JP2004205678A - Lens barrel driving mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a lens barrel driving mechanism so as to miniaturize optical system equipment such as a camera to which the lens barrel driving mechanism is applied. <P>SOLUTION: The lens barrel driving mechanism is equipped with a 1st lens barrel to hold a 1st lens group, a 1st lens frame to hold a 2nd lens group inside the 1st lens barrel, and a 2nd lens barrel to hold the 1st lens frame so as to freely move in an optical axis direction and also hold the 1st lens barrel so as to freely move in the optical axis direction. The lens barrel driving mechanism is equipped with a cam barrel on the outer peripheral surface of which a 1st helicoid screw is formed and also on the inner peripheral surface of which a plurality of cam grooves are formed, and which moves the 1st lens barrel and the 1st lens frame in the optical axis direction, and a fixed barrel on the inner peripheral surface of which a 2nd helicoid screw to be screwed on the 1st helicoid screw is formed and in which the cam barrel is housed and also the 2nd lens barrel is housed in a state where its movement in the optical axis direction is regulated. When the cam barrel is turned relatively to the fixed barrel, it is moved in the optical axis direction by the 1st and the 2nd helicoid screws. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lens barrel driving mechanism, and more particularly to a lens barrel driving mechanism used for an optical device.
[0002]
[Prior art]
The lens barrel drive mechanism is used to adjust the position of a lens group constituting an imaging optical system with respect to an imaging unit that captures a still image or a moving image. For example, a lens barrel drive mechanism is applied when a zoom lens group in a zoom mechanism of a camera is moved toward and away from an imaging unit (for example, see Patent Document 1).
In the conventional lens barrel driving mechanism, as shown in FIG. 5, the first lens frame 104 to the third lens frame 106, which respectively hold the first lens group 101 to the third lens group 103, are separated from each other by the first lens group. The fixed cylinders are arranged so that the optical axes of 101 to third lens groups 103 are coaxial and the first lens group 101, the second lens group 102, and the third lens group 103 are arranged in this order from the front (left side in the figure). 107. Further, inside the fixed barrel 107, a substantially cylindrical shape having an outer diameter slightly smaller than the inner diameter of the fixed barrel 107 is formed, and the first lens frame 104 and the second lens frame 105 are moved along the optical axis direction. A cam cylinder 108 is provided to be rotatable. Further, cam grooves 111 and 112 are provided on the inner peripheral surface of the cam cylinder 108, and the cam grooves 111 and 112 are provided at the rear ends of the first lens frame 101 and the second lens frame 102. The first lens frame 101 and the second lens frame 102 are guided by engaging with the driven projections 109 and 110. A drive source (not shown) for rotating the cam cylinder 108 is connected to the cam cylinder 108.
Further, inside the cam barrel 108, the second lens frame 102 is movably held in the optical axis direction, and is engaged with the driven projections 109, 110 of the first lens frame 101 and the second lens frame 102, and is A key barrel 115 having cutouts 113 and 114 for restricting movement in the direction is stored. The key barrel 115 and the fixed barrel 107 regulate the movement of the cam barrel 108 in the front-rear direction. The key barrel 115 is provided with a motor 116 for moving the second lens frame 102 along the optical axis to focus.
[0003]
In FIG. 5, the lens groups 101 to 103 are in a close state (collapsed state) when the camera is not used. When the camera is used, the drive source and the motor 116 are moved so that a desired magnification can be obtained. The first lens frame 104 to the third lens frame 106 are driven to move. At this time, the first lens frame 101 and the second lens frame 102 are moved into the cam grooves 111 and 112 while the driven projections 109 and 110 are along the cutouts 113 and 114 with the rotation of the cam barrel 108 by the driving source. Guided to move.
In use, shooting is performed from a state in which the subject in the widest range can be captured (wide state: FIG. 5) to a state in which the subject can be captured in the narrowest range but at the highest magnification (tele state: FIG. 6). A suitable state is selected.
[0004]
[Patent Document 1]
JP-A-2002-333566
[Problems to be solved by the invention]
In recent years, miniaturization of optical devices such as cameras as well as various devices has been desired, and a lens barrel drive mechanism that is a component of the optical devices is no exception. In order to reduce the size of the lens barrel driving mechanism, it is necessary to reduce the size of the fixed cylinder 107, which is an outer shape of the lens barrel. Since the first lens group 101 and the second lens group 102 can be moved only by an amount, the amount of movement of the first lens group 101 and the second lens group 102 decreases with the downsizing, and the zoomable range is reduced. Will be converted.
For this reason, a method of extending the movement amount of the first lens group 101 and the second lens group 102 by extending the cam cylinder 108 from the fixed cylinder 108 is considered. The key barrel 115 must be moved in the optical axis direction in the same manner as the cam barrel 108 so that the notches 113 and 114 correspond to the extended movement amount. In order to move the key barrel 115 in the optical axis direction, at least a mechanism for preventing the key barrel 115 and the cam barrel 108 from rotating in synchronization must be provided. It will be an evil.
Further, if the mechanism for moving the key barrel 115 in the optical axis direction is used, the positional relationship between the motor 116 and the second lens frame 102 fluctuates. Therefore, the motor 116 is fixed so that this positional relationship does not fluctuate. A member is required, which eventually results in a problem of downsizing of the lens barrel driving mechanism.
[0006]
The present invention reduces the size of the lens barrel drive mechanism by allowing the cam barrel to be extended without moving the key lens barrel in the optical axis direction, and the optical system such as a camera to which the lens barrel drive mechanism is applied. We aim to downsize the equipment.
[0007]
[Means for Solving the Problems]
The lens barrel driving mechanism according to the first aspect of the present invention
A first lens barrel having a first cylinder driven protrusion protruding outward and a second cylinder driven protrusion protruding inward, and holding the first lens group,
A first lens frame having a frame driven protrusion protruding outward and holding a second lens group disposed behind the first lens group inside the first lens barrel;
The first lens frame is arranged inside the first lens barrel, and the first lens frame is movably held in the optical axis direction while the driven follower for the frame is penetrated to restrict movement in the circumferential direction. A lens barrel moving mechanism comprising: a second lens barrel that holds the first lens barrel so as to be movable in the optical axis direction in a state where the second lens barrel is engaged with the second cylinder driven protrusion and restricts movement in the circumferential direction.
A first helicoid screw is formed on the outer peripheral surface, and a plurality of cam grooves are formed on the inner peripheral surface for engaging and guiding each of the first cylinder driven protrusion and the frame driven protrusion, and A lens barrel and a cam barrel for moving the first lens frame in the optical axis direction;
A second helicoid screw that is screwed to the first helicoid screw is formed on the inner peripheral surface, and the cam cylinder is housed in a state where the first helicoid screw and the second helicoid screw are screwed together, A fixed barrel that stores the second lens barrel in a state where movement in the axial direction is restricted,
When the cam cylinder is rotated relative to the fixed cylinder, the cam cylinder is moved in the optical axis direction by the first helicoid screw and the second helicoid screw.
[0008]
According to the first aspect of the present invention, since the cam cylinder is stored in the fixed cylinder in a state of being screwed with the first helicoid screw and the second helicoid screw, the screwing of the first helicoid screw and the second helicoid screw is made. The cam cylinder can be moved in the optical axis direction from the fixed cylinder as long as it can be maintained. Further, since the second lens barrel is stored in a state where the movement in the optical axis direction is restricted by the fixed barrel, if the fixed barrel is fixed and the cam barrel is rotated, the cam is rotated with the rotation. The tube itself can be extended. In addition, if the second lens barrel is also fixed at the time of this rotation, the cam groove of the cam cylinder is moved in the state in which the second lens barrel restricts the circumferential movement of the second cylinder driven projection. , The first lens barrel also moves in the optical axis direction. At this time, since the cam groove guides the frame driven protrusion in a state where the second lens barrel restricts the circumferential movement of the frame driven protrusion of the first lens frame, the first lens frame also moves along the optical axis direction. Moved.
As described above, the cam barrel can be extended without moving the second barrel (key barrel) in the optical axis direction, so that the second barrel and the cam barrel are not rotated in synchronization. It is not necessary to provide a mechanism or the like, and the lens barrel driving mechanism can be downsized. Therefore, the size of an optical device such as a camera to which the lens barrel driving mechanism is applied can be reduced.
[0009]
According to a second aspect of the present invention, in the lens barrel driving mechanism according to the first aspect,
The second cylinder driven projection is disposed rearward of the first cylinder driven projection,
At the rear end of the first lens barrel, a storage notch for housing the frame driven projection is formed when the first cylinder driven projection and the frame driven projection approach each other. And
[0010]
According to the second aspect of the present invention, a notch for accommodating the frame driven projection is formed at the rear end of the first lens barrel when the first cylinder driven projection and the frame driven projection approach each other. Therefore, the frame driven protrusion can be arranged on the front side of the rear end of the first lens barrel, and the moving distance of the first lens barrel and the first lens frame in the optical axis direction can be as large as possible. it can. Therefore, downsizing of the lens barrel drive mechanism can be improved.
[0011]
The invention according to claim 3 is the lens barrel drive mechanism according to claim 1 or 2,
A second lens frame that holds a third lens group disposed behind the second lens group inside the second lens barrel,
A motor for moving the second lens frame in the optical axis direction to adjust the position of the third lens group,
The motor is fixed to the second lens barrel.
[0012]
According to the third aspect of the present invention, since the motor is fixed to the second lens barrel, members for mounting the motor can be omitted as much as possible, and the inner diameter of the second lens barrel can be reduced.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a case will be described in which the lens barrel driving mechanism 1 is applied to a digital camera exemplified as an example of an optical device. FIG. 1 is a cross-sectional view along the optical axis of the lens barrel driving mechanism 1 according to the present embodiment in a retracted state. FIG. 2 is a cross-sectional view of the same in a wide state. FIG. 4 is an explanatory view showing the same sectional view in a telephoto state.
In the following description, a state in which the digital camera can capture an object in the widest range is referred to as a wide state (a state in which imaging can be performed in the widest range), and a state in which the digital camera can capture an object in the narrowest range but at the highest magnification. Is referred to as a telephoto state (a state in which an image can be captured in the narrowest range), and a state in which the digital camera is not used and each part is stored and is most compact is referred to as a collapsed state.
[0014]
Inside the lens barrel drive mechanism 1, a first lens group 2, a second lens group 3, and a third lens group 4 are moved forward by a first lens barrel 5, a first lens frame 6, and a second lens frame 7. The first lens group 2, the second lens group 3, and the third lens group 4 are held in this order from the left side (in the figure, left side), and the respective optical axes are coaxial.
[0015]
The first lens barrel 5 is formed in a substantially cylindrical shape with an open rear end, and holds the first lens group 2 at its front end. On the outer peripheral surface at the rear end of the first lens barrel 5, a first cylindrical driven protrusion 51 protruding outward is provided. On the inner peripheral surface behind the first cylindrical driven protrusion 51, an inner surface is provided inward. A protruding second cylinder follower projection 52 has a notch 53 cut out along the axial direction so that the rear end has an opening at the rear, and a notch 53 having the same circle centered on the center line of the first lens barrel 5. Three are provided at intervals of 120 degrees on the circumference. The first cylinder driven projection 51, the second cylinder driven projection 52, and the notch 53 are respectively installed at positions shifted in the circumferential direction.
[0016]
Inside the first lens barrel 5, there is provided a substantially cylindrical second lens barrel 8 for holding the first lens frame 6 and the second lens frame 7 movably along the optical axis direction. In the side wall of the second lens barrel 8, a slit 81 formed to penetrate the side wall is provided along the optical axis direction.
On the outer surface of the second lens barrel 8, a groove 82 with which the second barrel driven projection 52 of the first lens barrel 5 is engaged is provided along the optical axis direction. Since the groove 82 guides the second cylinder driven projection 52 in the optical axis direction while restricting the movement in the circumferential direction, the width thereof is slightly smaller than the outer diameter of the second cylinder driven projection 52. Is set to small.
Further, an extension portion 83 extending outward is provided on the peripheral edge of the rear end of the second lens barrel 8. Here, when the lens barrel drive mechanism 1 is applied to an optical system device, the imaging unit A of the digital camera is arranged at the rear end inside the second lens barrel 8.
[0017]
A first lens frame 6 that holds the second lens group 3 behind the first lens group 2 is provided inside the second lens barrel 8. The first lens frame 6 has a substantially cylindrical holding portion 61 that is in contact with and holds the periphery of the second lens group 3, and extends outward from the rear end of the holding portion 61 to form a second lens unit. A mounting portion 62 mounted on the lens barrel 8 is provided. Three mounting parts 62 are provided at intervals of 120 degrees on the same circumference centered on the center line of the holding part 61 (only one is shown in FIGS. 1 to 3).
At the rear of the mounting portion 62, a frame driven protrusion 63 protruding outward is formed so as to penetrate through the slit 81 of the second lens barrel 8 from inside. Here, since the outer diameter of the frame driven protrusion 63 is set slightly smaller than the width of the slit 81, the frame driven protrusion 63 is guided in the optical axis direction by the slit 81, but is guided in the circumferential direction. On the other hand, the movement is regulated.
Further, a light-shielding plate 64 and an expandable and contractable inter-group spring 65 are provided in front of the first lens frame 6.
[0018]
Further, a second lens frame 7 that holds the third lens group 4 is provided behind the second lens group 3 inside the second lens barrel 8. A motor 9 for adjusting the position of the third lens group 4 by moving the second lens frame 7 in the optical axis direction is connected to the outer periphery of the second lens frame 7. The motor 9 is fixed inside the second lens barrel 8, and when the motor 9 rotates, the distance between the third lens group 4 and the imaging unit A is adjusted so that focus is achieved. .
[0019]
Outside the first lens barrel 5, a cylindrical cam barrel 10 for moving the first lens barrel 5 and the first lens frame 6 in the optical axis direction is provided. A gear (not shown) to which power is transmitted by a drive unit (not shown) of the digital camera is formed on the outer peripheral surface of the cam cylinder 10. A first helicoid screw 11 is formed on the rear side of the outer peripheral surface of the cam cylinder 10. As shown in FIG. 4, the inner peripheral surface of the cam cylinder 10 has a plurality of cylinder cam grooves 12 and a plurality of frame engagement grooves which engage with the first cylinder driven projections 51 and the frame driven projections 63, respectively. A cam groove 13 is formed. The cylindrical cam groove 12 and the frame cam groove 13 are formed such that the first lens frame 6 moves to a position corresponding to the amount of extension while the first lens barrel 5 is extended. Here, the cylinder cam groove 12 is formed deeper than the frame cam groove 13 in order to easily withstand an impact when the digital camera is dropped. The positions of the first cylinder driven protrusion 51 and the frame driven protrusion 63 in the wide state are point B in FIG. 4, the position in the telephoto state is point C, and the position in the retracted state is point D.
[0020]
Outside the cam barrel 10, there is provided a fixed barrel 14 for rotatably storing the second barrel 8 in a state where movement in the optical axis direction is restricted. The outer diameter of the fixed barrel 14 is set to be substantially the same as the outer diameter of the extending part 83 of the second barrel 8, and when the second barrel 8 is stored in the fixed barrel 14, the extending part 83 And the rear end surface of the fixed barrel 14 comes into contact with each other, so that the forward movement of the second lens barrel 8 is restricted. A second helicoid screw 15 that is screwed to the first helicoid screw 11 of the cam cylinder 10 is formed on the inner peripheral surface of the fixed cylinder 14.
[0021]
Next, the operation of each unit when the lens barrel is driven will be described. Here, when the lens barrel drive mechanism 1 is applied to a digital camera, the fixed barrel 14 and the second lens barrel 8 are fixed to the structure of the digital camera, and their movement in the circumferential direction is restricted.
[0022]
As shown in FIG. 1, when the lens barrel drive mechanism 1 is in the collapsed state, since the first cylinder driven projection 51 and the frame driven projection 63 are close to each other, the frame The driven protrusion 63 is housed. That is, the notch 53 functions as the storage notch described above.
Then, when the cam cylinder 10 is rotated by the driving of a driving unit (not shown), the first cylinder driven projection 51 and the frame driven projection 63 move along the cylinder cam groove 12 and the frame cam groove 13. At this time, since the movement of the frame driven projection 63 in the circumferential direction is restricted by the slit 81 of the second lens barrel 8, the first lens frame 6 does not rotate in synchronization with the cam barrel 10 but in the optical axis direction. Go to Also, in the first lens barrel 5, since the movement of the second cylinder driven protrusion 52 in the circumferential direction is restricted by the groove 82 of the second lens barrel 8, the driven protrusion 52 does not rotate in synchronization with the cam barrel 10. Move in the optical axis direction.
[0023]
Thereafter, when the cam barrel 10 rotates by a predetermined distance, the first lens barrel 5 and the cam barrel 10 are extended, and a wide state as shown in FIG. 2 is obtained. Thereafter, when the cam barrel 10 is further rotated, the cam barrel 10 is extended from the fixed barrel 14, but the first lens barrel 5 is returned into the cam barrel 10 to be in the telephoto state as shown in FIG. Also at this time, since the first cylinder driven projection 51 and the frame driven projection 63 are close to each other, the frame driven projection 63 is stored in the notch 53 of the first lens barrel 5.
Here, according to the positions of the first lens group 2 and the second lens group 3, the motor 9 adjusts the position of the second lens frame 7 to move the third lens group 4, so that the focal point is shifted to the imaging unit A. Will fit.
[0024]
As described above, according to the lens barrel drive mechanism 1 of the present embodiment, the cam barrel 10 is housed in the fixed barrel in a state where the cam barrel 10 is screwed with the first helicoid screw 11 and the second helicoid screw 15. The cam cylinder 10 can be moved from the fixed cylinder 14 in the optical axis direction as long as the screw engagement between the helicoid screw 11 and the second helicoid screw 15 can be maintained. Further, since the second lens barrel 8 is stored in a state where the movement in the optical axis direction is restricted by the fixed barrel 14, if the fixed barrel 14 is fixed and the cam barrel 10 is rotated, the rotation Accordingly, the cam cylinder 10 itself can be extended. In addition, if the second barrel 8 is also fixed at the time of this rotation, the groove 82 of the cam barrel 10 is held in a state where the groove 82 of the second barrel 8 restricts the circumferential movement of the second cylinder driven protrusion 52. Since the cam groove 12 guides the first cylinder driven protrusion 51, the first lens barrel 5 also moves in the optical axis direction. At this time, since the frame cam groove 13 guides the frame driven protrusion 63 in a state where the slit 81 of the second lens barrel 8 restricts the circumferential movement of the frame driven protrusion 63 of the first lens frame 6, One lens frame 6 is also moved along the optical axis direction.
As described above, since the cam barrel 10 can be extended without moving the second barrel 8 in the optical axis direction, a mechanism for preventing the second barrel 8 and the cam barrel 10 from rotating in synchronization. It is not necessary to provide such a device, and the lens barrel drive mechanism 1 can be reduced in size. Therefore, an optical device such as a digital camera to which the lens barrel drive mechanism 1 is applied can be reduced in size.
A notch 53 is formed at the rear end of the first lens barrel 5 for accommodating the frame driven projection 63 when the first cylinder driven projection 51 and the frame driven projection 63 approach each other. In addition, the frame driven protrusion 63 can be disposed on the front side of the rear end of the first lens barrel 5, and the moving distance of the first lens barrel 5 and the first lens frame 6 in the optical axis direction can be as large as possible. it can. Therefore, downsizing of the lens barrel drive mechanism 1 can be improved.
Further, since the motor 9 is fixed to the second lens barrel 8, members for attaching the motor 9 can be omitted as much as possible, and the inner diameter of the second lens barrel 8 can be reduced.
[0025]
It is needless to say that the present invention is not limited to the above embodiment, but can be appropriately changed.
For example, in the present embodiment, the first barrel 5 and the cam barrel 10 themselves are extended from the fixed barrel 14 by rotating the cam barrel 10, but the second barrel 8 is rotated. By doing so, the first barrel 5 and the cam barrel 10 can be extended from the fixed barrel 14. In such a case, with the rotation of the second lens barrel 8, the cam barrel 10 is fed out while rotating to a position where the screw engagement between the first helicoid screw 11 and the second helicoid screw 15 of the fixed barrel 14 is fixed. . When the cam barrel 10 moves to this position, the rotation of the cam barrel 10 is restricted, but the first barrel 5 and the first lens frame 6 move with the rotation of the second barrel 8, Of the cylinder cam groove 12 and the frame cam groove 13.
[0026]
【The invention's effect】
According to the first aspect of the present invention, the cam cylinder can be moved in the optical axis direction from the fixed cylinder as long as the screw engagement between the first helicoid screw and the second helicoid screw can be maintained. Further, since the second lens barrel is stored in a state where the movement in the optical axis direction is restricted by the fixed barrel, if the fixed barrel is fixed and the cam barrel is rotated, the cam is rotated with the rotation. The tube itself can be extended. In addition, if the second barrel is also fixed at the time of this rotation, the cam groove of the cam barrel is used for the first barrel while the groove of the second barrel restricts the circumferential movement of the driven protrusion for the second barrel. Since the driven projection is guided, the first lens barrel also moves in the optical axis direction. At this time, since the cam groove guides the frame driven protrusion in a state where the notch of the second lens barrel restricts the circumferential movement of the frame driven protrusion of the first lens frame, the first lens frame is also moved in the optical axis direction. Moved along.
As described above, since the cam barrel can be extended without moving the second barrel in the optical axis direction, a mechanism for preventing the second barrel and the cam barrel from rotating in synchronization is installed. This is not necessary, and the lens barrel drive mechanism can be downsized. Therefore, the size of an optical device such as a camera to which the lens barrel driving mechanism is applied can be reduced.
According to the second aspect of the present invention, the frame driven protrusion can be disposed on the front side of the rear end of the first lens barrel, and the moving distance of the first lens barrel and the first lens frame in the optical axis direction can be minimized. It can be secured large. Therefore, downsizing of the lens barrel drive mechanism can be improved.
According to the third aspect of the invention, the member for attaching the motor can be omitted as much as possible, and the inner diameter of the second lens barrel can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view along an optical axis of a lens barrel drive mechanism according to an embodiment of the present invention in a collapsed state.
FIG. 2 is a cross-sectional view along the same plane as FIG. 1 and shows a case in a wide state.
FIG. 3 is a cross-sectional view along the same plane as FIG. 1 and shows a case in a telephoto state.
FIG. 4 is a developed view showing an inner peripheral surface of a cam barrel provided in the lens barrel drive mechanism of FIG.
FIGS. 5A and 5B are a cross-sectional view (a) and a rear view (b) of the conventional lens barrel driving mechanism along the optical axis in a collapsed state.
FIG. 6 is a cross-sectional view along the same plane as FIG. 5 and shows a case in a wide state.
7 is a cross-sectional view along the same plane as FIG. 5 and shows a case in a telephoto state.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 lens barrel drive mechanism 2 first lens group 3 second lens group 4 third lens group 5 first lens barrel 6 first lens frame 7 second lens frame 8 second lens barrel 9 motor 10 cam cylinder 11 first helicoid screw 12 Cam groove for cylinder (cam groove)
13 Frame cam groove (cam groove)
14 Fixed cylinder 15 Second helicoid screw 51 First cylinder driven projection 52 Second cylinder driven projection 53 Notch (storage notch)
63 Frame driven projection 81 Slit 82 Groove

Claims (3)

A first lens barrel having a first cylinder driven protrusion protruding outward and a second cylinder driven protrusion protruding inward, and holding the first lens group,
A first lens frame having a frame driven protrusion protruding outward and holding a second lens group disposed behind the first lens group inside the first lens barrel;
The first lens frame is arranged inside the first lens barrel, and the first lens frame is movably held in the optical axis direction while the driven follower for the frame is penetrated to restrict movement in the circumferential direction. A lens barrel moving mechanism comprising: a second lens barrel that holds the first lens barrel so as to be movable in the optical axis direction in a state where the second lens barrel is engaged with the second cylinder driven protrusion and restricts movement in the circumferential direction.
A first helicoid screw is formed on the outer peripheral surface, and a plurality of cam grooves are formed on the inner peripheral surface for engaging and guiding each of the first cylinder driven protrusion and the frame driven protrusion, and A lens barrel and a cam barrel for moving the first lens frame in the optical axis direction;
A second helicoid screw that is screwed to the first helicoid screw is formed on the inner peripheral surface, and the cam cylinder is housed in a state where the first helicoid screw and the second helicoid screw are screwed together, A fixed barrel that stores the second lens barrel in a state where movement in the axial direction is restricted,
A lens barrel driving mechanism, wherein when the cam barrel is rotated relative to the fixed barrel, the cam barrel is moved in the optical axis direction by the first helicoid screw and the second helicoid screw. . The lens barrel driving mechanism according to claim 1,
The second cylinder driven projection is disposed rearward of the first cylinder driven projection,
At the rear end of the first lens barrel, a storage notch for housing the frame driven projection is formed when the first cylinder driven projection and the frame driven projection approach each other. Lens barrel drive mechanism. The lens barrel drive mechanism according to claim 1,
A second lens frame that holds a third lens group disposed behind the second lens group inside the second lens barrel,
A motor for moving the second lens frame in the optical axis direction to adjust the position of the third lens group,
The lens barrel driving mechanism, wherein the motor is fixed to the second lens barrel.

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