JP6343887B2 - Lens barrel and optical device - Google Patents

Description

  The present invention relates to a lens barrel and an optical device.

There is a structure in which a guide shaft is fitted to a holding member of an optical member and slidably supported (see Patent Document 1).
[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-077705

  If the holding member is fitted to one guide shaft at a plurality of locations, the holding member may not slide smoothly with respect to the guide shaft.

  The first aspect of the present invention includes a first holding member that holds the first optical member, a first bearing member that is supported by the first holding member, and a guide shaft member that is inserted through the bearing member, The one holding member has a support hole that accommodates and supports the first bearing member, and the extending direction of the insertion hole through which the guide shaft member is inserted in the bearing member is inclined with respect to the extending direction of the support hole. A lens barrel is provided.

  In a second aspect of the present invention, an optical device 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 camera system 100. FIG. 2 is a schematic cross-sectional view of a lens unit 200. FIG. FIG. 6 is a schematic cross-sectional view of a fitting part 230. It is sectional drawing of the spherical bearing structure part 281. FIG. 3 is an exploded sectional view of a spherical bearing structure portion 281. FIG. FIG. 6 is a schematic cross-sectional view of a fitting part 230. It is sectional drawing of the spherical bearing structure part 281. FIG. It is sectional drawing of the spherical bearing structure part 282. FIG. It is sectional drawing of the spherical bearing structure part 283. FIG. It is sectional drawing of the cylindrical bearing structure part 284. FIG. 2 is a schematic cross-sectional view of a lens unit 201. 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 the camera system 100. The camera system 100 includes a lens unit 200 and a camera body 300.

  For the purpose of simplifying the description, in the following description, the object side on which the object to be imaged by the camera system 100 is located is described as the front side or the front end side. In the camera system 100, the side on which the camera body 300 is disposed with respect to the lens unit 200 is referred to as a rear side or a back side.

The lens unit 200 includes a fixed cylinder 210, lens groups L ₁ , L ₂ , L ₃ and a guide shaft 212 housed in the fixed cylinder 210. A lens side mount 260 is provided at the rear end of the fixed cylinder 210.

  The lens side mount part 260 is fitted to the body side mount part 360 of the camera body 300 to fix the fixed cylinder 210 to the camera body 300. Thereby, the lens unit 200 and the camera body 300 are mechanically coupled.

  The fitting of the lens side mount part 260 and the body side mount part 360 can be released by a specific operation. Therefore, the lens unit 200 can be replaced with another lens unit 200 having the lens side mount portion 260 of the same standard.

Inside the fixed cylinder 210, the lens groups L ₁ , L ₂ , L ₃ are arranged along a common optical axis X to form an optical system. Each of the pair of guide shafts 212 is supported from the fixed cylinder 210 and is fixed in parallel with the optical axis X.

At least one lens group L ₂ is held by a holding frame 220 having a pair of fitting portions 230 and a single engaging portion 250. The pair of fitting portions 230 are spaced apart from each other along the extending direction of the guide shaft 212, and the one guide shaft 212 is commonly inserted through the fitting holes 231 provided in each of the fitting portions 230. Each of the fitting holes 231 is slidably fitted to the guide shaft 212 via a bearing bush 240 accommodated therein.

In the holding frame 220, the single engaging portion 250 is also slidably engaged with the guide shaft 212. Thus, the lens group L ₂ held by the holding frame 220 along the guide shaft 212, moves parallel to the optical axis X. Thus, the lens group L ₂ moves parallel to the optical axis X. When the lens group L ₂ is moved, the lens group L _1, L _2, the focal length of the optical system L ₃ forms, the focus position or the like changes.

  The lens unit 200 also includes a lens side control unit 270. The lens side control unit 270 is disposed at a position off the optical path of the optical system, and controls the entire lens unit 200, and also communicates between the body side control unit 322 mounted on the camera body 300 and the lens unit 200 side. Bear. Thereby, the lens unit 200 attached to the camera body 300 operates in cooperation with the camera body 300.

  The camera body 300 includes a mirror unit 370 on the rear side of the body side mount portion 360. The mirror unit 370 has a main mirror holding frame 372 and a main mirror 371. The main mirror holding frame 372 is supported by a main mirror rotating shaft 373 while holding the main mirror 371.

  Further, the mirror unit 370 includes a sub mirror holding frame 375 and a sub mirror 374. The sub mirror holding frame 375 is pivotally supported from the main mirror holding frame 372 by a sub mirror rotating shaft 376 while holding the sub mirror 374. When the main mirror holding frame 372 rotates, the sub mirror 374 and the sub mirror holding frame 375 rotate with respect to the main mirror holding frame 372 while moving together with the main mirror holding frame 372.

  In the camera body 300, a focusing screen 352 and a pentaprism 354 are sequentially arranged above the mirror unit 370 in the drawing. In the camera body 300, a finder optical system 356 and a photometric sensor 390 are disposed behind the pentaprism 354 in the drawing. The rear end of the viewfinder optical system 356 is exposed as a viewfinder 350 on the back surface of the camera body 300. The photometric sensor 390 detects the intensity of incident light.

  In the camera body 300, a focal plane shutter 310, an optical filter 332, and an image sensor 330 are sequentially arranged behind the mirror unit 370 in the drawing. The focal plane shutter 310 opens and closes, and introduces or blocks a subject light beam incident on the image sensor 330.

  The optical filter 332 is installed immediately before the image sensor 330 and removes infrared rays and ultraviolet rays from the light incident on the image sensor 330. The optical filter 332 protects the surface of the image sensor 330. Further, the optical filter 332 includes a low-pass filter that reduces the spatial frequency of the incident subject light flux. Thereby, the optical filter 332 removes the spatial frequency component exceeding the Nyquist frequency of the image sensor 330 from the incident light and suppresses the generation of moire.

  The image pickup device 330 includes a photoelectric conversion device such as a CCD sensor or a CMOS sensor, and receives light incident through the optical filter 332. A substrate 320 and a rear display unit 340 are sequentially arranged behind the image sensor 330. On the substrate 320, a body side control unit 322, an image processing unit 324, and the like are mounted. The rear display unit 340 is formed of a liquid crystal display panel or the like, and is exposed on the rear surface of the camera body 300.

  The main mirror 371 in the state shown in the figure is at an observation position that obliquely crosses the light incident through the lens unit 200. A part of the main mirror 371 forms a half mirror region and transmits a part of the incident light.

  The light transmitted through the half mirror region of the main mirror 371 at the observation position enters the sub mirror 374 behind the main mirror 371. The sub mirror 374 reflects the incident light downward in the figure of the mirror unit 370. The light reflected by the sub mirror 374 enters the focusing sensor 382 through the focusing optical system 380 disposed below the mirror unit 370 in the drawing.

  Further, the light reflected by the main mirror 371 at the observation position is reflected toward the focusing screen 352. The focusing screen 352 is disposed at a position optically conjugate with the element arrangement surface of the imaging element 330, and visualizes an image formed by the optical system of the lens unit 200. The image connected to the focusing screen 352 is observed as an erect image from the viewfinder 350 through the pentaprism 354 and the viewfinder optical system 356.

  Part of the light emitted from the pentaprism 354 is received by the photometric sensor 390 disposed above the viewfinder optical system 356. When the release button of the camera body 300 is half-pressed, the photometric sensor 390 detects the light intensity of the incident light.

  The body-side control unit 322 calculates subject luminance based on the light intensity detected by the photometric sensor 390, and further calculates imaging conditions such as an aperture value, shutter speed, and ISO sensitivity according to the calculated subject luminance. As a result, the camera system 100 is in a state where it can shoot a subject under appropriate shooting conditions.

When the release button of the camera body 300 is half-pressed, the focus sensor 382 detects the defocus amount in the optical system of the lens unit 200 and notifies the body side control unit 322. Body side control unit 322 communicates with the lens control unit 270 moves the lens group L ₂ to the mobile amount sufficient to focusing the optical system to cancel the defocus amount detected.

  Thereby, the lens unit 200 forms a clear image of the subject on the focusing screen 352.

  Subsequently, when the release button is pushed deeply in the camera system 100, the main mirror holding frame 372 rotates clockwise together with the main mirror 371 in the drawing and stops substantially horizontally at the retracted position. As a result, the main mirror 371 retreats from the optical path of the incident light through the optical system of the lens unit 200.

  When the main mirror 371 rotates toward the shooting position, the sub mirror holding frame 375 also moves up with the main mirror holding frame 372 and rotates around the sub mirror rotation shaft 376 and stops substantially horizontally at the shooting position. To do. As a result, the sub mirror 374 is also retracted from the optical path of the incident light.

  When the main mirror 371 and the sub mirror 374 move to the photographing position, the focal plane shutter 310 is subsequently opened. Thereby, the light incident through the optical system of the lens unit 200 passes through the optical filter 332 and is received by the image sensor 330. In this way, a clear image of the subject formed on the element array surface of the image sensor 330 is converted into an electric signal by the image sensor 330. Thereafter, the rear film of the focal plane shutter 310 is closed, the main mirror 371 and the sub mirror 374 are returned to the observation position again, and a series of operations related to photographing is completed.

FIG. 2 is a cross-sectional view of the lens unit 200. Figure 2 includes a lens group L _2, shows a cross-section perpendicular to the optical axis X schematically. Elements that are the same as those in FIG. 1 are given the same reference numerals, and redundant descriptions are omitted. In the lens unit 200, the holding frame 220 for holding the lens group _{L 2} is, the fitting portion 230 on the upper side in the figure, the engaging portion 250 in the lower side in the drawing, each having.

  Each of the fitting holes 231 provided in the pair of fitting portions 230 forms a support hole that accommodates and supports the bearing bush 240. Each of the bearing bushes 240 has an insertion hole 241 having an inner surface shape substantially complementary to the cross-sectional shape of the guide shaft 212, and the guide shaft 212 is inserted into the insertion hole 241 of the bearing bush 240. Thereby, the fitting part 230 is accurately positioned with respect to the upper guide shaft 212 in the drawing.

  The engaging portion 250 of the fitting portion 230 engages with the guide shaft 212 with the guide shaft 212 sandwiched between a pair of opposed parallel surfaces. As a result, the holding frame 220 is restricted from rotating around the upper guide shaft 212 in the drawing. In this way, the holding frame 220 is allowed to move in a direction parallel to the optical axis X and is restricted from being displaced in other directions.

  FIG. 3 is a cross-sectional view of the fitting portion 230 in the holding frame 220. FIG. 3 shows a cross section of the fitting portion 230 in the plane including the optical axis X. Elements common to those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description is omitted.

  A pair of the fitting portions 230 are provided at positions separated along the longitudinal direction of the guide shaft 212. In each of the pair of fitting portions 230, the bearing bush 240 is accommodated in the fitting hole 231. The bearing bush 240 accommodated in the fitting hole 231 is supported from the fitting portion 230. Each of the bearing bushes 240 has an insertion hole 241 through which the guide shaft 212 is inserted.

Each of the fitting hole 231, as shown by a chain line A in the figure is formed generally along the extending direction to the optical axis X of the lens group L _2. Therefore, one guide shaft 212 can be inserted in common through the pair of bearing bushes 240 disposed inside the pair of fitting holes 231. Thus, the holding frame 220, since the fitting against one of the guide shaft 212 in the fitting portion of the two positions, the inclination of the lens group L ₂ with respect to the optical axis X is restricted.

  In each of the bearing bushes 240, the insertion hole 241 has a gap that can slide smoothly with respect to the outer peripheral surface of the guide shaft 212. Therefore, the bearing bush 240 slides smoothly along the guide shaft 212. A spherical bearing structure portion 281 that couples the bearing bush 240 to the fitting portion 230 is formed inside each fitting hole 231 of the fitting portion 230. Next, the spherical bearing structure portion 281 will be described with reference to FIG.

  FIG. 4 is a cross-sectional view of the spherical bearing structure portion 281. In FIG. 4, the fitting part 230 shown on the right side in FIG. Elements that are the same as those in FIG. 3 are given the same reference numerals, and redundant descriptions are omitted.

  The spherical bearing structure portion 281 includes a spherical seat 232 and a spherical portion 242. That is, a spherical seat 232 having a partially spherical inner surface is provided on the inner surface of the fitting hole 231 provided substantially horizontally through the fitting portion 230 in the drawing. A spherical portion 242 having a partially spherical outer surface is provided integrally with the bearing bush 240 on the outer peripheral surface of the bearing bush 240.

  The spherical seat 232 and the spherical surface portion 242 have complementary shapes and dimensions, and form a spherical bearing structure portion 281 that fits and contacts each other. Here, the partial spherical surface formed by the spherical seat 232 is narrower than the partial spherical surface formed by the spherical surface portion 242. Therefore, the bearing bush 240 integral with the spherical surface portion 242 can swing inside the fitting hole 231 of the fitting portion 230 with the common center of the spherical seat 232 and the spherical surface portion 242 as the swing axis.

  In other words, the bearing bush 240 is coupled to the fitting portion 230 by the spherical bearing structure portion 281. Therefore, while the bearing bush 240 is swingable with respect to the holding frame 220, the center axis of the bearing bush 240 is maintained in a fixed positional relationship determined with respect to the center axis of the guide shaft 212. .

  FIG. 5 is an exploded cross-sectional view showing a state in which the bearing bush 240 is removed from the fitting portion 230. Elements that are the same as those in FIG. 4 are given the same reference numerals, and redundant descriptions are omitted.

The outer diameter R ₀ of the spherical surface portion 242 in the bearing bush 240 is larger than the inner diameter R ₁ of the small diameter portion 233 of the fitting hole 231 in the fitting portion 230. Therefore, when the bearing bush 240 is press-fitted into the fitting hole 231 provided in the fitting portion 230, the spherical portion 242 is sandwiched between the small diameter portions 233 having a smaller inner diameter R ₁ inside the fitting hole 231. Thus, the escape from the inside of the fitting hole 231 is restricted. As described above, in the spherical bearing structure portion 281, the bearing bush 240 is in a state of being swingable with respect to the fitting portion 230, but the positional relationship of the swing center with respect to the fitting portion 230 is not changed. Become.

  FIG. 6 is a cross-sectional view of the fitting portion 230. 6 exaggeratedly shows the shape of the fitting portion 230 inserted through the guide shaft 212 when viewed from the same viewpoint as FIG.

  In the lens unit 200, the guide shaft 212 is fixed to the fixed cylinder 210. Therefore, the extending direction of the insertion hole 241 defined by the inner surface of the insertion hole 241 inserted through the guide shaft 212 coincides with the extending direction of the guide shaft 212 as indicated by a dashed line A in the drawing.

  On the other hand, of the pair of fitting portions 230, the right fitting portion 230 in the drawing far from the holding frame 220 is inclined counterclockwise to the angle θ with respect to the optical axis X with the lower end in the drawing as the rotation axis. . For this reason, in this fitting part 230, the extending direction of the fitting hole 231 defined by the inner peripheral surface of the fitting hole 231 is inclined with respect to the extending direction of the guide shaft 212. However, the bearing bush 240 is rotatably supported by the spherical seat 232 in the spherical portion 242 inside the fitting hole 231.

  The extending direction of the insertion hole 241 of the bearing bush 240 is inclined with respect to the extending direction of the fitting hole 231 of the fitting portion 230 as indicated by a two-dot chain line B in the drawing. As a result, even if the extending direction of the fitting hole 231 is inclined with respect to the extending direction of the guide shaft 212, the guide shaft 212 is oscillated with respect to the fitting hole 231 and inserted. Can be slid smoothly.

  When one of the pair of fitting portions 230 is inclined with respect to the other, the extending directions of the pair of fitting holes 231 formed in the fitting portion 230 are also different from each other. That is, as indicated by a two-dot chain line A in the figure, the extending direction of one fitting hole 231 forms an angle θ with the extending direction of the other fitting hole. For this reason, when one guide shaft 212 is inserted through a pair of fitting holes whose directions of the central axes are different from each other, the fitting portion 230 does not slide smoothly with respect to the guide shaft 212.

  Further, by increasing the gap with respect to the guide shaft 212, the fitting portion 230 can smoothly slide with respect to the guide shaft 212 even if the orientation of the central axis of the fitting hole 231 is different. However, if there is a gap between the fitting portion 230 and the guide shaft 212, the positioning accuracy of the fitting portion 230 by the guide shaft 212 is lowered.

  Thus, each holding part 220 has the bearing bush 240 joined by the spherical bearing structure part 281 in each holding frame 220. Therefore, even if one of the fitting portions 230 is inclined, the bearing bush 240 can swing with respect to the fitting portion 230 so that the center axis of the bearing bush 240 matches the center axis of the guide shaft 212. . Thereby, smooth sliding with respect to the guide shaft 212 of the fitting portion 230 can be maintained without deteriorating the positioning accuracy of the fitting portion 230 by the guide shaft 212.

  In the above example, the guide shaft 212 is inserted through the bearing bush 240 in each of the pair of fitting portions 230. However, even when the bearing bush 240 is used in one of the pair of fitting portions 230 and omitted in the other, the effect of causing the guide shaft 212 to slide smoothly occurs.

  FIG. 7 is a cross-sectional view of the spherical bearing structure portion 281. The spherical bearing structure portion 281 has the same structure as the spherical bearing structure portion 281 shown in FIG. 4 except for the portions described below. Therefore, common elements are denoted by the same reference numerals as in FIG.

  In the spherical bearing structure portion 281, the bearing bush 240 is fixed to the fitting portion 230 with an adhesive 244. That is, when manufacturing the lens unit 200 having the spherical bearing structure portion 281, first, the bearing bush 240 is assembled into the fitting hole 231 of the fitting portion 230 and the fitting portion 230 and the bearing bush 240 are coupled. .

  Thereafter, the guide shaft 212 is inserted into the bearing bush 240 while the bearing bush 240 is swingable with respect to the fitting portion 230. As a result, the bearing bush 240 swings, and the center axis of the bearing bush 240 becomes parallel to the center axis of the guide shaft 212.

  Further, the bearing bush 240 and the fitting portion 230 are fixed by the adhesive 244 in a state where the guide shaft 212 is inserted into the bearing bush 240. As a result, the swing of the bearing bush 240 with respect to the fitting portion 230 is restrained, and the fitting portion 230 that smoothly slides with respect to the guide shaft 212 is formed even if the gap with respect to the guide shaft 212 is small. Therefore, the fitting portion 230 can be smoothly slid with respect to the guide shaft 212 while the positioning accuracy of the fitting portion 230 with respect to the guide shaft 212 is kept high.

  When the single holding frame 220 includes a pair of fitting portions 230, the holding frame 220 is positioned with respect to the guide shaft 212 without fixing the bearing bush 240 to the fitting portion 230. Can do. However, in the case of a structure in which one fitting portion 230 is provided for the holding frame 220, the positioning of the holding frame 220 is completed by fixing the bearing bush 240 to the fitting portion 230.

  In the above example, the bearing bush 240 is fixed to the fitting portion 230 with the adhesive 244. However, the method for fixing the bearing bush 240 is not limited to the adhesive. For example, when one of the fitting portion 230 and the bearing bush 240 is a resin product, the bearing bush 240 can be fixed by welding. Further, the bearing bush 240 can be mechanically fixed by screws, springs, pins, or the like.

  FIG. 8 is a cross-sectional view of the spherical bearing structure portion 282. The spherical bearing structure portion 282 has the same structure as the spherical bearing structure portion 281 shown in FIG. 4 except for the portions described below. Therefore, common elements are denoted by the same reference numerals as in FIG.

In the illustrated spherical bearing structure portion 282, the bearing bush 240 is coupled to the fitting portion 230 by an annular member 234 that holds the spherical portion 242. The inner peripheral surface of the annular member 234 has an inner diameter R ₂ that is smaller than the outer diameter R ₀ of the spherical portion 242 of the bearing bush 240. Further, the outer peripheral surface of the annular member 234 has a thread that is screwed into the inner surface of the fitting hole 231 of the fitting portion 230.

In the spherical bearing structure portion 282, one end of the fitting hole 231 formed in the fitting portion 230 has the same diameter as the outer diameter _R0 of the spherical portion 242 of the bearing bush 240 or a larger inner diameter than the outer diameter _R0 . The other end of the fitting hole 231 has an inner diameter R ₁ that is smaller than the outer diameter R ₀ of the spherical portion 242 of the bearing bush 240.

When manufacturing the lens unit 200 having the spherical bearing structure portion 282 as described above, first, the spherical portion 242 of the bearing bush 240 is inserted from one end of the fitting hole 231 of the fitting portion 230. Thus, inside the fitting hole 231 that accommodates the spherical portion 242 provided in the fitting portion 230, the small diameter portion 233 of the fitting hole 231 having an inner diameter R ₁ that is smaller than the outer diameter R ₀ of the spherical portion 242. The spherical surface portion 242 is sandwiched between the spherical portion 242 of the bearing bush 240 by the annular member 234 screwed into the fitting hole 231 and having an opening having an inner diameter R ₂ smaller than the outer diameter R ₀ of the spherical surface portion 242. It can be held inside the fitting hole 231.

  Note that when the annular member 234 is shallowly screwed into the fitting hole 231, the bearing bush 240 easily swings inside the fitting hole 231. On the other hand, when the annular member 234 is screwed deeply into the fitting hole 231, the spherical member 242 can be pressed by the annular member 234 and the swing of the bearing bush 240 with respect to the fitting portion 230 can be restrained.

  Thus, even if the gap with respect to the guide shaft 212 is small, the fitting portion 230 that slides smoothly with respect to the guide shaft 212 is formed. Therefore, the fitting portion 230 can be smoothly slid with respect to the guide shaft 212 while the positioning accuracy of the fitting portion 230 with respect to the guide shaft 212 is kept high.

  FIG. 9 is a cross-sectional view of the spherical bearing structure portion 283. The spherical bearing structure portion 283 has the same structure as the spherical bearing structure portion 281 shown in FIG. 4 except for the portions described below. Therefore, common elements are denoted by the same reference numerals as in FIG.

  In the illustrated spherical bearing structure portion 283, the bearing bush 240 is coupled to the fitting portion 230 by a clip 236. The clip 236 extends from the upper end of the fitting portion 230 in the drawing to both side surfaces of the fitting portion 230. A latch 237 is provided at one end of the clip 236. The latch 237 prevents the clip 236 from falling off the fitting portion 230 due to a step of the fitting portion 230 when the clip 236 is fitted to the fitting portion 230.

The other end of the clip 236 is disposed across the upper and lower ends of the fitting hole 231 formed in the fitting portion 230 in the figure. In the clip 236, an inner diameter R ₃ smaller than the outer diameter R ₀ of the spherical surface portion 242 of the bearing bush 240 is provided in a region overlapping with the fitting hole 231.

Thereby, inside the fitting hole 231 provided in the fitting portion 230 and accommodating the spherical portion 242, the small diameter portion 233 of the fitting hole 231 having an inner diameter R ₁ smaller than the outer diameter R ₀ of the spherical portion 242, The clip 236 fitted in the fitting hole 231 and having an opening having an inner diameter R ₃ smaller than the outer diameter R ₀ of the spherical surface portion 242 forms a stopper that holds the spherical portion 242 of the bearing bush 240 therebetween. Therefore, the spherical surface portion 242 of the fitting portion 230 is held inside the fitting hole 231.

  Thus, even if the gap with respect to the guide shaft 212 is small, the fitting portion 230 that slides smoothly with respect to the guide shaft 212 is formed. Therefore, the fitting portion 230 can be smoothly slid with respect to the guide shaft 212 while the positioning accuracy of the fitting portion 230 with respect to the guide shaft 212 is kept high.

  In this way, the spherical bearing structure portions 281, 281, 282, and 283 can be formed by combining the spherical portion 242 and the spherical seat 232. However, in the above example, both the spherical surface portion 242 and the spherical seat 232 have a spherical surface, but if either one of the spherical surface portion 242 or the spherical seat 232 is a spherical surface, the other contacts at a plurality of different positions on the spherical surface. In the case of having a shape, the spherical bearing structure portions 281, 281, 282, and 283 can be formed even if they are not spherical.

  If the centers of the partial spherical surfaces coincide with each other and are concentric, the spherical bearing structures 281, 281, 282, and 283 can be formed by combining a plurality of spherical surfaces having different diameters. Furthermore, when the falling direction of the fitting part 230 is known in advance and the amount of the falling is indefinite, the bearing bush may be supported by a single shaft.

  FIG. 10 is a cross-sectional view of a cylindrical bearing structure portion 284 according to another embodiment. The cylindrical bearing structure portion 284 includes a cylindrical bearing bush 243 that fills the gap between the fitting portion 230 and the guide shaft 212.

  In the cylindrical bearing structure portion 284, the fitting portion 230 is slightly tilted toward the other fitting portion 230, so the extending direction of the fitting hole 231 defined by the inner peripheral surface is shown in the figure. As indicated by a two-dot chain line B, the guide shaft 212 is inclined with respect to the extending direction.

  Since the insertion hole 241 serving as the inner peripheral surface of the bearing bush 243 slides with the guide shaft 212, the insertion hole 241 has the same inclination as the guide shaft 212 as indicated by a one-dot chain line A in the drawing. For this reason, the extending direction of the insertion hole 241 is inclined with respect to the extending direction of the fitting hole 231.

  Here, the bearing bush 243 in the cylindrical bearing structure portion 284 has an outer peripheral surface having a shape complementary to the inner peripheral surface of the fitting hole 231. For this reason, the outer peripheral surface of the bearing bush 243 is in close contact with the inner surface of the fitting hole 231, and the inner peripheral surface of the bearing bush 243 is in close contact with the outer peripheral surface of the guide shaft 212. Thus, the bearing bush 243 absorbs the inclination of the fitting hole 231 and the insertion hole 241 that are inclined to each other, and causes the guide shaft 212 to slide smoothly.

  The fitting hole 231 in the cylindrical bearing structure portion 284 does not have the spherical seat 232 but has a simple cylindrical shape. Therefore, the fitting part 230 can be easily formed. Moreover, the assembly work of the bearing bush 243 with respect to the fitting part 230 is also facilitated. Therefore, when the inclination of the fitting portion 230 with respect to the optical axis X is known in advance, the cylindrical bearing structure portion 284 having a simpler structure can be formed.

  FIG. 11 is a cross-sectional view of another lens unit 201. Elements common to the lens unit 200 shown in FIG. 1 are given the same reference numerals, and redundant description is omitted.

The lens unit 201 has five lens groups L ₁ to L 5. As in the case of the lens unit 200, a lens group L ₁ is at the forefront, the lens group L ₃ is located in the rearmost end is fixed to the fixed cylinder 210. Similarly to the case of the lens unit 200, the central lens group L ₂ is held by a holding frame 220 having a fitting portion 230 and an engaging portion 250, guided by the guide shaft 212, and along the optical axis X. Moving.

Further, in the lens unit 201, a lens group L ₄ disposed between the lens groups L ₁ and the lens group L _2, and a lens group L ₅ disposed between the lens groups L ₂ and lens unit L ₃ Have. The holding frame 221 that holds the lens unit L ₄ and the holding frame 222 that holds the lens unit L ₅ are connected to each other by a connecting cylinder 290.

The connecting cylinder 290 has a pair of fitting portions 239 and a single engaging portion 259. The fitting portions 239 are fitted to the guide shaft 212, respectively. Further, the engaging portion 259 engages with the guide shaft 212. Thereby, the lens group L ₄ and the lens group L ₅ are guided by the guide shaft 212 and integrally move in a direction parallel to the optical axis X.

Here, the pair of fitting portions 230 for supporting and guiding the lens group L ₂ and the pair of fitting portions 239 for supporting and guiding the connecting tube 290 are fitted to the common guide shaft 212. Match. In addition, one of the pair of fitting portions 230 of the lens group L ₂ is disposed between the pair of fitting portions 239 of the connecting cylinder 290.

Accordingly, in the lens unit 201, and wide spacing of the fitting portion 230 paired respectively, the inclination of the lens group _{L 2, L 4, L 5} can be suppressed. Further, even if wide spacing of the fitting portion 230, each of the amount of movement of the lens group L ₂ and the coupling tube 290 is secured.

  Further, also in the connecting cylinder 290, the gap between the fitting portion 239 and the guide shaft 212 is filled with the bearing bush 249. As already described, the bearing bush 249 is coupled to the fitting portion 239 by the spherical bearing structure portion 281.

  Thereby, even if one of the pair of fitting portions 239 is inclined with respect to the other, the bearing bush 249 swings with respect to the fitting portion 239, and the center axis of the bearing bush 249 is set to the center of the guide shaft 212. Can match the axis. Therefore, smooth sliding with respect to the guide shaft 212 of the fitting portion 239 can be maintained without deteriorating the positioning accuracy of the fitting portion 239 by the guide shaft 212.

  The camera system 100 in which the lens units 200 and 201 can be exchanged has been described above as an example, but the above structure can be applied to a camera in which the lens units 200 and 201 and the camera body 300 are integrally formed. The same structure can be applied to the lens unit 200 of a non-reflex camera that does not include the main mirror 371. Furthermore, in addition to an imaging device such as a camera, the above structure can be widely applied to an optical device that includes an optical member that moves while being guided by a guide shaft 212.

  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 camera system, 200, 201 lens unit, 210 fixed cylinder, 212 guide shaft, 220, 221, 222 holding frame, 230, 239 fitting portion, 231 fitting hole, 232 spherical seat, 233 small diameter portion, 234 annular member, 236 Clip, 237 Latch, 240, 243, 249 Bearing bush, 241 Insertion hole, 242 Spherical surface part, 244 Adhesive, 250, 259 Engagement part, 260 Lens side mount part, 270 Lens side control part, 281, 282, 283 Spherical bearing structure section, 284 cylindrical bearing structure section, 290 connecting cylinder, 300 camera body, 310 focal plane shutter, 320 substrate, 322 body side control section, 324 image processing section, 330 image sensor, 332 optical filter, 340 display section 350 Finder, 35 Focusing screen, 354 pentaprism, 356 finder optical system, 360 body side mount, 370 mirror unit, 371 main mirror, 372 main mirror holding frame, 373 main mirror rotation axis, 374 sub mirror, 375 sub mirror holding frame, 376 sub mirror times Moving axis, 380 focusing optical system, 382 focusing sensor, 390 photometric sensor

Claims (12)

A guide axis parallel to the optical axis;
A holding portion for holding the optical member, having a first hole and a second hole through which the guide shaft is inserted;
A bearing portion provided on an inner peripheral side of at least one of the first hole and the second hole, and having an insertion hole through which the guide shaft is inserted;
The central axis of the second hole is inclined with respect to the central axis of the first hole,
The bearing portion is rotatable at least with a difference in inclination of the central axis of the second hole with respect to the central axis of the first hole. The lens barrel according to claim 1, wherein the bearing portion is rotatable so that a center axis of the insertion hole coincides with a guide axis. The said bearing part is rotatable so that the said guide shaft may become parallel to an optical axis, when the said guide shaft is penetrated by the said 1st hole and the said 2nd hole. Lens barrel. A first bearing portion provided on the inner peripheral side of the first hole and having a first insertion hole through which the guide shaft is inserted;
A second bearing portion provided on the inner peripheral side of the second hole and having a second insertion hole through which the guide shaft is inserted;
The said 1st bearing part and the said 2nd bearing part are rotatable according to the inclination of the central axis of the said 1st hole and the central axis of the said 2nd hole at least. The lens barrel according to the item. When the guide shaft is inserted into the first hole and the second hole, the first bearing portion and the second bearing portion include a central axis of the first insertion hole and a central axis of the second insertion hole. The lens barrel according to claim 4, wherein the lens barrel is rotatable so as to coincide with the guide shaft. The bearing portion has a spherical portion,
The holding portion has a spherical seat that contacts the spherical portion,
The lens barrel according to claim 1, wherein the spherical portion is supported so as to be swingable with respect to the spherical seat. The lens barrel according to claim 6, wherein a radius of the spherical portion is larger than a radius of the spherical seat. A stop member,
At least one of the first hole and the second hole has a small diameter portion on the inner peripheral side,
The lens barrel according to any one of claims 1 to 7, wherein the bearing portion is sandwiched between the stopper member and the small diameter portion. The lens barrel according to claim 8, wherein the stopper member is an annular member or a clip. A holding unit for holding the optical member;
A bearing portion supported by the holding portion;
A guide shaft inserted through the bearing portion,
The holding part has a support hole for receiving and supporting the bearing part,
The support hole has a spherical seat in contact with the spherical portion formed integrally with the bearing portion,
The spherical seat is
A small-diameter portion provided on an inner surface of a spherical support chamber provided in the holding portion and accommodating the spherical portion, and having an inner diameter smaller than an outer diameter of the spherical portion;
An annular part having an opening with an inner diameter smaller than the outer diameter of the spherical part, screwed into the spherical support chamber, and sandwiching the spherical part together with the small diameter part,
The lens barrel in which the extending direction of the insertion hole through which the guide shaft is inserted in the bearing portion is inclined with respect to the extending direction of the support hole. A holding unit for holding the optical member;
A bearing portion supported by the holding portion;
A guide shaft inserted through the bearing portion,
The holding part has a support hole for receiving and supporting the bearing part,
The support hole has a spherical seat in contact with the spherical portion formed integrally with the bearing portion,
The spherical seat is
A small-diameter portion provided on an inner surface of a spherical support chamber provided in the holding portion and accommodating the spherical portion, and having an inner diameter smaller than an outer diameter of the spherical portion;
A stopper having an opening with an inner diameter smaller than the outer diameter of the spherical portion, fitted to the holding portion, and sandwiching the spherical portion together with the small diameter portion;
The lens barrel in which the extending direction of the insertion hole through which the guide shaft is inserted in the bearing portion is inclined with respect to the extending direction of the support hole.   An optical device comprising the lens barrel according to any one of claims 1 to 11.

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