Source: http://www.google.com/patents/US5892999?dq=7,003,515
Timestamp: 2014-08-20 22:37:54
Document Index: 431246203

Matched Legal Cases: ['art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'arts 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'art 34', 'arts 34', 'Application No. 9701434']

Patent US5892999 - Zoom lens barrel with shutter mounting unit - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA lens supporting mechanism for a lens shutter camera includes a front lens group, a lens supporting barrel, a movable barrel, a rear lens group, and a shutter mounting barrel which includes a shutter with an AE function. The front lens group is fixed to the lens supporting barrel. Both the lens supporting...http://www.google.com/patents/US5892999?utm_source=gb-gplus-sharePatent US5892999 - Zoom lens barrel with shutter mounting unitAdvanced Patent SearchPublication numberUS5892999 APublication typeGrantApplication numberUS 08/777,482Publication dateApr 6, 1999Filing dateDec 30, 1996Priority dateJan 26, 1996Fee statusLapsedAlso published asDE19702485A1, DE19702485B4Publication number08777482, 777482, US 5892999 A, US 5892999A, US-A-5892999, US5892999 A, US5892999AInventorsHiroshi Nomura, Kazuyoshi Azegami, Takamitsu SasakiOriginal AssigneeAsahi Kogaku Kogyo Kabushiki KaishaExport CitationBiBTeX, EndNote, RefManPatent Citations (13), Non-Patent Citations (1), Referenced by (3), Classifications (37), Legal Events (5) External Links: USPTO, USPTO Assignment, EspacenetZoom lens barrel with shutter mounting unitUS 5892999 AAbstract A lens supporting mechanism for a lens shutter camera includes a front lens group, a lens supporting barrel, a movable barrel, a rear lens group, and a shutter mounting barrel which includes a shutter with an AE function. The front lens group is fixed to the lens supporting barrel. Both the lens supporting barrel and the shutter mounting barrel are fixed to the movable barrel. The rear lens group is attached to either the movable barrel or the shutter mounting barrel such that the rear lens group is movable along the optical axis relative to the moveable barrel. During operation of the zoom lens, the movable barrel advances and retreats along the optical axis.
What is claimed is: 1. A lens supporting mechanism for a camera, said mechanism comprising:a movable barrel that is driven along an optical axis with respect to a camera body; a lens supporting barrel for supporting a lens group; and a shutter unit that is attached to said movable barrel, and wherein one end of said lens supporting barrel is directly fixed to said movable barrel and the other end of said lens supporting barrel is directly fixed to said shutter unit thereby indirectly fixing said other end of said lens supporting barrel to said movable barrel through said shutter unit. 2. The lens supporting mechanism according to claim 1, wherein said lens group consists of a part of a photographing lens.
3. The lens supporting mechanism according to claim 2, wherein said photographing lens comprises a zoom lens having front and rear lens groups and said front lens group is supported by said lens supporting barrel.
4. The lens supporting mechanism according to claim 3, wherein said lens supporting barrel that supports said front lens group is fixed to a front end of said movable barrel and said shutter unit is fixed to a rear end of said lens supporting barrel.
5. The lens supporting mechanism according to claim 4, wherein said front end of said lens supporting barrel is fixed to said movable barrel by a bayonet mechanism.
6. The lens supporting mechanism according to claim 4, wherein an elastic member is interposed between said lens supporting barrel and said movable barrel to make said movable barrel water-resistant.
7. The lens supporting mechanism according to claim 6, wherein said elastic member comprises an O-ring.
8. The lens supporting mechanism according to claim 3, wherein said shutter unit is located between said front lens group and said rear lens group.
9. The lens supporting mechanism according to claim 8, wherein said rear lens group is installed in another lens supporting barrel that is movably mounted on said shutter unit.
10. The lens supporting mechanism according to claim 1, wherein said movable barrel includes a first inward flange at a front end such that said front end of said lens supporting barrel is fitted into an opening inside said first inward flange; andwherein said shutter unit includes a second inward flange formed such that a rear end of said lens supporting barrel is fitted into an opening of said second inward flange. 11. A lens supporting mechanism for a lens shutter camera having a zoom lens consisting of a front lens group and a rear lens group, said mechanism comprising:a movable barrel that is driven along an optical axis with respect to a camera body; a shutter unit that is attached to said movable barrel; a front lens supporting barrel which supports said front lens group, a front end of the front lens supporting barrel is fixed to the movable barrel, and said front lens group being arranged at an object side of said shutter unit, said shutter unit being fixed to a rear end of said front lens supporting barrel; and a rear lens supporting barrel for supporting said rear lens group arranged at an image side of said shutter unit, said rear lens supporting barrel being movably supported by said shutter unit. 12. The lens supporting mechanism according to claim 11, wherein said front lens supporting barrel is fixed a front end of said movable barrel.
13. The lens supporting mechanism according to claim 11, wherein said front and rear lens groups comprise a zoom lens.
14. The lens supporting mechanism according to claim 11, wherein said movable barrel includes a first inward flange at a front end such that said front end of said front lens supporting barrel is fitted into an opening inside said first inward flange; andwherein said shutter unit includes a second inward flange formed such that said rear end of said front lens supporting barrel is fitted into an opening of said second inward flange. 15. The lens supporting mechanism for a lens shutter camera having a zoom lens consisting of a front lens group and a rear lens group, said mechanism comprising:a front lens supporting barrel for supporting said front lens group; a movable barrel in which said front lens supporting barrel is fixed, said movable barrel adapted to be driven along an optical axis with respect to a camera body and a front end of the front lens supporting barrel is directly fixed to the movable barrel; and a shutter mounting barrel for supporting a shutter unit, said shutter mounting barrel being fixed on said movable barrel, wherein said front lens supporting barrel is provided with a front fitting portion for fitting with said movable barrel at the front end and a rear fitting portion for fitting with said shutter mounting barrel at the rear end thereof to locate the front and rear portions of the lens supporting barrel at accurate positions. 16. The lens supporting mechanism according to claim 15, further comprising a device for driving said movable barrel along said optical axis during zooming and during a release operation.
17. The lens supporting mechanism as set forth in claim 16, further comprising a device for driving said rear lens group with respect to said movable barrel during said shutter release operation.
18. The lens supporting mechanism according to claim 15, wherein said rear lens group is supported on a guide rod that protrudes rearwards from a movable block, said movable block comprising said movable barrel and a portion of said movable barrel that is driven by a shutter driving motor, andwherein said movable block is provided with a rear lens group driving motor for driving said rear lens group with respect to said movable block, and wherein said shutter driving motor drives said shutter unit. 19. The lens supporting mechanism according to claim 18, wherein said movable barrel is driven by a motor mounted on said camera body.
20. The lens supporting mechanism according to claim 15, wherein said movable barrel includes a first inward flange at the front end such that said front fitting portion of said front lens supporting barrel is fitted into an opening inside said first inward flange; andwherein said shutter mounting barrel includes a second inward flange formed such that said rear fitting portion of said lens supporting barrel is fitted into an opening of said second inward flange. 21. A lens supporting mechanism for a lens shutter camera having a zoom lens consists of a front lens group and a rear lens group, said mechanism comprising:a front lens supporting barrel for supporting said front lens group; a movable barrel, to which said front lens supporting barrel is fixed and which is driven along an optical axis; a rear lens supporting barrel for supporting said rear lens group, said rear lens supporting barrel being driven with respect to said movable barrel; and a shutter mounting barrel fixed to said movable barrel, said shutter mounting barrel including a shutter unit, wherein said movable barrel includes a first inward flange integrally formed at the front end of said movable barrel such that a front side of said front lens supporting barrel is fitted into an opening inside said first inward flange; and wherein said shutter mounting barrel includes a second inward flange integrally formed with said shutter mounting barrel such that a rear side of said lens supporting barrel is fitted into an opening of said second inward flange. 22. The lens supporting mechanism according to claim 21, wherein an annular elastic member is interposed between said front lens supporting barrel and said first inward flange of said movable barrel.
23. The lens supporting mechanism according to claim 21, further comprising a locking mechanism that locks said front lens barrel in a fixed relationship to said movable barrel, wherein a front side of said lens supporting barrel is locked, by said locking mechanism, to said movable barrel, and a rear side of said lens supporting barrel is formed to fit with said shutter mounting barrel.
The present invention relates to a lens supporting mechanism for a camera. In particular, the present invention relates to the mechanism to fix a lens supporting barrel supporting a lens group to a movable barrel that is driven in a direction of an optical axis.
A lens shutter camera may be provided with a shutter unit that is arranged between or behind lens groups of a photographing lens. Since the lens group comprises a plurality of lenses, generally they are installed in a lens supporting barrel. In the case where at least one of the lens groups are driven along an optical axis together with the shutter unit, i.e., the photographing lens is a zoom lens or the photographing lens can be switched between a retracted position and a photographing position, the lens group and the shutter unit are arranged on a movable barrel.
In the conventional lens shutter camera, the lens supporting barrel for a front movable lens group is fixed to the shutter unit at the rear side of the lens supporting barrel, and the shutter unit is fixed to the movable barrel at the rear side thereof. Alternatively, the lens supporting barrel is fixed to the movable barrel at the front side thereof and the shutter unit is fixed to the movable barrel at the front side thereof.
According to the conventional structures, an accurate alignment of the lens supporting barrel with the movable barrel is difficult because of a cantilever support for the lens supporting barrel. That is, when the lens supporting barrel is fixed to the shutter unit, the lens supporting barrel is only supported at the rear side. On the other hand, when the lens supporting barrel is fixed to the movable barrel at the front side, the lens supporting barrel is only supported at the front side. In either case, the positional relationships may be changed.
Furthermore, when a camera is provided with a zoom lens having front and rear lens groups, it is necessary to make optical axes of the lens groups coaxial. However, the front lens group and the rear lens group, which are driven along an optical axis respectively during zooming operation, are guided by the different guide mechanisms in a conventional camera, and it is difficult to keep the coaxial condition during zooming operation.
SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved lens supporting mechanism for a camera which provides for accurate alignment of the lens supporting barrel with the movable barrel.
Another object of the present invention is to provide an improved lens supporting mechanism for a camera having a zoom lens which maintains the coaxial condition of the optical axes of front and rear lens groups of the zoom lens.
In an aspect of a lens supporting mechanism according to the invention, the lens supporting mechanism includes a movable barrel that is driven along an optical axis direction, and a lens supporting barrel for supporting a lens group. The lens supporting barrel is fixed to the movable barrel at both front and rear sides along the optical axis.
Since the lens supporting barrel is fixed to the movable barrel at both front and rear sides, the relationship among the movable barrel and the lens supporting barrel can be accurately set.
In a particular case, a photographing lens may comprise a zoom lens having front and rear lens groups. In this case, the lens supporting barrel for the front lens group is fixed to the movable barrel at the front end thereof and the lens supporting barrel is fixed to the shutter unit at the rear end thereof.
In another aspect of the invention, the lens supporting mechanism may include a movable barrel that is driven along an optical axis direction, a shutter unit that is attached to the movable barrel, a front lens supporting barrel for supporting a front lens group arranged at an object side of the shutter unit, the front lens supporting barrel being fixed to the shutter unit at the rear end thereof, and a rear lens supporting barrel for supporting a rear lens group arranged at an image side of the shutter unit. The rear lens supporting barrel being movably supported by the shutter unit.
Since the front and rear lens groups are supported by the same base, i.e., the shutter unit positioned between the lens groups, it is easier to maintain the coaxial condition of the lens groups than the conventional mechanism where the lens groups are guided by the different guide mechanisms.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged schematic perspective view showing a part of a zoom lens barrel;
FIG. 12 is an enlarged perspective view of a lens supporting barrel in the zoom lens barrel;
FIG. 13 is a sectional view showing an upper part of the zoom lens barrel in a housed state;
FIG. 14 is a perspective view of the AE/AF shutter unit under the condition where the rear lens group supporting barrel is in a retracted position; and
FIG. 15 is a perspective view of the AE/AF shutter unit under the condition where the rear lens group supporting barrel is in an extended position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an encoder for detecting forward/reverse rotation of a rear lens group driving motor are described as applied to a lens-shutter type zoom lens camera.
The zoom lens camera is provided with a three-stage delivery-type zoom lens barrel 10 having three movable barrels, namely a first movable barrel 20, a second movable barrel 19 and a third movable barrel 16, which are concentrically arranged in this order from an optical axis O. In the zoom lens barrel 10, two lens groups are provided, namely a front lens group L1 having positive power and a rear lens group L2 having negative power.
When the zoom operating device 62 is operated, the zoom operating device 62 drives the whole optical unit driving motor 25 to move the front and rear lens groups L1 and L2 together as a whole along the optical axis O (optical axis direction). Simultaneous with such a movement, the rear lens group driving motor 30 may also be driven via the rear lens group driving motor controller 61 to move the rear lens group L2 relatively with respect to the first lens group L1. However, this above-described operation is not performed under the conventional concept of zooming, in which the focal length is varied sequentially while maintaining an in-focus condition. When the zoom operating device 62 is operated, the front lens group L1 and the rear lens group L2 move in the optical axis direction, without varying the distance therebetween, by driving only the whole optical unit driving motor 25.
The zoom lens barrel 10 is provided with the first movable barrel 20, the second movable barrel 19, the third movable barrel 16, and a fixed lens barrel block 12. The third movable barrel 16 engages a cylindrical portion 12p of the fixed lens barrel block 12, and moves along the optical axis O upon being rotated. A linear guide barrel 17 is provided on an inner periphery of the third movable barrel 16 which is rotationally restricted. The linear guide barrel 17 and the third movable barrel 16 move together as a whole along the optical axis O, with the third movable barrel 16 rotating relative to the linear guide barrel 17. The first movable barrel 20 moves along the optical axis O and is rotationally restricted. The second movable barrel 19 rotatably moves relative to the linear guide barrel 17 and the first movable barrel 20 along the optical axis O. The whole optical unit driving motor 25 is secured to the fixed lens barrel block 12. A shutter mounting stage 40 is secured to the first movable barrel 20. The AE motor 29 and the rear lens group driving motor 30 are mounted on the shutter mounting stage 40. The front lens group L1 and the rear lens group L2 are respectively supported by a lens supporting barrel (lens supporting annular member) 34 and a lens supporting barrel 50.
The fixed lens barrel block 12 is fixed in front of an aperture plate 14 fixed to the camera body. The aperture plate 14 is provided on a center thereof with a rectangular-shaped aperture 14a which forms the limits of each exposed frame. The fixed lens barrel block 12 is provided, on an inner periphery of the cylindrical portion 12p thereof, with a female helicoid 12a, and also a plurality of linear guide grooves 12b each extending parallel to the optical axis O, i.e., extending in the optical axis direction. At the bottom of one of the linear guide grooves 12b, namely 12b', a code plate 13a, having a predetermined code pattern, is fixed. The code plate 13a extends in the optical axis direction and extends substantially along the whole of the length of the fixed lens barrel block 12. The code plate 13a is part of a flexible printed circuit board 13 positioned outside the fixed lens barrel block 12.
A gear housing 12c is provided as shown in FIG. 7 or 10 in the fixed lens barrel block 12. The gear housing 12c is recessed outwardly from an inner periphery of the cylindrical portion 12p of the fixed lens barrel block 12 in a radial direction while extending in the optical axis direction,. In the gear housing 12c, a driving pinion 15, extending in the optical axis direction, is rotatably positioned. Both ends of an axial shaft 7 of the driving pinion 15 are rotatably supported by a supporting hollow 4, which is provided in the fixed lens barrel block 12, and a supporting hollow 31a, which is provided on a gear supporting plate 31 fixed on the fixed lens barrel block 12 by set screws (not shown), respectively. Part of the teeth of the driving pinion 15 project inwardly from the inner periphery of the cylindrical portion of the fixed lens barrel block 12, so that the driving pinion 15 meshes with an outer peripheral gear 16b of the third movable barrel 16, as shown in FIG. 7.
A plurality of linear guide grooves 16c are formed on an inner periphery of the third movable barrel 16, each of which extends parallel to the optical axis O. At an outer periphery of the rear end of the third movable barrel 16, a male helicoid 16a and the aforementioned outer peripheral gear 16b are provided as shown in FIG. 6. The male helicoid 16a engages with the female helicoid 12a of the fixed lens barrel block 12. The outer peripheral gear 16b engages with the driving pinion 15. The driving pinion 15 has an axial length sufficient to engage with the outer peripheral gear 16b throughout the entire range of movement of the third movable barrel 16 in the optical axis direction.
As shown in FIG. 10, the linear guide barrel 17 is provided with a rear end flange 17d on a rear part of an outer periphery. The rear end flange 17d has a plurality of engaging projections 17c each projecting away from the optical axis O in a radial direction. The linear guide barrel 17 is further provided with an anti-dropping flange 17e in front of the rear end flange 17d. A circumferential groove 17g is formed between the rear end flange 17d and the anti-dropping flange 17e. The anti-dropping flange 17e has a radius which is smaller than the rear end flange 17d. The anti-dropping flange 17e is provided with a plurality of cutout portions 17f. Each of the cutout portions 17f allows a corresponding engaging projection 16d to be inserted into the circumferential groove 17g, as shown in FIG. 9.
The third movable barrel 16 is provided with a plurality of engaging projections 16d on an inner periphery of the rear end thereof. Each of the engaging projections 16d projects towards the optical axis O in a radial direction. By inserting the engaging projections 16d into the circumferential groove 17g, through the corresponding cutout portions 17f, the engaging projections 16d are positioned in the circumferential groove 17g between the flanges 17d and 17e (see FIG. 9). By rotating the third movable barrel 16 relative to the linear guide barrel 17, the engaging projections 16d are engaged with the linear guide barrel 17.
An aperture plate 23 having a rectangular-shaped aperture 23a approximately the same shape as the aperture 14a is fixed on the rear end of the linear guide barrel 17. The relative rotation of the linear guide barrel 17, with respect to the fixed lens barrel block 12, is restricted by the slidable engagement of the plurality of engaging projections 17c with the corresponding linear guide grooves 12b, formed parallel to the optical axis O.
On the inner periphery of the linear guide barrel 17 a plurality of linear guide grooves 17a are formed, each extending parallel to the optical axis O. A plurality of lead slots 17b are also formed on the linear guide barrel 17 as shown in FIG. 10. The lead slots 17b are each formed oblique (inclined) to the optical axis O.
The second movable barrel 19 engages with the inner periphery of the linear guide barrel 17. A plurality of lead grooves 19c are provided on the inner periphery of the second movable barrel 19, in a direction inclined oppositely to the lead slots 17b. A plurality of follower projections 19a are provided On the outer periphery of the rear end of the second movable barrel 19. Each of the follower projections 19a has a trapezoidal cross-sectional shape projecting away from the optical axis O in a radial direction. Follower pins 18 are positioned in the follower projections 19a. Each follower pin 18 consists of a ring member 18a, and a center fixing screw 18b which supports the ring member 18a on the corresponding follower projection 19a. The follower projections 19a are in slidable engagement with the lead slots 17b of the linear guide barrel 17, and the follower pins 18 are in slidable engagement with the linear guide grooves 16c of the third movable barrel 16. With such an arrangement, when the third movable barrel 16 rotates, the second movable barrel 19 rotates while moving linearly in the optical axis direction.
As shown in FIGS. 1 and 2, the linear guide member 22 is provided with an annular member 22a, a pair of guide legs 22b and a plurality of engaging projections 28. The pair of guide legs 22b project from the annular member 22a in the optical axis direction. The plurality of engaging projections 28 each project from the annular member 22a away from the optical axis O in a radial direction. The engaging projections 28 slidably engage with the linear guide grooves 17a. The guide legs 22b are respectively inserted into linear guides 40c between the inner peripheral surface of the first movable barrel 20 and the AF/AE shutter unit 21.
The annular member 22a of the linear guide member 22 is connected to the rear of the second movable barrel 19, such that the linear guide member 22 and the second movable barrel 19 move along the optical axis O as a whole, and in addition are capable of relatively rotating with respect to each other around the optical axis O. The linear guide member 22 is further provided, on the outer periphery of the rear end thereof, with a rear end flange 22d. The linear guide member 22 is also provided with an anti-dropping flange 22c in front of the rear end flange 22d. A circumferential groove 22f is formed between the rear end flange 22d and the anti-dropping flange 22c. The anti-dropping flange 22c has a radius which is smaller than the rear end flange 22d. As shown in FIG. 1 or 2, the anti-dropping flange 22c is provided with a plurality of cutout portions 22e, each allowing a corresponding engaging projection 19b to be inserted into the circumferential groove 22f (see FIG. 9).
A plurality of engaging projections 19b, each projecting towards the optical axis O in a radial direction are provided on an inner periphery of the rear end of the second movable barrel 19. By inserting the engaging projections 19b into the circumferential groove 22f through the corresponding cutout portions 22e, the engaging projections 19b are positioned in the circumferential groove 22f between the flanges 22c and 22d. By rotating the second movable barrel 19 relative to the linear guide member 22, the engaging projections 19b are engaged with the linear guide member 22. With the above structure, when the second movable barrel 19 rotates in the forward or reverse rotational direction, the first movable barrel 20 moves linearly, forwardly or rearwardly along the optical axis O, but is restricted from rotating.
The supporting member 47, positioned in front of the shutter blade supporting ring 46, is provided with a circular aperture 47a, aligned with the circular aperture 46a of the shutter blade supporting ring 46, and with three pivotal shafts 47b (only one of which is illustrated in FIG. 10) at respective positions opposite the three supporting holes 46b. Each shutter blade 27a is provided at one end thereof with a hole 27b into which the corresponding pivotal shaft 47b is inserted, such that each shutter blade 27a is rotatable about the corresponding pivotal shaft 47b. The major part of each shutter blade 27a, that extends normal to the optical axis O from the pivoted end, is formed as a light-interceptive portion. All three light-interceptive portions of the shutter blades 27a together prevent ambient light, which enters the front lens group L1, from entering the circular apertures 46a and 47a when the shutter blades 27a are closed. Each shutter blade 27a is further provided, between the hole 27b and the light-interceptive portion thereof, with a slot 27c, through which the corresponding operating projection 49a is inserted. The supporting member 47 is fixed to the shutter blade supporting ring 46 in such a manner that, each shaft 47b, which supports the corresponding shutter blade 27a, is engaged with the corresponding supporting hole 46b of the shutter blade supporting ring 46.
As shown in FIG. 9, when the zoom lens barrel 10 is at the most retracted (withdrawn) position, i.e., the lens-housed condition. When the power switch is turned ON, the drive shaft of the whole optical unit driving motor 25 is driven to rotate in the forward rotational direction by a small amount. This rotation of the motor 25 is transmitted to the driving pinion 15 through a gear train 26, which is supported by a supporting member 32 integrally formed with the fixed lens barrel block 12, to rotate the third movable barrel 16 in one predetermined rotational direction to advance forwardly along the optical axis O. Therefore, the second movable barrel 19 and the first movable barrel 20 are each advanced by a small amount in the optical axis direction, along with the third movable barrel 16. Consequently, the camera is placed in a state capable of photographing, with the zoom lens positioned at the widest position, i.e., the wide end. In this state, the focal length may be detected in accordance with the amount of relative movement between the sliding movement of the code plate 13a and the contacting terminal 9 as the linear guide barrel 17 moves with respect to the fixed lens barrel block 12.
In the photographable state as above described, when the aforementioned zoom operating lever is manually moved towards a "tele" side, or the "tele" zoom button is manually depressed to be turned ON, the whole optical unit driving motor 25 is driven to rotate in the forward rotational direction through the whole optical unit driving motor controller 60. The rotation of the optical unit driving motor 25 causes the third movable barrel 16 to rotate in the rotational direction to advance along the optical axis O via the driving pinion 15 and the outer peripheral gear 16b. Therefore, the third movable barrel 16 is advanced from the fixed lens barrel block 12, according to the relationship between the female helicoid 12a and the male helicoid 16a. At the same time, the linear guide barrel 17 moves forwardly along the optical axis O together with the third movable barrel 16, without relatively rotating with respect to the fixed lens barrel block 12, and in accordance with the relationship between the engaging projections 17c and the linear guide grooves 12b. At this time, the simultaneous engagement of the follower pins 18 with the respective lead slots 17b and the linear guide grooves 16c causes the second movable barrel 19 to move forwardly relative to the third movable barrel 16 in the optical axis direction. In addition, the second movable barrel 10 rotates together with the third movable barrel 16 in the same rotational direction relative to the fixed lens barrel block 12. The first movable barrel 20 moves forwardly from the second movable barrel 19 along the optical axis O together with the AF/AE shutter unit 21, without relatively rotating with respect to the fixed lens barrel block 12 due to the above-noted structures in which the first movable barrel 20 is guided linearly by the linear guide member 22 and in which the follower pins 24 are guided by the lead grooves 19c. During such movements, according to the fact that the moving position of the linear guide barrel 17 with respect to the fixed lens barrel block 12 is detected through the relative slide between the code plate 13a and the contacting terminal 9, the focal length is detected.
In the following, the connection among the front and rear lens groups L1 and L2, the first movable barrel 20 and the AF/AE shutter unit 21, will be described in detail with reference to FIGS. 9 and 15.
In the zoom lens barrel 10, in order to accurately align the front lens group L1 with the first movable barrel 20, the front lens group L1 is supported by the front lens supporting barrel 34, the front lens supporting barrel 34 is fixed to the first movable barrel 20 in a bayonet-type mechanism at the front side, and the rear end of the front lens supporting barrel 34 is fitted to the AF/AE shutter unit 21 that is fixed to the first movable barrel 20. Thus, the front lens supporting barrel 34 is directly fixed to the first movable barrel 20 at the front side and is fixed to the first movable barrel 20 indirectly through the AF/AE shutter unit 21 at the rear side. Therefore, the front lens group L1 is accurately positioned with respect to the first movable barrel 20.
Further, to make the zoom lens water-resistant, an elastic member, such as an O-ring 70, is interposed between the front lens supporting barrel 34 and the first movable barrel 20 to prevent water from entering the first movable barrel 20.
The rear lens group L2 is supported by the rear lens supporting barrel 50 which is supported by the AF/AE shutter unit 21, such that the rear lens supporting barrel 50 is driven by the rear lens group driving motor 30 along the optical axis with respect to the AE/AF shutter unit 21. Thus, since the front lens supporting barrel 34 and the rear lens supporting barrel 50 are both supported by the first movable barrel 20 and driven as a whole, the optical axes of the front and rear lens groups L1 and L2 are maintained in coaxial alignment with greater accuracy as compared with the conventional zoom lens where the front and rear lens groups are supported by their respective, independently-driven barrels.
In particular, the arrangement of the front lens group L1, the rear lens group L2, the lens supporting barrel 34, the shutter mounting state 40, and the first movable barrel 20 is as described in the following. References herein to the front or rear of a particular part refer to what is normally considered the front or rear of a camera or camera lens.
With reference to FIG. 12, the front lens supporting barrel 34 includes a middle part 34c having a cylindrical shape with a predetermined diameter, a front annular fitting part 34e at the front of the middle part 34c which has a slightly larger diameter than the middle part 34c, and a rear annular fitting part 34a at the rear of the middle part 34c which has a slightly smaller diameter than the middle part 34c. The front of the front annular fitting part 34e is formed with an outward flange 34j having a larger diameter than the front annular fitting part 34e and a groove 34g which is formed on an outer surface of the front annular fitting part 34e along a parameter thereof. The O-ring 70 is provided to fit into the groove 34g.
Referring to FIG. 9, an inward flange 34b is formed at the inner rear end of the front lens supporting barrel 34. The inward flange 34b comes in contact with the rear face of the front lens group L1 when the front lens group L1 is inserted from the front of the front lens supporting barrel 34. The front lens supporting barrel 34 also includes a female screw thread 34i at the front inner peripheral portion. The front lens group L1 is fixed to the front lens supporting barrel 34 by a lens presser ring 72 that includes a male screw thread 72a that is screwed onto the female screw thread 34i of the front lens supporting barrel 34. The lens presser ring 72 also includes an annular contacting face 72b, which substantially comes into facial contact with the peripheral edge part of the front face of the front lens group L1. A waterproof coating is applied to the exterior of the annular contacting face 72b so that the joint between the front lens supporting barrel 34 and the front lens group L1 is water-resistant.
As further shown in FIG. 9, the first movable barrel 20 is provided, on the inner peripheral side, near the front thereof, with an integrally-formed inward flange 20b. The inward flange 20b has a predetermined inner diameter that defines a central hole 20e (see also FIG. 3). The diameter of the central hole 20e is slightly larger than the diameter of the front annular fitting part 34e of the front lens supporting barrel 34 such that the front annular fitting part 34e is fitted within the central hole 20e. Thus, the perimeter of the central hole 20e (i.e., the edge of the inward flange 20b restricts the movement of the front part of the front lens supporting barrel 34 in the radial direction, and sets the position, mainly in the radial direction, of the front lens group L1 with respect to the first movable barrel 20.
In order to securely connect the first lens barrel 20 and the front lens supporting barrel 34, a locking mechanism is provided. For example, three engaging claws 20c are formed at equiangular intervals on the inner peripheral edge of the inward flange 20b. During assembly, the engaging claws 20c are inserted into the groove 34g on the front lens supporting barrel 34. The engaging claws 20c enter the groove 34g via corresponding notches 34f (see FIG. 12) on the front lens supporting barrel 34. Then, by rotating the front lens supporting barrel 34 relative to the first movable barrel 20, the engaging claws 20c engage with corresponding hook parts 34h that are provided on the front annular fitting part 34e of the front lens supporting barrel 34 adjacent to the notches 34f.
Also at the front inner peripheral edge of the inward flange 20b, an annular notch 20d is formed such that when assembled, the outward flange 34j on the front lens supporting barrel 34 and the annular notch 20d sandwich and compress the O-ring 70. Thus, the O-ring 70 is positioned between the inward flange 20b of the first movable barrel 20 and the outward flange 34j of the front lens supporting barrel 34 to make the joint between the first movable barrel 20 and the front lens supporting barrel 34 water-resistant.
As described above, the annular member 40f of the shutter mounting stage 40 includes a circular opening 40d. The rear annular fitting part 34a of the front lens supporting barrel 34 has a slightly smaller diameter than the circular opening 40d. The front lens supporting barrel 34 is fitted to the circular opening 40d such that movement of the rear part of the front lens supporting barrel 34 is restricted in the radial direction by the circular opening 40d such that the position, mainly in the radial direction, of the front lens group L1 is set with regard to the shutter mounting state 40. Thus, the position of the front lens group L1 is set with respect to the rear lens group L2, which is supported by both the first movable barrel 20 and the shutter mounting stage 40.
The rear lens supporting barrel 50 is supported by the guide shafts 51 and 52 as shown in FIG. 1 and is driven by the screw shaft 43.
The screw shaft 43 includes a fitting portion 43a and a screw portion 43b. The fitting portion 43a fits into a fixing hole 50a formed on the rear lens supporting barrel 50 and the screw shaft 43 is tightly fixed to the rear lens supporting barrel 50. The screw portion 43b is engaged with the female thread hole of the driving gear 42a as shown in FIGS. 5 and 13. The driving gear 42a is held by a gear supporting portion 53a formed on the holding member 53 so that the driving gear 42a is rotatable about the screw portion 43b. The screw shaft 43 moves along the optical axis to drive the rear lens supporting barrel 50 as the driving gear 42a is rotated by the rear lens group driving motor 30 via the gear train 42.
FIG. 14 shows the AE/AF shutter unit 21 under the condition where the rear lens group supporting barrel 50 is in a retracted position, and FIG. 15 shows the unit 21 under the condition where the rear lens group supporting barrel 50 is in an extended position.
The assembly of the front lens group L1 and the lens supporting mechanism can, for example, be performed in the following manner. First, the AF/AE shutter unit 21 is assembled, including the rear lens supporting barrel 50 holding the rear lens group L2, the shutter mounting stage 40, the circular driving member 49, the supporting member 47, the shutter 27, and the shutter blade presser ring 46. The rear lens group L2 is supported by the shutter mounting stage 40 such that it is in a predetermined positional relationship with the circular opening 40d of the shutter mounting state 40.
The AF/AE shutter unit 21 is then inserted into the rear inner side of the first movable barrel 20, and the follower pins 24 are inserted through the holes 20a and fixed to the fixing holes 40a provided on the shutter mounting stage 40. Thus, the shutter mounting stage 40 is fixed to the first movable barrel 20 such that the rear lens group L2 is in a predetermined positional relationship with respect to the movable lens barrel 20. The follower pins 24 may be fixed by, for example, adhesion, a screw thread, or the like.
Thereafter, the front lens group L1 is fitted to the inner side of the front lens supporting barrel 34, abutting against the inward flange 34b, and is fixed by screwing the lens presser ring 72 onto the female screw thread 34i. Also, the O-ring 70 is fitted into the groove 34g of the front lens supporting barrel 34.
The front lens supporting barrel 34 is then inserted into the first movable barrel 20 from the front (i.e., the rear side of the front lens supporting barrel 34 first) through the central hole 20e. The rear part of the front lens supporting barrel 34 passes through the AF/AE shutter unit 21 (i.e., at the inward side of the AE motor 29 and other parts) until the rear annular fitting part 34a fits into the circular opening 40d. At the same time that the rear annular fitting part 34a (at the rear of the front lens supporting barrel 34) enters the circular opening 40d, the engaging claws 20c enter the notches 34f on the front annular fitting part 34e (at the front of the front lens supporting barrel 34) and the O-ring 70 is sandwiched between the annular notch 20d and the outward flange 34j.
At this point, the front end (i.e., the front annular fitting part 34e) of the front lens supporting barrel 34 is pushed against the inward flange 20b (to compress the O-ring 70 slightly) and is rotated slightly in the clockwise direction (as viewed in FIG. 12). Thus, when the front lens supporting barrel 34 is released, the O-ring 70 expands back to its original shape, and the three engaging claws 20c are respectively engaged with the three hook parts 34h to firmly secure the front lens supporting barrel 34 to the first movable barrel 20.
In this manner, because the front lens supporting barrel 34 is accurately positioned in a predetermined relationship with respect to both the first movable barrel 20 and the shutter mounting stage 40, and because the rear lens group L2 is positioned accurately in a predetermined relationship with the shutter mounting state 40, the position, particularly in the radial direction, of the front lens group L1 with respect to the rear lens group L2 is set accurately and the optical axes of the front lens group L1 and the rear lens group L2 are aligned with each other. Thus, the lens supporting mechanism for a lens shutter camera of the present embodiment provides that the optical axes of the front lens group L1 and the rear lens group L2 can be aligned with each other easily and accurately.
Although the structure and operation of a lens supporting mechanism for a lens shutter camera is described herein with respect to the preferred embodiments, many modifications and changes can be made without departing from the spirit and scope of the invention. It can be applied to a lens shutter camera having a movable barrel on which a lens barrel and a shutter unit is provided, even if a photographing lens does not comprise a zoom lens.
The present disclosure relates to subject matter contained in Japanese Patent Application Nos. HEI 08-013387, filed on Jan. 29, 1996, and HEI 08-012317 filed on Jan. 26, 1996, which are expressly incorporated herein by reference in their entirety.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4309077 *Dec 10, 1979Jan 5, 1982Asahi Kogaku Kogyo Kabushiki KaishaLens barrel capable of automatic and manual focalizing operationsUS4865432 *Feb 24, 1987Sep 12, 1989Canon Kabushiki KaishaLens mountingUS4910544 *Feb 14, 1989Mar 20, 1990Asahi Kogaku Kogyo K.K.Focus adjusting apparatus in zoom lens cameraUS5157429 *Feb 14, 1990Oct 20, 1992Asahi Kogaku Kogyo Kabushiki KaishaLens shutter camera including zoom lensUS5231449 *Jan 31, 1992Jul 27, 1993Asahi Kogaku Kogyo Kabushiki KaishaZoom lens barrel and camera incorporating such barrelUS5245476 *Mar 12, 1990Sep 14, 1993Asahi Kogaku Kogyo Kabushiki KaishaZoom lens barrelUS5305145 *Jul 2, 1992Apr 19, 1994Asahi Kogaku Kogyo Kabushiki KaishaWaterproof lensUS5453807 *Nov 2, 1994Sep 26, 1995Canon Kabushiki KaishaLens with moveable diaphragmUS5488513 *Aug 16, 1993Jan 30, 1996Asahi Kogaku Kogyo Kabushiki KaishaZoom lens barrelUS5510936 *Oct 24, 1994Apr 23, 1996Asahi Kogaku Kogyo Kabushiki KaishaApparatus for adjusting lens positionUS5774748 *Jul 5, 1996Jun 30, 1998Asahi Kogaku Kogyo Kabushiki KaishaZoom lens barrel and camera having such a barretGB854056A * Title not availableGB1238668A * Title not available* Cited by examinerNon-Patent CitationsReference1 *A United Kingdom Search Report, dated Apr. 16, 1997, with UK Application No. 9701434.4.* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6334029Dec 10, 1998Dec 25, 2001Asahi Kogaku Kogyo Kabushiki KaishaCamera having a motor-driven zoom lensUS6661970Oct 30, 2002Dec 9, 2003Pentax CorporationLens barrelUS7046457 *Oct 13, 2004May 16, 2006Canon Kabushiki KaishaOptical apparatus* Cited by examinerClassifications U.S. Classification396/462, 359/819International ClassificationG03B7/10, G03B17/02, G03B7/16, G02B7/08, G03B9/24, G02B7/10, H05K3/28, G03B17/14, G03B17/04, G03B7/097, G03B11/04, H05B41/32Cooperative ClassificationH05B41/325, G02B7/102, G03B11/04, G03B7/10, G03B17/14, G03B7/16, G03B7/097, H05K3/281, G03B9/24, G02B7/08, G03B17/02, G03B17/04European ClassificationG03B17/02, G03B7/16, G03B17/14, G03B7/097, G02B7/10A, G03B17/04, H05B41/32B, G03B9/24, G03B7/10, G03B11/04, G02B7/08Legal EventsDateCodeEventDescriptionJun 5, 2007FPExpired due to failure to pay maintenance feeEffective date: 20070406Apr 6, 2007LAPSLapse for failure to pay maintenance feesOct 25, 2006REMIMaintenance fee reminder mailedSep 19, 2002FPAYFee paymentYear of fee payment: 4Apr 1, 1997ASAssignmentOwner name: ASAHI KOGAKU KOGYO KABUSHIKI KAISHA, JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NOMURA, HIROSHI;AZEGAMI, KAZUYOSHI;SASAKI, TAKAMITSU;REEL/FRAME:008425/0627Effective date: 19970213RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google