JP5434275B2 - Lens barrel and imaging device - Google Patents

Description

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

  2. Description of the Related Art Conventionally, there is known a lens barrel configured such that a plurality of lens groups can be independently moved in the optical axis direction using a guide bar. As a related art related to a lens barrel having such a guide bar, there is known a lens barrel in which a cam follower is provided on a sleeve that engages a lens holding frame with a guide bar and is engaged with a cam groove of the cam barrel. (For example, refer to Patent Document 1).

JP-A-6-174998

  In the above-described conventional lens barrel, the cam follower that engages with the cam groove of the cam barrel is located outside the guide bar and away from the optical axis, so that the lens is held by the driving force applied from the cam barrel to the cam follower When the frame is moved in the optical axis direction, a large resistance force is generated between the engaging portion of the guide bar and the lens holding frame, which makes it difficult to drive the lens holding frame efficiently. It was.

  The subject of this invention is providing the lens barrel which can drive a lens holding frame efficiently, and an imaging device provided with the same.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention of claim 1 holds an optical system, the optical system of the optical axis (OA) holding member have the outer circumferential surface along the direction (30) extends before Symbol optical axis Direction A first guide shaft (51) with which the holding member is movably engaged, and a second guide shaft that is engaged with the holding member and that is disposed opposite the first guide shaft with respect to the optical system. A guide shaft (52); and a cam member (27) disposed between the first guide shaft and the outer peripheral surface and having a cam groove , wherein the holding member extends the first guide shaft. A first engagement portion (31F) and a second engagement portion (31R) that are arranged along the direction and engage with the first guide shaft; and the first engagement portion in the optical axis direction of the optical system ; the third engagement portion to be engaged with the second guide shaft is provided between the second engagement portion (32), provided on the outer peripheral surface, the cam portion The engaged with the cam groove, the lens barrel wherein the cam member and having a driving unit for driving the holding member in the optical axis direction by rotating about the optical axis (20) It is.
Invention according to claim 2, characterized in that a lens barrel according to claim 1 (20), the front SL driver, a cam follower (33) engaging the cam member (27) And
A third aspect of the present invention is the lens barrel (20) according to the second aspect, wherein the cam follower (33) is formed on the third engaging portion (32) with respect to the optical axis (OA) direction. It is arranged at a position corresponding to the position.
A fourth aspect of the present invention is the lens barrel (20) according to the second or third aspect, wherein the first guide shaft (51), the cam follower (33), and the optical axis (OA) are aligned. It is characterized by having been arranged in.
A fifth aspect of the present invention is the lens barrel (20) according to any one of the first to fourth aspects, wherein the third engagement portion (32) is an optical axis of the optical system ( With respect to OA), the first engaging portion (31F) and the second engaging portion (31R) are arranged at symmetrical positions.
The invention described in claim 6 is the lens barrel (20) according to any one of claims 1 to 5, and an image pickup device (16) for capturing an image by an optical system held in the lens barrel. And an imaging device (1).
Note that the configuration described with reference numerals may be modified as appropriate, and at least a part of the configuration may be replaced with another component.

  ADVANTAGE OF THE INVENTION According to this invention, the lens barrel which can drive a lens holding frame efficiently, and an imaging device provided with the same can be provided.

It is sectional drawing which shows the camera of embodiment conceptually. It is a side view which shows a lens inner cylinder and the guide member which guides the movement. It is a top view when it sees from the arrow A of FIG. It is a front view when it sees from the arrow B of FIG. It is a side view which shows a lens inner cylinder and the guide member which guides the movement. It is a top view when it sees from the arrow A of FIG. It is a front view when it sees from the arrow B of FIG. It is a graph which shows the relationship between the reaction force and the distance S of a X-axis direction. It is a graph which shows the relationship between the reaction force of the Y-axis direction, and the distance S.

  Hereinafter, embodiments of a lens barrel and an imaging apparatus including the lens barrel according to the present invention will be described with reference to the drawings. 1 to 7 are provided with an XYZ orthogonal coordinate system for easy explanation and understanding. In this coordinate system, the direction toward the left as viewed from the photographer at the position of the camera when the photographer shoots a horizontally long image with the optical axis OA horizontal (hereinafter referred to as a normal position) is defined as the X plus direction. Further, the direction toward the upper side in the normal position is defined as the Y plus direction. Further, the direction toward the subject at the normal position is defined as the Z plus direction. The Z plus direction toward the subject in the Z direction is also called the front side, and the Z minus direction is also called the back side. Furthermore, when it shows as a coordinate axis | shaft, it calls "~ axis | shaft" or "~ axial direction".

FIG. 1 is a cross-sectional view conceptually showing a lens barrel 20 as a lens barrel according to the present invention and a camera 1 as an image pickup apparatus provided with the lens barrel 20.
The camera 1 includes a camera body 10 and a lens barrel 20.

  The lens barrel 20 is a so-called zoom lens capable of variably adjusting the focal length. The lens barrel 20 includes a plurality of lens groups (L1 to L5) that constitute a photographing optical system. Further, the lens barrel 20 includes a lens mount LM at an end on the back side, and is detachably attached to the subject side (left side in FIG. 1) of the camera body 10 via the lens mount LM. As a result, the camera 1 can shoot by exchanging different lens barrels 20 according to the user's application.

  The camera body 10 includes a quick return mirror 11, a viewfinder screen 12, a pentaprism 13, an eyepiece optical system 14, a shutter 15, an image sensor 16, a display device 17, and the like.

  The quick return mirror 11 is a mirror that is swingably provided in the camera body 10 in order to bend the optical path of light (subject light) from the subject side that has passed through the lens barrel 20 toward the viewfinder screen 12. is there. In response to the release operation, the quick return mirror 11 moves to a retracted position (indicated by a two-dot chain line in FIG. 1) that does not prevent the subject light from entering the image sensor 16.

The viewfinder screen 12 is a screen that forms an image of subject light reflected by the quick return mirror 11 (hereinafter referred to as subject image), and is disposed between the quick return mirror 11 and the pentaprism 13.
The pentaprism 13 is a prism having a pentagonal cross-sectional shape, and is disposed on the upper part of the camera body 10 in a horizontal position. The pentaprism 13 guides the image formed on the finder screen 12 to the eyepiece optical system 14 as an erect image.

The eyepiece optical system 14 is an optical system for magnifying and observing a subject image that has become an erect image by the pentaprism 13, and is arranged on the back side (photographer side) of the pentaprism 13.
The shutter 15 opens and closes according to the user's release operation, and controls the exposure time of the subject image formed on the image sensor 16.

  The imaging element 16 is a part that converts the subject image formed by the lens barrel 20 into an electrical signal, and is configured by a photodiode and an element such as a CCD or a COMS. The imaging element 16 is provided on the back side (the right side shown in FIG. 1) inside the camera body 10 in a state where the light receiving surface is orthogonal to the optical axis OA.

  The display device 17 includes a display panel such as a liquid crystal provided on the back side (photographer side) outside the camera body 10. The display device 17 displays a photographed image, information relating to photographing such as an exposure time, and the like on the display panel.

And the camera 1 acts as follows at the time of imaging | photography.
That is, when a shutter button (not shown) is pressed (release operation) by the user, the quick return mirror 11 moves to the retracted position. The shutter 15 opens and closes in response to the release operation, and causes the image sensor 16 to expose the subject image for a predetermined time. The image sensor 16 converts the exposed subject image into an electrical signal. This electrical signal is converted into imaging data by an image processing unit (not shown) and further recorded in a recording unit (not shown).

Next, the lens barrel 20 will be described in detail.
The lens barrel 20 includes a cylindrical outer tube 21 and a cylindrical fixed barrel 22 that is cylindrical and is disposed concentrically inside the outer tube 21.
The outer cylinder 21 has a lens mount LM fixed to the end on the back side thereof, and a zoom operation ring 23 at the tip.
The fixed barrel 22 is coupled to the outer cylinder 21 so as not to be relatively rotatable at an end portion on the back side thereof.
The zoom operation ring 23 is mounted on the outer periphery of the outer cylinder 21 so as to be rotatable and immovable in the direction of the optical axis OA.

Between the outer cylinder 21 and the fixed barrel 22, a first group barrel 24 that holds the first lens group L1, a second group barrel 25 that holds the second lens group L2, and a cam barrel 26 are concentric. It is arranged.
The first group barrel 24 and the second group barrel 25 are each provided so as to be movable in the direction of the optical axis OA.

  The cam barrel 26 is provided on the outer periphery of the fixed barrel 22 so as to be rotatable relative to the fixed barrel 22 and immovable in the optical axis OA direction (Z-axis direction). A cam follower 26 </ b> A provided on the outer periphery of the cam cylinder 26 is fitted in a cam groove 23 </ b> A formed on the inner periphery of the zoom operation ring 23, and is rotated in conjunction with the rotation of the zoom operation ring 23. It will be.

A lens inner cylinder 30 as a holding member that holds the third lens group L3, the fourth lens group L4, and the fifth lens group L5 is disposed on the inner peripheral side of the fixed barrel 22.
The lens inner cylinder 30 is a cylindrical lens holding frame, and the third lens group L3, the fourth lens group L4, and the fifth lens group L5 are fixed at respective positions in order from the front side. The lens inner cylinder 30 is held by a guide member 50 provided in the fixed barrel 22 so as to be movable in the optical axis OA direction (Z-axis direction). The structure of the lens inner cylinder 30 including the guide member 50 will be described later.

  The first group barrel 24, the second group barrel 25, and the lens inner cylinder 30 are not described in detail, but are configured to be interlocked with the cam barrel 26 by a cam groove and a cam follower (not shown). Yes. As described above, the cam cylinder 26 is configured to be rotationally driven in conjunction with the rotation of the zoom operation ring 23. Accordingly, the first group barrel 24, the second group barrel 25, and the lens inner cylinder 30 move in the direction of the optical axis OA in conjunction with the rotation of the zoom operation ring 23.

  The lens barrel 20 configured as described above has a first lens group L1, a second lens group L2, and a lens inner cylinder 30 (third lens group) via a cam cylinder 26 by rotating the zoom operation ring 23. L3, the fourth lens unit L4, and the fifth lens unit L5) move relative to each other in a predetermined relationship, thereby changing the combined focal length.

  Next, the structure of the lens inner cylinder 30 will be described with reference to FIGS. 2 is a side view showing the lens inner cylinder 30 and a guide member 50 for guiding the movement thereof, FIG. 3 is a plan view when viewed from an arrow A in FIG. 2, and FIG. 4 is an arrow in FIG. It is a front view when seen from B. 2 to 4, the shape of the lens inner cylinder 30 shown in FIG. 1 is simplified. In FIG. 2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 are schematically depicted by broken lines.

The lens inner cylinder 30 is held by a guide member 50 provided in the fixed barrel 22 so as to be movable in the optical axis OA direction (Z-axis direction).
The guide member 50 is composed of two guide bars (an upper guide bar 51 and a lower guide bar 52) fixed to the fixed barrel 22. The upper guide bar 51 as the first guide axis is disposed on the upper side of the optical axis OA (Z axis). Further, the lower guide bar 52 as the second guide shaft is disposed on the opposite side of the upper guide bar 51 with respect to the optical axis OA (Z axis), that is, at a position 180 ° apart in the circumferential direction. .

The upper guide bar 51 and the lower guide bar 52 have a round bar shape with a predetermined diameter, and have a length over the entire Z-axis direction of the fixed barrel 22. The upper guide bar 51 and the lower guide bar 52 are made of a rigid material such as a stainless alloy.
As shown in FIG. 1, each of the upper guide bar 51 and the lower guide bar 52 is fitted to an inner peripheral flange 22 </ b> F formed at the end on the back side of the fixed barrel 22, and the other end The portion is fitted to a fixing ring 22L attached to the front surface side of the fixed barrel 22. Thereby, the upper guide bar 51 and the lower guide bar 52 are fixed to the fixed barrel 22 so as to be parallel to the optical axis OA.

  The lens inner cylinder 30 is a cylindrical member having a predetermined thickness, and is formed of metal, plastic, or the like. At a position corresponding to the upper guide bar 51 on the outer peripheral surface of the lens inner cylinder 30, an upper slide bearing portion 31F as a first engagement portion and an upper slide bearing portion 31R as a second engagement portion are provided. It is arranged. The upper slide bearing portion 31F is provided in the vicinity of the front end portion of the lens inner cylinder 30, and the upper slide bearing portion 31R is provided in the vicinity of the rear end portion. That is, the upper slide bearing portion 31F and the upper slide bearing portion 31R are disposed at a predetermined interval in the optical axis OA direction. Further, the upper slide bearing portions 31F and 31R are formed with bearing holes (not shown) in which the upper guide bar 51 is fitted so as to be slidable with a predetermined tolerance.

  A cam follower 33 is provided on the outer peripheral surface of the lens inner cylinder 30 as a drive unit that drives the lens inner cylinder 30 in the direction of the optical axis OA (not shown in FIG. 1). As shown in FIG. 2 or FIG. 3, the cam follower 33 is positioned in a straight line with the upper slide bearing portions 31F and 31R in the direction of the optical axis OA, and is provided between the upper slide bearing portions 31F and 31R. .

  On the other hand, a lower slide bearing portion 32 as a third engagement portion is provided at a position corresponding to the lower guide bar 52 on the outer peripheral surface of the lens inner cylinder 30. The lower slide bearing portion 32 is formed with a U-shaped groove (reference numeral omitted) in which the lower guide bar 52 is slidably engaged. As shown in FIG. 2 or FIG. 3, the lower slide bearing portion 32 is disposed in parallel with the upper slide bearing portions 31F and 31R in the optical axis OA direction, and is provided between the upper slide bearing portions 31F and 31R. It has been. Thus, as shown in FIG. 2 or FIG. 3, the lower slide bearing portion 32 is disposed at a position corresponding to the position of the cam follower 33 with respect to the optical axis OA direction.

  Further, as shown in FIG. 4, the lower slide bearing portion 32 is symmetrical with respect to the upper slide bearing portion 31F (31R) on the opposite side of the optical axis OA (Z axis), that is, 180 ° apart in the circumferential direction. It is provided at a position.

  A cam follower 33 provided in the lens inner cylinder 30 is engaged with a cam groove 27 </ b> A formed in the cam plate 27. The cam plate 27 is disposed between the upper guide bar 51 and the outer peripheral surface of the lens inner cylinder 30. The cam groove 27A of the cam plate 27 is formed with an inclination of an angle E with respect to the optical axis OA as shown in FIG. The cam plate 27 is formed in a semicircular arc shape (a part of which is shown in FIG. 4) and is configured to be rotationally driven in conjunction with the rotation of the zoom operation ring 23.

When the cam plate 27 is rotationally driven in the direction of arrow C in FIG. 4 in the lens inner cylinder 30 and the upper guide bar 51 and the lower guide bar 52 configured as described above, the cam groove 27A of the cam plate 27 is engaged. the cam follower 33 which, as shown in FIG. 3, the force is applied from the P ₁ direction, lens barrel 30 will move to the front side. On the other hand, when the cam plate 27 is rotated in the arrow D direction in FIG. 4, the cam follower 33 that engages with the cam groove 27A of the cam plate 27, as shown in FIG. 3, the force is applied from the P ₂ direction The lens inner cylinder 30 moves to the back side. Thus, when the lens inner cylinder 30 moves to the front side or the rear side, the lens inner cylinder 30 is moved in the X and Y axis directions by the upper slide bearing portions 31F and 31R and the lower slide bearing portion 32. Therefore, it moves along the upper guide bar 51 and the lower guide bar 52 held in the optical axis OA (Z-axis) direction.

  Therefore, when the user rotates the zoom operation ring 23, the lens inner cylinder 30 moves to the front side or the rear side according to the rotation direction, and the combined focal length of the lens barrel 20 changes from the wide angle side to the telephoto side. Will change between.

  Next, conditions for providing the cam follower 33 of the lens inner cylinder 30 at an optimum position will be described. 5 is a side view showing the lens inner cylinder 30 and a guide member 50 that guides the movement thereof, FIG. 6 is a plan view when viewed from the arrow A in FIG. 5, and FIG. 7 is an arrow in FIG. It is a front view when seen from B. 5 to 7 are views corresponding to FIGS. 2 to 4 described above, and the illustration of the cam plate 27 is omitted so that the position of each part is clear.

  For the sake of simplicity of explanation, it is assumed that the center of gravity of the lens inner cylinder 30 exists at the coordinate origin O (FIG. 5), and the load mg acts in the Y minus direction.

  First, the case where the cam plate 27 is rotated in the C direction (FIG. 4) will be described. In this case, as shown in FIG. 6, since the cam groove 27A is inclined by an angle E with respect to the optical axis OA, the cam follower 33 receives a force of Pz in the Z plus direction and Px in the X minus direction. Here, in the case where Px acts, the properties of the reaction forces X1, X2 and X3 in the X-axis direction and the reaction forces Y1 and Y2 in the Y-axis direction generated in the upper slide bearing portions 31F and 31R and the lower slide bearing portion 32 Will be described.

From the balance of forces generated in the X-axis direction X1 + X2 + X3-Px = 0 (1)
Because of the force generated in the Y-axis direction Y1 + Y2-mg = 0 (2)
From the balance of moments about the X axis -LY1 + LY2 = 0 (3)
From balance of moment about Y-axis LX1-LX2 = 0 (4)
-RX1-RX2 + RX3 + SPx = 0 ... (5)
Equation (5) is obtained. In the expression (3), “L” indicates the distance in the optical axis OA direction from the upper slide bearing portion 31F (31R) to the cam follower 33, as shown in FIG. Further, in the equation (5), “R” indicates each bearing hole of the upper slide bearing portion 31F (31R) and the lower slide bearing portion 32 arranged at equal intervals around the optical axis OA as shown in FIG. The distance to the center, “S”, indicates the distance from the optical axis OA to the cam follower 33, respectively.

When the reaction forces X1, X2, X3 in the X-axis direction and the reaction forces Y1, Y2 in the Y-axis direction are obtained from the above formula 5,
X1 = (R + S) Px / 4R (6)
X2 = (R + S) Px / 4R (7)
X3 = (R−S) Px / 2R (8)
Y1 = Y2 = mg / 2 (9)
It becomes. The reaction forces Y1 and Y2 in the Y-axis direction are determined by the load mg of the lens inner cylinder 30 as is apparent from the equation (9). On the other hand, the reaction forces X1, X2, and X3 in the X-axis direction are functions that change depending on the values of Px, R, and S. Therefore, when the reaction forces X1, X2, and X3 are calculated using the distance S as a variable, a graph as shown in FIG. 8 is obtained. In FIG. 8, the distance S is arranged on the horizontal axis, and the reaction forces X1, X2, and X3 are arranged on the vertical axis.

When the lens inner cylinder 30 moves along the upper guide bar 51 and the lower guide bar 52, the resistance force generated in the Z-axis direction is not related to the direction of the reaction force, that is, the reaction force X1, X2. , X3 is multiplied by the friction coefficient μ. The resistance force generated in the Z-axis direction refers to the magnitude of the force generated on the side opposite to the moving direction (Z plus direction or Z minus direction) when the lens inner cylinder 30 is moved in the Z axis direction. .
For this reason, the total resistance Rx is
Rx = μ (| X1 | + | X2 | + | X3 |) (10)
It becomes. Here, when comparing with a constant friction coefficient, the total resistance force Rx is proportional to the value of | X1 | + | X2 | + | X3 |, which is the absolute value of the reaction force. Therefore, as shown in FIG. 8, with respect to the distance S, it can be seen that when -R ≦ S ≦ R, the total resistance force Rx becomes the minimum value. Therefore, the total resistance Rx can be minimized by providing the cam follower 33 within the range of −R ≦ S ≦ R. Thereby, when the zoom operation ring 23 is rotated, the lens inner cylinder 30 can be moved with less force.

  Further, when the cam follower 33 is provided in the range of −R ≦ S ≦ 0, the load is concentrated on the lower slide bearing portion 32 (| X3 |) as compared with the case of providing in the range of 0 ≦ S ≦ R. This is disadvantageous with respect to wear of the lower slide bearing portion 32. Therefore, it is desirable that the distance S from the optical axis OA to the cam follower 33, which is the point of action of Px, is in the range of d (lens diameter) / 2 ≦ S ≦ R.

Next, the properties of the reaction forces Y1, Y2, and Y3 in the Y-axis direction generated in the upper slide bearing portions 31F and 31R and the lower slide bearing portion 32 will be described in the case where Pz acts.
Since the lower slide bearing portion 32 cannot support the force in the Y plus direction as shown in FIG.
Y3 = 0 (11)
It becomes. On the other hand, from the balance of forces generated in the Y-axis direction,
Y1 + Y2-mg = 0 (2)

Also, from the balance of moments about the X axis,
-LY1 + LY2 + SPz = 0 (12)
It becomes. From the above equations (2) and (12), when the reaction forces Y1 and Y2 in the Y-axis direction are obtained,
Y1 = (mg / 2) + (SPz / 2L) (13)
Y2 = (mg / 2)-(SPz / 2L) (14)
It becomes. Here, as in the case of Px, when the reaction forces Y1 and Y2 are calculated using the distance S as a variable, a graph as shown in FIG. 9 is obtained. In FIG. 9, the distance S is arranged on the horizontal axis, and the reaction forces Y1 and Y2 are arranged on the vertical axis. As for Pz, as shown in FIG. 9, the total resistance force Rz can be minimized when −mgL / Pz ≦ S ≦ mgL / Pz is satisfied with respect to the distance S. Furthermore, when the lens inner cylinder 30 moves, Px and Pz act simultaneously.
d / 2 ≦ S ≦ (R or mgL / Pz) (15)
It becomes. Therefore, it is desirable to compare R and mgL / Pz and set the distance S within the smaller range.
That is, if R <mgL / Pz,
d / 2 ≦ S ≦ R
If R> mgL / Pz,
d / 2 ≦ S ≦ mgL / Pz
It becomes.

According to embodiment mentioned above, there exist the following effects.
(1) In the lens inner cylinder 30, by setting the distance S from the optical axis OA to the cam follower 33 in the range of d / 2 ≦ S ≦ R, the upper slide bearing portions 31F and 31R and the lower slide bearing portion 32 Since the generated resistance can be reduced, the lens inner cylinder 30 can be driven efficiently.
(2) In particular, when d / 2 ≦ S ≦ (R or mgL / Pz), by setting the distance S within the smaller range of R and mgL / Pz, the upper slide bearing portion 31F, Since the resistance force generated in the 31R and the lower slide bearing portion 32 can be further reduced, the lens inner cylinder 30 can be driven more efficiently.
(3) Since the cam follower 33 is disposed between the upper guide bar 51 and the outer peripheral surface of the lens inner cylinder 30, the outer diameter of the lens barrel is not increased.

Therefore, according to the present embodiment, it is possible to provide the lens barrel 20 that can efficiently drive the lens inner cylinder 30 while reducing the size, and the camera 1 including the lens barrel 20.
(Deformation)

  Without being limited to the embodiment described above, the present invention can be variously modified and changed as described below, and these are also within the scope of the present invention.

(1) In the above embodiment, the lens barrel 20 includes the lens inner cylinder 30 that holds the third lens group, the fourth lens group, and the fifth lens group L5, and the first lens group L1 and the second lens group L2. As an example, a zoom lens in which the focal length is changed by relatively moving is described. However, the present invention is not limited to this, and can also be applied to a lens holding frame that holds a focusing lens for focus adjustment.
(2) In the above embodiment, the cam plate 27 formed in a semicircular shape is shown as an example. However, the present invention is not limited to this, and may be a cylindrical shape like the lens inner cylinder 30 or a flat plate. It may be a shape.

  Moreover, although the said embodiment and modification can be used in combination suitably, since the structure of each embodiment is clear by illustration and description, detailed description is abbreviate | omitted. Furthermore, the present invention is not limited by the embodiment described above.

  1: Camera, 10: Camera body, 16: Image sensor, 20: Lens barrel, 23: Zoom operation ring, 27: Cam plate, 27A: Cam groove, 30: Lens inner cylinder, 31F, 31R: Upper slide bearing 32: Lower slide bearing portion, 33: Cam follower, 50: Guide member, 51: Upper guide bar, 52: Lower guide bar

Claims (6)

A holding member holding the optical system and have a peripheral surface along the optical axis direction of the optical system,
With extending before Symbol optical axis direction, a first guide shaft that the holding member is movably engaged with,
A second guide shaft that engages with the holding member and is disposed opposite the first guide shaft with respect to the optical system;
A cam member disposed between the first guide shaft and the outer peripheral surface and having a cam groove;
With
The holding member is disposed along the extending direction of the first guide shaft, and in the optical axis direction of the optical system, a first engagement portion and a second engagement portion that engage with the first guide shaft. A third engagement portion provided between the first engagement portion and the second engagement portion and engaged with the second guide shaft; provided on the outer peripheral surface; and engaged with the cam groove of the cam member. A driving unit that drives the holding member in the optical axis direction by rotating the cam member around the optical axis ;
A lens barrel comprising: The lens barrel according to claim 1 ,
Before SL drive unit, a lens barrel, characterized in that the cam follower engages the cam member. The lens barrel according to claim 2,
The lens barrel is characterized in that the cam follower is disposed at a position corresponding to the position of the third engaging portion in the optical axis direction. The lens barrel according to claim 2 or 3,
The lens barrel, wherein the first guide shaft, the cam follower, and the optical axis are arranged in a straight line. The lens barrel according to any one of claims 1 to 4,
The lens barrel, wherein the third engaging portion is disposed at a position symmetrical to the first engaging portion and the second engaging portion with respect to the optical axis of the optical system. An imaging apparatus comprising: the lens barrel according to any one of claims 1 to 5; and an imaging element that captures an image by an optical system held by the lens barrel.

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