranging a rotary drive unit 2, an aperture unit 3, and a support plate 4 in this order from the front side (subject side) toward the lens drive mechanism X in the optical axis direction, and these are provided in a housing 6. The housing 6 is also used as the housing of the lens drive mechanism X. The support plate 4 is also used as the lens drive mechanism X. Inside the housing 6, in front of the rotary drive unit 2, one set or one lens 7 of the multiple lenses that make up the camera is provided.

[0015] The diaphragm mechanism 1 is provided in front of the lens driving mechanism X (excluding the housing). A cylindrical body X1, which is a part of the lens driving mechanism X, moves back and forth along the optical axis direction due to an autofocus function. The entire diaphragm mechanism 1 is also configured to move back and forth in conjunction with (synchronous movement with) the cylindrical body X1. By configuring the diaphragm mechanism 1 to move back and forth in this way in conjunction with the lens driving mechanism X, the optical characteristics (specifically, MTF) of the camera can be improved compared to a configuration in which the diaphragm mechanism 1 is fixedly provided regardless of the autofocus function.

[0016] The rotary drive unit 2 includes a rotary ring 21 that rotates in a direction R around an optical axis set in the camera, and a drive source unit 22 that generates a drive force to rotate the rotary ring 21. The rotary ring 21 rotates by receiving a drive force from the drive source unit 22 within a range in which an engagement protrusion 212 (described later) moves in a circumferential direction corresponding to a swing range of each diaphragm plate 31 for opening and closing the diaphragm unit 3. The rotary ring 21 may be configured to rotate steplessly through a predetermined angle according to the opening and closing of the diaphragm, or may be configured to rotate in multiple steps like a stepping motor. The rotary ring 21 is annular in shape with its center in the optical axis direction aligned with the optical axis so that light (light corresponding to a subject input to an imaging element of the camera) passes through the center.

[0017] In this embodiment, the radial cross section of the rotary ring 21 is rectangular. The rear surface (lower surface in the figure) of the rotary ring 21 has four recesses 211 recessed forward (upward in the figure) at four circumferential positions (the same as the number of the diaphragm plates 31-31). The rear surface of the recesses 211 is flat and abuts against the front surface of the second base portion 312 of each diaphragm plate 31, which is also flat. The outer peripheral surface 213 in the radial direction of the rotary ring 21 is provided with a gap so as not to interfere with the first base portion 311 of each diaphragm plate 31. The circumferential dimension of the recesses 211 is formed larger than the swing range of the second base portion 312 of each diaphragm plate 31. As shown in FIG. 3, an engagement protrusion 212 protrudes rearward (downward in the figure) from the recesses 211. The engagement protrusion 212 is cylindrical with a cross section that is a perfect circle. The protruding position of the engagement projection 212 in the recess 211 is determined according to the swing range of each diaphragm plate 31. In this embodiment, the engagement projection 212 is formed in a position offset from the center of the recess 211 in the circumferential direction toward the end portion.

[0018] The rotary drive unit 2 is held down from the front by the holding unit 5 (frame unit 51, sliding ring 52), and is positioned in the optical axis direction set in the camera. A plurality of (specifically, three) cylindrical pins 23 are embedded in the inner diameter part of the rotary ring 21. Each pin 23 abuts against the outer peripheral surface (not shown) on the radially outer side of the regulating wall part 511 provided on the inner peripheral side of the frame part 51. This positions the rotary ring 21 in the radial direction. In addition, the front surface of the rotary ring 21 is held down from the front by the frame part 51 via the sliding ring 52, and is positioned in the optical axis direction. The sliding ring 52 is a flat sheet with an annular shape, and the friction coefficient of the surface is smaller than that of other parts. Slip occurs between the front surface of the rotary ring 21 and the sliding ring 52, so that the rotary ring 21 can rotate smoothly without being hindered from rotating in the circumferential direction.

[0019] 2, permanent magnets 24 are embedded in the outer periphery of rotating ring 21, and a magnetic sensor (not shown), such as a Hall sensor or MR sensor, that reacts to the magnetism of permanent magnet 24 is provided on the outside of rotating ring 21, radially outward. This makes it possible to detect the rotational position of rotating ring 21. The detection result is sent to a control unit (not shown) of the smartphone or camera, and is used for controlling the aperture.

[0020] As shown in FIG. 6, the driving source unit 22 includes a base 221, a buffer unit 222, a guide pin 223, a holder 224, a first driving body 225, and a second driving body 226. In FIG. 6, the base 221 and the like are shown at the top, and the driving bodies 225 and 226 are shown at the bottom. The plate-like portion protruding to the side shown in FIG. 2 and the like is a power supply board (FPC) 228. Each of the first driving body 225 and the second driving body 226 includes piezoelectric elements 2251 and 2261 that are deformed (specifically, extended) by energization, and pressing parts 2252 and 2262 that are provided to be interlocked with the piezoelectric elements 2251 and 2261 and are provided so as to be able to abut against the surface of the rotating ring 21 in the rotating driving unit 2 (in this embodiment, the outer peripheral surface 213 in the radial direction of the rotating ring 21). In this embodiment, the rotating ring 21 and the driving source unit 22 can be arranged at the same position in the optical axis direction. Therefore, the driving side member (driving source unit 22) and the driven side member (rotating ring 21) can be arranged compactly in the optical axis direction. In addition, the rotating ring 21 and the driving source unit 22 have approximately the same dimensions in the optical axis direction. This makes it possible to prevent the optical axis direction dimension from increasing (becoming thicker) when the rotating ring 21 and the driving source unit 22 are combined. Therefore, in this embodiment, the optical axis direction dimension can be made smaller than in a configuration in which the diaphragm unit 3 is driven by, for example, a motor and gears. In addition, the configuration can be simplified.

[0021] The base 221 is a part fixed to the frame 51. The base 221 in this embodiment is formed in a cylindrical shape with a bottom, and the holder 224 is provided inside so as to be movable back and forth with respect to the base 221 (so as to be movable in the radial direction of the entire aperture mechanism 1). A first driving body 225 and a second driving body 226, which are symmetrically shaped, are fixed to the holder 224. In other words, the driving source unit 22 integrally includes the first driving body 225 and the second driving body 226. The buffer unit 222 is provided between the base 221 and the holder 224. The buffer unit 222 expands and contracts with the movement of the holder 224. The buffer unit 222 in this embodiment is made of a rubber plate made of silicon or the like. The guide pin 223 penetrates the base 221 along the optical axis direction. The holder 224 and the buffer part 222 are formed with an elongated hole 227 extending in the front-rear direction with respect to the base part 221, and the guide pin 223 passes through this elongated hole 227. Therefore, the holder 224, the first driving body 225 and the second driving body 226 are movable forward and backward within the range in which the elongated hole 227 is formed relative to the base part 221.

[0022] The first driving body 225 is located on one side in the circumferential direction of the rotary ring 21. The second driving body 226 is located on the other side in the circumferential direction of the rotary ring 21. Each of the first driving body 225 and the second driving body 226 includes piezoelectric elements 2251, 2261 that expand when a positive voltage is applied and contract when a reverse voltage is applied, and pressing parts 2252, 2262 that are provided to be interlocked with the piezoelectric elements 2251, 2261 and are capable of contacting the surface of the rotary ring 21 (the outer peripheral surface 213 in this embodiment). As shown in the figure, the pressing parts 2252, 2262 in this embodiment abut against the outer peripheral surface 213 of the rotary ring 21 when no current is applied to the piezoelectric elements 2251, 2261, but may be configured to abut only when a positive voltage is applied to the piezoelectric elements 2251, 2261 (when expanding).

[0023] The piezoelectric elements 2251, 2261 are hexahedral (rectangular parallelepiped) in shape and are fixed so as to be embedded in the holder 224. The pressing parts 2252, 2262 are plate-shaped made of ceramic, and one surface is bonded to the opposing surface of each of the piezoelectric elements 2251, 2261 to form an integral unit. The pressing parts 2252, 2262 are not fixed to the holder 224, and can move relative to the holder 224 as the piezoelectric elements 2251, 2261 expand and contract. The tips of the pressing parts 2252, 2262 have enlarged parts 2253, 2263 whose thickness dimensions are enlarged. In other words, the main body of the pressing parts 2252, 2262 and the enlarged parts 2253, 2263 are formed integrally. In this embodiment, the cross-sectional shape of the enlarged parts 2253, 2263 is circular. The enlarged portions 2253 and 2263 are positioned to face the outer circumferential surface 213 of the rotating ring 21 .

[0024] The first driving body 225 and the second driving body 226 are provided facing each other. The facing direction of the first driving body 225 and the second driving body 226 is along the circumferential direction of the diaphragm mechanism 1. The pressing portion 2252 of the first driving body 225 and the pressing portion 2262 of the second driving body 226 are formed so that the tip facing the outer circumferential surface 213 of the rotary ring 21 is farther away from each other than the base end. Both pressing portions 2252, 2262 are arranged in an inverted V shape as shown in FIG. 6. The extension directions 2251M, 2261M when a positive voltage is applied to the piezoelectric elements 2251, 2261 are the directions indicated by the arrows in the figure, and are the directions toward the symmetric center of both pressing portions 2252, 2262 that form the inverted V shape. The contraction direction when a reverse voltage is applied to the piezoelectric elements 2251, 2261 is the opposite direction to the extension direction. When the current is stopped, the piezoelectric elements 2251, 2261 return to their original shapes before expansion and contraction. The expansion of the piezoelectric elements 2251, 2261 causes the pressing portions 2252, 2262 to move in the same direction. By periodically supplying current, the pressing portions 2252, 2262 can be driven at a frequency corresponding to the current supply interval, and the pressing portions 2252, 2262 (specifically, the expansion portions 2253, 2263) can be intermittently pressed against the rotating ring 21 at a period corresponding to this frequency.

[0025] It is not essential to apply a reverse voltage to the piezoelectric elements 2251 and 2261, and a positive voltage may be applied intermittently. Regarding the application of a reverse voltage, for example, when a positive voltage is applied to the piezoelectric element 2251 of the first driving body 225, a reverse voltage is simultaneously applied to the piezoelectric element 2261 of the second driving body 226. Then, the piezoelectric element 2261 is shortened, and the pressing portion 2262 of the second driving body 226 is separated from the outer circumferential surface 213 of the rotating ring 21. Therefore, compared with the pressing portion 2262 remaining in contact with the outer circumferential surface 213 of the rotating ring 21, the pressing portion 2262 is less likely to become a resistance when rotating the rotating ring 21. When a positive voltage is applied to the piezoelectric element 2261 of the second driving body 226, the reverse of the above is applied to the piezoelectric element 2251 of the first driving body 225 at the same time.

[0026] The pressure applied to the outer peripheral surface of the rotating ring 21 by the pressing parts 2252, 2262 (expanded parts 2253, 2263) due to the expansion of the piezoelectric elements 2251, 2261 is made to have a circumferential component. Therefore, a force (friction force) directed in the circumferential direction can be applied to the rotating ring 21 during pressing. Therefore, the pressing parts 2252, 2262 (expanded parts 2253, 2263) perform an action of continuously kicking the rotating ring 21 in the circumferential direction according to the energization cycle. This causes the rotating ring 21 to rotate. At least the part of the outer peripheral surface of the rotating ring 21 that is pressed by the pressing parts 2252, 2262 has a constant curvature. Therefore, the rotational force of the rotating ring 21 generated by the pressing force of the pressing parts 2252, 2262 can be made constant, and stable rotation can be realized.

[0027] The diaphragm unit 3 has multiple diaphragm plates 31-31 of the same shape that engage with the rotary ring 21 of the rotary drive unit 2 and are swung in a direction M in a plane perpendicular to the optical axis direction as the rotary ring 21 rotates, and as the multiple diaphragm plates 31-31 swish, the opening area of ​​the aperture portion O through which light passes can be enlarged (for example, the state in Fig. 3 or Fig. 4) or reduced (for example, the state in Fig. 5) as the multiple diaphragm plates 31-31 swish. The multiple diaphragm plates 31-31 are arranged around the optical axis. The aperture portion O is formed to coincide with the optical axis.

[0028] The diaphragm unit 3 is composed of a plurality of diaphragm plates 31-31, more specifically an even number of diaphragm plates 31-31 (in this embodiment, four diaphragm plates 31-31 provided at 90 degrees in the circumferential direction), and the plurality of diaphragm plates 31-31 slide with the swing and partially overlap each other. That is, the diaphragm unit 3 is arranged so that the diaphragm plate 31 located at the front in the optical axis direction and the diaphragm plate 31 located at the rear are adjacent to each other in the circumferential direction at least in the portion that overlaps with each other during swing (in this embodiment, the entire diaphragm plate 31). The plurality of diaphragm plates 31-31 are provided rotationally symmetrically as viewed in the optical axis direction. By changing the opening shape of the diaphragm unit 3, the opening area of ​​the opening portion O can be enlarged or reduced by the four diaphragm plates 31-31 according to the aperture value set by the camera itself or a control unit of the camera-mounted device (such as a smartphone).

[0029] Each of the multiple diaphragm plates 31-31 (hereinafter simply referred to as "diaphragm plates 31") is formed in a substantially fan-shaped form, and a first base portion 311 and a second base portion 312, which is adjacent to the first base portion 311 in a radially outward direction based on the swing center of the first base portion 311 and has a smaller thickness than the first base portion 311, are provided at a main portion (base end portion) of the fan-shaped form. A flat plate portion 313, which is thinner than the second base portion 312, is provided adjacent to the second base portion 312 in a radially outward direction. The flat plate portion 313 is formed in a flat plate shape extending in a direction perpendicular to the optical axis direction. The flat plate portion 313 blocks light rays.

[0030] As described above, the diaphragm plate 31 located at the front in the optical axis direction and the diaphragm plate 31 located at the rear are arranged so as to be adjacent to each other in the circumferential direction. In this embodiment, the diaphragm plates 31 are arranged in front and rear directions by changing the thickness of the flange portion 81 provided on the shaft portion 8. The flange portion 81 is a disk-shaped portion that protrudes from the main body of the cylindrical shaft portion 8 in the radially outward direction of the shaft portion 8. The flange portion 81 is formed integrally with the main body of the shaft portion 8. The flange portion 81 is sandwiched between the rear surface of the first base portion 311 in the diaphragm plate 31 and the front surface of the support plate 4. As shown in FIG. 2, by arranging the relatively thin flange portion 81A, the diaphragm plate 31 can be arranged relatively rearward. And, by arranging the relatively thick flange portion 81B, the diaphragm plate 31 can be arranged relatively forward. By adjusting the position by the shaft portion 8 in this way, there is an advantage that the multiple diaphragm plates 31 to 31 can be unified into the same shape. In addition to adjustment using the flange portion 81 of the shaft portion 8, the front-to-rear position of the diaphragm plate 31 may be adjusted by changing the thickness of the first base portion 311 of the diaphragm plate 31, providing a step in the support plate 4, or attaching a shim.

[0031] At the edge portion facing the optical axis at the tip side of the swing of the diaphragm plate 31, a tip side notch 314 for enlarging and reducing the opening area of ​​the opening portion O is formed. The tip side notch 314 is provided on the optical axis side (diametrically inner side) of the diaphragm portion 3, and in this embodiment, is a portion cut out in a circular shape with a constant curvature. The curvature of the tip side notch 314 is set so that the opening portion O, which is the diaphragm space, becomes a perfect circle in the most expanded state as shown in Figs. 3 and 4. When the multiple diaphragm plates 31-31 swing to approach the optical axis, the multiple tip side notches 314 approach each other, thereby reducing the opening area of ​​the opening portion O.

[0032] At one end of the second base 312 in the swing direction, a base-end notch 3121 extending perpendicular to the optical axis direction is formed, and as shown in Figure 5, the edge of the flat portion 313 of the other diaphragm plate 31 fits into the base-end notch 3121, preventing adjacent diaphragm plates 31, 31 from interfering with each other as they swing.

[0033] The center of the swing is journaled on the radially outer side of the aperture section 3 (the radially outer side of the entire aperture section 3). Therefore, the swinging tip side of the aperture plate 31 is located on the radially inner side of the aperture section 3. The first base section 311 of the aperture plate 31 is provided with an axial hole 3111 (see FIG. 1 ) extending along the optical axis direction, through which the shaft 8 passes. The shaft 8 passes through a through hole 41 provided in the flat support plate 4, and the rear end is fixed to a support hole X2 of the lens drive mechanism X. As a result, the aperture plate 31 swings in the direction M around the shaft 8 passed through the axial hole 3111. The driving force for the swing is transmitted from the rotary ring 21.

[0034] The second base portion 312 is provided with an engagement hole 315 as an engagement portion for engaging with the rotary ring 21. This engagement hole 315 extends in the optical axis direction and penetrates the second base portion 312. The engagement hole 315 is provided between the pivotally supported portion and the tip side cutout portion 314.

[0035] Here, the rotation locus (direction R) of the rotary ring 21 and the swing locus (direction M) of each diaphragm plate 31 do not completely coincide with each other, but are in a relationship of intersecting when viewed in the optical axis direction. Here, the engagement by the engagement portion (engagement hole 315) is a combination of a convex portion (engagement protrusion 212 of the rotary ring 21 in this embodiment) provided on one of the diaphragm plate 31 and the rotary ring 21 and a concave portion (engagement hole 315 of each diaphragm plate 31 in this embodiment) provided on the other, and the transverse dimension of the concave portion perpendicular to the optical axis direction is larger than the transverse dimension of the convex portion, absorbing the deviation between the swing locus and the rotation locus accompanying the rotation of the rotary ring. In this embodiment, the engagement hole 315 as the concave portion has an elliptical shape when viewed in the optical axis direction, as shown in Figs. 4 and 5. The major axis direction of the ellipse can be a direction perpendicular to the rotation direction R (circumferential direction) of the rotary ring 21 or a direction perpendicular to the swing direction M of each diaphragm plate 31. It is not necessary to be strictly perpendicular, but it is sufficient to be approximately perpendicular. Because the engagement hole 315 has an oval shape, play can be created between the engagement protrusion 212 and the engagement hole 315, thereby absorbing the misalignment between the rotational trajectory (direction R) of the rotating ring 21 and the swinging trajectory (direction M) of each diaphragm plate 31.

[0036] The multiple diaphragm plates 31-31 swing evenly (in a rotationally symmetrical relationship). Depending on the overlap of the tip-side cutouts 314 of each of the multiple diaphragm plates 31-31 in the swinging direction, the opening portion O, which is the diaphragm space formed in line with the optical axis, can be changed between the most expanded state shown in Fig. 3 and Fig. 4 and the most contracted state shown in Fig. 5.

[0037] As described above, this embodiment includes a rotary drive unit 2 having a rotary ring 21 that rotates around the optical axis and a drive source unit 22 that generates a driving force to rotate the rotary ring 21, and an aperture unit 3 having a plurality of aperture plates 31-31 arranged around the optical axis that engage with the rotary ring 21 and are oscillated as the rotary ring 21 rotates, and the aperture unit 3 can expand and reduce the opening area through which light passes as the plurality of aperture plates 31-31 oscillate. The drive source unit 22 includes piezoelectric elements 2251, 2261 that deform when electricity is applied thereto, and pressing units 2252, 2262 that are arranged in conjunction with the piezoelectric elements 2251, 2261 and can abut against the rotary ring 21, and the piezoelectric elements 2251, 2261 are deformed when electricity is applied thereto, thereby pressing the pressing units 2252, 2262 against the rotary ring 21 with a force having a circumferential component, thereby rotating the rotary ring 21.

[0038] According to this configuration, the diaphragm plates 31-31 are swung by the rotary ring 21 rotated by the piezoelectric elements 2251 and 2261, and the opening area of ​​the opening portion O through which the light beam passes can be enlarged or reduced in accordance with this swing.

[0039] In addition, each of the multiple throttling plates 31-31 is supported at a portion that is the center of the oscillation on the radially outer side of the throttling section 3, and a tip-side notch 314 for enlarging and reducing the opening area is formed at the edge portion at the tip side of the oscillation, and an engagement portion (engagement hole 315) for engaging with the rotating ring 21 is provided between the supported portion and the tip-side notch 314.

[0040] With this configuration, the opening area through which light passes can be enlarged or reduced at the tip notch 314, and the rotational force of the rotating ring 21 can be received by the engagement portion (engagement hole 315) provided between the axially supported part that is the center of oscillation and the tip notch 314 to cause the aperture plate 31 to oscillate.

[0041] In addition, the rotation locus (direction R) of the rotating ring 21 and the oscillation locus (direction M) of each of the multiple throttling plates 31 to 31 intersect with each other, and engagement by the engagement portion (engagement hole 315) is achieved by a combination of a convex portion (engagement protrusion 212 of the rotating ring 21) provided on one of the throttling plate 31 and the rotating ring 21 and a concave portion (engagement hole 315 of the throttling plate 31) provided on the other, and the transverse dimension of the concave portion (engagement hole 315) is larger than the transverse dimension of the convex portion (engagement protrusion 212), thereby absorbing the deviation between the oscillation locus and the rotation locus that accompanies the rotation of the rotating ring 21.

[0042] According to this configuration, the driving force can be transmitted from the rotary ring 21 to the diaphragm plate 31 by a concave-convex engagement that can absorb misalignment.

[0043] Moreover, the recess (engagement hole 315) may have an elliptical shape when viewed in the optical axis direction.

[0044] According to this configuration, the oval recess (engagement hole 315) can absorb the deviation between the rotation trajectory (direction R) of the rotary ring 21 and the swing trajectory (direction M) of the diaphragm plate 31.

[0045] Further, the driving source portion 22 can be provided so as to be able to abut against an outer circumferential surface 213 of the rotary ring 21 in the radial direction.

[0046] According to this configuration, the rotary ring 21 and the drive source unit 22 can be disposed at the same position in the optical axis direction.

[0047] In addition, the diaphragm section 3 has an even number of the diaphragm plates 31-31, and in the portions that overlap each other during the swinging motion, the diaphragm plates 31 located in the front and rear in the optical axis direction are arranged adjacent to each other in the circumferential direction.

[0048] According to this configuration, the diaphragm plates 31, 31 adjacent to each other in the circumferential direction can be shifted forward and backward in the optical axis direction, so that interference due to swinging can be prevented.

[0049] Further, a permanent magnet may be provided on the rotary ring 21, and a magnetic sensor may be provided on the radially outer side of the rotary ring 21.

[0050] According to this configuration, the rotational position of the rotating ring 21 can be detected with a simple configuration.

[0051] According to the aperture mechanism 1 of this embodiment configured as described above, the opening area of ​​the opening portion O through which light passes can be enlarged or reduced by the rotating ring 21, the drive source unit 22, and the multiple aperture plates 31-31, so that the aperture configuration can be made compact, and an aperture mechanism 1 with a simple configuration can be provided.

[0052] Although the present embodiment is as described above, the present invention is not limited to the above-mentioned form, and can be appropriately modified in design within the intended scope of the present invention. Furthermore, the effects of the present invention are not limited to those described in the above-mentioned embodiment. In other words, the embodiment disclosed this time is an example in all respects and does not limit the present invention. The scope of the present invention is defined by the claims, not the above description. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the claims.

[0053] For example, in this embodiment, the rotary drive unit 2 is provided in the front in the optical axis direction, and the diaphragm unit 3 is provided behind it. However, this is not limited to this, and the rotary drive unit 2 may be provided behind the optical axis direction, and the diaphragm unit 3 may be provided in front.

[0054] The driving source 22 may press the rotary ring 21 on the surfaces (front and rear surfaces) in the optical axis direction of the rotary ring 21. The driving source 22 may also press the rotary ring 21 on the inner peripheral surface in the radial direction of the rotary ring 21.

[0055] Also, the dimensions of the rotating ring 21 in the optical axis direction and the radial direction are constant all around, and the shape has a constant curvature all around. However, this is not limited thereto, and it is sufficient that at least the curvature of the peripheral surface of the portion that receives the pressure from the driving source unit 22 is constant. Therefore, the rotating ring 21 does not have to be a ring shape that is connected all around, but may be a ring shape with a part missing (C-shape, etc.). Also, instead of a ring shape, it may be a frame shape.

[0056] In addition, the diaphragm section 3 in the above embodiment is composed of an even number of diaphragm plates 31-31, which is four. However, the number of diaphragm plates 31 may be two or three, or may be five or more. Moreover, the diaphragm section 3 may be composed of an odd number of diaphragm plates 31-31.

[0057] In the throttle section 3 of the above embodiment, the tip side cutout 314 is a portion cut out in a circular shape with a constant curvature. However, the shape of the tip side cutout 314 is not limited to this, and the tip side cutout 314 may be a portion cut out in a straight line (including a bent shape) or a curved line with a non-constant curvature. In addition, the shape of the tip side cutout 314 is not limited as long as the opening area of ​​the opening portion formed by the multiple throttle plates 31 can be enlarged and reduced depending on how the multiple throttle plates 31 overlap each other.

[0058] In the above embodiment, the engagement projection 212 of the rotary ring 21 is combined with the engagement hole 315 of the diaphragm plate 31. However, the opposite may be true, that is, a recess or a hole is formed in the rotary ring 21 and a protrusion is formed in the diaphragm plate 31, so that the two engage with each other. [Explanation of symbols]

[0059] 1 Aperture mechanism 2 Rotation drive unit 21 Rotating Ring 212 Convex portion, engagement protrusion 213 Outer surface 22 Drive unit 2251 Piezoelectric element 2252 Pressing part 2261 Piezoelectric element 2262 Pressing part 24 Permanent magnets 3. Squeezing section 31 Aperture plate 3111 Shaft hole 314 Notch, tip notch 315 Engagement part, recess, engagement hole 4 Support plate 5 Pressing part 6. Housing 7 Lenses 8 Shaft X Lens drive mechanism M Swing direction of aperture plate R Rotation direction of the rotating ring O Opening of the aperture

Claims

1. a rotation drive unit including a rotation ring that rotates around an optical axis and a drive source unit that generates a drive force to rotate the rotation ring; a diaphragm unit that is engaged with the rotary ring and is swung by the rotation of the rotary ring, the diaphragm unit having a plurality of diaphragm plates arranged around an optical axis, and that can expand and reduce an opening area through which light rays pass as the plurality of diaphragm plates swish, the drive source unit includes a base, a buffer unit, a guide pin, a holder, a first drive body, and a second drive body, the buffer unit is provided between the base and the holder, the guide pin penetrates the base along the optical axis direction, the holder and the buffer unit have elongated holes extending in the front-rear direction with the base as a reference, the guide pin penetrates the elongated hole, and the holder, the first drive body, and the second drive body are movable forward and backward within the range in which the elongated hole is formed relative to the base, Each of the first driving body and the second driving body includes a piezoelectric element that deforms when electricity is passed through it, and a pressing portion that is arranged in conjunction with the piezoelectric element and can abut against the rotating ring, and the piezoelectric element is deformed when electricity is passed through it, thereby pressing the pressing portion against the rotating ring with a force having a circumferential component, thereby rotating the rotating ring.

2. Each of the plurality of diaphragm plates is A portion that is a center of the swing is journaled on the radially outer side of the throttle portion, A notch is formed on the edge of the tip of the swing to expand and reduce the opening area, 2. The throttle mechanism according to claim 1, wherein an engagement portion that engages with the rotary ring is provided between the journaled portion and the notch.

3. a rotation locus of the rotary ring and a swing locus of each of the plurality of diaphragm plates are in an intersecting relationship, 3. The diaphragm mechanism according to claim 2, wherein engagement by the engagement portion is achieved by a combination of a convex portion provided on one of the diaphragm plate and the rotating ring and a concave portion provided on the other of the diaphragm plate and the rotating ring, and a transverse dimension of the concave portion is larger than a transverse dimension of the convex portion.

4. The diaphragm mechanism according to claim 3 , wherein the recess has an elliptical shape when viewed in the optical axis direction.

5. The throttling mechanism according to claim 1 , wherein the drive source portion is provided so as to be able to abut against an outer circumferential surface of the rotary ring in a radial direction.

6. The throttling section has an even number of the throttling plates, 2. The diaphragm mechanism according to claim 1, wherein the diaphragm plates located at the front and rear in the optical axis direction are arranged adjacent to each other in the circumferential direction with respect to the portions that overlap each other during the pivoting movement.

7. 2. The diaphragm mechanism according to claim 1, wherein a permanent magnet is provided on the rotary ring, and a magnetic sensor is provided radially outside the rotary ring.

8. One or more lenses; A camera module comprising: the aperture mechanism according to claim 1 .

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