DE7041703U - Optical system with infinitely variable magnification - Google Patents

Description

Ing.Karl Voekenhuber, 1180 Vienna, Pötzleinsdorferstrasse 118 «υ α

GDR. Raimund Hauser, 1040 Vienna, Goldegg-Gasse 2 * ^{¥ t}

Optical system continuously variable magnification

The object of the innovation is an optical system that can be continuously changed Magnification, especially for prism telescopes, preferably for binocular prism telescopes, with a multi-unit pancratic lens through which an image of an object is designed in a variable size and at least one eyepiece more fixed, more positive Focal length for viewing this image, possibly between the lens and the eyepiece a prism system for image reversal and, if necessary, for beam splitting is provided and the lens at least two in the axial direction for change the focal length has movable lens groups.

The basic structure of such optical systems is known per se and for example described in detail in French patent specification No. 1 427 872, also binoculars corresponding to the structure described are currently on the market. The image quality however, the built-in optical system is relatively modest.

The aim of the innovation is to create an optical system of the above-described

14h * Jk mm Λ, at

7U 41703 112.71

benen type, whose imaging properties also meet the highest demands. In every setting between the weakest and the strongest magnification, the modern pancratic system should be completely equivalent to the usual binocular systems of rigid magnification with the same performance in terms of image quality. , ■ ■

This object is achieved according to the invention in that the distances between the main points of the individual lens groups of the optical system reduced overall length 1 satisfies the following condition, in which EP is the diameter of the entrance pupil and ρ dea denotes the diameter of the exit pupil

4EP <1 <C 8 EP and

p ² >> 20.

According to an advantageous embodiment of the innovation, in which the lens of the system is made up of four lens groups, the two fixed positive lens groups I and IV includes, between which two for focal length adjustment in the axial

. VZ

Lens groups Π and ΠΙ that can be adjusted according to different laws of motion are arranged in the direction of the moving lens group Π, where the shiftable lens group Π in the second position has a dispersing effect, while the also shiftable lens group HL in the third position acts collectively, the refractive powers (J) ₁ to © _IV of Lens groups I to IV of the objective satisfy the following inequalities:

0.8 (j) ^ <d Y ₁ <C 1.25 (pjy

°> ⁸ L <Φπκ: ^{1 '25} L

^z > ⁵ £ iv <cl ^ n! ^{<< 3} ' ⁵ irr

In an expedient further development of the innovation; the refractive power © is sufficient the lens group acting as an eyepiece has the following relationship:

⁴ $ iv <$ v <= T ⁵ ίΐν

The innovation is described below with reference to some exemplary embodiments and below Explained in more detail with reference to the drawing:

Fig. 1 shows in a diagram the optical system of a binocular pankrati-

see prismatic glass, FIG. 2 shows the optical system in a first magnification setting, 3 shows the objective of the system illustrated in FIG. 2 in a second magnification setting. Fig. 4 also shows an axial section through a Variant of an eyepiece. ".. *

FIGS. 5 to 7 show the correction state of that corresponding to the example Π optical system both when set to the weakest, as well as to a medium and to the strongest magnification in each case for the image center (Fig. 5) a medium Image zone (Fig. 6) and the outermost edge of the image (Fig. 7). Figures 8-10 illustrate the corresponding figures of dispersion, with pos. a) in each case the setting on weakest, pos. b) to a medium and e) to a maximum magnification.

In the following, the subject of de / renewal in accordance with the Fig. 1 to 3 described in detail:

The positively refractive Gll ^ d IV, which is to be regarded as the actual Feldsteehergrunti lens, is preceded by an essentially afocal attachment of variable magnification; This attachment consists of a fixed link I with a positive elongation force in relation to the link IV, a link H with a negative Brfe gMcr aJfc φ _π , which is arranged to be displaceable along the optical axis for the purpose of varying the magnification, and of "one link ΠΙ with positive refractive power A _ ,, - which carries out a compensatory movement in a known manner in order to keep the image position constant.

The image of variable size created by members I, H, IH and IV of an object is made visible through an eyepiece with positive refractive power (Dy, the object-side focal plane of which coincides with said image. The one between member IV and member V. Plane-parallel plate P symbolizes a prism system which effects both the beam splitting required for binocular observation and an image reversal (see Fig. 1). The observer is thus presented with an upright, laterally correct image of variable size with constant sharpness of a distant object .

The total length 1 of the entire optical system should be from link I to link V

based on thin lenses between four and eight times that of with EP designated diameter of the entrance pupil lie:

4 EP ^ C 1 ^ C 8 EP

if ' " · ' . . .

P *> 20,

where ρ is the so-called "pupil square", a measure of the light intensity, with the cUe exit pupil lights up for a given object luminance (corresponding to that given by König and Koehler, "The telescopes and rangefinders", in the 3rd edition on page 78 Definition) means t

The choice of the refractive powers of the individual members of the overall system is on the one hand from the requirement for the shortest possible length, on the other hand from the economic one Necessity to accomplish the image aberration correction with the least possible means, certainly. An advantageous compromise is embodied in the following conditions:

The positive refractive power - (D _{1 of} the limb I and the positive refractive power ω _ of the limb ΙΠ are about the same as the positive refractive power Q) of the limb IV, while the negative refractive power G) _{n of} the limb Π is about three times as large in absolute terms like φ, is. The relationship between the refractive powers mentioned is given by the inequalities

f f fiv

² > ⁵ ^ | $ | I.

delimited.

The positive Breehkraft <| "The eyepiece marked with member V was"

about four to five times as strong as the expansion force (jh ^ of the actual binocular lens Element 17 selected, namely:

In order to correct the image errors, the above-mentioned elements

I, Π, ΠΙ, IV and V advantageously designed according to the following description:

Link I (r. To rj is composed in the manner of a modified Fraunhofer lens from a biconvex lens L _M and a negative meniscus L ₀ , which is separated from lens L ₁ by an air gap d and faces it with its concave surface Such lenses, provided the aperture ratio is not greater than 1: 3, can be corrected for spherical aberration, sine condition, zone errors and the chromatic difference of the spherical aberration, the so-called Gaussian error. between the lenses L and L ₀ it also enables the corrective state of the sagittal and meridional coma to be advantageously influenced and to prevent a disturbing increase in image errors with decreasing object distance:

n.

n.

1.60
1.80

if f. denotes the focal length of the link I.

'The magnification-dependent change in the image errors is primarily a function of the limb Π, the most powerfully refractive of the four forming the pancratic lens Limbs.

Link Π {r_ to r_) is made up of at least three lenses, of which the lens L adjacent to the described link I is "a simple biconcave lens, while a" further biconcave lens Ij- with a positive, essentially plano-convex lens L ^ _3, however may also be formed as a positive biconvex or Mensikus, is cemented to a negative achromatic Bi \ echkraft, the two L and L. Bikonkavliusen by an air distance d _ß are separated. the refractive powers © _ and 0. ₅ L of the lenses " or »L, ₅ are graduated in such a way that

4.5K

Since ia member I in favor of influencing the anastigmatic image field flattening

negative zonal deviation of the spherical aberration has not been completely eliminated, the _{kit radius r common to both L 4} and L_ must be dimensioned in such a way that this zone error is compensated. In-depth investigations have confirmed that the best result is obtained: if the refractive power φ r _{R is} the kit radius of the condition

is enough if

ί ^r 8

0.1 <r (n -n) <0.2 9 8

Another essential design feature is the low refractive power O r ₅ or φ r_ of the surfaces delimiting the link Π, which in terms of absolute value is no more than 1/10 of the refractive power ώ:

^{0 0}

IS segment ■ {r to ^)

■ {r ₁₀ to ^ ₁₂ ) »^ ⁵²⁵ ~ * ^s task falls to 1211 object space axially parallel and divergent behind member Π to collect so that its further course is essentially axially parallel again, can be used as a simple positive lens (where ' then r.,., 'omitted), but preferably as an ordinary achromatic achromatic cement surface similar to link 17 {X ₁ »to τ. ^) are executed. Link ΙΠ and link IV turn their more curved outer surface towards each other.

.- Behind link IV is that in the.Eig. 1 to 3 shown schematically, denoted by P. Prism system arranged. It is one with a beam splitting prism Connected Porro's reversal system of the first kind, whose function is from Pig. 1 can be seen in detail.

The state of correction of the ^{image of variable size created in the focal plane identified with F 1} , the described pancratic lens (member I, Π, IH, IV xmd P) and the following eyepiece (member V) is constant ϊξϊο like this for the entire adjustment that the image errors that occur in the eyepiece are practically completely compensated:
a) Spherical aberration and deviation from the sine condition exist in the sense of a

slight overcorrection.

b) The negatively curved meridional image shell of the objective agrees with the positive one curved of the eyepiece perfectly match, so that, for example, a concentric Ki'eisen built flat object is reproduced flawlessly.

c) The sagittal image shell of the objective is curved so slightly negatively that in cooperation with the flattened sagittal image shell of the eyepiece, the final resulting curvature remains practically below the limit of visibility.

d) The image is clearly barrel-shaped because all eyepieces have a pillow-shaped Distortion is common, as in the already mentioned work by König and Koehler is performed. The amount of barrel distortion was chosen so that for the picture of the overall system as it is finally presented to the eye of the beholder, not the Bow - Sutton condition, which is usually regarded as binding

is fulfilled, but the so-called angle condition

—— = const.

so that when the binoculars are swiveled, the effect of the so-called ^3S image distortion is suppressed and a natural view of the eye is conveyed (see König and Kühler, pg. 120).

e) The chromatic longitudinal and transverse errors of the lens are completely due to the state of correction of the eyepiece.

In order to achieve the desired state of correction while using the least amount of resources possible, two new types of Olmlar, not previously published in the literature, have been developed. The eyepiece shown in FIG. 2 is composed of a field lens L, _n and an eye-side group made up of three lenses L - .., L_ _{2 and L- ".} The field lens and the lens group on the eye side are separated from one another by an air gap which, as in the Kellner-type oculars, is about half the total focal length of the ocular. The lens group on the eye side is characterized by an almost refractive powerless achromatic lens L _n , L ₀ and a biconvex lens L ″ whose refractive power (9 approx

¹ * Λ

corresponds to the refractive power ^) öer field lens L, marked:

The distance of the exit pupil from the last lens vertex:

s ¹ y> 17

ensures that the field of view can be seen even when observing with glasses can.

Li FIG. 4 shows an eyepiece, the eye-side group of which is an _{achromatic lens cemented from the lenses L no} and I ₁₀ , while the field lens group consists of the two

ΧΔ Io '■ <-

x 1

Individual lenses 1, _d L ₁₁ consists. The refractive power O of the field diaphragm at ^T

next standing meniscus-shaped lens L is about half as great Avie's refractive power

O of the biconvex lens L, while the refractive power (j>, of the achromatic lens between j

* -ll '11 1 12j 13 -ΐ

see (j> ₁₀ and O lies: |

The embodiment of the eyepiece shown in FIG. 4 is also due to the position of the Exit pupil

s> 17

suitable for people who wear glasses.
In the protection claims 10 and 11 are the construction data for the telescope lenses (elements I to IV), in the protection claims 12 to 14 those for the eyepieces (elements V)

1 specified. The telescope magnification Γ is continuously variable between 2.6 and 8, | the diameter of the entrance pupil is 40 mm, the field of view has a maximum extension of 210 m at a distance of 1000 m. The twilight factor of around 18 makes the binoculars suitable for use on the hunt. |

In Figs. 5 to 7, the correction state is that corresponding to the example Π optical system both when set to the weakest, as well as to a medium- I re and at the highest magnification a middle image zone for the center of the image (FIG. 5) (Fig. 6) and the outermost edge of the picture (Fig. 7) shown; the angular

ι -

error for three barbel plotted as a function of the height of the exit pupil. Kg. 8 to 10 show the corresponding dispersal Egurs.

V-

Claims (5)

! ■ was it— ?! - ίο - Ϊ Claims for protection 1-. Optical system continuously variable magnification, especially for Prism telescopes, preferably for binocular prism telescopes, with a multi-section Pancratic lens, "iarch which is a picture of an object in variable Size is designed and at least one eyepiece with a fixed, positive focal length for viewing this image, possibly -ein between the lens and the eyepiece Prism system is provided for image reversal and optionally for beam splitting and . the lens at least two axially displaceable to change the focal length Has lens groups, characterized in that around the main point distances of the individual lens groups of the optical system reduced overall length 1 ] 'satisfies the following condition, in which EP is the diameter of the entrance pupil and ρ denotes the diameter of the exit pupil 4EP <1 <8EP and p ² > ■ 20. 2. Optical system according to claim 1 with one of four lens groups - built a lens comprising two fixed positive lens groups I and IV between which two for focal length adjustment in the axial direction according to different laws of motion adjustable lens groups II and BI are arranged, with the second Position standing, displaceable lens group II diffusing, the third standing, also displaceable lens group ΙΠ ^ r. that the refractive powers φ j to <[), "following the lens groups I to TV of the objective ai inequalities suffice: $ "< f
>><·
J • ·
• « * · ·
• »* V • * * * · V 0.8 ^. 1 QC A
'J] 0.8 -C * 2.5 ^ 3, 5 ^ ₁ 3. Optical system according to claim 2, characterized in that the Brech-Jcraft ^ _{v of} the lens group acting as an eyepiece satisfies the following relationship ⁴ Sv + ^ v ^ ⁵ $ rv- 4. Oplisches System according to one of the preceding claims, characterized in that diöFrontliasengruppe I of the lens is constructed in a manner known per se in the manner of a modified Fraunhofer lens, which is a biconvex lens L ·. and one negative. Meniscus L "exists, which is separated from" 3 lens L by an air gap d _o , the edge of its concave surface turns towards it, the refractive indices η, resp. ^{2 d} 2 n, lör the yellow heliuroline of the lenses ~ L and L respectively suffice with the following relation n. - ^ l 1.60 _d 1.80 uiiider air distance d "is delimited by the following inequality: d ₂ ^ 0.05 fj in which f, denotes the focal length of the first lens group L_ of the objective. 5. Optical system according to one of the preceding claims, dadurcli characterized in that the negative, displaceable lens group is composed of at least three lenses, of which the lens L ₀ adjacent to the first lens group I is a simple biconcave lens, while a wiser biconcave lens L> with one positive, preferably plano-convex lens L _ cemented to an achromatic lens of negative refractive power 1st and i> the two Bikonkavlinsen L ".and L" by an air distance d_ each other are separated, and the powers 0 "and O ^ g the simple biconcave lens UVD ^it achromatic LRJ with respect to the total refractive power east _π the second lens group L-. meet the following conditions: 4.5 1.5 6. Optical system according to claim 5, characterized in that the radius of curvature r _o of the cemented surface common to the two lenses L and L is dimensioned so that the surface refractive power φ satisfies the following condition: ^r 8 0.1 ^ - (n Z. 0.2 where η, and n, the refractive index of the lenses L ₄ and L ₅ for the yellow helium line δ 9 describe. 7. Optical system according to claims 5 or 6, characterized in that the surface powers O and φ of the surfaces delimiting the lens group Π ^r 5 ^r S are delimited by the following inequalities: O O $ 0.1 Optical system according to one of the preceding claims, characterized shows that the fifth lens group, acting as an eyepiece, is made up of a field lens L _nn and an eye made up of three lenses L _n -, L and L _{0 in a} manner known per se. -IU JLJ. JLZ JLo term group is composed, which _{is separated from the field lens L- Q} by an air gap d, which is about half as large as the total width f _{v of} the eyepiece, the lenses L_ _n and L__ of the lens group on the eye side to an approximately low refractive power jLJL JLZ sen achromatic lenses are cemented, further wherein the Prechkräfte ^> _Q and <p of the field lens L_ _n and preferably biconvex L correspond to the following condition jlu 3.0 13th cnd the distance of the exit pupil from the last lens unit s ¹ > - 17 - 13 - 9. Optical system according to one of claims 1 to 7, characterized in that that the fifth acting as an eyepiece lens group in a known manner from a composed of the two individual lenses L_ _fi and L-- field lens group and a augseitigen of the lenses L ₁₀ and L ₁ _ cemented achromatic lens, wherein preferably the e.iner field diaphragm adjacent Lens L ₀ meniscus-shaped the single lens L ₁ is biconvex, and the refractive powers O _1n , §>"and φ achromats satisfy the following relationships: $ 10 ^ T "$ 11 $ 10 - Φ _{Ί9 1Q} the two individual lenses or the $ 12.13 and the distance of the exit pupil from the last lens vertex s ¹ > 17. 10. Pancratic lens for an optical system according to the. Claims 1 to 7, characterized by the following data, understood with a deviation of the curvature of individual surfaces up to + 10% of the refractive power of the corresponding link, the thickness up to ί 10% of the corresponding link, the refractive indices up to - O ₁ 03 and the Abbe's numbers up to - 5: r +87.86 T ₂ -65.23 Γ - -58.25 r. -160.07 4 ' j ^ 6.6 / 1.658 / 50.9 ₂ = 2.31 d = 1.4 / 1.805 / 25.4 ^ = + 0.00909 = 1.72 to 43.19 Γ_ -387.16 r ₆ +36.26 c Γ ₇ -61.89 r _g +27.99 r _g +1034.50 d ₅ = 1.3 / 1. ₄ 652 / 44.9 d ₆ = 4.68 d _? = 1.3 / 1.669 / 45.0! ά _α = 3.5 / 1.785 / 25.1 | ο O = -0.01970 'Ot = -o, oo "l 68 O. = -0.00741 6r _Q = ^ 0.00414 - ■ *, o j- ö ^ $ r _g = -0 ₃ 0G076 d = 44.55 to 3.08 • ν r _io +157.48 ^p ii ⁺⁴⁷ * ^{00 1C} 1.640 / 34.6 U ₁ = 3.8 / 1.522 / 59.5! -69.03 ^1X . J > 0 = + 0.00909 ί ^χ I max. 12, ι min. 1, 09 00 r "_ +57.96 ^13th i = 4.1 / i _s 523 / 60-2 - S 0 _TV = + 0.00997 -46.11. ·· ■ y _IV . d ". = '1.2 / 1.640 / 34.6.1 A r ._- 180.62 Io 11. Pancratic lens for an optical system according to claims 1 to 7, characterized by the following data, understood with a deviation of the curvature of individual surfaces up to + 10% of the refractive power of the corresponding link, the thickness up to - 10% of the corresponding link, the refractive indices up to - 0.03 and the Abbe ¹ - numbers up to - 5: + 84.00 - 63.68 ^ = 6.6 / 1.622 / 53.2 - 56.91 σ_ = 1.4 / i, S05 / 25.4 -139.49 ° - ^ d ₄ = 1, S2 to 43.09 -387.16 d = 1.3 / 1.652 / 44.9. ^ = + 0.00909 r _g + 36.26 V ₁ - 61.89 T ₃ + 27.99 d ₆ = 4.69 = -0.02778- cL, = 1.3 / 1.669 / 45.0 d _g = 3.5 / 1.785 / 25.8 d _g = 45.23 to 3.76 = -0.01970 6 "= -0.00168 ^ ^Γ 5 . = - 0.00741 = + 0.00414 * = - 0.00076 r ₁₀ -1034.50 r ₁₂ - 53.97 1.517 / 64.2 = + 0.00909 12th 47.67 Jiaax. 12.09 1.00 ^X 14 ~ -221.3. d, = 4.5 / 1.517 / 64.2 d ₁₄ = 1.2 / 1.689 / 31.2 "O _iy = + 0.00998 • · * I » - 15 - 12. Eyepiece according to claim 8 for an optical system according to one of the claims 1 to 7 and, in particular for an optical system with a lens according to claim 10, characterized by the following data, understood by a deviation of the curvature a _r of individual areas of up to + 10% of the refractive power of the respective member, the thicknesses of up to - 10% of the corresponding member, the refractive indices up to - 0.03 and the Abbe ¹ see Numbers up to - 6: - \ Distance from field stop = 10.48 r ₁₆ +1 714.61 _r "" -22.44 16 = 2.7 / 1.650 / 39.2 +150.00. . O ₁₈ = 1.2 / 1.755 / 27.6 k 0 _{v = -r0.04505} d ₁₉ = 3.5 / 1.624 / 47.0 -100, 32 d 36 20 "'** 21 1 , 51 * 7 - 52 , 2 + 18, 71 = 2.4 / 7th J -600, O = + 0.02934 ! ll, 12 = ⁺⁰ ' ⁰⁰⁰³⁰ 113 = + 0, $ 02849 13. Eyepiece according to claim 9 for an optical system according to one of claims 1 ₅ to 7, in particular for an optical system with a Objeldiv according to claim 10, characterized by the following data, understood by a deviation of the curvature of individual areas of up to + 10% of the refractive power of the respective member, the thicknesses of "up to - 10% of the respective member , the refractive indices up to - 0.03 tmd the Abbe ¹ see numbers up to - 5: Distance from field stop = 16.29 -114.55 d - 35.87 = 2.0 / 1.623 / 58.1 +111.23 - 35.00 - 20.80 = 2.5 / 1.623 / 58.1 3 ^ = 3.5 / 1.623 / 56.9 ^Γ 22 - ⁶⁸³ » ⁰⁰ 21 = 1.3 / 1, « _V = + 0.04505 = + 0, 0120-38 14. Eyepiece according to claim 9 for an optical system according to one of the claims 1 to 7, in particular for an optical system with an objective according to claim 11, characterized by the following data, understood as a deviation of the curvature of individual surfaces up to + 10% of the refractive power of the corresponding member, the thickness of up to -10% of the corresponding member , the refractive indices up ^{to - 0.03 and the Abbe 1} see numbers up to - 5: Distance from field stop = 16.77 - 97.69 - 35.87 -d. _e = 1.8 / 1.620 / 60.3 16 + Üi, 23 - 35.00 +27.49 P ₂₁ - 21.57 ^r 22 - ⁶⁸³ ·. ⁰⁰ d ₁₈ = 2.5 / 1.620 / 60.3 d ₂₀ = 3.5 / 1.623 / 58.1 ₁ = I ₁ 2 / 4.805 / 25.4 > ί = + 0.0.4505 11th = + 0.02315 .- + 0.0157-3