JP6031858B2 - Lens barrel and imaging device - Google Patents

Description

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

There is a lens barrel having a structure in which a plurality of members such as a guide protrusion and a float key are engaged with one straight groove (see Patent Document 1).
[Patent Document 1] Japanese Patent Application Laid-Open No. 2009-069218

  The arrangement order of the plurality of members engaged with one rectilinear groove cannot be changed in the direction of the rectilinear groove. For this reason, the movement range of the member here is restricted.

In the first aspect of the present invention, an optical system having a first optical member and a second optical member, a first rectilinear protrusion that holds the first optical member and projects in the radial direction of the first optical member , A first holding member that has one of a first cam pin and a first cam groove that engage with each other on the circumferential side, and that moves in an optical axis direction parallel to the optical axis of the optical system, and holds the second optical member And a second rectilinear protrusion protruding in the radial direction of the second optical member, and a second cam pin and a second cam groove engaged with each other on the outer peripheral side, and moving in the optical axis direction. a second holding member, parallel to the optical axis, a first linear groove that engages with the first linear protrusion, parallel to the optical axis, to engage the second rectilinear projections, of the first linear groove and the circumferential direction and a second rectilinear grooves disposed at different positions, movable first holding member and the second holding member in the optical axis direction A support cylinder for supporting a inner peripheral side of the first holding member, and provided on the outer peripheral side of the second holding member, the other one and the second cam pin and the second cam groove of the first cam pin and the first cam groove There is provided a lens barrel that includes any one of the above and a cam barrel that rotates to drive the first holding member and the second holding member in the optical axis direction .

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

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

1 is a schematic cross-sectional view of a single-lens reflex camera 100. FIG. 2 is a schematic cross-sectional view of a lens barrel 200. FIG. 3 is a schematic cross-sectional view orthogonal to the optical axis of the lens barrel 200. FIG. 2 is a schematic cross-sectional view of the rear part of a lens barrel 200. FIG. 3 is a schematic development view of a fixed cylinder 201. FIG. FIG. 6 is a schematic development view of a front side moving frame 207. 3 is a schematic development view of a cam cylinder 290. FIG. 2 is a schematic cross-sectional view of the rear part of a lens barrel 200. FIG.

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

  FIG. 1 is a schematic cross-sectional view of a single-lens reflex camera 100. The single-lens reflex camera 100 includes a lens barrel 200 and a camera body 300.

  For the purpose of simplifying the description, in the following description, the object side with respect to the lens barrel 200 attached to the camera body 300 is described as the front side or the front side of the single-lens reflex camera 100. Further, the side far from the object with respect to the lens barrel 200 is referred to as a rear side or a back side in the single-lens reflex camera 100. Furthermore, a direction parallel to the optical axis X of the optical system of the lens barrel 200 is described as an optical axis direction.

  The lens barrel 200 includes a first lens group 210, a second lens group 220, a third lens group 230, a fourth lens group 240, a fifth lens group 250, and a sixth lens group arranged along the optical axis X. Including an optical system. The first lens group 210, the second lens group 220, the third lens group 230, the fourth lens group 240, the fifth lens group 250, and the sixth lens group have lens holding frames 212, 222, 232, 242, 252, respectively. 262 individually held.

  In the illustrated lens barrel 200, a first lens group 210, a second lens group 220, a third lens group 230, a fourth lens group 240, a fifth lens group 250, and a sixth lens group 260 are retracted. It is in. Thereby, the length of the lens barrel 200 in the optical axis X direction is shortened, and portability is improved. However, the lens barrel 200 in the retracted state cannot be used as an optical device.

  The lens barrel 200 has a barrel including a fixed barrel 201, a zoom ring 202, a rectilinear barrel 203, a leading barrel 204, a cam barrel 290, a guide barrel 206, a leading side moving frame 207 and a rear side moving frame 209. The fixed cylinder 201 has a lens side mount 208 at the rear end. The fixed cylinder 201 is coupled to the camera body 300 by coupling the lens side mount unit 208 to the body side mount unit 360 on the front surface of the camera body 300.

  The coupling between the lens side mount portion 208 and the body side mount portion 360 can be released. Therefore, the camera body 300 can be used in combination with another lens barrel 200 having the lens side mount portion 208 conforming to the standard.

  The zoom ring 202 is disposed on the outer peripheral surface of the fixed cylinder 201, and is rotated about the optical axis X of the optical system as a rotation axis by a user operation. The zoom ring 202 in the lens barrel 200 is rotated by the user when the lens barrel 200 is extended to cancel the retracted state. The zoom ring 202 is also rotated by the user when the optical system of the lens barrel 200 is scaled.

  In the lens barrel 200, the lens holding frame 242 that holds the fourth lens group 240 is supported to be movable with respect to the front side moving frame 207. The lens holding frame 242 is driven by a feed screw assembly 270 fixed to the front side moving frame 207.

  The feed screw assembly 270 includes a stepping motor 272, a feed screw 274 and a frame 276. The frame 276 integrally supports the stepping motor 272 and the feed screw 274 and is fixed to the front side moving frame 207. The stepping motor 272 drives the feed screw 274 to rotate. The feed screw 274 engages with the lens holding frame 242 via the rack member 278.

  Thereby, the fourth lens group 240 held by the lens holding frame 242 can be moved. When the fourth lens group 240 moves, the focal position of the optical system of the lens barrel 200 changes. Therefore, the lens barrel 200 can be focused by electrically controlling the stepping motor 272 based on the signal from the camera body 300 side.

  The camera body 300 includes a mirror unit 370 disposed behind the body side mount portion 360. A focusing optical system 380 is disposed below the mirror unit 370. A focusing screen 352 is disposed above the mirror unit 370.

  A pentaprism 354 is disposed further above the focusing screen 352, and a finder optical system 356 is disposed behind the pentaprism 354. The rear end of the viewfinder optical system 356 is exposed as a viewfinder 350 on the back surface of the camera body 300.

  Behind the mirror unit 370, a shutter unit 310, a low-pass filter 332, an image sensor 330, a substrate 320, and a display unit 340 are sequentially arranged. A display unit 340 formed by a liquid crystal display panel or the like appears on the back surface of the camera body 300. A control unit 322, an image processing unit 324, and the like are mounted on the substrate 320.

  The mirror unit 370 includes a main mirror 371 and a sub mirror 374. The main mirror 371 is supported by a main mirror holding portion 372 that is pivotally supported by a main mirror rotating shaft 373.

  The sub mirror 374 is supported by a sub mirror holding portion 375 that is pivotally supported by a sub mirror rotating shaft 376. The sub mirror holding unit 375 rotates with respect to the main mirror holding unit 372. Therefore, when the main mirror holding part 372 rotates, the sub mirror holding part 375 is also displaced together with the main mirror holding part 372.

  When the front end of the main mirror holding portion 372 is lowered, the main mirror 371 is positioned obliquely on the incident light beam incident from the lens barrel 200. When the main mirror holding part 372 moves up, the main mirror 371 retracts to a position avoiding the incident light beam.

  When the main mirror 371 is positioned on the incident light beam, the incident light beam incident through the lens barrel 200 is reflected by the main mirror 371 and guided to the focusing screen 352. The focusing screen 352 is disposed at a position conjugate with the optical system of the lens barrel 200, and visualizes an image formed by the optical system of the lens barrel 200.

  The image on the focusing screen 352 is observed from the viewfinder 350 through the pentaprism 354 and the viewfinder optical system 356. Here, an erect image can be observed from the viewfinder 350 by observing the image through the pentaprism 354.

  The photometric sensor 390 is disposed above the finder optical system 356 and receives a part of the branched incident light beam. The photometric sensor 390 detects the subject brightness and causes the control unit 322 to calculate an exposure condition that is a part of the photographing condition.

  The main mirror 371 has a half mirror region that transmits a part of the incident light beam. The sub mirror 374 reflects a part of the incident light beam incident from the half mirror region toward the focusing optical system 380. The focusing optical system 380 guides a part of the incident incident light beam to the focus detection sensor 382. Thereby, the control unit 322 determines the target position of the lens that moves when the optical system of the lens barrel 200 is focused.

  When the release button is half-pressed in the single-lens reflex camera 100 including the lens barrel 200 and the camera body 300 as described above, the focus detection sensor 382 and the photometric sensor 390 are enabled, and the subject image is captured under appropriate shooting conditions. Ready to go.

  Next, when the release button is fully pressed, the main mirror 371 and the sub mirror 374 move to the retracted position, and the shutter unit 310 is opened. Thereby, the incident light beam incident from the lens barrel 200 passes through the low-pass filter 332 and enters the image sensor 330. In this way, an image formed on the imaging surface of the imaging element 330 is captured by the optical system of the lens barrel 200.

  FIG. 2 is a cross-sectional view of the lens barrel 200. In FIG. 2, a cross section of the lens barrel 200 that is scaled to the wide angle side is shown on the upper side of the optical axis X in the drawing. Further, in FIG. 2, a cross section of the lens barrel 200 that is zoomed to the telephoto side is shown below the optical axis X in the drawing.

  In FIG. 2, the same elements as those in FIG. However, although FIG. 2 is common to FIG. 1 in that it is a cross section including the optical axis X, it shows a cross section different from FIG. Therefore, some of the common elements are drawn in a shape different from that in FIG.

  In the lens barrel 200, the rectilinear barrel 203 is engaged with the zoom ring 202 at the lead portion 281. Since the rectilinear cylinder 203 is suppressed from rotating with respect to the fixed cylinder 201, when the zoom ring 202 is rotated, a driving force that translates in the direction of the optical axis X is received from the zoom ring 202.

  The cam cylinder 290 engages in the vicinity of the rear end of the rectilinear cylinder 203 by a bayonet claw 286 disposed in the vicinity of the rear end of itself. Since the bayonet claw 286 engages with the bayonet groove extending in the circumferential direction on the inner surface of the rectilinear cylinder 203, the cam cylinder 290 can rotate around the optical axis X. However, when the rectilinear cylinder 203 translates in the optical axis X direction, the cam cylinder 290 also moves in the optical axis direction along with the rectilinear cylinder 203. In other words, the cam cylinder 290 and the rectilinear cylinder 203 are engaged only in the optical axis X direction.

  The cam cylinder 290 engages with a rectilinear groove 405 provided on the inner surface of the zoom ring 202 in parallel with the optical axis X through a connecting pin 285 fixed to the outer peripheral surface of the cam cylinder 290. Thereby, when the zoom ring 202 is rotated, the cam barrel 290 also rotates.

  As described above, when the zoom ring 202 is rotated, the rectilinear cylinder 203 translates in the optical axis X direction, and the cam cylinder 290 translates along with the rectilinear cylinder 203. Therefore, when the zoom ring 202 is rotated, the cam barrel 290 translates in the direction of the optical axis X while rotating around the optical axis X.

  The guide tube 206 is located inside the cam tube 290 and is coupled to the fixed tube 201 and fixed. Therefore, when the zoom ring 202 is rotated, the rectilinear cylinder 203 and the cam cylinder 290 also translate relative to the guide cylinder 206. Since the guide tube 206 extends toward the front end side of the lens barrel 200 in the direction of the optical axis X, the guide tube 206 supports the cam tube 290 from the inner surface side, and a key 287 provided at the rear end of the rectilinear tube 203. The rectilinear groove 288 to be engaged restricts the rotation of the rectilinear cylinder 203.

  The front tube 204 supports the lens holding frame 212 of the first lens group 210 at the tip. Further, the front tube 204 is supported from both sides by engaging with the rectilinear tube 203 and the cam tube 290 by the cam pins 282 and the like. Therefore, when the rectilinear cylinder 203 and the cam cylinder 290 translate in the optical axis X direction, the leading cylinder 204 also translates in the optical axis X direction.

  Further, when the zoom ring 202 is rotated, the leading cylinder 204 is driven between the rectilinear cylinder 203 that translates without rotating and the cam cylinder 290 that translates while rotating, and the rectilinear cylinder 203 and the cam cylinder. Translate to 290 as well. As a result, the first lens group 210 held at the tip of the front tube 204 is largely extended forward from the fixed tube 201.

  The front side moving frame 207 is disposed inside the cam cylinder 290 and the guide cylinder 206 and holds the lens holding frames 232 and 252 that hold the third lens group 230 and the fifth lens group 250 together. The rear moving frame 209 is disposed further inside the front moving frame 207 and supports the lens holding frame 262 that holds the sixth lens group 260. The front-side moving frame 207 and the rear-side moving frame 209 are engaged with the cam cylinder 290 and moved in the optical axis X direction when the zoom ring 202 is rotated. In the figure, a cam pin 264 for engaging the rear moving frame 209 with the cam cylinder 290 is visible.

  When the zoom ring 202 is rotated in the lens barrel 200 as described above, the first lens group 210, the second lens group 220, the third lens group 230, the fifth lens group 250, and the sixth lens group 260 are respectively set. It moves relative to the fixed cylinder 201. Thereby, the magnification of the optical system formed in the lens barrel 200 changes. When the zoom ring 202 is rotated beyond the zoom range of the lens barrel 200, the lens barrel 200 is contracted and retracted.

  FIG. 3 is a schematic cross-sectional view showing a cross section orthogonal to the optical axis X of the lens barrel 200. Elements common to those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description is omitted. In the lens barrel 200, the zoom ring 202, the fixed barrel 201, the front side moving frame 207, the cam barrel 290, and the rear side moving frame 209 are arranged coaxially with respect to the optical axis X, and are mutually arranged around the optical axis X. Rotate to.

  In the lens barrel 200, the connecting pin 285 fixed to the cam barrel 290 engages with a rectilinear groove 405 disposed on the inner surface of the zoom ring 202. As a result, the cam cylinder 290 rotates together with the zoom ring 202. Further, the cam pin 292 provided on the outer peripheral surface of the cam cylinder 290 engages with the cam groove 402 disposed on the inner surface of the fixed cylinder 201.

  Furthermore, the cam cylinder 290 has a cam pin 296 that protrudes to the outer peripheral surface, and a cam groove 294 provided on the inner peripheral surface. The cam pin 296 engages with a cam groove 256 formed on the inner peripheral surface of the front side moving frame 207. The cam groove 294 engages with a cam pin 264 fixed to the outer peripheral surface of the rear moving frame 209.

  In the lens barrel 200, a pair of rectilinear grooves 401 and 404 that are arranged adjacent to each other in the circumferential direction are provided on the inner surface of the fixed barrel 201. The rectilinear protrusion 259 of the front side moving frame 207 protrudes from the front side moving frame 207 toward the radially outer side of the lens barrel 200 and engages with a rectilinear groove 401 disposed on the inner surface of the fixed barrel 201. The rectilinear protrusion 269 of the rear moving frame 209 protrudes from the rear moving frame 209 toward the radially outer side of the lens barrel 200 and engages with a rectilinear groove 404 disposed on the inner surface of the fixed barrel 201. Thereby, the rotation of the front side moving frame 207 and the rear side moving frame 209 with respect to the fixed cylinder 201 is restricted.

  Three cam pins 264, 292, 296, connecting pins 285 and cam grooves 256, 294, 402, and rectilinear protrusions 259, 269 and rectilinear grooves 401, 404, 405 are arranged in the circumferential direction of the lens barrel 200. Arranged at approximately equal intervals. As a result, the cam barrel 290, the front side moving frame 207, the cam barrel 290, and the rear side moving frame 209 are driven in a balanced manner in the circumferential direction of the lens barrel 200 and are prevented from being inclined with respect to the optical axis X. The

  In the cam barrel 290, the connecting pin 285 is disposed in the vicinity of the cam pin 292 in the circumferential direction of the lens barrel 200. Thereby, when the connecting pin 285 is driven, it is possible to suppress the inclination of the cam cylinder 290 with respect to the optical axis X caused by the displacement of the position with respect to the cam pin 292.

  In the cam barrel 290, the cam pin 296 is driven by being engaged with the cam groove 256 in the vicinity of the rectilinear protrusion 259 in the circumferential direction of the lens barrel 200. Further, the cam pin 264 of the rear moving frame 209 is driven by being engaged with the cam groove 294 in the vicinity of the rectilinear protrusion 269 in the circumferential direction of the lens barrel 200.

  As a result, when the cam pins 296 and 264 are driven by the cam grooves 256 and 294, the front side moving frame 207 and the rear side moving frame 209 are caused by the positional deviation between the rectilinear protrusions 259 and 269 and the cam pins 296 and 264. The inclination with respect to the optical axis X can be suppressed. Similarly, the cam pin 264 is preferably arranged in the vicinity of the rectilinear protrusion 269 in the circumferential direction of the lens barrel 200.

  FIG. 4 is a schematic diagram showing a partial cross section of the lens barrel 200 in the retracted state. Although the shape is simplified for the purpose of simplifying the drawing, the same reference numerals are assigned to the same elements as those in FIGS. 1 and 2 to omit redundant description.

  As shown in FIG. 3, the cam pins 264, 292, 296, the connecting pin 285, the cam grooves 256, 294, 402, the rectilinear protrusions 259, 269, and the rectilinear grooves 401, 404, 405 are the lens barrels. It is arranged at different positions in the circumferential direction of 200. Thus, these elements do not all appear in a single cross section. However, FIG. 4 shows these elements together for the purpose of showing the positional relationship of each element in the optical X direction.

  In the lens barrel 200, the rectilinear protrusion 259 of the front moving frame 207 and the rectilinear protrusion 269 of the rear moving frame 209 individually engage with the rectilinear grooves 401 and 404 that are independent of each other. Thereby, when the lens barrel 200 is in the retracted state, the rear end portions of the front side moving frame 207 and the rear side moving frame 209 occupy different positions in the circumferential direction of the lens barrel 200. Further, the rear end portions of the front-side moving frame 207 and the rear-side moving frame 209 on which the rectilinear protrusions 259 and 269 are arranged are in a direction parallel to the optical axis X in the cross section including the optical axis X of the lens barrel 200. Occupies the same position.

  Therefore, the rear end portions of the front-side moving frame 207 and the rear-side moving frame 209 are retracted until they come into contact with the rear surface of the fixed barrel 201 without the interference of the respective rectilinear projecting portions 259 and 269. The length in the optical axis X direction can be shortened.

  FIG. 5 is a development view of the fixed cylinder 201 and shows a layout of the rectilinear grooves 401 and 404 and the cam groove 402 on the inner surface of the fixed cylinder 201. Elements that are the same as those in FIG. 4 are given the same reference numerals, and redundant descriptions are omitted. One of the three rectilinear grooves 401 and 404 and the cam groove 402 provided in each case will be described.

  In the fixed cylinder 201, the straight grooves 401 and 404 are arranged in the optical axis direction parallel to the optical axis X of the lens barrel 200, and are arranged adjacent to each other in the circumferential direction of the lens barrel 200. Therefore, the rectilinear protrusions 259 and 269 engaged with the rectilinear grooves 401 and 404 are restricted from being displaced in the circumferential direction of the lens barrel 200 while being allowed to be displaced in the optical axis X direction. Thereby, the front side moving frame 207 and the rear side moving frame 209 are each supported from the fixed cylinder 201 so as to be movable in the optical axis X direction.

  In other words, the fixed cylinder 201 includes a front-side moving frame 207 that supports the third lens group 230 and the fifth lens group 250, and a sixth lens group 260 that is different from the third lens group 230 and the fifth lens group 250. The rear moving frame 209 to be supported is supported in common. The front side moving frame 207 that supports the third lens group 230 and the fifth lens group 250 can move in a direction parallel to the optical axis X of the lens barrel 200.

  The cam groove 402 has a profile inclined with respect to the optical axis X. Therefore, when the cam pin 292 is displaced with respect to the cam groove 402, in the lens barrel 200, the cam barrel 290 moves in the optical axis X direction.

  The cam groove 402 includes a collapsible section 297 and a variable power section 298 that are formed continuously with each other. When the cam pin 292 is displaced with respect to the cam groove 402 in the zooming section 298, the magnification of the lens barrel 200 changes from the telephoto end to the wide angle end.

  When the cam pin 292 displaces the retractable section 297 beyond the wide angle end, the lens barrel 200 is contracted toward the retracted state. When the cam pin 292 reaches the retracted position, the lens barrel 200 is in the retracted state. In the above structure, when the cam pin 292 is provided in the fixed cylinder 201 and the cam groove 402 is provided in the cam cylinder 290, a drive mechanism having the same function as the above example can be formed.

  FIG. 6 is a development view of the front side moving frame 207, and shows a layout of the rectilinear protrusions 259 and the cam grooves 256 on the outer surface of the front side moving frame 207. Elements that are the same as those in FIG. 5 are given the same reference numerals, and redundant description is omitted. In addition, one of the rectilinear protrusion part 259 and the cam groove 256 provided 3 each is demonstrated.

  In the front side moving frame 207, the cam groove 256 has a profile inclined with respect to the optical axis X. Therefore, when the cam pin 296 is displaced with respect to the cam groove 256, the front side moving frame 207 moves in the optical axis X direction with respect to the cam barrel 290 in the lens barrel 200.

  The cam groove 256 includes a zooming section and a retracting section that are continuous with each other. When the cam pin 296 is displaced with respect to the cam groove 256 in the zooming section, the magnification of the lens barrel 200 changes from the telephoto end to the wide angle end.

  When the cam pin 296 displaces the retracted section beyond the wide angle end in the cam groove 256, the lens barrel 200 starts to shrink toward the retracted state. When the cam pin 292 reaches the retracted position, the lens barrel 200 is in the retracted state. In the above structure, even when the cam pin 296 is provided in the front side moving frame 207 and the cam groove 256 is provided in the cam cylinder 290, a drive mechanism having the same function as the above example can be formed.

  FIG. 7 is a development view of the cam cylinder 290, and shows the layout of the cam pins 264 and 292 on the outer surface of the cam cylinder 290 and the layout of the cam groove 294 on the inner surface of the cam cylinder 290. Elements that are the same as those in FIG. 5 are given the same reference numerals, and redundant description is omitted. FIG. 7 shows one of the three cam pins 292 and 296 and the cam groove 294 provided in each case.

  In the cam cylinder 290, the cam groove 294 has a profile inclined with respect to the optical axis X. Therefore, when the cam pin 264 is displaced with respect to the cam groove 294, the rear moving frame 209 moves in the optical axis X direction with respect to the cam barrel 290 in the lens barrel 200.

  The cam groove 294 includes a zooming section and a retracting section. When the cam pin 264 is displaced with respect to the cam groove 294 in the zooming section, the magnification of the lens barrel 200 changes from the telephoto end to the wide angle end.

  When the cam pin 264 is displaced beyond the wide-angle end of the cam groove 294, the lens barrel 200 starts to shrink toward the retracted state. When the cam pin 264 reaches the retracted position in the cam groove 294, the lens barrel 200 is in the retracted state. In the above structure, even when the cam pin 264 is provided in the cam cylinder 290 and the cam groove 294 is provided in the rear moving frame 209, a drive mechanism having the same function as the above example can be formed.

  FIG. 8 is a schematic cross-sectional view showing the state in which the lens barrel 200 is extended in the cross section shown in FIG. Although the shape is simplified for the sake of brevity, the same reference numerals are given to the same elements as those up to FIG.

  When the zoom ring 202 is rotated in the lens barrel 200, the cam barrel 290 engaged by the connecting pin 285 also rotates. The cam cylinder 290 also translates in the optical axis X direction with respect to the fixed cylinder 201 according to the profile of the cam groove 402 of the fixed cylinder 201 with which the cam pin 292 is engaged.

  The front side moving frame 207 is restricted from rotating by engaging the rectilinear protrusions 259 with the rectilinear grooves 401 of the fixed cylinder 201. Therefore, when the cam cylinder 290 rotates and translates, the front moving frame 207 is driven according to the profile of the cam groove 256 that engages with the cam pin 296 provided on the outer surface of the cam cylinder 290 and translates in the optical axis X direction. To do.

  Further, as described above, since the cam cylinder 290 itself translates in the optical axis X direction, the front-side moving frame 207 includes the fixed cylinder 201 of the cam cylinder 290 in addition to the amount of movement of the front-side moving frame 207 with respect to the cam cylinder 290. The amount of movement with respect to is also moved. Thereby, the lens barrel 200 can move the fifth lens group 250 greatly, and the magnification change rate can be increased.

  The rear movement frame 209 is restricted from rotating by engaging the rectilinear protrusion 269 with the rectilinear groove 404 of the fixed cylinder 201. Therefore, when the cam cylinder 290 rotates and translates, the rear moving frame 209 translates in the optical axis X direction by driving the cam pin 264 according to the profile of the cam groove 294 formed on the inner surface of the cam cylinder 290.

  Further, the front side moving frame 207 engages with the cam pins 296 of the cam cylinder 290 in cam grooves 256 formed on the inner surface. Thereby, when the cam cylinder 290 rotates and translates, the front-side moving frame 207 is driven with a driving amount that combines the translation of the cam cylinder 290 and the driving by the profile of the cam groove 256.

  Further, as described above, since the cam cylinder 290 itself translates in the optical axis X direction, the rear movement frame 209 has a fixed cylinder 201 of the cam cylinder 290 in addition to the amount of movement of the rear movement frame 209 relative to the cam cylinder 290. The amount of movement with respect to is also moved. Thereby, in the lens barrel 200, the sixth lens group 260 moves greatly.

  The single-lens reflex camera 100 including the interchangeable lens barrel 200 has been described above as an example, but the above structure can be applied even to a non-flex camera that does not include a quick return mirror. In addition to a camera in which the lens barrel 200 and the camera body 300 are integrally formed, the above structure can be applied to a telescope, a surveying instrument, a microscope, and the like that include an optical member that is driven by a cam mechanism.

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

100 single-lens reflex camera, 200 lens barrel, 201 fixed barrel, 202 zoom ring, 203 rectilinear barrel, 204 front barrel, 206 guide barrel, 207 front side moving frame, 209 rear side moving frame, 208 lens side mount, 210 One lens group, 212, 222, 232, 232, 242, 252, 262 Lens holding frame, 220 Second lens group, 230 Third lens group, 240 Fourth lens group, 250 Fifth lens group, 256, 294, 402 Cam groove, 259, 269 Straight projection, 260 Sixth lens group, 264, 282, 292, 296 Cam pin, 270 Feed screw assembly, 272 Stepping motor, 274 Feed screw, 276 Frame, 278 Rack member, 285 Connecting pin, 286 bayonet claws, 287 keys, 288, 401, 404, 4 5 Straight running groove, 290 Cam cylinder, 297 Retracting section, 298 Zooming section, 300 Camera body, 310 Shutter unit, 320 Substrate, 322 Control section, 324 Image processing section, 330 Imaging device, 332 Low pass filter, 340 Display section, 350 Finder, 352 focusing screen, 354 pentaprism, 356 finder optical system, 360 body side mount, 370 mirror unit, 371 main mirror, 372 main mirror holder, 373 main mirror rotation axis, 374 sub mirror, 375 sub mirror holder, 376 Sub-mirror rotation axis, 380 focusing optical system, 382 focus detection sensor, 390 photometric sensor

Claims (5)

An optical system having a first optical member and a second optical member;
The first optical member is held and has a first rectilinear protrusion protruding in the radial direction of the first optical member, and either a first cam pin or a first cam groove engaging each other on the inner peripheral side. A first holding member that moves in an optical axis direction parallel to the optical axis of the optical system;
A second rectilinear protrusion that holds the second optical member and projects in a radial direction of the second optical member; and one of a second cam pin and a second cam groove that engage with each other on the outer peripheral side. A second holding member that moves in the optical axis direction;
A first rectilinear groove that is parallel to the optical axis and engages with the first rectilinear protrusion, and a first rectilinear groove that is parallel to the optical axis and engages with the second rectilinear protrusion, and a circumferential direction . A second support groove arranged at different positions, and a support cylinder that supports the first holding member and the second holding member so as to be movable in the optical axis direction ;
One of the first cam pin and the first cam groove and the second cam pin and the second cam groove provided on the inner peripheral side of the first holding member and on the outer peripheral side of the second holding member. A lens barrel comprising: a cam barrel that has one of the other and rotates the first holding member and the second holding member in the optical axis direction by rotating .   The lens barrel according to claim 1, wherein the first rectilinear groove and the second rectilinear groove are provided in a support cylinder that supports the first holding member and the second holding member in common.   The lens barrel according to claim 2, wherein the first rectilinear groove and the second rectilinear groove are provided in the support cylinder adjacent to each other in the circumferential direction.   The first rectilinear projection and the second rectilinear projection are arranged at different positions in the circumferential direction and arranged at the same position in the optical axis direction. The lens barrel according to the item. An imaging device comprising the lens barrel according to any one of claims 1 to 4 .

Images