DE2141204C3 - Varifocal lens - Google Patents

Description

The invention relates to a zoom lens

of the type specified in the preamble of claim 1.

Such a lens became known through the apparently previously used camera "Viennette 8" from Eumig.

In the known lens, however, is the arrangement taken in such a way that it is not possible to move from the close-up position directly into a desired position of the normal range. Rather, the transition always takes place there to an end position of the normal range and only from there into the respectively desired position of the normal range. When over-

When moving to the close-up position, a previously selected distance range in the normal range is and focal length setting lost. The same applies mutatis mutandis to the older one Proposal according to DT-AS 2 029 254 trained varifocal lens.

In another known varifocal lens (DT-GM 1778 444), the axial adjustment is the an intermediate lens caused directly by the adjusting element, while the non-linear adjustment of the

so another intermediate lens over one with two curves provided control sleeve takes place, which is driven or actuated by the sleeve of the adjusting member. The adjusting element is designed like a lever, and a lever movement leads to a change in the sharpness

setting, while a turn of the handle is used to adjust the aperture. One or the other intermediate lens for the purpose of close-ups from their normal position to a close-up position to move out is not intended.

In the further known varifocal lens according to JA-PS 6866/1966, both the distance setting and the focal length change carried out by adjusting a front lens group, with a recording at a very short distance is adjustable. However, it is not possible to switch between these two modes of operation quickly.

The invention is therefore based on the object of providing a varifocal lens of the type specified at the beginning train that with good operability from any position in the normal range in a position of the Close-ups can be changed, in particular a very rapid change of focus between two objects in view, one of which is in the ultra-close range can, should be possible.

The problem posed is achieved by the features specified in the characterizing part of claim 1.

A varifocal lens designed according to the invention is discussed below with reference to the drawing.

So doing shows

Fig. 1 the varifocal lens in a schematic representation,

F i g. 2 a longitudinal section through the front part of the zoom lens in the normal position for changing the focal length,

Fig. 3 is the same view as FIG. 2, but in the Position for focusing for ultrashort distance, and

F i g. 4 developments of the tube sleeves with control curves to explain details of the varifocal lens, this being in the position according to FIG.

The optical system of a zoom lens shown in FIG. 1 has a focusing lens system L ₁

for focusing, a lens system for changing the magnification and an imaging lens system M for generating an image on a film surface. The lens system for changing

ο «ler enlargement consists of a first be ^ I insenerunpe L, and a second movable

^W f ' ^C lens group ί! ,, which both for changing Linseng W ^ ^ _{AufrecnlerhaUung}

^{When the} focal length is adjusted, the first Λ the second movable lens group L., and L ₃ Se are moved axially and with respect to one another in a certain ratio.

Straight guide channel SB of the second cam cylinder cooperate to connect the cylinders to one another.

Normal focal length adjustment is described below. In Fig. 2, the steel ball 10 forming the holder is received by the latching groove 4 C , around the first and second movable lens groups L, and L ₃ in their relative position to

nth ratio Dcwcgi. To keep focal length adjustment. If the loading

The first and the second lens actuation ring can never be rotated, the second curve L or L _{3 is} rotated individually from its relative position with cylinder 5, and the first curve ^g race length adjustment into a position relative to the sewing cylinder 4 is also rotated with it be moved to the second Kurvenzy- ^tO fiahrne, so'daß by a movement _relieving 5 is rotated because the pin 9 on the first Kuru of the two lens groups in the same reference _V enzylinder4 in the straight guide channel 5 ti in crops ratio for focusing ultra- i ₅ second cam cylinder S extends and a VerDinfvFntfernungen can be obtained. _{connection of} the cam cylinders 4 and 5 with each other

_{Fe 2 is actually} an embodiment of the invention. Such rotation has the consequence that the application ■ second to the illustrated in Fig. 1 Vario and the third lens frame 2 and 3, axial loading "hiVklTv" shows. A fixed tube 1 is _moved from one another with the _who, because the Cam pins 7 and 8ί follow the Ku-7i at a distance, axially extending ₂₀ vennuten AA and SA and formed by the channels ρ ih ünaskanälen 1 A and I B , which _{pass through j A and} ι β of the fixed tube 1. The LS extend to ^ tables axis (s. Figure 4). _e irst and second movable ^ "TSSV FokussierlinsensystemL is, on the front _{and L who} begt therefore the corresponding V d Rükbeegung Vhäli whereby

en

the combined stems vj-ranaen certain student

shown vorwans ucwcgi, wv, v. _u
at 4 C and 10 is released so that the second cam cylinder 5 can move along the optical axis. The straight guide channel S B guides the

kissing lens system, _{and L} p

of the tube 1 to the forward and backward movement _th ratio moves, whereby

screwed, and the imaging lens .5 focal length of the whole lens system is Stem M _is detected within the tube 1 to the rear, however, the image plane in a determ end thereof disposed toward. ment is maintained. _ _ilf " _nim . _will

The first and the second movable lens group- To convert to ultrashort distance is used

pe L and L ₁ , which change the magnification of the actuating ring 6 first along aer. ⁰ positioning system, lens mounts 2 and 3, 3 "axis from the position in Fig. 2 into the m bdie within the fixed tube! moved forward between the photo shown, as a result of which the kissing _{lens system L 1} and the imaging lens system M are slidably arranged

Inside tube 1 around is a first curve cylinder 4 canoe, ^ »- i _& ^.« "~ = ■ ·.,,„ _

rotatable, which is formed with a first cam groove 4 A and with 35 linder 5 by merging the am ^ one Aust.ittsnut 4 B. A second cam cylinder 4 fixed pins 9. The zwMte De cam cylinder, the wegliche with a second cam groove lens group L ₃ ^billion. ^ L ^ \ ^ NDL · SA is shaped, is rotatable about the first Kurvenzy- 5 ie di Z ⁸⁸ ™ ^ ¹ ^ " ⁸ ^

find * 4 arranged around. As in Fig. 4 Shown is pin 8 in dr _γ ^^^

dimension the outlet groove AB so that its circumferential 4o and that in the cam cylinder 5 length at least equal to the circumferential length of the two groove 5 A moves axially. In this way, α th cam groove SA is, while its axial width intentional adjustment can be achieved.

is equal to the axial amount over which the If the actuating ring 6 from the btel ung κ

second cam groove S A can be moved. To the F i g. 3 rotated wildly ^a ; ^ ZcTd \ l to the second cam cylinder around an actuation * -45 cam cylinder 4 and 5 are arranged together du cn di ^ u ring 6 and attached to this. Curve compilation between pin 9 of the first. _N stifle 7 and 8 are attached to the lens mounts 2 and 3 venzylinders4 and * ^m tan guide channels ₅ , the cam pin 7 rotating through the second cam cylinder 5. LJe ^ ers straight guide channel 1 A in the first curve groove 4 A movable lens group L ₂ is ^ J the /. extends. The cam pin 8 extends through the interaction between the curve 7 uc ^ straight guide channel 1 ß and the exit groove 4 B first curve groove 4 A moves forward and into the second curve groove S A. Movable lens group L ₃ ^w ' ^rd _m ^eb _K ™ _s ^ _t 7 _and

As shown in Fig. 2 to 4, the first cure-interaction is the mixing of the cambered valve and cylinder 4 with a snap-in groove. 4 C shaped, the second cam groove 5 A _ wrwarts moving H cooperates with a steel ball 10, which is achieved in 55 by the focus for a uiiranu a distance provided in the second cam cylinder 5. Hole is arranged, with a leaf spring 11 on
second cam cylinder 5 is attached. The snap-in groove

4C, the steel ball 10 and the leaf spring 11 form gesosowuu. _u . * together a detachable holder for the upright lens group L ₂ and L ₃ moving, direction of the relative position between the first and il Bn of the attachment

the second cam cylinder 4 or 5 and thus the

relative position, wipe the first and the two- ^

th movable lens group L ₂ or L ₃ . The second movement of the f ^^^ "^^^ end through the cam cylinderS is with an elongated straight- S ₅ lens _{groupsL s} and L, " ewegt _MOVE

the guide channel SB is formed, which extends along a rotation of the ^ ring6 only d ^ e two te ^ J of the optical axis. One on the first cure lens _{group L 3} moves ^w JF ^d · "" ^ ines langge. venzylinder4 provided. With the pin 9, the guide channel SB has the shape of an ia gg

Distance to be reached.

In the embodiment described above, both the first and the second movable lens group L ₂ and L _{3 are} moved by rotating the actuating ring 6, while only the second movable lens group L _{3 is} moved when the actuating ring 6 is axially moved. In another arrangement, an axial movement of the retainer tube 6 makes both movable

elongated channel which extends in the circumferential direction les second cam cylinder 5.

Furthermore, instead of the second movable lens group L _3, the first movable lens group L _{2 can} be provided separately movably.

For this purpose 2 sheets of drawings

Claims (6)

Patent claims: 1. Varifocal lens with a fixed tube, in which a focusing lens system and an imaging lens system are housed, with a lens system provided between these two systems, which is used to change the focal length and for focusing in the close-up range and contains a first and second lens group, each via a first or second control cam are movable, and with an actuator which moves both lens groups together for the purpose of changing the focal length, characterized in that the first and second control cam (4 A, SA) are arranged in a first and second sleeve (4, 5) , which are guided concentrically to the fixed tube (1) and via their respective control cam (4/1, SA) with one of the lens groups (L ₂ , L ₃ ) are coupled, and that the actuator (6) both in rotary and in is movable in the axial direction, the movement in one direction, the change in focal length and the focusing in the near range by moving both r sleeves (4, S) and when the actuating member (6) is moved in the other direction, the switchover to close range takes place by moving only one of the two sleeves (5). 2. Varifocal lens according to claim 1, characterized in that the first sleeve (4) has a recess (4B) for the passage of a coupling pin (8) of the second sleeve (5). 3. varifocal lens according to claim 2, characterized in that the circumferential length of the recess {4 B) correspond to at least the circumferential length of the second control cam (5 A) and the axial width of the recess (4 B) equal to the axial displacement range of the second control cam (SA) . 4. varifocal lens according to claim 1, 2 or 3, characterized in that each sleeve (4, 5) in each case a straight tube fixed groove (1/1, 15) is assigned is through which the associated coupling pin (7, 8) passes and is guided. 5. Varifocal lens according to one of claims 1 to 4, characterized in that the sleeves (4, 5 ) are releasably connected to one another via a detent (4 C, 10), the detent position being the correct position of the lens groups (L ₂ , L, ) intended to each other for changing the focal length and allowing the lens groups to be driven simultaneously by the adjusting element (6). 6. varifocal lens according to claim 5, characterized in that when the detent (4 C, 10) is released, the sleeves (4, 5) are connected to one another via a further coupling pin (9) and a longitudinal slot (5 B) , the adjusting member (6 ) with axial displacement that _{drives one lens group (L 2} ), while with rotation both lens groups (L ₂ , L ₃ ) are driven.