JP6583365B2 - Lens barrel and imaging device - Google Patents

Description

  The present invention relates to a lens barrel and an imaging apparatus.

In the lens barrel, there is a structure in which a part of the profile of the cam groove is cut out and the cut part is replaced with a key and a key groove in order to avoid interference between the cam groove for driving the cam pin and other members (Patent Document) 1).
[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-029318

  The drive mechanism using the key and the keyway cannot change the curvature in the middle of the profile. For this reason, the cam profile that can be assigned to the keyway is limited, and the layout of the members in the lens barrel is restricted.

  In the first aspect of the present invention, the first cylinder, the second cylinder disposed inside the first cylinder, rotating with respect to the first cylinder and moving in the optical axis direction, and the first cylinder A main cam groove and a sub cam groove formed on one of the cylinder and the second cylinder, and formed on the other of the first cylinder and the second cylinder and engaged with the main cam groove, and the second cylinder is A main projection that moves the second cylinder relative to the first cylinder in the optical axis direction when rotated relative to the first cylinder, and a sub-cam formed on the other of the first cylinder and the second cylinder A second protrusion that engages with the groove and moves the second cylinder relative to the first cylinder in the optical axis direction when the second cylinder rotates with respect to the first cylinder; Has a state where the main cam groove and the main projection are not engaged with each other and the sub cam groove and the sub projection are engaged with each other when rotating with respect to the first tube and moving in the optical axis direction, The secondary cam groove is formed with the secondary cam groove. The lens barrel is provided which is formed by side walls raised from the surface.

  In the second aspect of the present invention, an imaging apparatus including the lens barrel is provided.

  The above summary of the present invention does not enumerate all necessary features of the present invention. A sub-combination of these feature groups can also be an invention.

1 is a schematic cross-sectional view of an imaging apparatus 100. FIG. 1 is a schematic cross-sectional view of an imaging apparatus 100. FIG. 2 is a partial perspective view of a lens barrel 200. FIG. 2 is a partial perspective view of a lens barrel 200. FIG. 2 is a partially exploded perspective view of a lens barrel 200. FIG. 2 is a partially exploded perspective view of a lens barrel 200. FIG. 2 is a partially exploded perspective view of a lens barrel 200. FIG. 4 is a schematic development view of a fixed cam cylinder 140. FIG. 2 is a partial rear view of a lens barrel 200. FIG. 2 is a partial perspective view of a lens barrel 200. FIG.

  Hereinafter, the present invention will be described through embodiments of the invention. The following embodiments do not limit the invention according to the claims. Not all combinations of features described in the embodiments are essential for the solution of the invention.

  FIG. 1 is a schematic cross-sectional view of the imaging apparatus 100. The imaging device 100 includes an imaging element 102 and a lens barrel 200. In FIG. 1, the lens barrel 200 is in an expanded state. In the following description, the side closer to the subject with respect to the imaging apparatus 100 is referred to as the front, and the side farther from the subject is referred to as the rear.

  The imaging element 102 is supported by the sensor base 101 and is fixed near the rear end of the imaging apparatus 100. The image sensor 102 converts the subject luminous flux incident through the lens barrel 200 into an electrical signal and outputs the electrical signal.

  The lens barrel 200 includes a first lens group 111, a second lens group 121, and a third lens group 131, a fixed cam cylinder 140, a rotating cam cylinder 150, and a rectilinear cylinder 160. The first lens group 111, the second lens group 121, and the third lens group 131 are arranged along a common optical axis X, and form an optical system of the lens barrel 200.

  The first lens group 111 is held at the tip of the first group cylinder 113 via the first lens chamber 112. The first group cylinder 113 is driven by the rotating cam cylinder 150 through a cam pin 114 provided in the vicinity of the rear end while being restricted in rotation by engaging with the rectilinear guide groove 161 of the rectilinear cylinder 160. As a result, the first group cylinder 113 advances and retracts the first lens group 111 along the optical axis X.

  The second lens group 121 is held in the second lens chamber 122. A cam pin 124 is provided on the outer peripheral surface of the second lens chamber 122. The cam pin 124 is driven by the rotating cam cylinder 150 while its rotation is restricted by the rectilinear guide groove 164 of the rectilinear cylinder 160. As a result, the second lens chamber 122 advances and retracts the second lens group 121 along the optical axis X.

  The third lens group 131 is held in the third lens chamber 132. The third lens chamber 132 is connected to the fitting portion 133 and the nut 134. The fitting portion 133 is fitted to the guide shaft 103 fixed to the sensor base 101 in parallel with the optical axis X. Thereby, it is supported so that a movement in the direction parallel to the optical axis X is possible.

  The fitting portion 133 is fitted to the guide shaft 103 at a plurality of locations. As a result, the third lens chamber 132 maintains the state in which the third lens group 131 is orthogonal to the optical axis X, and restricts the tilting of the third lens group 131.

  The nut 134 is screwed with a lead screw 172 disposed parallel to the optical axis X. The lead screw 172 is rotationally driven by a motor 171. When the lead screw 172 is driven to rotate, the nut 134 moves along the longitudinal direction of the lead screw 172. Thus, the third lens group 131 is moved along the optical axis X by electrically controlling the driving amount of the motor 171 and the focal position of the optical system of the lens barrel 200 is moved along the optical axis X. Can be made.

  In the lens barrel 200, the fixed cam barrel 140 is fixed to the sensor base 101. On the inner surface of the fixed cam cylinder 140, a rectilinear guide groove 142 that guides the rectilinear movement while restricting the rotation of the rectilinear cylinder 160 is provided. Further, the fixed cam cylinder 140 is formed with a notch portion 144 provided for the purpose of avoiding interference with the fitting portion 133 of the third lens chamber 132. Further, the fixed cam barrel 140 has a main cam groove 146 on the inner surface that engages with a main cam pin 154 provided near the rear end of the rotating cam barrel 150.

  The rotating cam barrel 150 has a main cam pin 154 that is disposed inside the fixed cam barrel 140 and protrudes radially outward of the lens barrel 200 in the vicinity of the rear end. The main cam pin 154 engages with the main cam groove 146 of the fixed cam cylinder 140. As a result, when the rotary cam cylinder 150 is rotationally driven from the outside, the rotary cam cylinder 150 advances and retreats in the optical axis X direction by the driving force received through the main cam pin 154.

  The rotating cam cylinder 150 has a plurality of cam grooves 151 and 152 on the inner surface. One cam groove 151 engages with a cam pin 114 provided near the rear end of the first group cylinder 113 to drive the first group cylinder 113. The other cam groove 152 engages with the cam pin 124 of the second lens chamber 122 to drive the second lens chamber 122.

  The rectilinear cylinder 160 is engaged with the first group cylinder 113 by a rectilinear guide groove 161 provided on the outer peripheral surface. Thereby, the rotation of the first group cylinder 113 around the optical axis X is restricted. Further, the rectilinear cylinder 160 engages the guide pin 162 provided at the rear end with the rectilinear guide groove 142 of the fixed cam cylinder 140. Thereby, the movement of the rectilinear cylinder 160 in the direction of the optical axis X is guided, and the rotation of the rectilinear cylinder 160 itself around the optical axis X is restricted.

  Further, the rectilinear cylinder 160 engages with the circumferential groove 153 of the rotating cam cylinder 150 at a rib 163 provided on the outer peripheral surface near the rear end. Thus, the rectilinear cylinder 160 moves in the optical axis X direction as the rotating cam cylinder 150 advances and retreats in the optical axis X direction while allowing the rotation cam cylinder 150 to rotate around the optical axis X.

  In the imaging apparatus 100 having the above-described structure, the first lens group 111 and the second lens group 121 are moved forward and backward in the optical axis X direction in association with each other, whereby the magnification of the optical system of the lens barrel 200 is increased. Change. In addition, by moving the third lens group 131 in the optical axis X direction, the subject image formed by the optical system of the lens barrel 200 can be focused on the imaging surface of the imaging element 102.

  In the lens barrel 200, the rotary cam barrel 150 rotates around the optical axis X. As the rotating cam cylinder 150 rotates, the main cam pin 154 of the rotating cam cylinder 150 moves across the sheet. In FIG. 1, the main cam pin 154 is illustrated for the purpose of indicating that the rotating cam cylinder 150 is engaged with the fixed cam cylinder 140 through the main cam pin 154, but the main cam pin 154 does not necessarily appear in the illustrated cross section.

  FIG. 2 is a schematic cross-sectional view of the imaging apparatus 100. As illustrated, the lens barrel 200 moves through the first lens chamber 112, the second lens chamber 122, and the third lens chamber 132 to the end of the movable range, so that the total length of the lens barrel 200 is increased. Is greatly shortened. Thereby, portability can be improved. However, when the lens barrel 200 is retracted, the first lens chamber 112 and the second lens chamber 122 are moved to a range that is different from the range of movement for zooming or focusing.

  FIG. 3 is a partial perspective view of the lens barrel 200. FIG. 3 shows a state in which the assembly of the fixed cam barrel 140, the rotating cam barrel 150, and the third lens chamber 132 is looked up from the oblique rear side of the imaging device 100. In the illustrated assembly, a rotating cam cylinder 150 is arranged inside the fixed cam cylinder 140, and a third lens chamber 132 is arranged inside the rotating cam cylinder 150.

  On the upper side in the drawing, a part of the third lens chamber 132 extends to the outer peripheral side of the fixed cam cylinder 140 across the rotating cam cylinder 150. As a result, the third lens chamber 132 is connected to the fitting portion 133 fitted to the guide shaft 103. Therefore, the third lens chamber 132 is guided by the guide shaft 103 and moves the third lens group inside the fixed cam barrel 140.

  A gear portion 155 is provided on the outer peripheral surface of the rotating cam cylinder 150 on the lower left side in the drawing. The gear portion 155 meshes with an output gear of an actuator housed in a housing 145 provided on the outer peripheral surface of the fixed cam cylinder 140 and is driven to rotate. Thereby, the first cam group 111 and the second lens group 121 are driven by rotating the rotary cam cylinder 150.

  FIG. 4 is a partial perspective view of the lens barrel 200. FIG. 4 shows a state in which the assembly of the fixed cam barrel 140 and the third lens chamber 132 is looked up from the oblique front side of the imaging device 100.

  In the illustrated assembly, the rotating cam cylinder 150 is removed, so that the inner surface of the fixed cam cylinder 140 appears widely. A main cam groove 146 is further formed on the inner surface of the fixed cam cylinder 140 covered with the light shielding line 149.

  In the fixed cam cylinder 140, the main cam groove 146 is arranged so as to intersect with the notch portion 144. Therefore, the cam profile of the main cam groove 146 is temporarily interrupted in the section where the notch 144 is provided, and a pair of partial cam grooves 147 sandwiching the notch 144 is formed.

  The main cam pin 154 of the rotating cam cylinder 150 passes between the pair of partial cam grooves 147 that pass through the notch portion 144 and form the main cam groove 146. However, the main cam pin 154 cannot be driven by the main cam groove 146 in the section where the cam profile is cut by the notch 144.

  FIG. 5 is a partial exploded perspective view of the lens barrel 200. FIG. 5 shows the engagement relationship between the fixed cam barrel 140 and the rotating cam barrel 150 by looking up from the oblique rear side in the imaging apparatus 100.

  The rotating cam cylinder 150 has a plurality of main cam pins 154 provided as protrusions on the outer periphery near the rear end. In the illustrated example, three main cam pins 154 are provided at substantially equal intervals in the circumferential direction of the rotating cam cylinder 150.

  Corresponding to the three main cam pins 154, three sets of main cam grooves 146 are also provided on the inner surface of the fixed cam cylinder 140. Each main cam groove 146 has a cam surface as a side wall formed by recessing a part of the inner surface of the fixed cam cylinder 140 in the thickness direction.

  Of these three main cam grooves 146, one main cam groove 146 that intersects the notch portion 144 is formed by a pair of partial cam grooves 147. In other words, the other two main cam grooves 146 are formed as one cam groove that completes a continuous cam profile without intersecting with the notch portion 144.

  FIG. 6 is a partial exploded perspective view of the lens barrel 200. FIG. 6 shows a state in which the same fixed cam cylinder 140 and the rotating cam cylinder 150 as those in FIG. 5 are looked down from different perspectives on the rear side.

  The rotating cam cylinder 150 further includes a single sub cam pin 158 provided as a protrusion between the pair of main cam pins 154. The auxiliary cam pin 158 is provided in the vicinity of the rear end of the rotating cam cylinder 150 so as to protrude outward in the radial direction. The sub cam pin 158 is provided adjacent to the main cam pin 154 that engages with the main cam groove 146 combined with the partial cam groove 147.

  In a region where the auxiliary cam pin 158 is sandwiched in the circumferential direction of the rotating cam cylinder 150, a small diameter portion 159 in which the diameter of the rotating cam cylinder 150 is reduced is provided. In other words, the sub cam pin 158 is provided in the small diameter portion 159 having a smaller diameter than the portion where the main cam pin 154 is provided.

  FIG. 7 is a partially exploded perspective view of the lens barrel 200. FIG. 7 shows a state in which the same fixed cam barrel 140 and rotating cam barrel 150 as those in FIG. 6 are looked up from a symmetrical position with respect to the optical axis X.

  As illustrated, a sub cam groove 148 that engages with the sub cam pin 158 is disposed on the inner surface of the fixed cam cylinder 140. The sub cam groove 148 has a cam surface as a side wall formed by a pair of hook-shaped portions that protrude radially inward from the inner surface of the fixed cam cylinder 140.

  Thus, the main cam groove 146 in the fixed cam cylinder 140 is provided so as to be recessed with respect to the inner surface of the fixed cam cylinder 140. On the other hand, the auxiliary cam groove 148 in the fixed cam cylinder 140 is formed to protrude from the inner surface of the fixed cam cylinder 140.

  FIG. 8 is a schematic development view of the fixed cam cylinder 140. In FIG. 8, the left side in the figure is the front side of the imaging apparatus 100.

  In FIG. 8, the main cam pin 154 and the sub cam pin 158 of the rotating cam cylinder 150 are drawn together for the purpose of explaining the functions of the main cam groove 146 and the sub cam groove 148. Further, for the purpose of showing the correspondence between FIG. 8 and FIG. 9, a part of the fixed cam barrel 140 and the rotating cam barrel 150 viewed from the rear side in the optical axis X direction is surrounded by a dotted line A.

  Of the three main cam grooves 146, a part of the cam profile of the main cam groove 146 that intersects with the notch portion 144 is cut off by the notch portion 144 to form a pair of partial cam grooves 147. The cam profiles of the pair of partial cam grooves 147 form part of the cam profile of the entire main cam groove 146, respectively. However, the cam profile in the region overlapping the notch 144 is not included in any of the pair of partial cam grooves 147.

  The single sub cam groove 148 has a cam profile including a part of the cam profile cut out by the notch 144 in the main cam groove 146. Further, the sub cam groove 148 and the main cam groove 146 are in phase with the main cam groove 146 so that the engagement of the sub cam pin 158 with the sub cam groove 148 is in phase with the engagement of the main cam pin 154 with the main cam groove 146. It is arranged between the cam groove 146.

  When the main cam pin 154 moved in the main cam groove 146 reaches the notch 144 in the process of rotating the rotary cam cylinder 150 and comes out of the partial cam groove 147, the main cam groove 146 is separated from the main cam pin 154. The state is not engaged. However, even in this state, the auxiliary cam groove 148 and the auxiliary cam pin 158 are engaged, and the driving force is transmitted from the fixed cam cylinder 140 to the rotating cam cylinder 150.

  Thus, the lens barrel 200 has the main cam groove 146 and the main cam pin 154 that have the notch portion 144 and are not partially engaged, but the other two sets that do not intersect with the notch portion 144. In addition to the main cam groove 146 and the main cam pin 154, a set of the sub cam groove 148 and the sub cam pin 158 are engaged. As a result, even if one main cam groove 146 intersects the notch portion 144, the rotating cam cylinder 150 is driven or positioned by the three cam grooves and cam pins throughout the cam profile of the main cam groove 146. The

  Of the cam profile of the main cam groove 146, the cam profile of the portion cut from the main cam groove 146 and held by the sub cam groove 148 includes a curve. However, the secondary cam pin 158 has a circular cross section perpendicular to the insertion direction with respect to the secondary cam groove 148, and therefore moves smoothly in the secondary cam groove 148 having a bent cam profile. Therefore, the sub cam groove 148 can handle a part of the cam profile of the main cam groove 146 regardless of whether the cam profile is a straight line or a curve.

  Further, the sub cam groove 148 has a cam profile corresponding to a part of the cam profile of the main cam groove 146. Therefore, the length of the auxiliary cam groove 148 in the extending direction is shorter than the length of the main cam groove 146 in the extending direction.

  On the other hand, the auxiliary cam pin 158 is provided on the rotating cam cylinder 150 common to the main cam pin 154. Therefore, when the rotating cam cylinder 150 rotates with respect to the fixed cam cylinder 140, the movement amounts of the main cam pin 154 and the sub cam pin 158 relative to the fixed cam cylinder 140 are equal to each other. Therefore, as the rotating cam cylinder 150 rotates, the sub cam pin 158 comes out of the sub cam groove 148 or enters the sub cam groove 148.

  Here, both ends of the sub cam groove 148 are open. Accordingly, by widening the distance between the pair of side walls forming the sub cam groove 148 at the end of the sub cam groove 148, the sub cam pin 158 can be smoothly moved in and out of the sub cam groove 148.

  Further, at the position where the sub cam pin 158 is separated from or enters the sub cam groove 148, the cam profile of the sub cam groove 148 is orthogonal to the circumferential direction of the fixed cam barrel 140, that is, the optical axis X of the lens barrel 200. It extends substantially linearly in the direction to be. This prevents the driving force in the optical axis X direction from changing in the rotating cam cylinder 150 through the auxiliary cam pin 158 when entering and exiting the auxiliary cam groove 148.

  By the way, in the cam profile of the main cam groove 146, the portion located in the lower side in the figure makes the first lens group 111 and the second lens group 121 optically significant for the purpose of changing the magnification of the lens barrel 200. It becomes an optical region to be moved to. On the other hand, in the cam profile of the main cam groove 146, the upper part in the drawing is a non-optical region in which the first lens group 111 and the second lens group 121 are moved for the purpose of retracting the lens barrel 200. .

  In the lens barrel 200, a portion cut from the cam profile of the main cam groove 146 is included in the non-optical region. Therefore, even when the driving force transmitted to the rotating cam barrel 150 changes when the main cam pin 154 enters and exits from the partial cam groove 147 and the sub cam pin 158 enters and exits from the sub cam groove 148, the lens barrel 200 It is possible to prevent the performance as an optical instrument from being affected.

  In FIG. 8, the side view in which the dotted line A is oriented shows a portion including the auxiliary cam groove 148 from the partial cam groove 147 on the non-optical region side in the main cam groove 146 from the rear side of the lens barrel 200 in the optical axis X direction. Show how it looked. FIG. 9 is an enlarged view of the same portion shown in FIG.

  FIG. 9 is a partial rear view of the lens barrel 200, and shows a portion surrounded by a dotted line A in FIG. However, in FIG. 9, the corresponding part is enlarged, and the fixed cam cylinder 140 and the rotating cam cylinder 150 are shown separated from each other.

  In the fixed cam cylinder 140, each of the partial cam grooves 147 forming the main cam groove 146 is formed so as to be recessed from the inner surface of the fixed cam cylinder 140. On the other hand, the sub cam groove 148 is formed by a bowl-shaped side wall raised from the inner surface of the fixed cam cylinder 140. Therefore, in the lens barrel 200, the side wall of the sub cam groove 148 is closer to the opposing rotating cam cylinder 150 than the side wall of the main cam groove 146.

  The sub cam pin 158 that engages with the sub cam groove 148 is disposed in the small diameter portion 159 having a smaller diameter than the region where the main cam pin 154 is formed. Therefore, the auxiliary cam groove 148 raised from the fixed cam cylinder 140 does not interfere with the outer surface of the rotating cam cylinder 150.

In the sub cam pin 158, the diameter D ₂ of the cross section perpendicular to the direction in which fitted to the sub cam groove 148 is smaller than the diameter D ₁ of the cross section perpendicular to the direction in which fitted to the main cam groove 146 in the main cam pin 154 . Also, the difference of the diameter, depth of engagement _{H 1} relative to the main cam groove 146 of the main cam pin 154 is deeper than the depth of engagement _{H 2} to the sub cam groove 148 of the sub cam pin 158.

  However, the sub cam pin 158 is responsible for driving the rotary cam barrel 150 only in the non-optical region of the cam profile of the main cam groove 146 where the lens barrel 200 is retracted. In the non-optical region, the secondary cam pin 158 stops only when the lens barrel 200 is fully retracted or fully extended. For this reason, the sub cam pin 158 does not stop at the intermediate portion where the cam profile of the sub cam groove 148 is inclined, and even if the sub cam pin 158 is thinner than the main cam pin 154, the positioning accuracy of the rotating cam cylinder 150 is not affected. .

  As described above, the notch portion 144 is provided in the fixed cam barrel 140, and the passage path of the fitting portion 133 of the third lens chamber 132 and the passage passage of the main cam pin 154 are intersected, thereby the diameter of the lens barrel 200. The fitting part 133 can be arranged more inside in the direction, and the diameter of the lens barrel 200 can be reduced. Further, by providing the sub cam groove 148 and the sub cam pin 158, it is possible to prevent the rotation and positioning accuracy of the rotating cam cylinder 150 from being lowered regardless of the arrangement as described above. Further, by making the secondary cam pin 158 cylindrical or frustoconical, the cam profile handled by the secondary cam groove 148 is not restricted.

  Further, an engaging portion of the main cam pin 154 with respect to the main cam groove 146 intersecting with the notch portion 144 and an engaging portion of the sub cam pin 158 with respect to the sub cam groove 148 that supplements the notch portion 144 of the main cam groove 146 are provided as lenses. By disposing the lens barrel 200 in the radial direction, the sliding resistance by the sub cam pin 158 can be reduced, and the load on the actuator can be reduced. Further, by shortening the length in the extending direction of the auxiliary cam groove 148 provided on the inner surface of the fixed cam barrel 140, the area of the light shielding line provided on the inner surface of the fixed cam barrel 140 is increased, and the optical characteristics of the lens barrel 200 are improved. Can be improved.

  10 is a partial perspective view of the lens barrel 200. The third lens chamber 132 driven by the motor 171 and the lead screw 172 moves from the state shown in FIG. 4 to the front side of the lens barrel 200. FIG. Shows the state. In this case, the fitting part 133 of the third lens chamber 132 enters deeply into the notch part 144. For this reason, the fitting part 133 enters between the partial cam grooves 147, and the main cam pin 154 of the rotating cam cylinder 150 cannot pass through the notch part 144.

  Therefore, by controlling so that the third lens chamber 132 is moved only when the main cam pin 154 is engaged with the partial cam groove 147, the main cam pin 154 and the third lens chamber 132 of the rotating cam cylinder 150 are moved. Interference with the fitting part 133 can be prevented. In addition, when the fitting portion 133 of the third lens chamber 132 is located between the partial cam grooves 147, the main cam pin 154 and the fitting portion 133 are also controlled by restricting the movement of the third lens chamber 132. Interference can be prevented.

  Further, when the interference between the main cam pin 154 of the rotating cam barrel 150 and the fitting portion 133 of the third lens chamber 132 occurs, the main cam pin 154 is moved away from the notch portion 144 of the fixed cam barrel 140. The interference state can be canceled by moving it once in the direction. Next, as described above, the rotation cam cylinder 150 and the third lens chamber 132 are sequentially moved to prevent interference from occurring again.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Image pick-up device, 101 Sensor base, 102 Image pick-up element, 103 Guide shaft, 111 1st lens group, 112 1st lens chamber, 113 1st group cylinder, 114, 124 Cam pin, 121 2nd lens group, 122 2nd lens chamber 131 Third lens group, 132 Third lens chamber, 133 Fitting portion, 134 Nut, 140 Fixed cam barrel, 142, 161, 164 Straight guide groove, 144 Notch, 145 Housing, 146 Main cam groove, 147 part Cam groove, 148 Sub cam groove, 149 Shading line, 150 Rotating cam cylinder, 151, 152 Cam groove, 153 Circumferential groove, 154 Main cam pin, 155 Gear part, 158 Sub cam pin, 159 Small diameter part, 160 Straight cylinder, 162 Guide pin 163 Rib, 171 Motor, 172 Lead screw, 200

Claims (9)

A first cylinder having a first cam groove and a second cam groove;
A second cylinder having a first protrusion that engages with the first cam groove and a second protrusion that engages with the second cam groove;
A lens holding part for holding the lens;
A guide shaft for guiding the lens holding portion in the optical axis direction,
The lens holding portion has an engaging portion that engages with the guide shaft,
The first cylinder has a notch that avoids interference with the engaging portion,
The lens barrel in which the second cam groove and the second protrusion are engaged when at least the first protrusion is at a position corresponding to the notch. The lens barrel according to claim 1 , wherein the first cam groove and the second cam groove have different shapes. The second cam groove, the lens barrel according than a short claim 1 or 2, wherein the first cam groove. The lens barrel according to any one of claims 1 to 3 , wherein the second tube rotates about an optical axis. The lens according to any one of claims 1 to 4 , wherein a depth at which the first protrusion engages with the first cam groove is deeper than a depth at which the second protrusion engages with the second cam groove. A lens barrel. The lens barrel according to any one of claims 1 to 5 , wherein a portion of the second tube where the second protrusion is provided has a smaller diameter than a portion where the first protrusion is provided. The lens barrel according to any one of claims 1 to 6 , wherein the second cam groove is formed by a pair of side walls protruding in a radial direction from a surface of the first tube. 8. The first cam groove is divided into a first partial cam groove and a second partial cam groove by the notch within a range in which the first protrusion can move to retract . The lens barrel according to item 1 . An imaging device comprising the lens barrel according to any one of claims 1 to 8 .

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