aperture mechanism

Abstract

An aperture mechanism (1) includes a rotation driving section (2) including a rotation ring (21) that rotates around an optical axis and a driving source section (22) that generates a driving force that rotates the rotation ring (21), and an aperture section (3) including a plurality of diaphragm plates (31-31) that are arranged around the optical axis, the plurality of diaphragm plates (31-31) being engaged with the rotation ring (21) and oscillating by rotation of the rotation ring (21), and an opening area through which light passes being able to be enlarged and reduced by oscillation of the plurality of diaphragm plates (31-31), the driving source section (22) including a piezoelectric element that deforms by energization, and a push section that is provided in a linked manner with the piezoelectric element and is arranged so as to be able to abut against the rotation ring (21), the piezoelectric element being deformed by energization, and the push section being pushed toward the rotation ring (21) by a force having a circumferential component to rotate the rotation ring (21).

Description

Technical Field

[0001] This invention relates to aperture mechanisms for built-in cameras in smartphones and small cameras. Background Technology

[0002] As prior art, for example, the aperture mechanism described in Japanese Patent Application Publication No. 2011-90028 is cited. In this prior art, the structure is complex because it is configured to use a lever to move the aperture. Summary of the Invention

[0003] The problem the invention aims to solve

[0004] Therefore, the objective of this invention is to provide an aperture mechanism that can be miniaturized and has a simple structure for aperture applications.

[0005] Solution for solving the problem

[0006] One embodiment of the present invention is an aperture mechanism comprising: a rotation drive unit having a rotating ring that rotates around an optical axis and a drive source unit that generates a driving force to rotate the rotating ring; and an aperture unit having a plurality of aperture plates arranged around the optical axis, the plurality of aperture plates engaging with the rotating ring and oscillating with the rotation of the rotating ring, thereby expanding and shrinking the opening area for light to pass through as the plurality of aperture plates oscillate; the drive source unit comprising: a piezoelectric element that deforms upon energization; and a pushing part provided in a manner linked to the piezoelectric element and configured to abut against the rotating ring; by energizing the piezoelectric element to deform it, the pushing part is pushed against the rotating ring by a force having a circumferential component, thereby causing the rotating ring to rotate.

[0007] Additionally, each of the plurality of aperture plates can be configured such that, on the outer side of the aperture portion, the portion serving as the center of the swing is axially supported, and a cutout portion for expanding and shrinking the opening area is formed at the edge of the front end side of the swing, and an engaging portion that engages with the rotating ring is provided between the axially supported portion and the cutout portion.

[0008] In addition, the rotation trajectory of the rotating ring can be configured to intersect with the swing trajectory of each of the plurality of aperture plates. The engagement performed by the engaging part is a combination of a protrusion provided on one of the aperture plates and the rotating ring and a concave part provided on the other, wherein the cross-sectional dimension of the concave part is larger than the cross-sectional dimension of the protrusion.

[0009] Additionally, the recess can be configured to appear as an elongated oval when viewed along the optical axis.

[0010] Additionally, the drive source can be configured to abut against the radially outer peripheral surface of the rotating ring.

[0011] Furthermore, the aperture portion can be configured to have an even number of aperture plates, and for the portions that overlap during the swing, the aperture plate located in front of the aperture in the optical axis direction and the aperture plate located behind the aperture are arranged adjacent to each other in the circumferential direction.

[0012] Alternatively, it can be configured to have a permanent magnet on the rotating ring and a magnetic sensor on the outer side of the diameter of the rotating ring.

[0013] Another embodiment of the present invention is a lens module, which includes one or more lenses and the aperture mechanism described in any of the above embodiments. Attached Figure Description

[0014] Figure 1 This is an exploded perspective view schematically illustrating the structure of an aperture mechanism according to an embodiment of the present invention, showing the constituent components broken down and arranged along the optical axis.

[0015] Figure 2 This is a perspective view showing the assembled state of the aperture mechanism.

[0016] Figure 3 This is a perspective view of the rotary drive unit and the aperture unit in the aperture mechanism, viewed from the bottom side.

[0017] Figure 4 This is a perspective view showing the open state of the aperture section.

[0018] Figure 5 This is a three-dimensional view showing the aperture state of the aperture section.

[0019] Figure 6 This is a top view of the drive source section of the rotary drive unit (as an aperture mechanism). Detailed Implementation

[0020] An aperture mechanism 1 according to one embodiment of the present invention will be described with reference to the accompanying drawings. Unless otherwise specified, "optical axis direction," "circumferential direction," "radial direction," "inner radial direction," and "outer radial direction" in the following description refer to the overall orientation of the aperture mechanism 1. That is, the direction in which the aperture mechanism 1 rotates relative to the optical axis direction is circumferential. Furthermore, the direction orthogonal to the optical axis direction is radial. Additionally, "front" is defined as the direction towards the subject in the optical axis direction, and "rear" is defined as the direction towards the imaging element of the camera in the optical axis direction.

[0021] Figure 1 The image shows an exploded view of the entire structure. The top of the image represents the front along the optical axis, and the bottom represents the rear along the optical axis. Figure 1 The exploded, but not shown, portion shown in the lower left corner is the lens drive mechanism X, which receives the light focused by the aperture mechanism 1. Furthermore, since the lens drive mechanism X is not directly related to this invention, it will not be described in detail below except for necessary information. The aperture mechanism 1 is configured such that, along the optical axis, it is arranged from the front (subject side) towards the lens drive mechanism X, in the order of rotation drive unit 2, aperture unit 3, and support plate 4, and they are housed within the housing 6. The housing 6 also serves as the housing for the lens drive mechanism X. Additionally, the support plate 4 also serves as the lens drive mechanism X. Inside the housing 6, in front of the rotation drive unit 2, is one set or a single lens 7, one of the multiple lenses constituting the camera.

[0022] The aperture mechanism 1 is located in front of the lens drive mechanism X (excluding the housing). The lens drive mechanism X, through its autofocus function, has its barrel portion X1 moving back and forth along the optical axis. The aperture mechanism 1 as a whole is also configured to move back and forth in conjunction with (synchronously with) the barrel portion X1. By configuring the aperture mechanism 1 in this way, in conjunction with the lens drive mechanism X, compared to a structure that is fixed independently of the autofocus function, the optical characteristics (specifically, MTF) of the camera are improved.

[0023] The rotation drive unit 2 includes a rotating ring 21 that rotates around the optical axis of the camera, and a drive source unit 22 that generates a driving force to rotate the rotating ring 21. The rotating ring 21 rotates under the driving force of the drive source unit 22 within the range of circumferential movement of the engagement protrusion 212 (described later) corresponding to the swing range of each aperture plate 31 used for opening and closing the aperture 3. The rotating ring 21 can be configured to rotate infinitely at a predetermined angle corresponding to the opening and closing of the aperture, or it can be configured to rotate in multiple stages like a stepper motor. The rotating ring 21 is configured as a ring with its center aligned with the optical axis in the optical axis direction, so that light (the light corresponding to the subject input to the imaging element of the camera) passes through the center.

[0024] In this embodiment, the radial cross-sectional shape of the rotating ring 21 is rectangular. The rear surface (lower surface in the illustration) of the rotating ring 21 has four circumferentially recessed portions 211 (corresponding to the number of aperture plates 31-31) that are recessed forward (upper in the illustration). The rear surface of the recess 211 is planar and abuts against the front surface of the second base 312 of each aperture plate 31, which is also planar. Furthermore, the radially outer peripheral surfaces 213 of the rotating ring 21 are spaced apart to avoid interference with the first base 311 of each aperture plate 31. The circumferential dimension of the recess 211 is larger than the swing range of the second base 312 of each aperture plate 31. Figure 3As shown, the engaging protrusion 212 protrudes rearward from the recess 211 (lower part of the illustration). The engaging protrusion 212 is cylindrical with a perfectly circular cross-section. The protruding position of the engaging protrusion 212 in the recess 211 depends on the swing range of each aperture plate 31. In this embodiment, the engaging protrusion 212 is formed at a position offset from the circumferential center of the recess 211 towards the end side.

[0025] The rotating drive unit 2 is pressed from the front by the pressing part 5 (frame 51, sliding ring 52), achieving positioning in the optical axis direction of the camera. Multiple (specifically three) cylindrical pins 23-23 are embedded in the inner diameter of the rotating ring 21. Each pin 23 abuts against the outer peripheral surface (not shown) of the limiting wall 511 located on the inner circumference side of the frame 51. This achieves radial positioning of the rotating ring 21. Furthermore, positioning in the optical axis direction is achieved by pressing the front surface of the rotating ring 21 from the front via the sliding ring 52 by the frame 51. The sliding ring 52 is a flat, annular sheet material with a surface friction coefficient lower than other parts. By sliding between the front surface of the rotating ring 21 and the sliding ring 52, the rotating ring 21 can rotate smoothly without hindering its circumferential rotation.

[0026] In addition, such as Figure 2 As shown, a permanent magnet 24 is embedded in the outer periphery of the rotating ring 21. A Hall sensor, MR sensor, or other magnetic sensor (not shown) that reacts with the magnetic force of the permanent magnet 24 is disposed outside and radially outward of the rotating ring 21. This allows the rotational position of the rotating ring 21 to be detected. The detection result is sent to the control unit (not shown) of a smartphone or camera for aperture control.

[0027] like Figure 6 As shown, the drive source unit 22 includes a base 221, a buffer unit 222, a guide pin 223, a bracket 224, a first drive body 225, and a second drive body 226. Furthermore, in Figure 6 In the diagram above, the base 221 is shown, and in the diagram below, the driving bodies 225 and 226 are shown. Additionally, Figure 2The plate-like portion protruding to the side shown is the power supply substrate (FPC) 228. The first drive body 225 and the second drive body 226 each include: piezoelectric elements 2251 and 2261, which deform (specifically, elongate) when energized; and pressing portions 2252 and 2262, which are provided in conjunction with the piezoelectric elements 2251 and 2261 and are configured to abut against the surface of the rotating ring 21 in the rotating drive unit 2 (in this embodiment, the radially outer peripheral surface 213 of the rotating ring 21). In this embodiment, the rotating ring 21 and the drive source unit 22 can be arranged at the same position in the optical axis direction. Therefore, the drive-side component (drive source unit 22) and the driven-side component (rotating ring 21) can be compactly arranged in the optical axis direction. Furthermore, the rotating ring 21 and the drive source unit 22 are approximately the same size in the optical axis direction. Therefore, the situation where the size in the optical axis direction increases (becomes thicker) when the rotating ring 21 and the drive source unit 22 are combined is avoided. Therefore, compared to structures that utilize, for example, motors and gears to drive the aperture section 3, this embodiment can achieve miniaturization of the optical axis dimension. Furthermore, it simplifies the structure.

[0028] The base 221 is fixed to the frame 51. In this embodiment, the base 221 is formed as a bottomed cylindrical shape, and the internal bracket 224 is configured to be able to move back and forth with respect to the base 221 (the aperture mechanism 1 as a whole can move radially). A first drive body 225 and a second drive body 226 with symmetrical shapes are fixed to the bracket 224. That is, the drive source part 22 integrally includes the first drive body 225 and the second drive body 226. A buffer part 222 is provided between the base 221 and the bracket 224. The buffer part 222 extends and retracts as the bracket 224 moves. In this embodiment, the buffer part 222 is made of a rubber sheet made of silicon or the like. A guide pin 223 passes through the base 221 along the optical axis. An elongated hole 227 extending in the back and forth direction with respect to the base 221 is formed on the bracket 224 and the buffer part 222, and the guide pin 223 passes through the elongated hole 227. Therefore, the bracket 224, the first drive body 225, and the second drive body 226 can move back and forth relative to the base 221 within the range of the elongated hole 227.

[0029] The first driving body 225 is located on one side of the circumference of the rotating ring 21. The second driving body 226 is located on the other side of the circumference of the rotating ring 21. The first driving body 225 and the second driving body 226 each include: piezoelectric elements 2251 and 2261, which extend when a positive voltage is applied and shorten when a reverse voltage is applied; and pressing portions 2252 and 2262, which are provided in conjunction with the piezoelectric elements 2251 and 2261 and are configured to abut against the surface of the rotating ring 21 (the outer peripheral surface 213 in this embodiment). As shown in the figure, the pressing portions 2252 and 2262 of this embodiment abut against the outer peripheral surface 213 of the rotating ring 21 when the piezoelectric elements 2251 and 2261 are not energized, but they can also be configured to abut only when a positive voltage is applied to the piezoelectric elements 2251 and 2261 (when they extend).

[0030] The piezoelectric elements 2251 and 2261 are hexahedral (cubic prism) in shape and are fixed by being embedded in the bracket 224. The pressing portions 2252 and 2262 are plates made of ceramic, one side of which is bonded to the opposing surfaces of each piezoelectric element 2251 and 2261, forming a single unit. Furthermore, the pressing portions 2252 and 2262 are not fixed to the bracket 224 and can move relative to the bracket 224 as the piezoelectric elements 2251 and 2261 extend and retract. The front ends of the pressing portions 2252 and 2262 have enlarged portions 2253 and 2263 with increased thickness. In other words, the main body of the pressing portions 2252 and 2262 and the enlarged portions 2253 and 2263 are formed integrally. In this embodiment, the enlarged portions 2253 and 2263 have a circular cross-sectional shape. The enlarged portions 2253 and 2263 are located opposite each other on the outer peripheral surface 213 of the rotating ring 21.

[0031] The first drive body 225 and the second drive body 226 are disposed opposite each other. The direction in which the first drive body 225 and the second drive body 226 are opposite each other is along the circumference of the aperture mechanism 1. The pushing part 2252 of the first drive body 225 and the pushing part 2262 of the second drive body 226 are formed such that the front end of the pushing part 2252 and the pushing part 2262 opposite to the outer peripheral surface 213 of the rotating ring 21 is further away from the base end. The two pushing parts 2252 and 2262 are as follows: Figure 6The configuration shown is an inverted V-shape. When a positive voltage is applied to the piezoelectric elements 2251 and 2261, the elongation directions 2251M and 2261M are as indicated by the arrows in the figure, and are towards the center of symmetry of the two pressing portions 2252 and 2262 that constitute the inverted V-shape. When a reverse voltage is applied to the piezoelectric elements 2251 and 2261, the shortening direction is opposite to the elongation direction. Furthermore, if the energizing is stopped, the piezoelectric elements 2251 and 2261 return to their original shape. Due to the elongation of the piezoelectric elements 2251 and 2261, the pressing portions 2252 and 2262 move in the same direction. By periodically energizing, the pressing portions 2252 and 2262 can be driven at a frequency corresponding to the energizing interval, and the pressing portions 2252 and 2262 (specifically, the enlarged portions 2253 and 2263) can be intermittently pushed against the rotating ring 21 at a period corresponding to this frequency.

[0032] Furthermore, applying a reverse voltage to piezoelectric elements 2251 and 2261 is not necessary; a positive voltage can be applied intermittently. Regarding the application of a reverse voltage, for example, a positive voltage can be applied to the piezoelectric element 2251 of the first drive body 225, while simultaneously applying a reverse voltage to the piezoelectric element 2261 of the second drive body 226. This shortens the piezoelectric element 2261, causing the pressing portion 2262 of the second drive body 226 to separate from the outer peripheral surface 213 of the rotating ring 21. Therefore, compared to the case where the pressing portion 2262 remains in contact with the outer peripheral surface 213 of the rotating ring 21, the pressing portion 2262 is less likely to become a resistance to the rotation of the rotating ring 21. The case of applying a positive voltage to the piezoelectric element 2261 of the second drive body 226 is the opposite of the above, while simultaneously applying a reverse voltage to the piezoelectric element 2251 of the first drive body 225.

[0033] As the piezoelectric elements 2251 and 2261 elongate, the pushing force of the pressing portions 2252 and 2262 (enlarged portions 2253 and 2263) on the outer peripheral surface of the rotating ring 21 becomes circumferential. Therefore, a circumferential force (friction) can be applied to the rotating ring 21 during pressing. Thus, the pressing portions 2252 and 2262 (enlarged portions 2253 and 2263) continuously kick the rotating ring 21 circumferentially according to the energizing cycle. This causes the rotating ring 21 to rotate. At least the portion of the outer peripheral surface of the rotating ring 21 pressed by the pressing portions 2252 and 2262 is provided with a constant curvature. Therefore, the rotational force of the rotating ring 21 generated by the pushing force of the pressing portions 2252 and 2262 can be kept constant, achieving stable rotation.

[0034] The aperture section 3 has multiple aperture plates 31-31 of the same shape. These aperture plates 31-31 engage with a rotating ring 21 in the rotation drive section 2 and, through rotation of the rotating ring 21, swing in a plane orthogonal to the optical axis, i.e., in direction M. As the multiple aperture plates 31-31 swing, the aperture can be enlarged (e.g.,...). Figure 3 , Figure 4 (state) and shrinkage (e.g.) Figure 5 The opening area of ​​the opening portion O (in the state of light) allows light to pass through. Multiple aperture plates 31-31 are arranged around the optical axis. The opening portion O is formed to be aligned with the optical axis.

[0035] The aperture section 3 is composed of a plurality of, more specifically, an even number of aperture plates 31-31 (in this embodiment, four aperture plates 31-31 are arranged at 90 degrees in the circumferential direction). The plurality of aperture plates 31-31 slide with the swing and partially overlap. That is, the aperture section 3 is configured such that, at least for the portion that overlaps with each other during the swing (the entire aperture plate 31 in this embodiment), the aperture plate 31 located in front in the optical axis direction is adjacent to the aperture plate 31 located behind in the optical axis direction. The plurality of aperture plates 31-31 are configured to be rotationally symmetrical when viewed in the optical axis direction. By changing the opening shape of the aperture section 3, the opening area of ​​the opening portion O can be enlarged or reduced by the four aperture plates 31-31 according to the aperture value set by the camera itself or the control unit of the camera-mounted device (smartphone, etc.).

[0036] Each of the plurality of aperture plates 31 to 31 (hereinafter referred to as "aperture plate 31") is configured in a generally fan shape. The main part (base end part) of the fan shape is provided with a first base 311 and a second base 312. The second base 312 is adjacent to the first base 311 in a radially outward direction with reference to the swing center of the first base 311, and its thickness is smaller than that of the first base 311. Furthermore, a flat plate portion 313 is provided adjacent to the second base 312 in the radially outward direction and its thickness is smaller than that of the second base 312. The flat plate portion 313 is configured as a flat plate extending in a direction orthogonal to the optical axis. The flat plate portion 313 blocks light.

[0037] Here, as described above, the aperture plate 31 located at the front and the aperture plate 31 located at the rear are arranged adjacent to each other in the circumferential direction. In this embodiment, this front-rear arrangement of the aperture plates 31 is achieved by changing the thickness of the flange portion 81 provided in the shaft portion 8. The flange portion 81 is a circular plate-shaped portion that protrudes from the cylindrical body of the shaft portion 8 in a radially outward direction. The flange portion 81 is integrally formed with the body of the shaft portion 8. The flange portion 81 is sandwiched between the rear surface of the first base portion 311 in the aperture plate 31 and the front surface of the support plate 4. Figure 2As shown, by configuring a relatively thin flange portion 81A, the aperture plate 31 can be positioned relatively rearward. Then, by configuring a relatively thick flange portion 81B, the aperture plate 31 can be positioned relatively forward. By adjusting the position in this way by the shaft portion 8, it is advantageous to unify multiple aperture plates 31 to 31 into the same shape. In addition to the adjustment by the flange portion 81 of the shaft portion 8, the front-rear position of the aperture plate 31 can also be adjusted by changing the thickness of the first base portion 311 in the aperture plate 31, or by providing steps or mounting shims on the support plate 4.

[0038] A front-side cutout 314 is formed on the edge facing the optical axis at the front end of the oscillating aperture plate 31 for expanding and shrinking the opening area of ​​the opening portion O. The front-side cutout 314 is located on the optical axis side (inner diameter) of the aperture portion 3, and in this embodiment, its curvature is a portion cut into a certain circular shape. The curvature of the front-side cutout 314 is set as follows: Figure 3 as well as Figure 4 As shown, the opening portion O, which serves as the aperture space, becomes a perfect circle when it is expanded to its maximum size. Furthermore, as the multiple aperture plates 31 to 31 oscillate close to the optical axis, they approach each other through the multiple front-end side cutouts 314, causing the opening area of ​​the opening portion O to shrink.

[0039] One end of the second base 312 in the swing direction has a base end side cutout 3121 extending orthogonally to the optical axis direction, such as Figure 5 As shown, the edge of the flat plate portion 313 of the other aperture plates 31 enters the base end side cutout portion 3121, so that adjacent aperture plates 31, 31 will not interfere with each other as they swing.

[0040] In the outer radial side of the aperture section 3 (the outer radial side of the aperture section 3 as a whole), the portion serving as the center of the swing is supported by a shaft. Therefore, the front end of the swing of the aperture plate 31 is located in the inner radial side of the aperture section 3. The first base 311 of the aperture plate 31 is provided with a shaft hole 3111 extending along the optical axis (see reference). Figure 1 The shaft portion 8 passes through the shaft hole 3111. The shaft portion 8 passes through the through hole 41 provided in the flat support plate 4, and the rear end is fixed to the support hole X2 of the lens drive mechanism X. As a result, the aperture plate 31 swings in the direction M with the shaft portion 8 passing through the shaft hole 3111 as the center. The driving force for swinging is transmitted from the rotating ring 21.

[0041] The second base 312 is provided with an engagement hole 315, which serves as an engagement portion for engaging with the rotating ring 21. The engagement hole 315 extends through the second base 312 along the optical axis. The engagement hole 315 is located between the shaft-supported portion and the front end side cutout 314.

[0042] The rotation trajectory (direction R) of the rotating ring 21 is not completely consistent with the swing trajectory (direction M) of each aperture plate 31, and they intersect when viewed along the optical axis. The engagement by the engaging portion (engaging hole 315) is achieved by a combination of a protrusion (engaging protrusion 212 of the rotating ring 21 in this embodiment) and a recess (engaging hole 315 of each aperture plate 31 in this embodiment) on one of the aperture plates 31 and the rotating ring 21. The cross-sectional dimension of the recess, orthogonal to the optical axis, is larger than that of the protrusion, absorbing the deviation between the swing trajectory and the rotation trajectory accompanying the rotation of the rotating ring. In this embodiment, as... Figure 4 as well as Figure 5 As shown, the engagement hole 315, which serves as the recess, is oblong when viewed along the optical axis. The longitudinal direction of this oblong shape can be set to be orthogonal to the rotation direction R (circumferential direction) of the rotating ring 21, or orthogonal to the swing direction M of each aperture plate 31. Furthermore, strict orthogonality is not required; approximate orthogonality is sufficient. By making the engagement hole 315 oblong, a clearance can be generated between the engagement protrusion 212 and the engagement hole 315, thereby absorbing the deviation between the rotation trajectory (direction R) of the rotating ring 21 and the swing trajectory (direction M) of each aperture plate 31.

[0043] Multiple aperture plates 31-31 oscillate uniformly (with rotational symmetry). Furthermore, based on the overlap of the front end side cutouts 314 of each of the multiple aperture plates 31-31 in the oscillation direction, the opening portion O, which forms the aperture space aligned with the optical axis, can be made to... Figure 3 , Figure 4 The state shown is expanded to the maximum and Figure 5 The changes shown are between the smallest possible states.

[0044] As described above, this embodiment is an aperture mechanism 1, comprising: a rotation drive unit 2, which includes a rotating ring 21 that rotates around an optical axis, and a drive source unit 22 that generates a driving force to rotate the rotating ring 21; and an aperture unit 3, which has a plurality of aperture plates 31-31 arranged around the optical axis, the plurality of aperture plates 31-31 engaging with the rotating ring 21 and oscillating by the rotation of the rotating ring 21, thereby expanding and shrinking the aperture through which light passes as the plurality of aperture plates 31-31 oscillate. The drive source unit 22 includes: piezoelectric elements 2251 and 2261, which deform when energized; and pushing parts 2252 and 2262, which are arranged in conjunction with the piezoelectric elements 2251 and 2261 and are configured to abut against the rotating ring 21. When energized, the piezoelectric elements 2251 and 2261 are deformed, thereby pushing the pushing parts 2252 and 2262 against the rotating ring 21 with a force having a circumferential component, thereby causing the rotating ring 21 to rotate.

[0045] According to this structure, the aperture plates 31-31 are oscillating by the rotating ring 21, which is rotated by the piezoelectric elements 2251 and 2261. With this oscillation, the opening area of ​​the opening portion O through which light passes can be expanded and reduced.

[0046] Additionally, each of the plurality of aperture plates 31 to 31 can be configured such that, on the outer radial side of the aperture portion 3, the portion serving as the center of the swing is axially supported, and a front-side cutout portion 314 for expanding and shrinking the opening area is formed at the edge of the front-end side of the swing. An engaging portion (engaging hole 315) that engages with the rotating ring 21 is provided between the axially supported portion and the front-side cutout portion 314.

[0047] According to this structure, the opening area for light to pass through can be enlarged and reduced by the front side cutout 314, and the engagement part (engaging hole 315) provided between the shaft-supported part, which is the center of the swing, and the front side cutout 314 can receive the rotational force of the rotating ring 21 for the swing of the aperture plate 31.

[0048] Furthermore, the rotation trajectory (direction R) of the rotating ring 21 can be configured to intersect the swing trajectory (direction M) of each of the plurality of aperture plates 31-31. The engagement by the engaging part (engaging hole 315) is performed by a combination of a protrusion (engaging protrusion 212 of the rotating ring 21) provided on one of the aperture plates 31 and the rotating ring 21 and a concave part (engaging hole 315 of the aperture plate 31) provided on the other. The cross-sectional dimension of the concave part (engaging hole 315) is larger than the cross-sectional dimension of the protrusion (engaging protrusion 212), absorbing the deviation between the swing trajectory and the rotation trajectory accompanying the rotation of the rotating ring 21.

[0049] According to this structure, by utilizing the interlocking mechanism that can absorb deviations, driving force can be transmitted from the rotating ring 21 to the aperture plate 31.

[0050] Additionally, the recess (engaging hole 315) can be configured to appear as an elongated oval when viewed along the optical axis.

[0051] According to this structure, the deviation between the rotation trajectory (direction R) of the rotating ring 21 and the swing trajectory (direction M) of the aperture plate 31 can be absorbed by the oblong recess (engaging hole 315).

[0052] Additionally, the drive source 22 can be configured to abut against the radially outer peripheral surface 213 of the rotating ring 21.

[0053] According to this structure, the rotating ring 21 and the drive source 22 can be arranged at the same position in the optical axis direction.

[0054] Furthermore, the aperture portion 3 can be configured to have an even number of aperture plates 31 to 31, and for the portions that overlap during the swing, the aperture plate 31 located in front of the optical axis and the aperture plate 31 located behind are arranged adjacent to each other in the circumferential direction.

[0055] According to this structure, the adjacent aperture plates 31, 31 in the circumferential direction are staggered in the front and back directions in the optical axis direction, so that they can avoid interference due to swinging.

[0056] Alternatively, it can be configured to have a permanent magnet on the rotating ring 21 and a magnetic sensor on the outer diameter of the rotating ring 21.

[0057] Based on this structure, the rotational position of the rotating ring 21 can be detected with a simple structure.

[0058] 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 and reduced by the rotating ring 21, the drive source 22, and the plurality of aperture plates 31 to 31. Therefore, the structure for the aperture can be miniaturized, and the aperture mechanism 1 with its simple structure can be improved.

[0059] This embodiment has been described above, but the present invention is not limited to the above-described manner, and appropriate design changes can be made within the scope of the present invention. Furthermore, the effects of the present invention are not limited to those described in the above embodiments. That is, the embodiments disclosed herein are illustrative in all respects and not limitations on the present invention. The scope of the present invention is defined by the claims rather than the foregoing description. Moreover, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the claims.

[0060] For example, in this embodiment, a rotation drive unit 2 is provided in front of the optical axis and an aperture unit 3 is provided behind it. However, it is not limited to this, and the rotation drive unit 2 may also be provided behind the optical axis and the aperture unit 3 may be provided in front of it.

[0061] Furthermore, the pushing action of the rotating ring 21 by the drive source 22 can also be performed on the surface (front surface, rear surface) of the rotating ring 21 in the optical axis direction. Alternatively, it can be performed on the inner circumferential surface in the radial direction of the rotating ring 21.

[0062] Furthermore, the rotating ring 21 is designed to have a constant optical axis and radial dimension throughout the entire circumference, and a constant curvature throughout the entire circumference. However, it is not limited to this, as long as the curvature of the circumferential surface of at least the portion subjected to the push from the drive source 22 is constant. Therefore, the rotating ring 21 may not be a ring that is connected throughout the entire circumference, but rather a partially missing ring (such as a C-shape). Alternatively, it may not be a ring but a frame shape.

[0063] Furthermore, in the above embodiment, the aperture section 3 is composed of an even number, i.e., four aperture plates 31 to 31. However, the number of aperture plates 31 can also be two or three, or even five or more. Alternatively, the aperture section 3 can be composed of an odd number of aperture plates 31 to 31.

[0064] Furthermore, in the aperture portion 3 of the above embodiment, the front-end side cutout portion 314 is a portion cut into a circular shape with constant curvature. However, the shape of the front-end side cutout portion 314 is not limited to this, and it can also be a portion cut into a straight line (including a curved shape) or a curved line shape with non-constant curvature. In addition, as long as the structure can expand or shrink the opening area of ​​the opening portion formed by the multiple aperture plates 31 to 31 according to the overlapping of the multiple aperture plates 31 to 31, the shape of the front-end side cutout portion 314 is not limited.

[0065] Furthermore, in the above embodiment, it is constituted by a combination of the engaging protrusion 212 of the rotating ring 21 and the engaging hole 315 of the aperture plate 31. However, it can also be the opposite, with a recess or hole formed in the rotating ring 21 and a protrusion formed in the aperture plate 31, so that the two engage.

[0066] Explanation of reference numerals in the attached figures:

[0067] 1: Aperture Mechanism

[0068] 2: Rotary drive unit

[0069] 21: Rotating Ring

[0070] 212: convex part, engaging protrusion

[0071] 213: Outer circumference

[0072] 22: Driver Source Section

[0073] 2251: Piezoelectric element

[0074] 2252: Pushing section

[0075] 2261: Piezoelectric element

[0076] 2262: Pushing section

[0077] 24: Permanent magnet

[0078] 3: Aperture section

[0079] 31: Aperture plate

[0080] 3111: Shaft hole

[0081] 314: Incision site, anterior lateral incision site

[0082] 315: Engagement part, recess, engagement hole

[0083] 4: Support plate

[0084] 5: Pressing part

[0085] 6: Casing

[0086] 7: Lens

[0087] 8: Shaft

[0088] X: Lens drive mechanism

[0089] M: Direction of the aperture oscillation

[0090] R: Direction of rotation of the rotating ring

[0091] O: The opening of the aperture section

Claims

1. An aperture mechanism, characterized in that, have: A rotary drive unit includes a rotating ring that rotates about an optical axis and a drive source unit that generates a driving force to rotate the rotating ring; and The aperture section includes multiple aperture plates arranged around the optical axis. These aperture plates engage with the rotating ring and swing due to the rotation of the rotating ring. As the aperture plates swing, the opening area for light to pass through can be expanded or reduced. The drive source unit includes: a base, a buffer portion, a guide pin, a bracket, a first drive body, and a second drive body. The buffer portion is disposed between the base and the bracket. The guide pin passes through the base along the optical axis. An elongated hole extending in the front-rear direction with the base as a reference is formed on the bracket and the buffer portion. The guide pin passes through the elongated hole. The bracket, the first drive body, and the second drive body are capable of moving back and forth relative to the base within the range formed by the elongated hole. The first driving body and the second driving body each include: a piezoelectric element that deforms when energized; and a pushing part that is configured to be linked with the piezoelectric element and to abut against the rotating ring. When energized, the piezoelectric element is deformed, thereby pushing the pushing part against the rotating ring with a force having a circumferential component, so as to make the rotating ring rotate.

2. The aperture mechanism according to claim 1, characterized in that, Each of the plurality of aperture plates The portion outside the aperture section, serving as the center of the swing, is supported by a shaft. A slit is formed on the edge of the swinging front end side for expanding and reducing the opening area. The engaging portion that engages with the rotating ring is located between the shaft-supported portion and the cut-out portion.

3. The aperture mechanism according to claim 2, characterized in that, The rotation trajectory of the rotating ring intersects with the swing trajectory of each of the plurality of aperture plates. The engagement by the engaging portion is achieved by a combination of a protrusion provided on one of the aperture plate and the rotating ring and a concave portion provided on the other, wherein the cross-sectional dimension of the concave portion is larger than the cross-sectional dimension of the protrusion.

4. The aperture mechanism according to claim 3, characterized in that, The recess appears as an elongated oval when viewed along the optical axis.

5. The aperture mechanism according to any one of claims 1 to 4, characterized in that, The drive source is configured to abut against the radial outer peripheral surface of the rotating ring.

6. The aperture mechanism according to any one of claims 1 to 4, characterized in that, The aperture section has an even number of aperture plates. For the portions that overlap during the swing, the aperture plate located in front of the optical axis and the aperture plate located behind are arranged adjacent to each other in the circumferential direction.

7. The aperture mechanism according to any one of claims 1 to 4, characterized in that, A permanent magnet is provided on the rotating ring, and a magnetic sensor is provided on the outer side of the diameter of the rotating ring.

8. A lens module, characterized in that, include: One or more lenses; The aperture mechanism according to any one of claims 1 to 7.

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