JP2013054189A - Lens unit and optical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the positioning accuracy of a moving lens.SOLUTION: The lens unit comprises: a lens holding part for holding a lens; and a guide shaft extending parallel to the direction of the optical axis of the lens and used for guiding the lens holding part. One of the lens holding part and guide shaft has a regulation part in such a shape that a cross section perpendicular to the direction of the optical axis circumscribes a pair of circles. The other one of the lens holding part and guide part has an abutting part that abuts on the pair of circles of the regulation part. In the lens unit, the guide shaft may be formed by arranging a pair of round rods parallel to each other, and the regulation part may be formed by the peripheral faces of the pair of round rods.

Description

  The present invention relates to a lens unit and an optical apparatus.

There is an apparatus for guiding a moving lens by a shaft (see Patent Document 1).
[Patent Document 1] Utility Model Registration No. 2585804

  It is difficult to measure the gap between the shaft and the hole through which the shaft is inserted. For this reason, it is difficult to adjust a metal mold | die etc. and to manufacture a highly accurate product with a sufficient yield.

  As a first aspect of the present invention, a lens holding portion that holds a lens, and a guide shaft that extends parallel to the optical axis direction of the lens and guides the lens holding portion, either one of the lens holding portion and the guide shaft is provided. Has a restricting portion whose cross section perpendicular to the optical axis direction is formed by circumscribing a pair of circular shapes, and the other of the lens holding portion and the guide shaft is in contact with both of the pair of circular shapes of the restricting portions. A lens unit having a portion is provided.

  As a second aspect of the present invention, there is provided an optical apparatus comprising the lens unit and a drive unit that drives the lens holding unit, and the lens holding unit guided by the guide shaft is moved by the driving force of the drive unit.

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

1 is a schematic cross-sectional view of a single-lens reflex camera 100. FIG. 2 is a partial perspective view of a lens unit 200. FIG. 2 is a partial perspective view of a lens unit 200. FIG. 2 is a partial perspective view of a lens unit 200. FIG. 3 is a schematic cross-sectional view of a guide mechanism 401. FIG. 2 is a partial perspective view of a lens unit 200. FIG. 3 is a schematic cross-sectional view of a guide mechanism 402. FIG. 2 is a partial perspective view of a lens unit 200. FIG. It is a typical sectional view of guide mechanism 403.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a schematic cross-sectional view of a single-lens reflex camera 100 that is a kind of optical apparatus. The single-lens reflex camera 100 includes a lens unit 200 and a camera body 300.

  In the following description, the object side in the lens unit 200 attached to the camera body 300 is referred to as “front” or “front”. Similarly, the image side in the lens unit 200 is referred to as “rear” or “back”.

  The lens unit 200 includes a fixed barrel 210, lenses 220, 230, and 240, a barrel side control unit 250, and a barrel side mount portion 260. A lens barrel side mount portion 260 is provided at one end of the fixed barrel 210. The lens barrel side mount portion 260 is engaged with the body side mount portion 360 of the camera body 300 to couple the lens unit 200 to the camera body 300.

  The coupling between the lens barrel side mount portion 260 and the body side mount portion 360 can be released by a specific operation. Therefore, another lens unit 200 having the lens barrel side mount 260 of the same standard can be exchanged and attached to the camera body 300.

  The lenses 220, 230, and 240 are arranged along the optical axis X inside the fixed cylinder 210 to form an optical system. When zooming or focusing the optical system, some or all of the lenses 220, 230, and 240 move in a direction parallel to the optical axis X. Each of the lenses 220, 230, and 240 may be a lens group in which a plurality of lenses are combined.

  The lens barrel side control unit 250 controls the lens unit 200 itself and also communicates with the body side control unit 322 of the camera body 300. Thereby, the lens unit 200 attached to the camera body 300 operates in cooperation with the camera body 300.

  In the camera body 300, a mirror unit 380 is disposed on the opposite side of the lens unit 200 with the body side mount portion 360 interposed therebetween. A focusing screen 346 is disposed horizontally above the mirror unit 380.

  A pentaprism 344 is disposed further above the focusing screen 346, and a finder optical system 342 is disposed behind the pentaprism 344, respectively. The rear end of the viewfinder optical system 342 is exposed as a viewfinder 340 on the back surface of the camera body 300.

  In the camera body 300, a focal plane shutter 310, an optical filter 372, and an image sensor 370 are sequentially arranged behind the mirror unit 380. The focal plane shutter 310 opens and closes to introduce or block the incident constraint to the image sensor 370.

  The optical filter 372 is installed immediately before the image sensor 370 and removes components outside the visible band from the incident light flux. Further, the optical filter 372 protects the surface of the image sensor 370. Further, the optical filter 372 is a low-pass filter that reduces the moiré by reducing the spatial frequency of the incident light beam.

  The image sensor 370 is disposed behind the optical filter 372. The imaging element 370 is formed by a photoelectric conversion element such as a CCD sensor or a CMOS sensor.

  A substrate 320 and a display unit 330 are sequentially disposed behind the image sensor 370. On the substrate 320, a body side control unit 322, an image processing unit 324, and the like are mounted. The display unit 330 is formed of a liquid crystal display panel or the like, and is exposed on the back surface of the camera body 300.

  The mirror unit 380 has a main mirror holding frame 381 and a main mirror 382. The main mirror holding frame 381 is supported by a main mirror rotating shaft 383 while holding the main mirror 382. As a result, the main mirror holding frame 381 rotates between a position contacting the positioning pin 384 and a position contacting the stopper 388.

  The mirror unit 380 also has a sub mirror holding frame 385 and a sub mirror 386. The sub mirror holding frame 385 is pivotally supported from the main mirror holding frame 381 by the sub mirror rotating shaft 387 while holding the sub mirror 386.

  As a result, the sub mirror 386 rotates with respect to the main mirror holding frame 381. When the main mirror holding frame 381 rotates, the sub mirror 386 and the sub mirror holding frame 385 rotate with respect to the main mirror holding frame 381 while moving together with the main mirror holding frame 381.

  In the illustrated mirror unit 380, the front end of the main mirror holding frame 381 is lowered and is in contact with the positioning pin 384. As a result, the main mirror 382 is positioned at an observation position that obliquely crosses the optical path of the incident light beam incident through the lens unit 200.

  Part of the subject light incident on the main mirror 382 at the observation position passes through a half mirror region formed on a part of the main mirror 382 and enters the sub mirror 386. Part of the subject light incident on the sub mirror 386 is reflected toward the focusing optical system 390 and eventually enters the focusing position sensor 392.

  The in-focus position sensor 392 detects the defocus amount in the optical system of the lens unit 200 and notifies the body side control unit 322 of it. The body side control unit 322 communicates with the lens barrel side control unit 250, and moves any of the lenses 220, 230, and 240 so as to cancel the detected defocus amount. In this way, the lens unit 200 is focused to form a subject image on the imaging surface of the image sensor 370.

  Further, the main mirror 382 at the observation position reflects most of the incident light beam toward the focusing screen 346. The focusing screen 346 is disposed at a position optically conjugate with the imaging surface of the imaging element 370, and visualizes the subject image formed by the optical system of the lens unit 200.

  The subject image connected to the focusing screen 346 is observed from the viewfinder 340 through the pentaprism 344 and the viewfinder optical system 342. The subject image through the pentaprism 344 is observed as an erect image from the finder 340.

  A part of the light beam emitted from the pentaprism 344 is received by the photometric sensor 350 disposed above the finder optical system 342. When the release button of the camera body 300 is half-pressed, the photometric sensor 350 detects subject brightness from a part of the incident light beam.

  The body-side control unit 322 calculates imaging conditions such as an aperture value, a shutter speed, and ISO sensitivity according to the detected subject brightness. Accordingly, the single-lens reflex camera 100 is in a state where it can shoot a subject under appropriate shooting conditions.

  When the release button is pressed in the single-lens reflex camera 100, the main mirror holding frame 381 rotates clockwise together with the main mirror 382 in the drawing, contacts the stopper 388, and stops substantially horizontally at the retracted position. As a result, the main mirror 382 is retracted from the optical path of the incident light beam through the optical system of the lens unit 200.

  When the main mirror 382 rotates toward the shooting position, the sub mirror holding frame 385 also rises together with the main mirror holding frame 381 and rotates around the sub mirror rotation shaft 387 and stops substantially horizontally at the shooting position. To do. As a result, the sub mirror 386 is also retracted from the optical path of the incident light beam.

  When the main mirror 382 and the sub mirror 386 are moved to the photographing position, the focal plane shutter 310 is subsequently opened in the camera body 300. Thereby, the image light incident through the optical system of the lens unit 200 is received by the image sensor 370 after passing through the optical filter 372. After photographing, the rear film of the focal plane shutter 310 is closed, and the main mirror 382 and the sub mirror 386 are rotated again to return to the observation position.

  FIG. 2 is a perspective view partially showing the internal structure of the lens unit 200. FIG. 2 shows a front flange 214, a rear flange 216, and a cam ring 290 in the lens unit 200 from which an exterior member such as an operation ring is removed.

  The front flange 214 and the rear flange 216 are molded separately from each other and disposed near the front end and the rear end of the lens unit 200. The front flange 214 and the rear flange 216 each have an opening through which an optical path of an incident light beam with respect to the lens unit 200 passes.

  The front flange 214 is fixed to the fixed cylinder 210 of the lens unit 200 while holding the front ends of the two pairs of round bar members 272 at equal intervals on the circumference of the opening. The rear flange 216 is also fixed to the fixed cylinder 210 of the lens unit 200 while holding the rear ends of the round bar members 272 at equal intervals on the periphery of the opening. Therefore, the round bar member 272 is held in parallel with the optical axis X in the lens unit 200, respectively.

  The cam ring 290 is a cylindrical member disposed in parallel with the optical axis X, and is disposed between the pair of front flange 214 and rear flange 216. The cam ring 290 is supported so as to be rotatable about the optical axis X, and rotates in conjunction with, for example, an operation ring attached to the lens unit 200 as an exterior member.

  The cam ring 290 has a cam groove 292 whose position in the longitudinal direction of the cam ring 290 itself changes along the circumferential direction. A cam follower 238 is inserted into the cam groove 292 in the radial direction of the cam ring 290.

  FIG. 3 is a partial perspective view of the lens unit 200. FIG. 3 shows a state in which the cam ring 290 is further removed from the lens unit 200 in the state shown in FIG. The front flange 214 and the rear flange 216 are connected by an intermediate cylinder 218 and fixed to each other.

  The intermediate cylinder 218 has a pair of fitting surfaces 211 at both ends of the outer peripheral surface. The outer diameter of the fitting surface 211 is larger than the outer diameter of the other part of the intermediate cylinder 218 and is substantially equal to the inner diameter of the cam ring 290. Therefore, when the cam ring 290 is mounted outside the intermediate cylinder 218, the cam ring 290 is supported at both ends in the optical axis X direction and smoothly rotates between the front flange 214 and the rear flange 216.

  Further, the intermediate cylinder 218 has a rectilinear groove 212 parallel to the optical axis X on the peripheral surface. A cam follower 238 is inserted into the rectilinear groove 212. That is, in the lens unit 200, the cam follower 238 is inserted through both the rectilinear groove 212 and the cam groove 292. Therefore, when the cam ring 290 rotates around the optical axis X with respect to the intermediate cylinder 218, the cam follower 238 receives a driving force in a direction parallel to the optical axis X and is driven along the rectilinear groove 212. .

  FIG. 4 is a partial perspective view of the lens unit 200 including the guide mechanism 401. FIG. 4 is also a diagram showing a state in which the intermediate cylinder 218 is further removed from the lens unit 200 in the state shown in FIG.

  FIG. 4 shows a state where the lens unit 200 is viewed from the rear flange 216 side in the optical axis X direction. Thereby, like the front flange 214, it can be seen that the rear flange 216 holds the round bar member 272.

  When the intermediate cylinder 218 is removed from the lens unit 200, two pairs of round bar members 272 arranged in parallel to each other and in parallel to the optical axis X appear between the pair of front flanges 214 and rear flanges 216. . Each of the paired round bar members 272 forms a guide shaft 270. The pair of round bar members 272 as the guide shaft 270 are arranged at equal intervals in the circumferential direction of the front flange 214 and the rear flange 216.

  A lens holding frame 232 that holds the lens 230 is disposed between the front flange 214 and the rear flange 216 and between the pair of guide shafts 270. The lens holding frame 232 includes steel ball holding portions 231 and 234 and a cam follower 238.

  The steel ball holding part 234 located on the upper side in the drawing holds two steel balls 280. Each of the steel balls 280 is pressed by the retaining portion 236 and is prevented from falling off from the steel ball holding portion 234.

  Each of the steel balls 280 can be replaced by detaching the retaining portion 236 from the steel ball holding portion 234. Therefore, the clearance gap between the guide shaft 270 and the steel ball 280 can be adjusted by preparing and exchanging a plurality of steel balls 280 having different diameters.

  In the steel ball holding part 234, the two steel balls 280 are arranged along the extending direction of the guide shaft 270, and individually contact the guide shaft 270 to form the guide mechanism 401. Accordingly, the lens holding frame 232 is positioned from the guide shaft 270 at a pair of contact points that are separated from each other in the axial direction of the guide shaft 270.

  Therefore, the inclination of the lens holding frame 232 with respect to the guide shaft 270 is defined, and the optical axis X of the lens 230 held by the lens holding frame 232 is parallel to the guide shaft 270. Moreover, the inclination of the lens holding frame 232 relative to the guide shaft 270 can be adjusted by exchanging the pair of steel balls 280 held by the steel ball holding part 234 with those having different diameters.

  Further, the lens holding frame 232 has a steel ball holding portion 231 that holds one steel ball 280 on the lower side in the drawing. The steel ball 280 is held by the retaining portion 233 so as not to fall out of the steel ball holding portion 231. Further, the steel ball 280 can be replaced by detaching the retaining portion 233 from the steel ball holding portion 231.

  The steel ball 280 held by the steel ball holding part 231 is in contact with the lower guide shaft 270 in the drawing. As a result, the guide mechanism 401 is formed, and the lens holding frame 232 is also positioned from the guide shaft 270. Thus, the lens 230 is positioned with respect to the fixed cylinder 210 including the intermediate cylinder 218 by arranging the plurality of guide shafts 270 in the circumferential direction of the lens 230 and guiding the lens holding frame 232.

  Further, each of the steel balls 280 moves along the guide shaft 270. As a result, the lens 230 moves while being guided by the guide shaft 270 while keeping the optical axis X parallel to the guide shaft 270.

  The lower end of the cam follower 238 is coupled to the lens holding frame 232. As already described, when the cam ring 290 rotates with respect to the front flange 214, the rear flange 216, and the intermediate cylinder 218, the cam follower 238 is driven in a direction parallel to the optical axis X. Therefore, the lens holding frame 232 coupled to the cam follower 238 is also driven in a direction parallel to the optical axis X.

  Further, the cam follower 238 is disposed in the vicinity of the steel ball holding portion 234 in the circumferential direction of the lens 230. Thereby, the driven cam follower 238 moves the lens holding frame 232 efficiently.

  FIG. 5 is a schematic cross-sectional view of the guide mechanism 401. Elements common to FIGS. 1 to 4 are given the same reference numerals, and redundant description is omitted.

  The steel ball holding portions 231 and 234 formed on the outer peripheral side of the lens holding frame 232 accommodate the steel balls 280, respectively. The steel ball holding portions 231 and 234 are sealed by retaining portions 233 and 236 each having an opening having an inner diameter smaller than the outer diameter of the steel ball 280. This prevents the steel ball 280 from falling off the steel ball holding portions 231 and 234.

  Further, the inside of the steel ball holding portion 231 is covered with a material having a small friction with respect to the steel ball 280. Thereby, the steel ball 280 hold | maintained at the steel ball holding | maintenance part 231 rotates smoothly.

  The guide shaft 270 is formed by a pair of round bar members 272. The pair of round bar members 272 circumscribe each other to form a groove-shaped restricting portion having a cross-sectional shape including a pair of arcs. The steel balls 280 abut against each of the pair of arcs inside the restricting portion formed by the pair of round bar members 272. Thereby, the positional relationship between the guide shaft 270 that forms the restricting portion and the steel ball 280 that contacts the restricting portion is determined.

  The round bar member 272 and the steel ball 280 are supplied with a material with high dimensional accuracy at a low price. In particular, steel balls 280 having various dimensions are supplied as bearing parts. Therefore, the lens holding frame 232 can be accurately positioned by forming the guide mechanism 401 with the round bar member 272 and the steel ball 280.

  Moreover, the steel ball 280 rotates smoothly inside the steel ball holding part 234. Therefore, the lens holding frame 232 can be smoothly moved along the guide shaft 270 while maintaining high positioning accuracy in the guide mechanism 401.

  FIG. 6 is a partial perspective view of the lens unit 200 including another guide mechanism 402 in addition to the guide mechanism 401 shown in FIGS. 4 and 5. In FIG. 6, the same elements as those in FIGS. 4 and 5 are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 6 shows a state in which the cam ring 290 and the intermediate cylinder 218 are removed and the guide shaft 270, the lens 230, and the lens holding frame 232 are exposed as in FIG. In FIG. 6, the upper guide mechanism 401 in the drawing has the same structure as the lens unit 200 shown in FIG. 4. In contrast, in FIG. 6, the lower guide mechanism 402 in the figure has a structure different from that of the guide mechanism 401.

  That is, in the guide mechanism 402, the guide shaft 270 is formed by a single round bar member 272. The round bar member 272 of the guide mechanism 402 is supported by the front flange 214 and the rear flange 216 at both ends, and is arranged in parallel with the optical axis X. The guide shaft 270 formed by a single round bar member 272 is arranged at equal intervals in the circumferential direction of the front flange 214 and the rear flange 216 from the guide shaft 270 formed by a pair of round bar members 272.

  Further, in the guide mechanism 402, the pair of steel balls 280 is held by a steel ball holding part 235 provided on the peripheral surface of the lens holding frame 232. In addition, each of the steel balls 280 is pressed by the retaining portion 237 and is prevented from falling off from the steel ball holding portion 235.

  The steel ball 280 can be replaced by detaching the retaining portion 237 from the steel ball holding portion 235. Therefore, the clearance gap between the guide shaft 270 and the steel ball 280 can be adjusted by preparing and exchanging a plurality of steel balls 280 having different diameters.

  In the steel ball holding part 235, the two steel balls 280 are arranged adjacent to each other in a direction orthogonal to the extending direction of the guide shaft 270. A guide shaft 270 formed by a single round bar member 272 contacts both the pair of steel balls 280. Accordingly, the lens holding frame 232 is positioned in a direction that intersects the axial direction of the guide shaft 270.

  The guide mechanism 401 including the steel ball holding part 234 positions the lens holding frame 232 with respect to the upper guide shaft 270 in the drawing. Therefore, by the cooperation of the guide mechanisms 401 and 402, the lens holding frame 232 can be guided and moved by the guide shaft 270 while keeping the optical axis X parallel to the guide shaft 270.

  As already described, the lower end of the cam follower 238 is coupled to the lens holding frame 232. Therefore, when the cam follower 238 is driven, the lens holding frame 232 is driven in a direction parallel to the optical axis X.

  FIG. 7 is a schematic cross-sectional view of the guide mechanism 402. A steel ball holding part 235 formed on the outer peripheral side of the lens holding frame 232 in the lower side of the drawing accommodates a pair of steel balls 280. The steel ball holding part 234 is sealed by a retaining part 237 having a pair of openings having an inner diameter smaller than the outer diameter of the steel ball 280. This prevents the steel ball 280 from falling off the steel ball holding portion 235. In other words, the steel ball 280 can be exchanged by detaching the retaining portion 237.

  Further, the inside of the steel ball holding part 235 is covered with a material having a small friction against the steel ball 280. Thereby, the steel ball 280 hold | maintained at the steel ball holding part 235 rotates smoothly.

  The steel balls 280 held by the steel ball holding part 235 circumscribe each other at one point of a circular cross section. A peripheral surface of a single round bar member 272 forming the guide shaft 270 contacts both the pair of steel balls 280.

  That is, in the guide mechanism 402, the restricting portion is formed by a pair of circular cross sections in which the pair of steel balls 280 circumscribe each other. In addition, the round bar member 272 having a cross section that abuts both of the pair of circular cross sections forming the restricting portion and forming the abutting member is orthogonal to the optical axis X by contacting the restricting portion at two points. Displacement in the direction is restricted.

  As already described, the round bar member 272 and the steel ball 280 are supplied with low dimensional accuracy at a low price. Therefore, the guide mechanism 402 that can accurately position the lens holding frame 232 by the round bar member 272 and the steel ball 280 can be manufactured at low cost.

  Moreover, the steel ball 280 rotates smoothly inside the steel ball holding part 234. Therefore, the guide mechanism 402 can smoothly move the lens holding frame 232 along the guide shaft 270 while maintaining high positioning accuracy.

  In addition, since the guide mechanism 402 forms the guide shaft 270 by the single round bar member 272, the number of parts can be reduced and the lens unit 200 can be reduced in weight. In addition, by providing a pair of guide mechanisms 402 that combine a pair of steel balls 280 and a single round bar member 272 in the axial direction of the guide shaft 270, a guide mechanism that regulates the inclination of the lens holding frame 232 relative to the guide shaft 270. 402 can also be formed.

  FIG. 8 is a partial perspective view of another lens unit 201. The lens unit 201 has the same structure as the lens unit 200 except for the parts described below. Therefore, common elements are denoted by the same reference numerals, and redundant description is omitted.

  The lens unit 201 includes three sets of guide shafts 270 each including a pair of round bar members 272. Each guide shaft 270 is the same as the guide shaft 270 in the lens unit 200. Further, the three sets of guide shafts 270 are arranged at equal intervals in the circumferential direction on the front flange 214 and the rear flange 216.

  For the three guide shafts 270 described above, the lens holding frame 232 includes a pair of steel ball holding portions 231 that hold a single steel ball 280 and a single steel that holds the pair of steel balls 280. The ball holding portion 234 makes contact with the guide shaft 270. Thereby, the lens holding frame 232 is positioned more stably inside the guide shaft 270.

  Note that at least one of the plurality of guide mechanisms 401 provided in the lens unit 201 may have another structure. That is, for example, one of the guide mechanisms 401 may be changed to a guide mechanism 402 including a single round bar member 272 and a pair of steel balls 280.

  FIG. 9 is a schematic cross-sectional view of another guide mechanism 403. The guide mechanism 403 has the same structure as the other guide mechanisms 401 and 402 except for the parts described below. Therefore, common elements are denoted by the same reference numerals, and redundant description is omitted.

  In the guide mechanism 401 having the guide shaft 270 formed by the pair of round bar members 272, the pair of round bar members 272 are arranged adjacent to each other in the circumferential direction of the lens 230 on the cross section orthogonal to the optical axis X. . In this regard, in the guide mechanism 403, a pair of round bar members 272 are arranged adjacent to each other in the radial direction of the lens 230 on a cross section orthogonal to the optical axis X.

  On the side surfaces in the figure of the guide shafts 270 arranged adjacent to each other, a restricting portion sandwiched between a pair of arcs is formed. Therefore, the lens holding frame 232 can be positioned with respect to the guide shaft 270 by bringing the steel balls 280 into contact with these restricting portions. However, the lens holding frame 232 is restricted in the guide mechanism 403 in the direction orthogonal to the optical axis X, and the displacement moving along the guide shaft 270 is not restricted.

  As described above, the guide mechanism 403 can be formed by the pair of round bar members 272 and the pair of steel balls 280. The guide mechanism 403 may be combined with other guide mechanisms 401 and 402, or a plurality of guide mechanisms 403 may be combined to position and move the lens holding frame 232.

  In the above example, the guide mechanisms 401, 402, 403 in which round bars and spheres are combined are shown. However, a guide mechanism may be formed by abutting a contact member formed by a pair or one round bar member 272 against a guide shaft 270 formed by one or a pair of round bar members 272. it can. Further, in one lens unit 200, 201, these plural kinds of guide mechanisms 401, 402, 403 may be mixed.

  In the above example, the drive mechanism formed by a combination of the intermediate cylinder 218 having the rectilinear groove 212 and the cam ring 290 having the cam groove 292 is illustrated. However, not only a driving mechanism based on the rotation of the operation ring but also a driving mechanism using an electric actuator, an ultrasonic actuator, or the like as a driving force source may be combined.

  Furthermore, in the above example, the single-lens reflex camera 100 is taken as an example of the optical apparatus. However, in other optical devices such as a telescope, a microscope, and a surveying instrument as well as an imaging device such as a mirrorless camera, a compact camera, and a video camera, the guide members 401, 402, and 403 support and guide the optical member. be able to.

  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 SLR camera, 200, 201 Lens unit, 210 Fixed tube, 211 Fitting surface, 212 Straight groove, 214 Front flange, 216 Rear flange, 218 Intermediate tube, 220, 230, 240 Lens, 231, 234, 235 Steel ball Holding portion, 232 Lens holding frame, 233, 236, 237 Retaining prevention portion, 238 Cam follower, 250 Lens barrel side control portion, 260 Lens barrel side mount portion, 270 Guide shaft, 272 Round bar member, 280 Steel ball, 290 Cam ring , 292 Cam groove, 300 Camera body, 310 Focal plane shutter, 320 Substrate, 322 Body side control unit, 324 Image processing unit, 330 Display unit, 340 Viewfinder, 342 Viewfinder optical system, 344 Penta prism, 346 Focusing screen, 350 Photometry Sensor, 360 body side mount, 370 image sensor, 372 optical filter, 380 mirror unit, 381 main mirror holding frame, 382 main mirror, 383 main mirror rotating shaft, 384 positioning pin, 385 sub mirror holding frame, 386 sub mirror, 387 Sub mirror rotation axis, 388 stopper, 390 focusing optical system, 392 focusing position sensor, 401, 402, 403 guide mechanism

Claims (12)

A lens holding part for holding the lens;
A guide shaft that extends parallel to the optical axis direction of the lens and guides the lens holding portion;
Either one of the lens holding part and the guide shaft has a restricting part whose cross section perpendicular to the optical axis direction is a shape circumscribed by a pair of circular shapes, and the other of the lens holding part and the guide shaft is A lens unit having a contact portion that contacts both of the pair of circular shapes of the restriction portion.   The lens unit according to claim 1, wherein a shape of a cross section of the contact portion perpendicular to the optical axis direction is circular.   The lens unit according to claim 1, wherein the guide shaft is formed by a pair of round bars juxtaposed, and the restricting portion is formed by an outer peripheral surface of the pair of round bars.   The lens unit according to claim 3, wherein the contact portion is formed of a rotatable sphere.   The lens unit according to claim 4, wherein the contact portion includes a plurality of the spheres arranged along the extending direction of the guide shaft.   The lens unit according to claim 4, wherein the lens holding portion includes a receiving portion that receives the sphere in a rotatable and detachable manner.   The lens unit according to any one of claims 3 to 6, wherein a plurality of sets of the pair of round bars are arranged in a circumferential direction of the lens, and a plurality of the contact portions are arranged corresponding to each of the sets.   The lens unit according to claim 7, wherein a plurality of pairs of the pair of round bars are arranged at equal intervals in a circumferential direction of the lens.   The lens unit according to any one of claims 1 to 8, further comprising a pair of support members formed separately from each other for supporting both ends of the guide shaft.   The lens unit according to claim 1, wherein the lens holding portion includes a pair of spheres arranged orthogonal to the optical axis direction, and the restricting portion is formed by an outer peripheral surface of the pair of spheres.   The lens unit according to claim 10, wherein the guide shaft is formed of a round bar. The lens unit according to any one of claims 1 to 11,
A drive unit for driving the lens holding unit,
An optical apparatus in which the lens holding unit guided by the guide shaft moves by the driving force of the driving unit.

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