Optical equipment

Abstract

To provide an optical instrument with improved reliability.SOLUTION: An optical instrument has at least a first optical element and a second optical element, and the optical instrument has a first movable lens barrel that holds the first optical element, a second movable lens barrel that holds the second optical element, and a base member that limits a moving range in an optical axis direction of the first movable lens barrel. The first movable lens barrel and the second movable lens barrel are arranged adjacent to each other, and the moving range in the optical axis direction of the first movable lens barrel partially overlaps a moving range in the optical axis direction of the second movable lens barrel. The first movable lens barrel is arranged with a buffer having a first contact surface in contact with the second movable lens barrel and a second contact surface in contact with the base member. The first contact surface and the second contact surface are formed on a partial surface of the same buffer.SELECTED DRAWING: Figure 6

Description

Technical Field

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[0001] The present invention relates to optical devices such as lens barrels.

Background Art

[0002] In order to shorten the shortest shooting distance or improve the closest focusing image quality, a technique of moving a plurality of lens groups during focus adjustment is known. As a technique of moving a plurality of lens groups using respective separate driving means, a method called direct drive, in which a lens group is directly moved by a driving means such as a VCM or an ultrasonic motor, may be adopted.

[0003] In the case of the direct drive method, a configuration for straight-ahead guiding based on the relationship between a guide bar, which is a fixed part, and a guide hole provided in the lens barrel is common. Also, when the direct drive type lens barrel is impacted when not energized, it may collide with the base member at the moving end and receive a large impact.

[0004] For example, in Patent Document 1, there is a buffer portion between the body and the lens barrel, and it is arranged so as to project toward the body on the moving direction side of the lens barrel and at both ends of the guide portion, thereby mitigating the impact when the lens barrel collides with the mechanical end.

[0005] In Patent Document 2, in two adjacent movable lens barrels, one movable lens barrel is provided with a biasing member that can be compressed in the optical axis direction when the lens barrels come into contact with each other, thereby mitigating the impact caused by the collision of the lens barrels during a rapid zoom operation.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the prior art disclosed in Patent Document 1 above does not consider countermeasures against collisions between multiple lens barrels. Furthermore, while the prior art disclosed in Patent Document 2 is effective against collisions between lens barrels, it does not mention a collision mitigation mechanism that includes impact with the base member. Therefore, it cannot be directly applied to the placement of cushioning material for adjacent movable lens barrels.

[0008] Therefore, the object of the present invention is to provide an optical instrument with improved reliability. [Means for solving the problem]

[0009] To achieve the above objective, one aspect of the optical instrument of the present invention is: A first movable lens barrel that holds a first optical element, A second movable lens barrel that holds a second optical element, A base member that limits the range of movement of the first movable lens barrel in the optical axis direction, The cushioning material provided in the first movable lens barrel, First and second guide members that guide the movement of the first and second movable lens barrels in the respective optical axis directions, It has, The first and second movable lens barrels are arranged adjacent to each other in the optical axis direction. The respective ranges of movement of the first and second movable lens barrels in the optical axis direction overlap with each other. The second movable lens barrel and the base member abut against the same surface of the cushioning material. Occasionally, When viewed from the direction of the optical axis, the optical axis and the previous 1 and When the axes passing through each of the second guide members are defined as the first and second axes, and the region where the angle formed by the first and second axes is 180 degrees or less is defined as the first region, the contact surfaces of the cushioning material and the base member are positioned in the first region. It is characterized by the following: [Effects of the Invention]

[0010] According to the present invention, it is possible to provide optical instruments with improved reliability. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view of the lens barrel of Example 1. [Figure 2] It is an exploded perspective view of the main part of the lens barrel of FIG. 1. [Figure 3] It is a view of the main part seen from the X2 direction of the optical axis. [Figure 4] It is a view of the main part with the rear group cover and the cover member removed. [Figure 5] (A) and (B) are cross-sectional views at the object side end and the image plane side end of the main part. [Figure 6] (A) and (B) are explanatory diagrams of the arrangement of the buffer material. [Figure 7] It is an explanatory diagram of the arrangement of the first movable lens barrel and the buffer material when viewed from the optical axis direction. [Figure 8] It is an explanatory diagram of the arrangement of the main part seen from the X2 direction of the optical axis. [Figure 9] It is a schematic diagram of the arrangement of the main components when viewed from the optical axis direction in Example 1. [Figure 10] It is a schematic diagram of the arrangement of the main components when viewed from the optical axis direction in a modified example of Example 1. [Figure 11] It is a schematic diagram of the arrangement of the main components when viewed from the optical axis direction in Example 2. [Figure 12] It is a schematic diagram of the arrangement of the main components when viewed from the optical axis direction in a modified example of Example 2. [Figure 13] It is a schematic diagram of the arrangement of the main components when viewed from the optical axis direction in Example 3. <​​​​​​​​​​​​​​​Example 1 will be described in detail below with reference to the attached drawings. Figure 1 is a cross-sectional view of the lens barrel of Example 1, and Figure 2 is an exploded perspective view of the main part of the lens barrel of Figure 1. Referring to Figures 1 and 2, the configuration of the interchangeable lens 100, which is an optical instrument serving as a lens barrel in an embodiment of the present invention, will be described. Note that the interchangeable lens 100 in Embodiment 1 is an interchangeable lens for a single-lens reflex camera. In the following description, the optical axis of the interchangeable lens 100 will be described with X1 being the object side and X2 being the image plane side.

[0014] The interchangeable lens 100 in this embodiment is a lens device with a 6-group configuration consisting of 1st to 6th lens groups L1 to L6, which are multiple optical elements. During the focusing operation (focusing operation) of the interchangeable lens 100, the 4th lens group L4, which is the focusing lens group, and the 5th lens group L5, which is the floating lens group, move in the direction of the optical axis. Also, during the zooming operation (zoom, magnification operation) of the interchangeable lens 100, each lens of the 2nd lens group L2 moves in the direction of the optical axis along predetermined trajectories.

[0015] At this time, the control unit 122, acting as a control means, drives and controls the fourth lens group L4 and the fifth lens group L5 so that the focus position and each aberration amount, which have changed due to the zoom operation, are kept below a certain level. The control unit 122 has a built-in CPU as a computer, and while communicating with a CPU provided on the camera side (not shown), it controls the operation of each part of the entire interchangeable lens 100 based on a computer program stored in memory (not shown) as a storage medium.

[0016] The camera body (not shown) functions as an imaging device, equipped with a CPU and memory as described above, as well as an image sensor such as a CCD image sensor or a CMOS image sensor. The interchangeable lens 100 is held so that it can be attached to and detached from the camera body by the user, and the camera system is formed by the interchangeable lens 100 and the camera body.

[0017] The lens mount 111 has a bayonet section for attaching to the camera body and is fixed to the outer ring 113 with screws. The outer ring 113 is fixed to the fixing cylinder 112 with screws. The outer ring 113 is fitted with zoom indicators and operating switches (not shown). The guide tube 117 is fixed to the fixed tube 112 with screws.

[0018] The guide tube 117 has a linear groove formed therein that guides each lens group in the straight direction. The cam tube 118, which is rotatable relative to the guide tube 117, has three phases of cam grooves formed therein that correspond to the trajectory of the second lens group L2 during zoom operation. The zoom operating tube 119 is held rotatably around the optical axis by diameter fitting with the guide tube 117 and by a fixed-position rotating roller (not shown).

[0019] The zoom operating tube 119 is equipped with a zoom key (not shown) connected to the cam tube 118. When zooming is performed, the rotational force of the zoom operating tube 119 is transmitted to the cam tube 118, causing the cam tube 118 to rotate around the optical axis. The rotational force of the zoom operating tube 119 is converted into straight-line movement of the second lens retaining frame 102 through the action of a cam groove provided in the cam tube 118, a cam follower provided in the second lens retaining frame 102, and a straight-line groove provided in the guide tube 117. Then, when zooming is performed, the second lens retaining frame 102 moves in a straight line. The first lens retaining frame 101, which holds the first lens group L1, is fixed to the guide tube 117 with screws.

[0020] Next, we will describe each lens group in detail. The first lens retaining frame 101 is a retaining frame that holds the first lens group L1. The lens retaining ring 120 has a screw on its outer diameter and is fixed by screwing it into a screw on the inner diameter of the first lens retaining frame 101, and in doing so, plays the role of fixing the first lens group L1.

[0021] A protective ring is fixed to the first lens retaining frame 101 by screws (not shown). The protective ring has recesses on its outer circumference for attaching a hood, and threads on its inner circumference, allowing accessories such as hoods, caps, and filters to be attached.

[0022] The second lens retaining frame 102 is a retaining frame that holds the second lens group L2. As described above, the rotation of the zoom operating barrel 119 and the cam barrel 118 is converted into the straight movement of the second lens retaining frame 102, and the focal length of the interchangeable lens 100 can be changed by the straight movement of the second lens retaining frame 102 when the zoom is operated.

[0023] The third A lens retaining frame 103A is a retaining frame that holds the third A lens group L3A. The third A lens retaining frame 103A is fixed to the guide tube 117 with screws. It also holds the electromagnetic diaphragm unit 110, which is composed of an diaphragm drive unit and an diaphragm blade unit. The third B lens retaining frame 103B is a retaining frame that holds the third B lens group L3B. The third B lens retaining frame 103B is held in place by rollers (not shown) relative to the guide tube 117.

[0024] The third C lens retaining frame 103C is a retaining frame that holds the third C lens group L3C. The third C lens retaining frame 103C constitutes part of the image stabilization unit 108. The shake correction unit 108 holds the third C lens holding frame 103C so that it can be driven in a direction perpendicular to the optical axis (direction perpendicular to the optical axis), and performs shake correction by driving the third C lens holding frame 103C with a shake correction drive unit consisting of a magnet and a coil. The shake correction unit 108 is suspended and held by the fixed cylinder 112 by rollers.

[0025] The third lens retaining frame 103D is a retaining frame that holds the third lens group L3D. The third lens retaining frame 103D is fixed to the rear group base 140, which is a base member, by screws. The fourth lens retaining frame 104, which is a second movable lens barrel, is a retaining frame that holds the fourth lens group L4, which is a second optical element that is a focusing group.

[0026] The fourth lens retaining frame 104 is guided to move in the optical axis direction by the second main guide bar 153 (second guide member) and second sub-guide bar 154, which are held by the rear group base 140, the first rear group cover 160, and the second rear group cover 161. It is driven in the optical axis direction relative to the rear group base 140 by the second driving means 152, which is a drive unit.

[0027] Here, the drive force transmission mechanism consists of a motor stator 130, a motor movable element 131, and a motor drive transmission section which is part of the movable element. Furthermore, it consists of a second rack, which is a drive transmission member that transmits the drive force from the motor drive transmission section to the fourth lens holding frame 104, and a second rack biasing spring that eliminates play between the second rack and the motor drive transmission section by biasing.

[0028] The fourth lens retaining frame 104, which acts as a second movable lens barrel, is equipped with a scale for detecting its position in the optical axis direction. A corresponding optical sensor is also provided on the rear group base 140 via a flexible printed circuit board (FPC), and together the scale and the optical sensor constitute a focus position detection means.

[0029] The fifth lens retaining frame 105, which functions as the first movable lens barrel, is a retaining frame that holds the fifth lens group L5, which functions as the first optical element and is a floating group. The fifth lens retaining frame 105 is guided to move in the optical axis direction by the first main guide bar 155 (first guide member) and the first sub-guide bar 156 (third guide member), which are held by the rear group base 140, the third rear group cover 162, and the fourth rear group cover 163.

[0030] The fifth lens retaining frame 105 is driven in the optical axis direction relative to the rear group base 140 by the first driving means 151, which is the drive unit. Here, the driving force transmission mechanism and the like have the same configuration as the fourth lens group L4. The sixth lens retaining frame 106 is a retaining frame that holds the sixth lens group L6. The sixth lens retaining frame 106 is fixed to the rear group base 140 with screws.

[0031] In this embodiment, when driving the fourth lens holding frame 104 and the fifth lens holding frame 105, a motor using a piezoelectric element is used, and the motor movable element 131 is configured to be driven in the optical axis direction relative to the motor stator 130. Furthermore, for example, a stepping motor may be used, and the movable element and motor drive transmission section may be connected to the rack by using a lead screw shaft and its screw. When using a stepping motor, it is also possible to eliminate the detection system and control it as an open drive.

[0032] The cam cylinder 118 is provided with a sensor key (not shown) that fits onto the movable element of a resistive sensor (potentiometer), which is a zoom position detection means (not shown) fixed to the guide cylinder 117. The output of the resistive linear sensor changes according to the amount of rotation of the cam cylinder 118. Since the cam cylinder 118 rotates in conjunction with the rotation of the zoom operation cylinder 119, zoom position information can be detected.

[0033] The focus control tube 114 is held outside the intermediate outer ring 115 so that it can rotate to a fixed position. The amount and direction of rotation of the focus control tube 114 are detected by a light detection element provided on the guide tube 117 and a scale with black and white light and dark markings provided on the inner diameter of the focus control tube 114.

[0034] The multi-purpose operating tube 121 is held by the front outer casing 116 so that it can rotate in a fixed position outside the first lens holding frame 101. The multi-purpose operating tube 121 has multiple comb teeth that detect the amount and direction of rotation of the multi-purpose operating tube 121 in relation to the photointerrupter provided on the first lens holding frame 101. The control unit 122 is responsible for the control of the entire interchangeable lens 100, including focus drive control, electromagnetic diaphragm unit 110, and shake correction unit 108, and is fixed to the rear group base 140 with screws.

[0035] Next, the structure of the main part of the lens barrel will be explained using Figures 2 to 4. As mentioned above, Figure 2 is an exploded perspective view of the main part of the lens barrel shown in Figure 1, Figure 3 is a view of the main part from the X2 direction of the optical axis, and Figure 4 is a view of the main part with the rear group cover and cover members removed.

[0036] As described above, the fourth lens group L4 held by the fourth lens holding frame 104 is the focusing group and is driven in the optical axis direction by the second driving means 152. The front ends of the second main guide bar 153 and the second sub-guide bar 154, which serve as second guide means, are held by the rear group base 140, and the rear ends are held by the first rear group cover 160 and the second rear group cover 161, which are fastened and fixed to the rear group base 140.

[0037] The second main guide bar 153 and the second sub-guide bar 154 guide the movement of the fourth lens retaining frame 104 in the optical axis direction, and the sleeve hole 104a of the fourth lens retaining frame 104 engages with the second main guide bar 153. In addition, a second rack biasing spring is provided between the fourth lens retaining frame 104 and the second drive means 152.

[0038] The movable part of the second drive means 152 and the second rack engage at a location not shown, and the biasing force of the second rack biasing spring generates a rotation M2 around the axis of the second main guide bar 153 in the fourth lens holding frame 104. Furthermore, the position of the fourth lens holding frame 104 relative to the rear group base 140 is determined by the contact between the second sub guide bar 154 and the bearing 104b fixed to the fourth lens holding frame 104.

[0039] The position of the fourth lens retaining frame 104 in the optical axis direction relative to the rear group base 140 is read by detecting a second scale 158 fixed to the fourth lens retaining frame 104 with a position sensor (not shown) fixed to the rear group base 140.

[0040] As described above, the fifth lens group L5 held by the fifth lens retaining frame 105 is a floating group and is driven in the optical axis direction by the first driving means 151. The front ends of the first main guide bar 155 and the first sub-guide bar 156, which serve as the first guide means, are held by the rear group base 140, and the rear ends are held by the third rear group cover 162 and the fourth rear group cover 163, which are fastened and fixed to the rear group base 140.

[0041] The first main guide bar 155 and the first sub-guide bar 156 guide the movement of the fifth lens retaining frame 105 in the optical axis direction, and the sleeve hole 105a of the fifth lens retaining frame 105 engages with the first main guide bar 155. Furthermore, a first rack 132 and a first rack biasing spring 133 that generates a biasing force to rotate the rotatably mounted first rack 132 are provided.

[0042] The movable part of the first drive means 151 and the first rack 132 are engaged at a location not shown, and the biasing force of the first rack biasing spring 133 generates a rotation M1 around the axis of the first main guide bar 155 in the fifth lens holding frame 105. Furthermore, the position of the fifth lens retaining frame 105 relative to the rear group base 140 is determined by the contact between the first sub-guide bar 156 and the bearing 105b fixed to the fifth lens retaining frame 105.

[0043] The position of the fifth lens holding frame 105 in the optical axis direction relative to the rear group base 140 is read by detecting the first scale 157 held in the fifth lens holding frame 105 with a position sensor (not shown) fixed to the rear group base 140. In this embodiment, the fifth lens group L5 is a floating group and the fourth lens group L4 is a focusing group, and an example in which the two lens groups are driven during focus adjustment has been described, but this is not limited to this. For example, one group may move during magnification and the other during focus adjustment.

[0044] Next, using Figures 5 to 7, we will explain the range of motion of the first movable lens barrel and the second movable lens barrel, and the relationship between the placement of the cushioning material. Figs. 5(A) and (B) are cross-sectional views at the object-side end and the image-plane side end of the main part, Figs. 6(A) and (B) are explanatory diagrams of the arrangement of the buffer materials, and Fig. 7 is an explanatory diagram of the arrangement of the first movable lens barrel and the buffer materials when viewed from the optical axis direction.

[0045] First, the movement range of the movable lens barrel will be described using Fig. 5. The fifth lens holding frame 105, which is the first movable lens barrel, is movably held within a first movement range D1 defined between the buffer material 180 and the fixed-side contact surface 140b, between the fifth lens holding frame 105 and the buffer material 170a, or between the fifth lens holding frame 105 and the buffer material 171a.

[0046] The fourth lens holding frame 104, which is the second movable lens barrel, is movably held within a movement range D10 defined between the buffer material 140a and the buffer material 170a, or between the buffer material 140a and the buffer material 171a. Further, the first movable lens barrel and the second movable lens barrel are arranged adjacent to each other, and the first movement range D1 of the first movable lens barrel partially overlaps (overlaps) with the movement range D10 of the second movable lens barrel. Therefore, there is a possibility that the lens barrels may collide with each other when not energized in the overlap range OL.

[0047] Here, when the movement range restricted by the movable lens barrels, that is, when the fourth lens holding frame 104 is located in the overlap range OL, the range within which the fifth lens holding frame 105 can move is defined as the second movement range D2. Since the second movement range D2 is determined by the position of the fourth lens holding frame 104, it is variable and varies within the range shown by the following formula 1. D1 - OL ≦ D2 < D1 ···· (Formula 1)

[0048] Also, in this embodiment, when the fourth lens holding frame 104 and the fifth lens holding frame 105 move to the movement ends on the object side and the image-plane side, respectively, the lens barrels are configured not to contact each other. This is because if one movement end is determined only by the contact between the lens barrels, the possibility of collision in the face-to-face situation increases. Therefore, movement ends are provided between each lens barrel and the rear group base 140, which is the fixed part, the first cover member 170, and the second cover member 171.

[0049] Next, as mentioned above, Figure 6 is an explanatory diagram of the arrangement of the cushioning material, and the arrangement of the cushioning material will be explained using Figure 6. In the following explanation, "cushioning material" refers to materials that can mitigate impact, such as urethane, rubber, or porous sheets.

[0050] A first cover member 170 and a second cover member 171, which restrict the range of movement of the fourth lens retaining frame 104 and the fifth lens retaining frame 105 respectively, are screwed to the rear group base 140. The first cover member 170 is provided with a cushioning material 170a, and the second cover member 171 is provided with a cushioning material 171a. The cushioning materials 170a and 171a come into contact with the object-side moving end of the fourth lens holding frame 104.

[0051] Furthermore, the cushioning materials 170a and 171a abut against the object-side moving end of the fifth lens retaining frame 105. In addition, the rear group base 140 is provided with cushioning material 140a, which abuts against the object-side moving ends of the fourth lens retaining frame 104 and the fifth lens retaining frame 105. In other words, the rear group base 140, as a base member, limits the range of movement of the first movable lens barrel.

[0052] Furthermore, a cushioning material 180 is placed on the fifth lens retaining frame 105, which is the first movable lens barrel, and is positioned to contact the fixed contact surface 140b of the rear group base 140 and the lens barrel side contact surface 104d of the second movable lens barrel. The cushioning material 180 has a first contact surface, which is a contact surface 180a with the rear group base 140, and a second contact surface, which is a contact surface 180b with the second movable lens barrel, and the two contact surfaces of the cushioning material 180 are made up of the same side.

[0053] Therefore, the impact of collisions with the base and collisions between the movable lens barrels can be mitigated by using the same side surface of the same cushioning material. In this embodiment, the contact surfaces 180a and 180b of the cushioning material 180 are formed on the same side and on the same surface, but the contact surfaces 180a and 180b of the cushioning material 180 may be surfaces of different heights on the same side.

[0054] If cushioning material or shock-absorbing components are provided on each contact surface as in conventional examples, the amount of cushioning material per location becomes small, leading to poor assembly and a risk of peeling off when force is applied during a collision. Furthermore, increasing the size of the cushioning material requires a larger bonding area, which could affect the size of the lens barrel due to the increased size of the base component. Therefore, it is necessary to efficiently attach large cushioning material.

[0055] However, by placing the cushioning material that acts between multiple parts on the lens barrel side, as in this embodiment, the bonding area can be secured, thereby improving ease of assembly. Furthermore, since only a contact surface needs to be provided on the base side, the cushioning material can be placed without increasing its size, and the reliability against impact can also be improved.

[0056] Figure 7 shows the layout of the fifth lens retaining frame 105 and the buffer material as viewed from the optical axis direction, and shows the five-group lens barrel unit including the fifth lens retaining frame 105 as viewed from the object side. The cushioning material 180 is arranged in three phases offset by approximately 120 degrees from the fifth lens retaining frame 105, with substantially identical cushioning materials 180 spaced apart, and the cushioning material 180 is fixed to the fifth lens retaining frame 105 with double-sided tape (not shown). That is, in the example of Figure 7, the cushioning material consists of a first cushioning material, a second cushioning material, and a third cushioning material arranged spaced apart on the end face of the first movable lens barrel.

[0057] In this embodiment, the buffer material was divided into multiple spaced buffer materials and arranged to contact the base member and the movable lens barrel in three phases. However, the first buffer material, the second buffer material, and the third buffer material could be connected so that a single buffer material contacts the base member and the movable lens barrel in three phases. Furthermore, the buffer material 180 was positioned so that it contacts both the base member and the movable lens barrel by offsetting the contact surface 180a and the contact surface 180b of the buffer material radially. However, they could also be offset circumferentially.

[0058] The arrangement of the configuration of this embodiment as seen from the optical axis direction will be explained using Figures 8 and 9. Figure 8 is an explanatory diagram of the arrangement of the main components as viewed from the X2 direction of the optical axis, and Figure 9 is a schematic diagram of the arrangement of the main components as viewed from the optical axis direction in Embodiment 1. In Figure 9, the arrangement of the driving means, main guide bar, sub-guide bar, and cushioning material contact surface as viewed from the X2 direction of the optical axis is schematically depicted.

[0059] In Figure 9, the first main guide bar 155 in Figure 8 is designated MB1, the second main guide bar 153 is designated MB2, the first sub-guide bar 156 is designated SB1, and the second sub-guide bar 154 is designated SB2. Furthermore, the arrangement is schematically explained by designating the first drive means 151 as ACT1, the second drive means 152 as ACT2, and the contact phases of the buffer material 180 with the rear group base 140 and the second movable lens barrel as S1, S2, and S3. The base member holds the first drive means 151 and the second drive means 152.

[0060] The first axis A1, the second axis A2, the sixth axis A6, and the seventh axis A7 are lines that pass through the optical axis and also through MB1, MB2, SB1, and SB2, respectively. That is, the axes that pass through the optical axis and through the first guide member and the second guide member are designated as the first axis and the second axis, respectively, and the axes that pass through the optical axis and through the first sub-guide bar 156 and the second sub-guide bar 154 are designated as the sixth axis and the seventh axis, respectively.

[0061] Furthermore, the third axis A3, the fourth axis A4, and the fifth axis A5 are lines that pass through the optical axis and also through S1, S2, and S3. When the area enclosed by the first axis A1 and the second axis A2 is defined as the first region AR1, Figures 8 and 9 show the case where the angle of the first region AR1 is within 90 degrees. In this embodiment, the third axis A3 is positioned at approximately the midpoint within the first region AR1. That is, S1, which is the contact surface between the cushioning material and the base member, is positioned approximately midway within the first region between the first axis and the second axis.

[0062] Let me explain the effect of arranging them in this way. First, as mentioned above, in this embodiment, the movement ranges of the fourth lens retaining frame 104 and the fifth lens retaining frame 105 are arranged to overlap. While electrically controlled, the movement can be controlled so that the lens barrels do not interfere with each other. However, if the interchangeable lens 100 is subjected to an impact when the power is not supplied, each lens group will move along the optical axis, potentially causing a collision. Furthermore, since the lens barrel supported by the guide bar is prone to large stresses around the main guide bar support, it is necessary to increase the strength of the area around the main guide bar with ribs or the like.

[0063] While impacts received at strong points result in less deformation of the telescope tube, the placement of cushioning material allows for efficient shock absorption through the deformation of the cushioning material. Specifically, by placing cushioning material in the first region AR1, which is adjacent to the main guide bar, shock absorption can be efficiently achieved. Furthermore, by placing cushioning material approximately midway between the two main guide bars, distortion can be minimized.

[0064] Furthermore, in this embodiment, three cushioning materials 180 are arranged, and the second triangular region AR2 formed by connecting S1, S2, and S3 is positioned to surround the center of gravity G1 of the fifth lens retaining frame 105 and the center of gravity G2 of the fourth lens retaining frame 104. The center of gravity expressed here refers to the center of gravity including the parts attached to the fifth lens retaining frame 105 and the fourth lens retaining frame 104 that move together as a single unit.

[0065] In other words, the second region, formed by connecting the positions where the first to third cushioning materials each contact the base member, is positioned to surround the center of gravity of the first movable lens barrel and the center of gravity of the second movable lens barrel when viewed in a cross-section perpendicular to the optical axis. By arranging the cushioning material to surround the center of gravity of each telescope tube in this way, the generation of moments due to the misalignment between the contact point between the telescope tube and the cushioning material and the center of gravity is suppressed, allowing for balanced shock absorption.

[0066] Figure 10 is a schematic diagram of the arrangement of the main components as viewed from the optical axis direction in a modified example of Embodiment 1. Figure 10 shows a case in which the sub-guide bars of the first movable lens barrel and the second movable lens barrel are shared, thereby reducing the number of parts and improving space efficiency. In Figure 10, the eighth axis A8, which is a predetermined axis, is a line that passes through the optical axis and also through the shared sub-guide bar SB3 (third guide section). In the configuration shown in Figure 10, the second triangular region AR2 formed by connecting S1, S2, and S3 surrounds the center of gravity G1 of the fifth lens retaining frame 105 and the center of gravity G2 of the fourth lens retaining frame 104, thus enabling balanced shock absorption.

[0067] As described above, by placing the same type of cushioning material acting between multiple parts on the same surface of the lens barrel, the bonding area can be secured, thereby improving ease of assembly. Furthermore, since only a contact surface needs to be provided on the base side, the cushioning material can be placed without increasing its size, and the reliability against impact can also be improved.

[0068] Furthermore, if the angle of the first region AR1, which is the area enclosed by the two main guide bars, is within 90 degrees, the cushioning material can be placed within the first region AR1 to efficiently absorb shock. In addition, by arranging the second region AR2, which connects the contact phases of multiple cushioning materials, to surround the center of gravity of the movable telescope tube, shock can be absorbed in a well-balanced manner. [Examples]

[0069] In Example 1, the ideal arrangement when there are three contact points for the cushioning material was described, but in Example 2, the ideal arrangement when there are two contact points for the cushioning material will be explained using Figures 11 and 12. That is, in Example 2, the cushioning material consists of a first cushioning material and a second cushioning material placed on the end face of the first movable lens barrel. Figure 11 is a schematic diagram of the arrangement of the main components as viewed from the optical axis direction in Example 2, and Figure 12 is a schematic diagram of the arrangement of the main components as viewed from the optical axis direction in a modified example of Example 2. Explanations of some overlapping component arrangements are omitted as they were explained in Example 1.

[0070] As shown in Figure 11, the sub-guide bars SB1 and SB2 are positioned opposite the main guide bar across the optical axis, and in Embodiment 2, a contact point with a second buffer material is provided between the sub-guide bars. Furthermore, the ninth axis A9 is a straight line passing through the optical axis and connecting the contact phase S4 of the buffer material, and is positioned approximately on the same straight line as the third axis A3 across the optical axis.

[0071] In other words, the positions where the first and second cushioning materials contact the base member are opposite each other across the optical axis. By positioning the cushioning materials in this way, approximately opposite each other across the optical axis, the impact can be absorbed in a range close to the center of gravity of the telescope tube, thus enabling efficient shock absorption even with only two cushioning materials.

[0072] Next, a modified example of Example 2 will be explained using Figure 12. In Figure 12, the first and second movable telescope tubes share a sub-guide bar, and a shared sub-guide bar SB3 is positioned opposite S1, one of the contact points for the buffer material. Therefore, the straight line B1, which connects the contact points S1 and S4 of the buffer material, does not pass through the optical axis. In this case, the support will be biased towards either the center of gravity G1 of the fifth lens retaining frame 105 or the center of gravity G2 of the fourth lens retaining frame 104.

[0073] Therefore, the position of the contact phase S4 of the cushioning material is brought as close as possible to the shared sub-guide bar SB3. That is, if the cushioning material consists of a first cushioning material and a second cushioning material positioned on the end face of the first movable telescope tube, the contact surface between the first cushioning material and the base member is positioned in a first region between the first axis and the second axis, and the contact surface between the second cushioning material and the base member is positioned near the eighth axis.

[0074] As a result, the impact can be absorbed by the cushioning material, including the area near the center of gravity. In other words, in this modified example, impact can be effectively absorbed by placing the eighth axis A8 and the ninth axis A9 in close proximity. By arranging the components as in this embodiment, even if it is not possible to provide three contact points with the cushioning material due to constraints on the placement of other components, impact can be absorbed efficiently. [Examples]

[0075] Examples 1 and 2 show the case where the main guide bars of the first movable lens barrel and the second movable lens barrel are adjacent with a buffer material in between, and the first region AR1 is within 90 degrees. In Example 3, the main guide bars of the first movable lens barrel and the second movable lens barrel are spaced apart, and the angle of the first region AR1 is 90 degrees or more.

[0076] Figure 13 is a schematic diagram of the arrangement of the main components in Example 3, as viewed from the optical axis direction. In Figure 13, the sub-guide bars of the first and second movable telescope tubes are adjacent to the main guide bar of the other, and the drive means ACT1 and ACT2 are positioned near the respective main guide bars. The angle of the first region AR1, which is the area enclosed by the first axis A1 and the second axis A2, that is, the angle formed by the first axis and the second axis with respect to the optical axis, is between 90 degrees and 180 degrees, and the arrangement of the buffer material is different from that of Embodiment 1.

[0077] In Example 3, there are three contact points for the cushioning material. If cushioning material were placed only near the respective main guide bars MB1 and MB2, and only at the contact points S2 and S3, the straight line B2 connecting S2 and S3 would be far from the center of gravity G1 and G2 of the telescope tube, thus generating a moment as described above.

[0078] Therefore, in Example 3, the contact points of the cushioning material are set to three points, and the second triangular region AR2 formed by connecting S1, S2, and S3 is arranged to surround the centers of gravity G1 and G2. Similar to Example 1, by arranging the cushioning material to include the center of gravity of each telescope tube, the generation of moments due to the misalignment between the contact points of the telescope tubes and the center of gravity is suppressed, thereby enabling balanced shock absorption. By adopting a configuration like that of this embodiment, even when the first region AR1 is greater than 90 degrees, the impact can be absorbed in a balanced manner, thereby improving the impact resistance of the lens barrel. [Examples]

[0079] Example 4 is an example in which the main guide bars of the first and second movable lens barrels are spaced apart, similar to Example 3, the angle of the first region AR1 is 90 degrees or more, and there are two buffer materials. Figure 14 is a schematic diagram of the arrangement of the main components in Example 4 as viewed from the optical axis direction.

[0080] As shown in Figure 14, the buffer material contact positions are at two points, S1 and S2, and are positioned adjacent to the main guide bars of the first and second movable telescope tubes, respectively. That is, the buffer material consists of a first buffer material and a second buffer material positioned on the end face of the first movable telescope tube, with the contact surface between the first buffer material and the base member positioned near the first axis, and the contact surface between the second buffer material and the base member positioned near the second axis. Furthermore, the fourth axis A4 is positioned approximately on the same straight line as the fifth axis A5, with the optical axis in between.

[0081] By placing the cushioning material in approximately symmetrical positions across the optical axis, the shock can be absorbed in a range close to the center of gravity of the telescope tube, thus efficiently absorbing shock even with only two cushioning materials. As described above, according to Example 4, even when the first region AR1 enclosed by the first axis A1 and the second axis A2 is 90 degrees or more, and there are two contact points for the cushioning material, impact can be absorbed efficiently.

[0082] Although the present invention has been described in detail above based on preferred embodiments, the present invention is not limited to the above embodiments, and various modifications are possible based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention. [Explanation of symbols]

[0083] 100... interchangeable lenses 101····First lens retaining frame 102...Second lens retaining frame 103A...3A lens retaining frame 103B...3B lens retaining frame 103C...3C lens retaining frame 103D...3D lens retaining frame 104...4th lens retaining frame 104d... Contact surface on the telescope tube side 105...5th lens retaining frame 106...6th lens retaining frame 122.....Control Unit 130...Motor stator 131...Motor movable part 140... Rear group base 140a...Buffer material 140b...Fixed side contact surface 151...First driving means 152...Second driving means 153...Second main guide bar 154...Second sub-guide bar 155...First main guide bar 156...First sub-guide bar 160...First rear group cover 161...Second rear group cover 162...Third rear group cover 163...4th rear group cover 170...First cover component 170a...Buffer material 171...Second cover component 171a...Buffer material 180...Buffer material 180a...First contact surface 180b...Second contact surface

Claims

1. A first movable lens barrel that holds a first optical element, A second movable lens barrel that holds a second optical element, A base member that limits the range of movement of the first movable lens barrel in the optical axis direction, The cushioning material provided in the first movable lens barrel, It comprises first and second guide members that guide the movement of the first and second movable lens barrels in the respective optical axis directions, The first and second movable lens barrels are arranged adjacent to each other in the optical axis direction. The respective ranges of movement of the first and second movable lens barrels in the optical axis direction overlap with each other. The second movable lens barrel and the base member are in contact with the same surface of the cushioning material. An optical device characterized in that, when viewed from the direction of the optical axis, the axes passing through the optical axis and the first and second guide members, respectively, are defined as the first and second axes, and the region in which the angle formed by the first and second axes is 180 degrees or less is defined as the first region, and the contact surfaces of the cushioning material and the base member are arranged in the first region.

2. The base member is in contact with multiple positions on the cushioning material, The optical instrument according to claim 1, characterized in that, when viewed from the direction of the optical axis, the respective centers of gravity of the first and second movable lens barrels are included in the region connecting the plurality of positions.

3. The optical device according to claim 1, characterized in that the base member is in contact with first and second positions on opposite sides of the optical axis in the cushioning material.

4. The cushioning material includes the first and second cushioning materials, The optical device according to claim 1, characterized in that the contact surfaces of the first cushioning material and the base member are located near the first axis, and the contact surfaces of the second cushioning material and the base member are located near the second axis.

5. A first movable lens barrel that holds a first optical element, A second movable lens barrel that holds a second optical element, A base member that limits the range of movement of the first movable lens barrel in the optical axis direction, The first and second cushioning materials provided in the first movable lens barrel, It comprises first and second guide members that guide the movement of the first and second movable lens barrels in the respective optical axis directions, The first and second movable lens barrels are arranged adjacent to each other in the optical axis direction. The respective ranges of movement of the first and second movable lens barrels in the optical axis direction overlap with each other. The second movable lens barrel and the base member are in contact with the same surface of the first and second cushioning materials. An optical instrument characterized in that, when viewed from the direction of the optical axis, the axes passing through the optical axis and the first and second guide members, respectively, are defined as the first and second axes, the contact surface of the first cushioning material and the base member is positioned near the first axis, and the contact surface of the second cushioning material and the base member is positioned near the second axis.

6. The cushioning material includes the first and second cushioning materials, The first movable lens barrel and the second movable lens barrel have a common third guide portion. When viewed from the direction of the optical axis, the axis passing through the optical axis and the third guide portion is defined as a predetermined axis, The contact surfaces of the first cushioning material and the base member are arranged in the first region between the first axis and the second axis. The optical device according to claim 1, characterized in that the contact surfaces of the second cushioning material and the base member are arranged near the predetermined axis.

7. The optical instrument according to any one of claims 1 to 6, characterized in that it has first and second driving means for driving the first and second movable lens barrels in the direction of the optical axis, respectively.

8. The optical device according to claim 7, characterized in that the base member holds the first and second driving means.

9. The optical instrument according to any one of claims 1 to 8, characterized in that it is detachable from the imaging device.

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