DE102005038279A1 - Cam mechanism for a zoom lens - Google Patents

Abstract

Described is a cam mechanism for a zoom lens, which includes a front optical element (LG2) and a rear optical element (LG3) arranged in the direction of the optical axis (Z1) behind the front optical element (LG2). The front optical element (LG2) and the rear optical element (LG3) are straight guided along the optical axis (Z1). The cam mechanism includes a cam ring (31) having a first cam groove (CG2) for moving the front optical element (LG2) along the optical axis (Z1) and a second cam groove (CG3) for moving the rear optical element (LG3) along the optical path Axis, wherein both the first cam groove (CG2) and the second cam groove (CG3) on the inner peripheral surface or the outer peripheral surface of the cam ring (31) are arranged. The first cam groove (CG2) is arranged in the direction of the optical axis (Z1) behind the second cam groove (CG3).

Description

The The invention relates to a zoom lens, in particular one in the Vario lens included cam mechanism for moving optical Elements, e.g. Lens groups.

In usual Varifocal lenses are often one single cam ring included on its inner peripheral surface or its outer peripheral surface two Phrases cam or cam grooves has, through the two straightened optical elements (front optical Element and rear optical element), e.g. two lens groups, to be moved. The miniaturization of such a cam ring At times, it may be necessary for the two sets of keys to engage each other to cut. Consequently, must in a zoom lens with such a cam ring measures be taken by which prevents the two associated Sets of Cam followers (cam followers) which are assigned to them Cam grooves grip, at the intersections of the two groove sets solve the curve grooves. An example for such a mechanism that prevents the curve engaging members from the associated Loosen cam grooves, is a well-known from the prior art mechanism, the sup sponding Teilkurvennuten and related supportive Includes cam followers that prevent the two Engaging member sets from the two groove sets to solve. Here are the supporting ones Part curve grooves independent from the two groove sets (Main cam grooves) in which the associated cam followers are guided, intended. The supporting ones Curve-engaging members engage in their assigned Teilkurvennuten, when the cam followers at the two above-mentioned intersections pass the Kurvennuten. This type of mechanism is e.g. in Japanese Patent Publication H10-282394 described.

These Activities, prevent the respective cam follower from the groove assigned to it releases, However, make the cam mechanism complicated and large. Become by contrast, the two formed on the cam ring groove sets in the direction the optical axis separated from each other so that they each other do not cut, so take the length the cam ring to what the miniaturization of the zoom lens difficult.

The Invention provides a cam mechanism for a lens barrel, which contains a cam ring, on its one peripheral surface, namely the inner peripheral surface or the outer peripheral surface, at least a front cam groove and at least one rear cam groove formed are having different curved paths. By the invention is a miniaturization of the cam ring and at the same time a simplification reached the cam mechanism.

The The invention achieves this by the subject matters of the independent claims. Advantageous developments are in the subclaims specified.

In a cam mechanism of a lens barrel having a cam ring contains in which on the same peripheral surface a front cam groove and a rear cam groove formed with different cam tracks the invention achieves miniaturization of the cam ring and at the same time a simplification of the cam mechanism.

The The invention will be explained in more detail below with reference to the figures. In this demonstrate:

1 a longitudinal section through a zoom lens according to embodiment in the wide-angle limit setting,

2 a longitudinal section through the in 1 shown zoom lens in the telegraph setting,

3 a longitudinal section through the in 1 shown zoom lens in the fully retracted state,

4 an exploded perspective view of various elements of the in the 1 to 3 shown zoom lens,

5 an exploded perspective view of a CCD holder, a stationary tube and other elements of the in the 1 to 3 shown zoom lens,

6 an exploded perspective view of a first Geradführungsrings, a Mehrfachgewinderings and a third outer tube of the in the 1 to 3 shown zoom lens,

7 an exploded perspective view of a cam ring, a second Geradführungsrings, a Verstellfassung for the second lens group and a Verstellfassung for the third lens group accordingly 4 .

8th an exploded perspective view of the cam ring, the second linear guide ring, the second lens group Verstellfassung and the Verstellfassung for the third lens group in the 4 and 7 shown Vario lens, wherein the arrangement of the two Verstellfassungen is shown relative to each other in the wide-angle limit setting of the zoom lens,

9 an exploded perspective view of the cam ring, the second linear guide ring, the second lens group Verstellfassung and the Verstellfassung for the third lens group in the 4 and 7 shown Varioobjektivs, wherein the arrangement of the two Verstellfassungen each other in the Telegrezeinstellung the zoom lens is shown

10 an exploded perspective view of the cam ring, the second linear guide ring, the adjustment for the second lens group and the Verstellfassung for the third lens group from a different direction than in 7 .

11 an exploded perspective view of a holding structure that holds the second lens group and the third lens group of the zoom lens,

12 an exploded perspective view of a support structure holding the first lens group,

13 a developed representation of in 6 shown first straight guide ring,

14 a developed view of the Mehrfachgewinderings and the third outer tube, the 6 are shown

15 a developed view of a set of roller engaging members which are attached to the cam ring, the first linear guide ring, the multi-threaded ring and the third outer tube, wherein the arrangement of these components to each other in the retracted state of the zoom lens is shown,

16 a representation similar to the one after 15 showing the arrangement of the roller engaging members, the first linear guide ring, the multiple threaded ring and the third outer tube to each other in a state in which the zoom lens is extended slightly from its retracted state,

17 a representation similar to the one after 15 omitting the first linear guide ring,

18 a representation similar to the one after 16 omitting the first linear guide ring,

19 9 is a developed view of parts of the multi-threaded ring and the third outer tube, showing the relative disposition between an engagement recess of the multi-threaded ring and engagement projections of the third outer tube;

20 a representation similar to the one after 19 showing a state in which the engagement recess of the multi-threaded ring and the engagement projections of the third outer tube are engaged with each other,

21 an unwound representation of the cam ring,

22 an unwound representation of the proposed for the second lens group Verstellfassung,

23 an unwound representation of the Verstellfassung provided for the third lens group,

24 an unwound representation of the second Geradführungsrings,

25 a developed view of the Verstellfassung provided for the second lens group, provided for the third lens group Verstellfassung, the cam ring and the second Geradführungsrings showing the arrangement of these components to each other in the retracted state of the zoom lens,

26 a developed view of the Verstellfassung provided for the second lens group, provided for the third lens group Verstellfassung, the cam ring, the second Geradführungsrings showing the arrangement of these components to each other in the wide-angle limit setting of the zoom lens,

27 a developed view of the Verstellfassung provided for the second lens group, provided for the third lens group Verstellfassung, the cam ring and the second Geradführungsrings showing the arrangement of these components to each other in the Telegrezeinstellung the zoom lens,

28 a developed view of the Verstellfassung provided for the second lens group, provided for the third lens group Verstellfassung, the cam ring and the second Geradführungsrings showing a state in which the two Verstellfassungen are installed during assembly in the cam ring,

29 a perspective view of a portion of the CCD holder in the vicinity of the Positioning provided curve bar,

30 a perspective view of the cam ring, provided for the third lens group Verstellfassung and a third, radially retractable lens frame in the receptive state of the zoom lens from obliquely behind,

31 a perspective view of the cam ring, the third lens group determined Verstellfassung and the third lens frame in the retracted state of the zoom lens from obliquely behind,

32 a rear view of the cam ring, provided for the third lens group Verstellfassung and the third lens frame in the in 30 shown state in which the third lens frame is held in its receiving position, and

33 a rear view of the cam ring, provided for the third lens group Verstellfassung and the third lens frame in the in 31 shown state in which the third lens frame is held in its radially retracted position.

The 1 to 3 show an embodiment of a zoom or zoom lens according to the invention in different states. 1 shows the state of the zoom lens 10 in the wide angle limit setting. 2 shows the state of the zoom lens 10 in the telegraph setting. 3 shows the state of the zoom lens in its fully retracted position. The zoom lens 10 is included in a digital camera whose camera body is not shown in the figures. As in the 1 and 2 shown, consists of the recording optics of the zoom lens 10 in the receptive state, a first lens group LG1, a second lens group (front optical element) LG2, a shutter S, a third lens group (rear optical element) LG3, a fourth lens group LG4, a low-pass filter (optical filter) 11 and a CCD image sensor (solid state image pickup device) 12 , The first lens group LG1, the second lens group LG2 and the third lens group LG3 are moved in a predetermined manner along a photographic optical axis Z1 for zooming, while the fourth lens group LG4 is moved for focusing along the photographic optical axis Z1. In the following description, unless otherwise specified, the term "in the direction of the optical axis" or "along the optical axis" means a direction parallel to the photographic optical axis Z1.

4 is an exploded view of elements of the zoom lens 10 , In the 5 to 12 these elements are shown enlarged. The zoom lens 10 is installed in a camera body, not shown, and with a stationary tube 13 provided, which is fixed to the camera body. A CCD holder (fixed element) 14 is from the back of the rear part of the stationary tube 13 attached. The CCD image sensor 12 is via a CCD base plate 15 in the middle of the CCD holder 14 held. The low pass filter 11 is on the CCD holder 14 so kept it in front of the CCD image sensor 12 is arranged. An annular sealing element 16 is between the low-pass filter 11 and the CCD image sensor 12 mounted to seal the gap between these elements.

In the stationary tube 13 of the zoom lens 10 is an AF lens mount (fourth lens mount for holding the fourth lens group LG4) 17 provided, which is guided straight in the direction of the optical axis Z1 and does not rotate about the optical axis Z1. The zoom lens 10 has a pair of AF guide axes 18A and 18B which are arranged parallel to the optical axis Z1 and the AF lens frame 17 along the optical axis Z1 rotate freely, ie without the AF lens mount 17 rotates about the optical axis Z1. Every leadership axis 18A . 18B is with its front end to the stationary tube 13 and with its rear end on the CCD holder 14 attached. The AF lens mount 17 has on its radially opposite sides two guide holes (guide grooves) into which the AF guide axes 18A and 18B are inserted, so the AF lens mount 17 on the two AF guide axes 18A and 18B is displaceable. The parts of the stationary tube 13 and the CCD holder 14 containing the two AF guide axes 18A and 18B hold over the outer diameter of the stationary tube 13 out radially outward so that the AF guide axes 18A and 18B radially outside the stationary tube 13 are arranged.

The zoom lens 10 contains an AF motor 19 attached to the stationary tube 13 is attached. The AF lens mount 17 can by the from the AF motor 19 applied driving force in the direction of the optical axis to be moved forward and backward. A rotating drive shaft of the AF motor 19 is threaded to form a rotating feed screw. This drive shaft is screwed into a female threaded hole on an AF nut 20 is formed (see. 6 ). The AF lens mount 17 is thus engaged with the AF nut 20 in that it is displaceable thereon in the direction of the optical axis Z1. The AF lens mount 17 is by a tension coil spring (biasing element) 21 biased forward in the direction of the optical axis Z1. The limit for the Vor downward movement of the AF lens frame 17 is by the investment of in the direction of the optical axis Z1 opposing surfaces of the AF nut 20 and the AF lens mount 17 established. By getting the AF mother 20 by turning the drive shaft of the AF motor 19 is moved backward in the direction of the optical axis Z1, the AF lens frame 17 through the AF mother 20 pressed backwards, so that they are opposite to that of the tension coil spring 21 applied biasing force moved backwards. In this construction, therefore, by forward and backward rotation of the drive shaft of the AF motor 19 the AF lens mount 17 in the direction of the optical axis Z1 moves forward and backward.

The zoom lens 10 has a zoom or vario gear 22 attached to the stationary tube 13 is stored so that it is on a gear axle 22a , which extends parallel to the optical axis Z1, is rotatable. The gear axle 22a is with its front end to the stationary tube 13 and with its rear end on the CCD holder 14 attached. The Variozahnrad 22 is arranged so that its teeth from the inner peripheral surface of the stationary tube 13 partially radially inward. The Variozahnrad 22 Can be a Variomotor 23 who in 4 schematically shown as a rectangle, are rotated forward and backward.

As in 5 shown has the stationary tube 13 on its inner peripheral surface an internal multiple thread 13a , one of three straight guide grooves 13b existing groove set, one of three oblique grooves 13c existing groove set and one of three Drehführungsnuten 13d existing groove set. The threads of the internal multiple thread 13a extend in a direction that is both with respect to the optical axis Z1 and the circumferential direction of the stationary tube 13 is inclined. The three straight guide grooves 13b extend parallel to the optical axis Z1. The three slanted grooves 13c extend parallel to the internal multiple thread 13a , The three rotary guide grooves 13d are near the front end of the inner peripheral surface of the stationary tube 13 designed so that they are along the circumference of the stationary tube 13 extend and the front ends of the three oblique grooves 13c connect with each other. In a specific front area of the inner peripheral surface of the stationary tube 13 , which is immediately behind the three Drehführungsnuten 13d is the internal multiple thread 13a not trained. Each of the three groove sets mentioned above (ie the three straight guide grooves 13b , the three diagonal grooves 13c and the three rotary guide grooves 13d ) consists of three grooves on the inner peripheral surface of the stationary tube 13 offset in the circumferential direction are arranged to each other. However, in 5 not to see all three grooves of the groove set.

Within the stationary tube 13 of the zoom lens 10 there is a multiple threaded ring (rotating drive element) 25 , The multiple threaded ring 25 has on its outer peripheral surface an external multiple thread 25a and a set of three rotary guide tabs 25b , The external multiple thread 25a is in engagement with the internal multiple thread 13a , and the three rotary guide projections 25b are in engagement with the three oblique grooves 13c or the three rotary guide grooves 13d , The multiple thread 25a of the multiple threaded ring 25 is a ring toothing 25c superimposed, which engages with the Variozahnrad 22 located. Will the rotational movement of the Variozahnrads 22 on the ring toothing 25c transmitted, so moves the Mehrfachgewindering 25 in the direction of the optical axis Z1 forward or backward and thereby rotates within a predetermined range in which the external multiple threads 25a in engagement with the internal multiple thread 13a remains to the photographic optical axis Z1. Will the Mehrfachgewindering 25 with respect to the stationary tube 13 Moving forward beyond a predetermined point, the external male thread is released 25a from the internal multiple thread 13a , and by the interlocking of the three rotary guide projections 25b and the three rotary guide grooves 13d rotates the multiple threaded ring 25 around the optical axis Z1, without being in the direction of the optical axis Z1 relative to the stationary tube 13 to move. Is the internal multiple thread 13a in engagement with the external multiple thread 25a so are the three rotary guide tabs 25b in the three oblique grooves assigned to them 13c arranged. Accordingly, disturb the three Drehführungsvorsprünge 25b and the internal multiple thread 13a not each other.

Like from the 1 and 2 is apparent, is the zoom lens 10 a telescopic, ie telescoping lens having three telescoping outer tubes, namely a first outer tube (socket for optical element) 37 , a second outer tube 34 and a third outer tube (rotating drive element) 26 which are concentrically arranged around the photographic optical axis Z1. The multiple threaded ring 25 moves together with the third outer tube 26 in the direction of the optical axis Z1 and thereby rotates about the optical axis Z1. On the inner circumferential surface of the multiple threaded ring 25 At three different circumferential positions are three rotation transmission recesses (engaging recesses) 25d formed, whose front ends to the front end of the Mehrfachgewinderings 25 are open. The third outer tube 26 has three pairs of rotation-transmitting protrusions (engaging protrusions) in three corresponding circumferential positions 26a coming from the rear end of the third outer tube 26 protrude to the rear and from the front into the three rotation transmission recesses 25d can grab (comp. 14 ). The three pairs of rotary transmission tabs 26a and the three rotation transmission recesses 25d are movable relative to each other in the direction of the optical axis Z1, but are not rotatable relative to each other about the optical axis Z1. The multiple threaded ring 25 and the third outer tube 26 namely, turn as a unit. The multiple threaded ring 25 has on the front surfaces of the three rotary guide projections 25b at three different circumferential positions a set of three engagement recesses 25e attached to the inner peripheral surface of the multiple threaded ring 25 are formed open to the front end. The third outer tube 26 has in three corresponding circumferential positions a set of three engagement protrusions 26b coming from the rear end of the third outer tube 26 protrude to the rear and at the same time radially outward, so that they from the front with the three associated engagement recesses 25e can be brought into engagement. The three engagement projections 26b that with the three engaging depressions 25e be engaged, at the same time engage in the three Drehführungsnuten 13d when the three rotary guide projections 25b in engagement with the three Drehführungsnuten 13d to be brought.

The third outer tube 26 and the multiple threaded ring 25 are biased in opposite directions away from each other by compression coil springs, not shown, along the optical axis Z1. These compression coil springs are compressed between the third outer tube 26 and the multiple threaded ring 25 appropriate. The three engagement projections 26b the third outer tube 26 be in the associated Drehführungsnuten by the spring forces exerted by the compression coil springs 13d pressed against the front guide surfaces. At the same time, the three rotary guide projections 25b by the spring forces exerted by the compression coil springs in the rotation guide grooves 13d pressed against the rear guide surfaces.

As in 14 shown has the third outer tube 26 on its inner peripheral surface a set of three Drehübertragungsnuten 26c which extend parallel to the photographic optical axis Z1. The front end of each rotation transmission groove 26c is at the front end of the third outer tube 26 closed while the rear end of each Drehübertragungsnut 26c to the rear end of the third outer tube 26 is open. The circumferential positions of the three rotation transmission grooves 26c correspond to those of the three pairs of rotation transmission projections 26a , As in the 13 . 18 and 19 As shown, each pair of rotation-transmitting protrusions 26a from a long lead 26a1 and a short lead 26a2 , which protrudes to the rear by a shorter Kraglänge in the direction of the optical axis Z1 than the long projection 26a1 , In this case, there is the rear end opening of the associated Drehübertragungsnut 26c between the long projection 26a1 and the short lead 26a2 so that the circumferential direction of the third outer tube 26 opposite surfaces of the projections 26a1 and 26a2 a part (namely, the rear end opening) of the associated rotation transmission groove 26c form.

In contrast, the Mehrfachgewindering 25 on its inner peripheral surface a set of three idler grooves 25f which allow relative rotation and with the three rotation transmission recesses 25d keep in touch. The three idling grooves 25f extend circumferentially on a lying around the photographic optical axis Z1 circle, wherein the in 14 left end of the respective Leerlaufnut 25f in conjunction with the associated rotation transmission recess 25d communicates while the in 13 right end of the respective Leerlaufnut 25f forms a closed end. Are the multiple threaded ring 25 and the third outer tube 26 coupled with each other, so is each Leerlaufnut 25f with the rear end opening of the associated Drehübertragungsnut 26c (right side surface of the associated long projection 26a1 in 20 ) in conjunction, leaving the idle groove 25f and the rotation transmission groove 26c together form an L-shaped groove, as in 20 is shown.

The zoom lens 10 has inside the third outer tube 26 and the multiple threaded ring 25 a first straight guide ring 30 , The multiple threaded ring 25 has on its inner peripheral surface an annular groove 25g which extends circumferentially about the photographic optical axis Z1. The third outer tube 26 has on its inner peripheral surface near its rear end a rear annular groove 26d and near its front end a front annular groove 26e each extending circumferentially about the photographic optical axis Z1 (see FIG. 6 ). As in the 6 and 13 shown has the first linear guide ring 30 on its outer peripheral surface a plurality of first rotation guide projections 30a , several second rotary guide tabs 30b and a plurality of third rotation guide projections 30c in this order from the rear end of the first linear guide ring 30 are arranged in the direction of the optical axis Z1. The first rotary guide projections 30a grab into the ring groove 25g , the second rotation guide protrusions 30b in the rear ring groove 26d and the third rotation guide protrusions 30c in the front ring groove 26e , Due to this interlocking, the multiple threaded ring becomes 25 and the third outer tube 26 so from the first linear guide ring 30 held that they are relative to the first linear guide ring 30 rotatable but at a movement along the optical axis Z1 relative to the first linear guide ring 30 are hindered. The multiple threaded ring 25 and the third outer tube 26 are through the first linear guide ring 30 prevented from being completely detached from each other in the direction of the optical axis Z1. The first straight guide ring 30 has in the vicinity of its rear end in different circumferential positions, ie offset in the circumferential direction to each other, a set of three Geradführungsvorsprüngen 30d that protrude radially outward. The first straight guide ring 30 is due to the fact that the three Geradführungsvorsprünge 30d and the three straight guide grooves 30b of the stationary tube 13 mesh, rotationally free guided along the optical axis Z1.

The first straight guide ring 30 has a set of three continuous slots 30e that the first linear guide ring 30 penetrate radially. As in 13 As shown, each slot includes 30e a peripheral portion 30e-1 extending in the circumferential direction of the first linear guide ring 30 extends, a first lead or pitch section 30e-2 slanting from one end (right end in 13 ) of the peripheral portion 30e-1 extends from, and a second guide or gradient section 30e-3 slanting from one end (right end in 13 ) of the first slope section 30e-2 extends out. The angle of inclination of the first slope section 30e-2 relative to the circumferential direction of the first linear guide ring 30 is greater than that of the second pitch section 30e-3 , The zoom lens 10 has a cam ring 31 whose front part is in the first outer tube 37 sitting. A set of three role-engaging members 32 attached to the outer peripheral surface of the cam ring 31 are arranged in different circumferential positions, is in engagement with the of the three slots 30e existing slot set. The three roller engagement members also engage through the three slots 30e through in the three Drehübertragungsnuten 26c (or the three idle grooves 25f ).

The following is the extension of the moving elements of the zoom lens 10 from the stationary tube 13 to the cam ring 31 described. By the Variomotor 23 the Variozahnrad 22 turns in the tube extension direction, the Mehrfachgewindering 25 moved forward and by the intermeshing of the internal multiple thread 13a and the external multiple thread 25a shot at the same time. By turning the multiple threaded ring 25 becomes the third outer tube 26 together with the multiple threaded ring 25 moves forward and rotates together with the multiple threaded ring 25 , Furthermore, thereby the first linear guide ring 30 together with the multiple threaded ring 25 and the third outer tube 26 moved forward, since both the Mehrfachgewindering 25 as well as the third outer tube 26 with the first straight guide ring 30 are coupled. By the first rotary guide projections 30a in the ring groove 25g , the second rotation guide protrusions 30b in the rear ring groove 26d and the third rotation guide protrusions 30c in the front ring groove 26e So, the third outer tube can take hold 26 and the first straight guide tube 30 as well as the multiple threaded ring 25 and the first straight guide ring 30 rotate relative to each other and move together in the direction of the common axis of rotation, ie in the direction of the photographic optical axis Z1.

In the retracted state of the zoom lens 10 are the three role engagement members 32 in engagement with the peripheral portions 30e-1 the three through slots 30e as well as at its closed end portions in engagement with the three Leerlaufnuten 25f as in the 15 and 17 is shown. In the 15 and 17 the same state is shown. However, in 17 the first straight guide ring 30 except for the three continuous slots 30e omitted the operation of the role-engaging members 32 easier to represent. In the 14 and 16 is also the first Geradführungsring 30 (or from the three continuous slots 30e existing slot set) are shown with solid lines, although actually hidden below (ie radially inside) the multiple threaded ring 25 and the third outer tube 26 lies.

Be the Mehrfachgewindering 25 and the third outer tube 26 Moving forward in a rotational movement, this rotational movement of the Mehrfachgewinderings 25 and the third outer tube 26 in the initial phase of forward movement not on the cam ring 31 transmitted, since the three role engagement Glie the 32 in engagement with the three associated Leerlaufnuten 25f are located. The three role engaging members 32 move together with the multiple threaded ring 25, the third outer tube 26 and the first linear guide ring 30 in the direction of the optical axis Z1, by engaging with the peripheral portions 30e-1 the three through slots 30e are located. In the initial phase of the extraction operation of the zoom lens 10 from its retracted state of the cam ring 31 rotationally free in the direction of the optical axis Z1 moves forward.

The 16 and 18 show a state of the multi-threaded ring 25 and the third outer tube 26 in which the latter, starting from the one in the 15 and 17 shown retracted state of the zoom lens 10 rotated through an angle of about 30 ° from their respective retracted positions. In the in the 16 and 18 As shown, each roller engaging member is located 32 at a crossing point between the associated Leerlaufnut 25f and the associated Drehübertragungsnut 26c so that the rotary motion of the multiple threaded ring 25 and the third outer tube 26 over a side surface (left Area in 20 ) of the rotation transmission groove 26c at the left end of the Leerlaufnut 25f can be transferred. By the Mehrfachgewindering 25 and the third outer tube 26 turning further forward, the respective roller engaging member 32 from the peripheral section 30e-1 in the 16 and 18 to the right in the first slope section 30e-2 of the associated slot 30e emotional. Because the first slope section 30e-2 of the respective slot 30e opposite to the circumferential direction of the first linear guide ring 30 so inclined is that it is in one of the peripheral section 30e-1 of the associated slot 30e pioneering direction towards the front end (upper end in 16 ) of the first linear guide ring 30 approaches, causes a forward movement of the respective roller engaging member 32 in the first slope section 30e-2 of the associated slot 30e to make the role engaging member 32 from the associated Leerlaufnut 25f releases and engages with the associated Drehübertragungsnut 26c comes (ie the roller engaging member 32 is from the associated Leerlaufnut 25f in the associated Drehübertragungsnut 26c guided). In a state where the three roller engaging members 32 in engagement with the three rotation transmission grooves 26c are by the interlocking of the three role engaging members 32 and the rotation transmission grooves 26c the torque (torque) of the third outer tube 26 on the cam ring 31 transfer whenever the third outer tube 26 rotates. Then the cam ring moves 31 according to the lines of the first slope sections 30e-2 the three slots 30e forward and rotates relative to the first Geradführungsring 30 , In doing so, each roller-engaging member moves 32 in the associated Drehübertragungsnut 26c forward in the direction of the optical axis Z1 while passing from the same rotation transmission groove 26c receives a torque. Because the first linear guide ring 30 itself in the manner described above together with the Mehrfachgewindering 25 and the third outer tube 26 has moved rectilinearly, the cam ring moves 31 by the intermeshing of the three roller engaging members 32 and the first pitch sections 30e-2 the three through slots 30e by a resulting amount of movement forward in the direction of the optical axis Z1, which is the sum of the amount of forward movement of the first Geradführungsrings 30 (and multiple threaded ring 25 and the third outer tube 26 ) and the amount of forward movement of the cam ring 31 equivalent.

The above-described turning / discharging operations of the multi-threaded ring 25 and the third outer tube 26 are only executed when the external multiple threads 25a and the internal multiple thread 13a are engaged with each other. The three rotary guide projections move 25b in the three associated oblique grooves 13c , Will the Mehrfachgewindering 25 moved forward by a predetermined distance, so solve the external multiple thread 25a and the internal multiple thread 13a from each other, so that the three rotary guide protrusions 25b from the three diagonal grooves 13c in the three Drehführungsnuten 13d move. Since the Mehrfachgewindering 25 not along the optical axis Z1 relative to the stationary tube 13 moves, even if the external multiple thread 25a from the internal multiple thread 13a releases, the multiple threaded ring rotate 25 and the third outer tube 26 by the sliding engagement of the three rotary guide projections 25b in the three Drehführungsnuten 13d in each case associated axially fixed positions, without moving in the direction of the optical axis Z1.

After lapse of a predetermined time since the moment in which the three rotary guide projections 25b from the three diagonal grooves 13c in the three Drehführungsnuten 13d slide, kick the three role engaging members 32 from the first pitch sections 30e-2 the three slots 30e in the second pitch sections 30e-3 one. Because the second slope section 30e-3 of the respective slot 30e opposite the first linear guide ring 30 in one of the associated first pitch section 30e-2 pointing away direction and the front end (upper end in 16 ) of the first linear guide ring 30 approximates, further rotates the multiple threaded ring 25 and the third outer tube 26 in their axially fixed positions in the tube extension direction, that the respective roller engaging member 32 in the second slope section 30e-3 of the associated slot 30e is moved forward. The cam ring 31 moves accordingly according to the line of the second pitch sections 30e-3 the three slots 30e forward and rotates relative to the first Geradführungsring 30 , The multiple threaded ring 25 and the third outer tube 26 form a rotating drive element that generates torque on the cam ring 31 transmits by the three roller engaging members 32 in engagement with the three slots 30e and engaged with the three rotation transmission grooves 26c are.

By the Variozahnrad 22 through the Variomotor 23 is rotated in tube retraction direction, the above-described movable elements of the zoom lens 10 vice versa to the Ausfahroperation described above from the stationary tube 13 to the cam ring 31 emotional. In this reverse operation, the multiple threaded ring moves 25 and the third outer tube 26 rotating in their axially fixed positions, rotating backwards along the optical axis Z1, after the male external thread 25 and the internal multiple thread 13a have solved each other. The first straight guide ring 30 always moves in a straight line and rotationally free in the direction of the optical axis Z1 while reversing the rectilinear motion of the multiple threaded ring 25 and the third outer tube 26 follows. Grasping the three reel handling members 32 in the first slope sections 30e-2 or the second pitch sections 30e-3 the three slots 30e , so the cam ring moves 31 backward in the direction of the optical axis Z1 relative to the multi-threaded ring 25 , the third outer tube 26 and the first linear guide ring 30 by the Mehrfachgewindering 25 and the third outer tube 26 be rotated in tube retraction. In doing so, each roller-engaging member moves 32 in the associated Drehübertragungsnut 26c backward in the direction of the optical axis Z1, while from the same rotation transmission groove 26c receives a torque. Subsequently, each roller engaging member releases 32 with his movement from the first slope section 30e-2 in the peripheral section 30e-1 of the associated slot 30e from the rear open end of the associated rotation transmission groove 26c to engage with the associated Leerlaufnut 25f get. At this time, it ceases the rotation of the multi-threaded ring 25 and the third outer tube 26 on the three role engaging members 32 transferred to. Accordingly, the cam ring 31 in the direction of the optical axis Z1 moves backwards, without together with the multiple threaded ring 25 , the third outer tube 26 and the first linear guide ring 30 to rotate. Each role-engaging member 32 moves in the associated Leerlaufnut 25f , where the zoom lens 10 comes into its retracted position when the roller engaging member 32 the closed end (right end in 14 ) of the associated Leerlaufnut 25f reached.

The following is the radially inside of the cam ring 31 horizontal construction of the zoom lens 10 described. As in 6 shown has the first linear guide ring 30 on its inner peripheral surface a groove set consisting of three pairs of first Geradführungsnuten 30f , which are formed in different circumferential positions so as to extend parallel to the photographic optical axis Z1, and a groove set consisting of six second Geradführungsnuten 30g which are formed in different circumferential positions so as to extend parallel to the photographic optical axis Z1. In each case, two first Geradführungsnuten 30f in the circumferential direction of the first Geradführungsrings 30 on opposite sides of the associated second Geradführungsnut 30g , more precisely every second of these grooves 30g arranged. The zoom lens 10 has within the first linear guide ring 30 a second linear guide ring (linear guide element) 33 , The second linear guide ring 33 has on its outer edge a set of three bifurcated protrusions 33a (Comp. 7 to 10 and 24 ), by a ring part 33b of the second linear guide ring 33 protrude radially outward. Each of these forked tabs 33a has at its radially outer end a pair of radial projections in the associated two first Geradführungsnuten 30f to grab. On the outer peripheral surface of the second outer tube 34 is at its rear end a set of six radial projections 34a (Comp. 12 ) are formed, which protrude radially outward and with the six Geradführungsnuten 30g are longitudinally displaceable in engagement. The second linear guide ring 33 and the six radial projections 34a the second outer tube 34 are therefore over the first Geradführungsring 30 guided in the direction of the optical axis Z1. The zoom lens 10 has inside the cam ring 31 a movable adjustment frame (socket for optical element) 35 which indirectly stores and holds the second lens group LG2. The first outer tube 37 indirectly holds the first lens group LG1 and is inside the second outer tube 34 arranged. The zoom lens 10 has radially inside the cam ring 31 a movable adjustment frame (socket for optical element) 36 for the third lens group LG3. The second linear guide ring 33 forms a Geradführungselement, both the Verstellfassung 35 , which holds the second lens group LG2, as well as the Verstellfassung 36 , which holds the third lens group LG3, straight, without the two Verstellfassungen 35 and 36 to be turned around. Meanwhile, the six radial projections serve 34a the second outer tube 34 as linear guide elements, the first outer tube 37 straight ahead.

As in the 7 to 10 and 24 shown has the second linear guide ring 33 on his ring part 33b a set of three straight guide rods 33c parallel to each other from the ring part 33b protrude forward. As in the 1 to 3 shown is the interrupted trained outer edge of the ring member 33b with an interrupted trained annular groove 31a attached to the inner circumferential surface of the cam ring 31 is formed at the rear end thereof, so as to engage around the optical axis Z1 relative to the cam ring 31 rotatable and along the optical axis Z1 relative to the cam ring 31 immovable. The three straight guide rods 33c stand by the ring part 33b forward into the cam ring 31 into it. The adjustment frame 35 has a corresponding set of three guide grooves 35a into which the three straight guide rods 33c grab (comp. 25 to 28 ). As in 22 shown, has the Verstellfassung 35 also a ring part 35b whose central axis lies on the optical axis Z1 and a set of three projections (straight guide sections) 35c parallel to each other from the ring part 35b in the direction of the optical axis Z1 protrude to the rear. The three straight guide grooves 35a are at the three rearwardly projecting protrusions 35c educated. The three protruding projections 35c are in the circumferential direction of the Verstellfassung 35 arranged at substantially equal angular intervals from each other. The one from the three projections 35c existing set is in engagement with a corresponding groove set consisting of three straight guide grooves (straight guide sections) 36a exists on the outer peripheral surface of the Verstellfassung 36 are arranged in different circumferential positions. Here are the three projections 35c along the three Geradführungsnuten 36a at the Verstellfassung 36 displaceable (cf. 8th . 9 and 25 to 28 ). As in 23 shown, has the Verstellfassung 36 a ring part 36b whose central axis lies on the optical axis Z1 and a set of six projections 36c coming from the ring part 36b protrude radially outward and at the same time parallel to each other in the direction of the optical axis Z1 forward. Each of the three straight guide grooves 36a is composed of the outer peripheral surface of the ring member 36b (Bottom surface of the straight guide groove 36a ) and the side surfaces of two adjacent, forward projections 36c wherein these side surfaces are circumferentially on opposite sides of said outer surface of the ring member 36b lie. The side surfaces of each protruding projection 36c related to the circumferential direction of the Verstellfassung 36 on opposite sides of the projection 36c are arranged and extend in the direction of the optical axis Z1, and the side surfaces of each projecting rearward projection 35c related to the circumferential direction of the Verstellfassung 35 on opposite sides of the projection 35c are arranged and extend in the direction of the optical axis Z1, serve as a linear guide surfaces, which determine the second lens group LG2 Verstellfassung 35 and the Verstellfassung determined for the third lens group LG3 36 along the optical axis Z1 straight ahead, so that the Verstellfassungen 35 and 36 along the optical axis Z1 are movable relative to each other. The Verstellfas solutions 35 and 36 are biased towards each other in the direction of the optical axis Z1. Through this engagement construction between the two Verstellfassungen 35 and 36 is the Verstellfassung determined for the second lens group LG2 35 through the second linear guide ring 33 and the Verstellfassung determined for the third lens group LG3 36 again by the Verstellfassung 35 along the optical axis Z1 straight.

As in the 7 to 10 and 21 shown has the cam ring 31 on its inner peripheral surface, a set of three front inner cam grooves CG3 and a set of three rear inner cam grooves (first cam grooves) CG2 arranged behind the three front cam grooves (second cam grooves) CG3. The three front inner cam grooves CG3 and the three rear inner cam grooves CG2 determine how the second lens group LG2 and the third lens group LG3 are moved. The adjustment frame 35 has on the outer peripheral surfaces of the three rearward projections 35c three rear cam engagement members (first cam follower members) CF2 that fit into the three rear cam grooves CG2 of the cam ring 31 to grab. The adjustment frame 36 has on the outer peripheral surfaces of three of the six forward protrusions 36c a set of three front cam engaging members (second cam engaging members) CF3 that fit into the three front cam grooves CG3 of the cam ring 31 to grab. The elements of each of the four sets of grooves or engaging members, namely the set of the three front cam grooves CG3, the set of the three rear cam grooves CG2, the set of the three front cam followers CF3, and the rear cam followers CF2 Set, are arranged in the circumferential direction about the optical axis Z1 at substantially equal angular intervals. As each of the Verstellfassungen 35 and 36 directly or indirectly through the second linear guide ring 33 along the optical axis Z1 is straightened, with turning of the cam ring 31 the adjustment frames 35 and 36 is moved in a predetermined manner along the optical axis Z1 according to the line guides of the three rear cam grooves CG2 and the three front cam grooves CG3. This cam mechanism will be described later in more detail.

The zoom lens 10 has a second lens frame 40 holding the second lens group LG2. The second lens frame 40 is on the ring part 35b the Verstellfassung 35 held (see. 11 ). The second lens frame 40 is on the ring part 35b the Verstellfassung 35 fixed by one on the outer peripheral surface of the second lens frame 40 formed external thread (adjusting screw) into engagement with an internal thread (adjusting screw) is engaged, which on the inner peripheral surface of the Verstellfassung 35 is trained. The external thread of the second lens frame 40 and the internal thread of the Verstellfassung 35 are formed so that their central axes lie on the photographic axis Z1. By turning the second lens mount 40 relative to the Verstellfassung 35 so can the position of the lens barrel 40 relative to the Verstellfassung 35 be adjusted along the optical axis Z1.

The zoom lens 10 has a shutter unit between the second and third lens groups LG2, LG3 41 containing the shutter S. The closure unit 41 is radially inside the Verstellfassung 36 arranged and held to the latter.

The zoom lens 10 has within the Ver Vice-making 36 a third lens mount (radially retractable lens mount / swivel mount) 42 in which the third lens group LG3 behind the shutter unit 41 is stored and held. The third lens frame 42 becomes a pivot axis 44 pivoted, the at the Verstellfassung 36 is attached and protrudes forward. The pivot axis 44 is arranged at a predetermined distance from the photographic optical axis Z1 and extends parallel to the optical axis Z1. The third lens frame 42 is about the pivot axis 44 between one in the 1 . 2 . 30 and 32 shown receiving position in which the optical axis of the third lens group LG3 coincides with the photographic optical axis Z1, and one in the 3 . 31 and 33 shown radially retracted position in which the optical axis of the third lens group LG3 is retracted radially. In the 3 and 33 is the radially retracted optical axis of the third lens group LG3 designated Z2. At the Verstellfassung 36 is a Drehan strike pin 46 attached, which prevents the third lens mount 42 in 32 is pivoted clockwise beyond a predetermined point, whereby the receiving position of the third lens frame 42 is determined. The third lens frame 42 is by a torsion coil spring 47 in a swivel direction (clockwise to 32 ) biased so that they are in contact with the rotation stopper pin 46 comes. A compression coil spring 48 sits on the pivot axis 44 and tense the third lens frame 42 along the optical axis Z1 backwards, whereby the game between the third lens frame 42 and the Verstellfassung 36 is eliminated.

The third lens frame 42 moves together with the Verstellfassung 36 along the optical axis Z1. As in the 5 and 29 shown has the CCD holder 14 on its front surface a positioning bar (retraction element / stationary cam bar) 49 taken from the CCD holder 14 protrudes forward to the third lens frame 42 to get in touch. Moves the Verstellfassung 36 in the retraction direction to the rear, approaching the CCD holder 14 on, so comes a Rückziehkurvenfläche 49a (Comp. 29 ), which on the front face of the curve bar 49 is formed in contact with a certain portion of the third lens frame 42 , whereby the latter is pivoted to its radially retracted position. The position control cam bar 49 has a holding surface along an inner bar edge 49b extending from the retraction cam 49a extends rearwardly parallel to the optical axis Z1 and serves to hold the radially retracted position.

As in 12 shown has the second outer tube 34 on its inner circumferential surface a set of three Geradführungsnuten 34b , which are arranged in different circumferential positions and parallel to the optical axis Z1. The first outer tube 37 has at its outer peripheral surface at its rear end a set of three engaging projections 37a , which are in sliding engagement with the three Geradführungsnuten 34b are located. Accordingly, the first outer tube is 37 over the first straight guide ring 30 and the second outer tube 34 rotationally free guided along the optical axis Z1. The second outer tube 34 has on its inner peripheral surface near its rear end a broken inner flange 34c which extends along the circumference of the second outer tube 34 runs. The cam ring 31 has on its outer peripheral surface a broken annular groove 31b with which the inner flange 34c is in sliding engagement so that the cam ring 31 is rotatable about the optical axis Z1 relative to the second outer tube and the second outer tube 34 in the longitudinal direction relative to the cam ring 31 immovable (the second outer tube 34 So moves together with the cam ring 31 along the optical axis Z1). The first outer tube 37 has on its inner peripheral surface a set of three cornering access members CF1, which are radially inward. The cam ring 31 has on its outer circumferential surface a set of three outer cam grooves (third cam grooves) CG1 with which the three cam followers CF1 are slidably engaged.

The zoom lens 10 has inside the first outer tube 37 a first lens frame 51 , which has a setting ring 50 on the first outer tube 37 is held. The first lens group LG1 is on the first lens frame 51 attached. The first lens frame 51 has on its outer peripheral surface an outside partial thread 51a while adjusting ring 50 on its inner peripheral surface an inside partial thread 50a has, which engages with the outside partial thread 51a is located (see. 12 ). When assembling the zoom lens can on the partial thread 51a and 50a the position of the first lens frame 51 relative to the adjusting ring 50 be adjusted along the optical axis Z1.

The zoom lens 10 has at the front end of the first outer tube 37 a cover mechanism 54 (Comp. 4 ), which automatically a front end opening of the zoom lens 10 closes, if the latter after 3 is retracted to the foremost lens element of the recording optics of the zoom lens 10 , ie the first lens group LG1, to protect against dirt and scratches when the digital camera is not in operation. The cover mechanism 54 has several cover slats 54a namely a front pair of slats and a rear pair of slats. The cover mechanism 54 works so that the cover slats 54a in the 3 shown driven state of the zoom lens 10 are completely closed before the first lens group LG1, while in the in the 1 and 2 shown receptive state of the zoom lens 10 are completely open.

The following describes how the lens barrel of the zoom lens constructed as mentioned above 10 extended and retracted. In the in 3 shown retracted state of the zoom lens 10 is characterized by the fact that the variomotor 23 the Variozahnrad 22 in the tube extension direction, the combination of the multiple threaded ring 25 and the third outer tube 26 by the interlocking of the internal multiple thread 13a and the external multiple thread 25a rotating forward moves and also the first Geradführungsring 30 together with the multiple threaded ring 25 and the third outer tube 26 moved straight forward. The cam ring rotates 31 not at first, but moves only together with the Mehrfachgewindering 25 , the third outer tube 26 and the first linear guide ring 30 straight forward. Subsequently, by the engagement of the roller engaging members 32 and the first pitch sections 30e-2 the through slots 30e a torque from the third outer tube 26 on the cam ring 31 transferred to move it forward and thereby relative to the first Geradführungsring 30 after being rotated by the above-described rotation of the combination of the multiple threaded ring 25 and the third outer tube 26 has been rotated by an angle of about 30 °. Immediately after the multiple threaded ring 25 and the third outer tube 26 are extended forward in their respective predetermined positions, the outer multiple thread 25a of the multiple threaded ring 25 and the internal multiple thread 13a of the stationary tube 13 detached from each other, so that the Mehrfachgewindering 25 and the third outer tube 26 by the sliding engagement of the three rotary guide projections 25b in the three associated Drehführungsnuten 13b rotate about the photographic optical axis Z1 without moving along the optical axis Z1. Since since the moment in which the Mehrfachgewindering 25 and the third outer tube 26 are stopped in their forward movement along the optical axis Z1 (ie the moment in which the three rotary guide projections 25b from the three diagonal grooves 13c in the three Drehführungsnuten 13d slide) has elapsed a predetermined time, the three roller engaging members come 32 from the first pitch sections 30e-2 the three through slots 30e in the second pitch sections 30e-3 one, leaving the cam ring 31 moved forward and at the same time relative to the first Geradführungsring 30 is turned.

By turning the cam ring 31 Both are provided for the second lens group LG2 Verstellfassung 35 as well as provided for the third lens group LG3 Verstellfassung 36 inside the cam ring 31 arranged and directly or indirectly through the second Geradführungsring 33 rotationally free along the optical axis Z1 are guided, with respect to the cam ring 31 in a predetermined manner, which is determined by the engagement of the front curve engaging members CF3 and the front (inner) cam grooves CG3 and by the engagement of the rear curve engaging members CF2 and the rear (inner) cam grooves CG2, moved along the optical axis Z1. In the in 3 shown retracted state of the zoom lens 10 is the in the Verstellfassung 36 provided third lens frame 42 through the cam bar 49 about the pivot axis 44 pivoted to be held in its radially retracted position above the photographic optical axis Z1. Thereby, the optical axis of the third lens group LG3 has been transferred from the photographing optical axis Z1 to the retracted optical axis Z2 which lies above the photographing optical axis Z1. During the movement of the Verstellfassung 36 from the withdrawn position into one in the 1 . 2 . 30 and 32 shown in the zoom or zoom range, the third lens mount 42 through by the torsion coil spring 47 applied spring force from the position control cam bar 49 dissolved and from the radially retracted position about the pivot axis 44 in the in the 1 . 2 . 30 and 32 pivoted recording position shown in which the optical axis of the third lens group LG3 coincides with the photographic optical axis Z1. Then the third lens frame remains 42 held in the receiving position until the zoom lens 10 in the in 3 shown retracted position.

By turning the cam ring 31 becomes the first outer tube 37 that's around the cam ring 31 around and guided along the optical axis Z1 without rotation, by the engagement of the three cam followers CF1 and the three outer cam grooves CG1 in a predetermined manner relative to the cam ring 31 moved along the optical axis Z1.

When the first lens group LG1 is moved forward from the retracted position, its axial position is relative to the image plane, ie, the photosensitive surface of the CCD image sensor 12 , determined by the sum of the amount of forward movement of the cam ring 31 relative to the stationary tube 13 and the amount of movement of the first outer tube 37 relative to the cam ring 31 , If the second lens group LG2 is moved forward from the retracted position, then its axial Position relative to the image plane determined by the sum of the amount of forward movement of the cam ring 31 relative to the stationary tube 13 and the amount of movement of the adjustment 35 relative to the cam ring 31 , When the third lens group LG3 is moved forward from the retracted position, its axial position relative to the image plane is determined by the sum of the amount of forward movement of the cam ring 31 relative to the stationary tube 13 and the amount of movement of the adjustment 36 relative to the cam ring 31 , A zoom or zoom operation is effected by moving the first, second and third lens groups LG1, LG2, LG3 on the photographic optical axis Z1, the pitches of these lens groups changing from each other. Will the zoom lens 10 from the in 3 extended retracted position shown, so moves the zoom lens 10 first forward in the 1 shown position in which the zoom lens 10 in the wide angle limit setting. Subsequently, the zoom lens moves 10 by further turning the Variomotors 23 in tube extension direction forward into the in 2 shown position in which the zoom lens 10 is in the telegraph setting. As from the in the 1 and 2 shown sectional views of the zoom lens 10 is apparent in the wide-angle limit setting of the zoom lens 10 the distance between the first and second lens groups LG1, LG2 is minimum and the distance between the second and third lens groups LG2, LG3 is large. Is the Varioob jektiv 10 set to the telegram setting, the distance between the first and second lens groups LG1, LG2 is large, and the distance between the second and third lens groups LG2, LG3 is small. This change in the distances between the first, second and third lens groups LG1, LG2, LG3 for zooming is effected by the line guides of the three outer cam grooves CG1, the three rear inner cam grooves CG2 and the three front inner cam grooves CG3. In the zoom range between the wide-angle limit setting and the telegram setting, the multi-threaded ring rotates 25 and the third outer tube 26 without moving along the optical axis Z1. By contrast, the cam ring moves in the same range of variations 31 by the intermeshing of the three roller engaging members 32 and the second pitch sections 30e-3 the three through slots 30e of the first linear guide ring 30 rotating forwards and backwards along the optical axis.

When the first to third lens groups LG1, LG2, LG3 are in the zoom range, focusing is effected by the AF lens barrel 17 holding the fourth lens group LG4 by rotating the AF motor 19 is moved according to the object distance along the photographic optical axis Z1.

By the Variomotor 23 is driven in tube retraction, the zoom lens operates 10 in contrast to the Ausfahroperation described above, in the in 3 retract shown state. In the course of this retraction movement of the zoom lens 10 becomes the third lens mount 42 through the curve bar 49 around the pivot axis 44 pivoted in the radially retracted position and moves together with the Verstellfassung 36 to the rear. Will the zoom lens 10 in the in 3 The third lens group LG3 is retracted into the space located radially outside the space into which the fourth lens group LG4, the low-pass filter, moves 11 and the CCD image sensor 12 be retracted, as in 3 is shown. This means that the third lens group LG3 is radially retracted into an axial region that is substantially identical to an axial region in the direction of the optical axis Z1, in which the fourth lens group LG4, the low-pass filter 11 and the CCD image sensor 12 are arranged. This construction of the zoom lens 10 for retracting the third lens group LG3 in the above-described manner enables the zoom lens 10 to shorten in the fully retracted state. Accordingly, the thickness of the camera body in the horizontal direction 3 , ie in the direction of the optical axis Z1, can be reduced.

The one in the zoom lens 10 The cam mechanism which moves the second lens group LG2 and the third lens group LG3 in a predetermined manner along the optical axis Z1 will be described below in detail. The 21 and 25 to 28 FIG. 12 shows the shapes (line courses) of the three rear inner cam grooves CG2 and the three front inner cam grooves CG3 constituting elements of this cam mechanism. Although 21 a developed view of the outer peripheral surface of the cam ring 31 3, in this figure, the three rear inner cam grooves CG2 and the three front inner cam grooves CG3 are on the inner circumferential surface of the cam ring 31 are formed, shown by solid lines, to make the shape of the respective cam groove clearer. Although in the 25 to 28 each a developed view of the outer peripheral surface of the cam ring 31 2, the adjustment frames intended for the second lens group LG2 are shown 35 and the Verstellfassung determined for the third lens group LG3 36 represented in these figures by solid lines, although they are radially inside the cam ring 31 are arranged. How best in the 25 to 28 As can be seen, the three front inner cam grooves CG3 are in the direction of the optical axis Z1 on the inner circumferential surface of the cam ring 31 in front of the three back ren, inner cam grooves CG2 arranged. Thus, the second lens group LG2 and the third lens group LG3 are reversely arranged in the direction of the optical axis Z1 relative to each other like the three rear inner cam grooves CG2 serving the movement of the second lens group LG2 and the three front inner cam grooves CG3 which are the one Movement of the third lens group LG3 serve.

As in 21 is shown, each rear, inner cam groove CG2 at its one end (rear end) has a receiving portion CG2-1, which is wider than the rest of the rear cam groove CG2, ie opposite this widened and the rear end face of the cam ring 31 is open. Further, each rearward inner cam groove CG2 has a tapered leading or trailing portion CG2-2 extending straightly obliquely from the receiving portion CG2-1 to the front of the cam ring 31 extends, and a return portion CG2-3, of the in 21 left end of the inclined slope portion CG2-2 is returned from. In addition, each rear inner cam groove CG2 has a mounting portion CG2-4 projecting forward from the front end of the receiving portion CG2-1 in the direction of the optical axis Z1. On the other hand, each front inner cam groove CG3 has a receiving portion CG3-1 extending in the circumferential direction of the cam ring 31 extends, an inclined guide or pitch portion CG3-2, the straight from the receiving portion CG3-1 obliquely to the back of the cam ring 31 and a return section CG3-3 different from the one shown in FIG 21 left end of the inclined slope section CG3-2 is returned from. The cam ring 31 has at its front edge a set of three cutouts 31v , which each have the shape of a semicircle in cross section. The three sections 31v are designed so that they have one end (right ends in 21 ) are in communication with the receiving portions CG3-1 of the associated three front inner cam grooves CG3 so that these ends of the receiving portions CG3-1 are toward the leading edge of the cam ring 31 are open. The three front cam followers CF3 are over the three cutouts 31v introduced into the three front inner grooves CG3.

In each rear, inner cam groove CG2, a certain part, which is defined by the range between a wide-angle limit position (W) and a teleposition position (T), becomes 21 is used as a recording area for a zoom or vario operation. Correspondingly, in each front inner cam groove, a certain part passing through the area between a wide-angle limit position (W) and a teleposition position (T) will become smaller 21 is set, used as a recording area for a Variooperation. That is, each rear cam follower CF2 is disposed in the associated rear cam groove CG2 in its wide-angle limit position (W), and each front cam follower CF3 is disposed in the associated front cam groove CG3 in its wide-angle limit position (W), as in FIG 26 is shown, so is the zoom lens 10 in the wide angle limit setting. Is each rear cam follower CF2 in the associated rear cam groove CG2 in the Telegrenzposition (T) and each front cam follower CF3 in the associated front cam groove CG3 in the Telegrenzposition (T) arranged as in 27 is shown, so is the zoom lens 10 in the telegraph setting. Is the zoom lens 10 in the wide-angle limit setting (cf. 8th and 26 ), the distance between the second lens group LG <b> 2 and the third lens group LG <b> 3 is large, and the engagement distance (overlay distance) between the three rearward protrusions 35c the Verstellfassung 35 and the associated three Geradführungsnuten 36a the Verstellfassung 36 along the optical axis Z1 small. On the other hand, is the zoom lens 10 in the telegram setting (cf. 9 and 27 ), the distance between the second lens group LG2 and the third lens group LG3 is small, and the engaging distance (overlapping distance) between the three rearwardly projecting protrusions 35c the Verstellfassung 35 and the three associated Geradführungsnuten 36a the Verstellfassung 36 along the optical axis Z1 large. Is the zoom lens 10 in his in 3 In the retracted state shown, each rear cam follower CF2 is disposed in the accommodating portion CG2-1 of the associated rear cam groove CG2 and each front cam follower CF3 is disposed in the receiving portion CG3-1 of the associated front cam groove CG3 (see FIG. 25 ).

The inclined slope portion CG2-2 of each rear cam groove CG2 is opposite to the circumferential direction of the cam ring 31 inclined so that it faces away from the associated receiving portion CG2-1 towards the front end of the cam ring 31 approaches. On the other hand, the return portion CG2-3 of each rear cam groove CG2 is opposite to the circumferential direction of the cam ring 31 inclined so that it is in a direction away from the associated pitch section CG2-2 direction the rear end of the cam ring 31 approaches. In contrast, the inclined slope portion CG3-2 of each front cam groove CG3 is opposite to the circumferential direction of the cam ring 31 inclined so that it faces the rear end of the cam ring in a direction away from the associated receiving portion CG3-1 direction 31 while the return portion CG3-3 of each front cam groove CG3 is opposite to the circumferential direction of the cam ring 31 is inclined so as to be in a direction away from the associated pitch section CG3-2 direction the front end of the cam ring 31 approaches. As the unwound representation of the cam ring 31 to 21 Thus, each rearward inner cam groove CG2 has substantially the shape of an inverted V whose apex is approximately in the middle of the cam groove CG2, while each front inner cam groove CG3 has substantially the shape of a V whose lower part is substantially in the middle of the curve groove CG3 lies. The three rear inner cam grooves CG2 are circumferentially arranged at predetermined intervals from each other, while the three front inner cam grooves CG3 are arranged circumferentially at predetermined intervals from each other in a direction in the same direction as the optical axis Z1 or interlocking arrangement. In this case, the groove set consisting of the three rear cam grooves CG2 and the groove set consisting of the three front cam grooves CG3 are in the circumferential direction of the cam ring 31 offset from one another (in particular, the set consisting of the three rear corner engagement members CF2 and the set consisting of the three front corner engagement members CF3 are in the circumferential direction of the cam ring 31 offset from one another). The arrangement pattern of the cam grooves CG2 and CG3 on the cam ring 31 makes it possible to shorten the distance between the three rear cam grooves CG2 on the one hand and the three front cam grooves CG3 on the other hand in the direction of the optical axis Z1. This allows the cam ring 31 be shortened in the direction of the optical axis Z1. In the described embodiment of the cam mechanism according to the invention, the three front cam grooves CG3 are in the circumferential direction of the cam ring 31 arranged at equal angular intervals from each other. Also, the three rear cam engagement members CF2 are circumferentially of the cam ring 31 arranged at equal angular intervals from each other, so that in the wide-angle limit position (W) lying part of each rear cam groove CG2 in the circumferential direction of the cam ring 31 essentially corresponds to the receiving portion CG3-1 of the associated front curves groove CG3. By this arrangement of the three rear cam grooves CG2 and the three front cam grooves CG3 to each other, the grooves CG2 and CG3 can be arranged in the direction of the optical axis Z1 in close spatial proximity to each other, without cutting each other. Accordingly, the length of the cam ring 31 in the direction of the optical axis Z1 is significantly smaller than the sum of the measured in the direction of the optical axis Z1 width W1 (see FIG. 21 ) of the groove set consisting of the three rear cam grooves CG2 and the width W2 measured in the direction of the optical axis Z1 (see FIG. 21 ) of the groove set consisting of the three front cam grooves CG3.

As stated above, each rear cam groove CG2 has a curved path in the form of an inverted V and each front cam groove CG3 has a curved path in the form of V. However, neither the inverted V-shaped cam track nor the V-shaped cam track is symmetrical. If the three rear cam grooves CG2 and the three front cam grooves CG3 were on the cam ring 31 formed so that the three rear cam grooves CG2 in a direction opposite to the above-described embodiment of the cam mechanism arrangement in the direction of the optical axis Z1 in front of the three front cam grooves CG3 would be in the same circumferential region of the cam ring 31 (Within the same range in the direction of the optical axis Z1) the corresponding front set of keys and the corresponding rear set of keys intersect each other, even if the rear set of keys and the front set of keys with respect to their arrangement in the circumferential direction of the cam ring 31 would be adjusted. If, as described in the beginning, a single cam ring on its inner peripheral surface or on its outer peripheral surface is provided with two sets of grooves for moving two straight-guided optical elements, it is necessary to prevent the two associated sets of cam engagement members being engaged with the two sets of grooves at the intersections of the two sets of grooves from the cam grooves solve. However, appropriate measures make the cam mechanism complicated. For example, one known solution to this problem is to provide the cam ring with supporting cam grooves having the same cam tracks as the main cam grooves to prevent the two sets of cam followers from disengaging from the associated sets of keys. However, in order to form such supporting cam grooves in addition to the main cam grooves, an additional area must be provided on the cam ring on which the supporting cam grooves are arranged. Accordingly, the cam ring becomes larger. On the contrary, in the present invention, the relative arrangement of the groove set consisting of the three rear cam grooves CG2 and the groove set consisting of the three front cam grooves CG3 in the direction of the optical axis Z1 has been changed in the direction of the optical axis Z1 irrespective of the relative arrangement of the lens groups. these lens groups (second lens group LG2 and third lens group LG3 in this embodiment) being straight in the direction of the optical axis Z1. Thereby, the three rear inner cam grooves CG2 and the three front inner cam grooves CG3 can be formed on the inner circumferential surface of the cam ring 31 be trained without cutting each other. An enlargement of the cam ring 31 is thus avoided.

In that each rear cam follower CF2 for moving the second lens group LG2 and each front cam follower CF3 for Moving the third lens group LG3 is in engagement with the associated rear cam groove CG2 and the front cam groove CG3 and these curves CG2, CG3 as described above arranged as swapped, various novel design concepts regarding this arrangement and the construction, with the three rear Curve engagement members CF2 and the three front cam followers CF3 are assembled. In particular, the three rear cam engagement members CF2 are on the outer circumferential surfaces of the projections 35c formed by the ring part 35b the Verstellfassung determined for the second lens group LG2 35 protrude to the rear, while the three front cam engagement members CF3 on the outer peripheral surfaces of three of the six projections 36c are formed by the ring part 36c the Verstellfassung determined for the third lens group LG3 36 protrude forward. Further, the three rear cam engagement members CF2 are integral with the three rearwardly projecting projections 35c educated. The three front cam followers CF3 are elements separate from the recliner 36 are provided. At the associated three of the six protruding projections 36c are near the front ends of three mounting holes 36v trained (comp. 11 ) into which the three front cam followers CF3 are inserted to be fixed there.

What the two Verstellfassungen 35 and 35 concerns, the relative arrangement of the ring member 35b holding the second lens group LG2 and the ring part 36b holding the third lens group LG3 are not changed in the direction of the optical axis Z1, whereas the relative arrangement of the three rear cam engaging members CF2 and the three front cam engaging members CF3 in the direction of the optical axis Z1 corresponding to the three projections 35c or the three projections 36c which are slidable in the direction of the optical axis Z1 relative to each other are provided, can be freely changed without causing mutual interference. Therefore, the three rear cam engagement members CF2 and the three front cam engagement members CF3 can be smoothly brought into engagement with the three rear cam grooves CG2 and the three front cam grooves CG3 (whose relative arrangement has been changed in the direction of the optical axis Z1). The positional relationship between the three rear cam engagement members CF2 and the three front cam engagement members CF3 in the optical axis Z1 direction is determined by the cam tracks of the three rear cam grooves CG2 and the three front cam grooves CG3, the three front cam engagement members CF3 in the cam ring 31 are not always located in front of the three rear corner engagement members CF2. For example, the three front cam followers CF3 are located in the 25 shown retracted state of the zoom lens 10 as well as in the 27 shown state in which the zoom lens 10 is in the telegraph setting, in the direction of the optical axis Z1 in front of the three rear corner engagement members CF2 corresponding to the positional relationship between the three rear cam grooves CG2 and the three front cam grooves CG3, while the three rear corner engagement members CF2 in the in FIG 26 shown state in which the zoom lens 10 in the wide-angle limit setting, are arranged in the direction of the optical axis Z1 in front of the three front cam engagement members CF3.

The following describes how the Verstellfassung determined for the second lens group LG2 35 and the Verstellfassung determined for the third lens group LG3 36 when assembling the zoom lens 10 on the cam ring 31 be attached. First, the second lens mount 40 at the Verstellfassung 35 attached, and it will be the locking unit 41 and the third lens frame 42 at the Verstellfassung 36 attached. Subsequently, the three protruding projections back 35c and the six protrusions projecting forward 36c engaged with each other to the two Verstellfassungen 35 and 36 to merge into a single entity (cf. 7 ). In this assembled state, the two Verstellfassungen 35 and 36 by the sliding engagement of the three protruding projections 35c and the six protrusions projecting forward 36c in the direction of the optical axis Z1 guided straight relative to each other. Subsequently, the from the two Verstellfassungen 35 and 36 existing unit from behind in the cam ring 31 used. In this phase, the three front cam engagement members CF3 are not yet on the Verstellfassung 36 assembled. The three rear cam followers CF2 are defined by the corresponding openings on the rear face of the cam ring 31 are formed, inserted into the three rear cam grooves CG2. Subsequently, the two Verstellfassungen 35 and 36 as an integral unit forward in the cam ring 31 pushed so that the three rear curve engaging members CF2 enter the mounting portions CG2-4 of the three rear cam grooves CG2. Then there are the three mounting holes 36v attached to the three of the six protrusions 36c are formed by the three cutouts 31v of the cam ring 31 from the cam ring 31 radially outward free, as in 28 is shown. In this phase, the three front cam engagement members CF3 are replaced by the three cutouts 31v through in the three mounting holes 36v assembled. Then the cam ring 31 slightly in tube extension direction (in 28 turned to the right), so are the two Verstellfassungen 35 and 36 by the relationship between the three rear corner engagement members CF2 and the second lens group LG2 (inclined surface which is the mounting portion CG2-4 in the respective rear cam groove CG2 connects to the receiving portion CG2-1) slightly as a unit moves backward and at the same time the three front cam followers CF3 from the three cutouts 31v moved into the openings of the three front cam grooves CG3. Turn the cam ring 31 in the in 25 3, the three rear corner engagement members CF2 have moved away from the openings of the three rear cam grooves CG2 and have reached the receiving portions CG2-1, while the three front corner engagement members CF3 are moved away from the openings of the three front cam grooves CG3 and the receiving portions CG3- 1 have reached, so that the two Verstellfassungen 35 and 36 in the cam ring 31 are held.

As is clear from the above description, in the cam mechanism according to the invention, the Verstellfassung determined for the second lens group LG2 35 and the Verstellfassung determined for the third lens group LG3 36 slightly in the cam ring 31 having the three rear inner cam grooves CG2 (for moving the second lens group LG2 in the direction of the optical axis Z1) and the three front inner cam grooves CG3 (for moving the third lens group LG3 in the direction of the optical axis Z1). The cam grooves CG2, CG3 are thus on the cam ring 31 is formed such that the three front cam grooves CG3 are located in front of the three rear cam grooves CG2, although the third lens group LG3, which is moved over the three front cam grooves CG3 in the direction of the optical axis Z1, is disposed behind the second lens group LG2 passing over the three rear cam grooves CG2 is moved in the direction of the optical axis Z1.

The Invention is not limited to the embodiment described. For example are in the embodiment of the zoom lens described above three grooves or engagement members in each of the described four sentences (namely the groove set consisting of the three rear, inner cam grooves CG2, the groove set consisting of the three front, inner cam grooves CG3, the consisting of the three rear corner engagement members CF2 sentence and consisting of the three front cam followers CF3 Sentence). It can but also more or less than three grooves or engagement members be provided per sentence.

Claims (13)

Cam mechanism for a zoom lens with two optical elements (LG2, LG3), one of which (LG3) is arranged in the direction of the optical axis (Z1) behind the other (LG2), wherein both the front optical element (LG2) and the Rear optical elements (LG3) along the optical axis (Z1) are guided, comprising: a cam ring ( 31 ) having a first cam groove (CG2) for moving the front optical element (LG2) along the optical axis (Z1) and a second cam groove (CG3) for moving the rear optical element (LG3) along the optical axis (Z1), both the first cam groove (CG2) and the second cam groove (CG3) on the inner peripheral surface or the outer peripheral surface of the cam ring (FIG. 31 ), wherein the first cam groove (CG2) is arranged in the direction of the optical axis (Z1) behind the second cam groove (CG3). A cam mechanism according to claim 1, wherein the first cam groove (CG2) and the second cam groove (CG3) are formed on the inner circumferential surface of the cam ring (CG3). 31 ), the cam mechanism further comprises: a first socket ( 35 ) for holding the front optical element (LG2) and a second version ( 36 ) for holding the rear optical element (LG3) straight along the optical axis (Z1); and a first cam follower (CF2) attached to the first socket (CF2) 35 ) and in engagement with the first cam groove (CG2), and a second cam follower (CF3) attached to the second socket (FIG. 36 ) and engaged with the second cam groove (CG3). A cam mechanism according to claim 2, wherein one of the two cam grooves (CG2, CG3) has a front engaging member insertion opening at the front end of the cam ring (Fig. 31 ) and the other of the two engagement grooves (CG2, CG3) has a rear engagement member insertion opening at the rear end of the cam ring (FIG. 31 ) has one (CF2) of the two cam followers (CF2, CF3) integral with the associated socket ( 35 ) and the other one (CF3) of the two cam engagement members (CF2, CF3) is formed from the other ( 36 ) is separately provided element, and when assembling the zoom lens, the first version ( 35 ) and the second version ( 36 ) are coupled together so that they are straight along the optical axis (Z1), while the one-piece with the associated version ( 35 ) cam engaging member (CF2) is inserted via the associated engaging member insertion opening in the associated cam groove (CG2) and then the other cam follower member (CF3) after attachment to the associated other version ( 36 ) is introduced via the associated other engaging member insertion opening into the associated other cam groove (CG3). Cam mechanism according to claim 3, in which the first socket ( 35 ) a front straight guide section ( 35c ) and the second version ( 36 ) a rear straight guide section ( 36c ) on points, wherein the two Geradführungsabschnitte ( 35c . 36c ), the first version ( 35 ) and the second version ( 36 ) along the optical axis (Z1) to be guided relative to each other, and wherein one of the two versions ( 35 . 36 ) by a linear guide element ( 33 ), independent of the two versions ( 35 . 36 ) is provided along the optical axis (Z1) is guided straight. Cam mechanism according to claim 4, in which the first version ( 35 ) a front ring part ( 35b ) for holding the front optical element (L2) and the second version ( 36 ) a rear ring part ( 36b ) for holding the rear optical element (LG3), wherein the two ring parts ( 35b . 36b ) are facing away from one another along the optical axis (Z1), and the front straight guide section has at least one backward-pointing projection (FIG. 35c ) and the rear straight guide section at least one forward-facing projection ( 36c ) facing each other along the optical axis (Z1). Camming mechanism according to one of claims 3 to 5, in which that of the two cam grooves (CG2) into which the integral with the associated socket (CG2) 35 ) formed cam follower (CF2) is inserted, a mounting portion (CG2-4) which is formed so that it communicates with the associated engaging member insertion opening and in the direction of the optical axis (Z1) is aligned thereon, if that is in one piece with the corresponding version ( 35 ) cam engaging member (CF2) is arranged in the mounting portion (CG2-4), the other cam engaging member (CF3) to the outside of the cam ring ( 31 ) is exposed radially. Curve mechanism according to claim 6, wherein the cam ring ( 31 ) at least one section ( 31v ), by which said other cam follower (CF3) extends outwardly of the cam ring ( 31 ) is radially exposed when the one cam follower (CF2) is disposed in the mounting portion (CG2-4). Camming mechanism according to one of claims 2 to 7, in which the first cam follower (CF2) and the second cam follower (CF3) in the circumferential direction of the cam ring ( 31 ) are staggered when the first cam follower (CF2) is in engagement with the first cam groove (CG2) and the second cam follower (CF3) is engaged with the second cam groove (CG3). Camming mechanism according to one of the preceding claims, wherein at least two first cam grooves (CG2) are provided, which in the circumferential direction of the cam ring ( 31 ) are offset from one another, at least two second cam grooves (CG3) are provided, which in the circumferential direction of the cam ring ( 31 ) are staggered with respect to each other, and none of the first and second cam grooves (CG2, CG3) intersect another cam groove. Cam mechanism according to one of the preceding Claims, characterized in that the front optical element has a second Lens group (LG2) and the rear optical elements a third Lens group (LG3) is a recording optics of the zoom lens. A cam mechanism according to any one of the preceding claims, wherein the first cam groove (CG2) and the second cam groove (CG3) are formed on the inner circumferential surface or the outer peripheral surface of the cam ring (CG3). 31 ), the zoom lens includes a foremost optical element (LG1) disposed in the direction of the optical axis (Z1) in front of the front optical element (LG2) and on the peripheral surface of the cam ring (LG1). 31 ) at which the first cam groove (CG2) and the second cam groove (CG3) are not formed, a third cam groove (CG1) for moving the foremost optical element (LG1) along the optical axis (Z1) is formed. Cam mechanism according to one of the preceding Claims, wherein one (CG3) of the two cam grooves (CG2, CG3) is substantially V-shaped and the other (CG2) of the two cam grooves (CG2, CG3) in essence vice versa is V-shaped. Lens system comprising a front optical element (LG2) and a rear optical element (LG3) guided along the optical axis (Z1), the lens system including a cam mechanism comprising the front optical element (LG2) and the rear optical element (LG2). LG3) moves in a predetermined manner while changing their distance from each other along the optical axis (Z1), the cam mechanism a cam ring ( 31 ) having a first cam groove (CG2) for moving the front optical element (LG2) along the optical axis (Z1) and a second cam groove (CG3) for moving the rear optical element (LG3) along the optical axis (Z1) wherein both the first cam groove (CG2) and the second cam groove (CG3) on the inner peripheral surface or the outer peripheral surface of the cam ring ( 31 ), and the first cam groove (CG2) is arranged in the direction of the optical axis (Z1) behind the second cam groove (CG3).