DD144125A1 - SPIEGELLINSENOBJEKTIV WITH TELECENTRIC RADIATION - Google Patents

Abstract

The invention relates to a mirror lens objective with a telecentric beam path for imaging a circular ring from the object plane into the image plane in the scale 1: 1. It is the object of the invention to provide a mirror lens objective with a telecentric beam path and a circular pupil without central shading, which allows optimal Kontrastuebertragung, which should be achieved in that each half of the lens of a concave mirror with a central through hole, a raised rear mirror and a lens system of at least two lenses of opposite refractive power C ind1, D ind1, C ind2, D ind2, which are located within the through hole of the concave mirror consists. - Fig. 1 -

Description

Title ; Mirror lens objective with 'teecentric beam path

Applicatio ndungs area ^of: He fin-making:

The invention relates to a mirror lens objective with a telecentric beam path for imaging a circular ring from the object plane into the image plane on a scale of 1i1 and serves for producing graduated graduated circles and corresponding inscriptions, but also from others. Scales or curves arranged on a circular ring as they are needed in many optical devices, in particular surveying equipment, by means of photolithographic processes.

Characteristic of known technical solutions. For the illustration of relatively large picture fields or partial sections of these fields on a scale of 1: 1 symmetrically constructed lens lenses are used. This has the disadvantage that the lens objectives, which correspond to the task, have a large length and a correspondingly large object image distance. The length of these lens lenses is 4-5 times larger, their object image distance up to 7.5 times larger than the usable Bil'dfelddurchmesser. The lenses are therefore prone to vibrations and are very sensitive to shocks. The chromatic correction of lens objectives of these dimensions is

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difficult and. can be combined with the demand for high resolution and good contrast only with a large. Number of lenses with consistently large diameter of z.T. technologically. realize consuming to produce glass types.

Symmetrically designed mirror objectives with or without additional lenses have been proposed for imaging at a scale of 1: 1. Although these lenses have a smaller object-image distance, they all have the disadvantage that their entrance and exit pupils have the shape of a circular ring , However, they do not allow for optimal contrast transmission, since the optical transmission function of a system having a circular pupil, even when there are no aberrations, is considerably lower than that of a comparable objective without central shading of the pupil,

A special imaging system, which uses only mirror surfaces, is equipped with the same radii of curvature of all mirrors for the magnification ratio 1: 1 ". This can achieve a flattened field of view, but to correct the aperture error, all mirror surfaces must be aspherical." In addition, this lens also has one Circle pupil and produces the final image by means of an intermediate image, so that even with this lens optimal imaging is not possible «,

Concentric mirror lenses are also known in which all the mirror surfaces have a common center of curvature. With these lenses, very good imaging properties can be achieved in a restricted section of a circular ring

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- 3 ~ 2

Illustration of a full one. However, circular ring is not possible with this structure ». . · ..-... '

Symmetrical mirror lens lenses, in which all mirrors are broken, are also used for the magnification 1: 1. They are intended for extremely large angles in the objeitt image space, work with a small aperture, two intermediate images and have only a moderate resolution «

Object of the invention; ,

The aim of the invention is to provide a Spiegelklinikobjelrtivs with telecentric beam path and ^: circular 'pupil without Zentralabschattung that allows optimal contrast transmission and high resolving power in the region of the imaged circular ring with a diameter of about 100 mm.

Dar laying of ₁ spirit of the invention:

The object of the invention is to achieve this goal with minimal object image distance, compact design "and the largest possible aperture." This object is achieved according to the invention by a mirror lens objective with a telecentric beam path and a circular pupil without central shading, the '.' consisting of two halves symmetrical with respect to a plane of symmetry E and serving to image a circle K in scale 1: 1 in an image plane 0 * located in object plane 0, solved by having each of the halves of the objective consist of a concave mirror A 1, A _" with a central through-hole, a raised rear-view mirror and a lens system of at least z-white lenses of opposite refractive power C ₁₅ D., 0, I) ₀ , which are located inside the bore of the concave mirror," The invention will be advantageous characterized by the fact that the value of the focal length of the half ob--

 .. ·. 3469

OQ Ci-InQl Q $ R- | U

jektivs fA between 90% and 110% of the outer annulus diameter -0_, the ratio of the radii of the mirror surfaces r-otr. is between the values 1, 35 and 1.50, the distance d ~ between the mirror surfaces is between 24% and 26% of the radius of the concave mirror r _A and the focal length of the lens system f4 is 1.8 2 times greater than the focal length fJV of the Half lens "Pur the lens are expressed in formulas" the following values:. , 0.90 0 ^ c f ^ c 1.10 0 ^

.1,35 r _A c r _B ^ 1,50 r- _A. ' , , 0,24 r _A cd ₃ ^ O, 26r _A 1,8 f ^. ^. F ^ c 2,0 f ^

It is expedient to choose the focal length of the overall system f ^f greater than 10 times, but smaller than 20 times the outer circular diameter 0-, and to arrange all the lenses of the objective in a common version in the direction of the optical axis of the objective, which is slightly displaceable relative to the fixed mirrors. The raised rear-view mirrors can each be attached to a plane-parallel plate made of optical glass. The plane of symmetry has a circular diaphragm whose diameter can be varied in order to be able to vary the aperture and the depth of field.

exemplary embodiment

The invention is further illustrated by two schematic drawings.-Be "It _pointers:

FIG. 1 is a sectional view of a mirror lens objective according to the invention with beam path ''

34 6 y

g.2 is a sectional view of an inventive Spiegellirisenobjektivs, in which the rearview mirrors are fixed to glass plates, _ff , _ff perpendicular to an optical. Axis ^v is a bee. Thelevel'E representing the symmetry plane of the telecentric mirror lens objective. Immediately at the diaphragm plane E are two pairs of correction lenses C ₁ D. and Cp ^D 2 * ~ ⁿ ^ ^he bore of two concave mirrors A-, and arranged Ap «The curved surface of the concave mirror A 1 is at a distance d ^ arranged raised rear mirror B. and one in the object plane

0 located circular ring «, The curved surface of the concave mirror Ap is at a distance d _o arranged raised rear mirror Bp and the image plane

0 ¹ facing, in which the circular ring K in the scale 1: 1 is shown. Starting from the object plane Ό, the image of the circular ring K via the concave mirror A- and the raised rear mirror B- through the lens pairs. CjD and D ₂ Cp over the raised rearview mirror B ₂ and concave mirror A ₂ in the image plane in the scale 1: 1 projected /:.

In addition, the conditions that are advantageous in the application of the mirror lens objective according to the invention are shown. First, the focal length of the half lens f-A- is determined when the outer diameter is 0

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For this purpose, the equation for the image size of a distortion-free lens y '= f ^f tan (f) applies to the object ffs. Even if a half-objective does not have to be strictly distortion-free, because a second half-objective is symmetrical with the first is combined, is the name ί'Λ "tan e? V = 0 ^ / 2 good liähe tion 'Den. aperture angle 6" _B is chosen as large as possible, the

according to the invention allows CC = 24 ° -29 °, if

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f. ri i "ι -ι Π" i Π -ν Κ 'Ά Γι

one strives at the same telecentric beam path in the object picture area, ^^ receives these values the aperture angle to the focal length of the half-lens f ^ the relationship 0.9 ψ ^ £ f £ ^ -. 1.1 0g "we also want a möglichst- For example, the ratio of the mirrors in the range 1, .35 3?, <£ rg <1.50 r., and the distance of the mirrors A ₁ and Ap = d _Q according to 0.24 are chosen ^γ λ ^<:. d ~ <0.26 r .. In this way, the length of the lens can be kept smaller than twice the object image distance smaller than three times the outer diameter 0 of the circular ring to be imaged the task of the lens system, the value for the Petzvaisumme, for the mirror system of

15. Half lens -0.4 to -0.5 is to improve, and at the same time to compensate for the other aberrations of the "mirror." System, without introducing noticeable chromatic aberration.This is achieved for the 'half-lens with a system of two lenses opposite refractive power, which is constructed in the manner of Altachromaten * the necessary power of the lens system 1 / r4 need only about half the size to be FJJ as that of .Halbobjektivs 1 /. consequently You choose the focal length of the lens system f! in Range 1, δr ≤f- ^ <-2, ö fj. The value of the Petzval sum for the half-objective is suitably chosen on the order of -0.03 with respect to fJl = 1, in order to obtain an optimal demarcation in the region of the image to be imaged Since a mirror system is completely free of chromatic aberration and the power of the lens system can be chosen to be small, the overall system also has very little chromatic aberration. The position of the lenses inside b the puncture of the. Concave mirror has no decisive influence on the image quality. From spatial and technical

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Reasons, it is advisable to arrange them as close as possible to the iris plane. »

2 shows the objective according to the invention in which the rear-view mirrors IL and Bp are fastened to a respective plane-parallel glass plate 1 and 2. If the beam path is as telecentric as possible in the region of the circular ring K to be imaged, this facilitates the adjustment of the Object 0 and image plane Q ¹ to the object quite considerably, since small changes in position of this Ebe ~

1Nen 0 and O ¹ do not affect the picture scale. It achieves this by choosing the focal length f ^r of the overall lens greater than 10 times but less than 20 times of the outer circular ring diameter "Will you, however, selectively change the magnification by small amounts, as. For example, to compensate for Pertigungsverauigkeiten may be desirable, it is appropriate to all lenses of the lens in a common fit in the direction of the optical axis relative to

20. The stationary concave mirrors A | and slightly shift Ap,

Immediately at the diaphragm plane E, at a distance e from each other symmetrically about the diaphragm plane E are the lenses C ^ T) ^ ¥, and Cp Dp ^ p ⁱⁿ ^ - ^en bores of the concave mirrors A-, and arranged Ap * 'This is it possible to achieve a perfect ideal image within the circle to be imaged. r. ₅ r _? , r-, γ and rn the outer surfaces of the plane-parallel. Glass plates 1 and 2 of thickness d. where the raised rear view mirror B, and B ^ with-the radii of curvature r, and. The radii of the concave mirrors are defined by ro and r ^^. The correction lines F., and Fp each have a convex curvature iv and r. ^, a concave curvature iv and r, ^ the radii of curvature correction lenses CL and Cp are labeled

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η ο OCi -iO'7-0, i {. Ri ti

draws through the radii of curvature, rγ. and r-tp * ^ - ^e

γ.

Lenses D and Dp, each with two convex curvatures, are determined by the radii r _{g and} ... R-- and r "and r ₀ for the sides of the lenses D and D facing the diaphragm plane at a distance ir / ₂ . The size d ₂ is a measure of the distance of the imaginary vertices P- and P _{2 of} the drilled concave mirrors A- and Ap to the surface r _{2 of} the glass plate 1 and r -.-, the glass plate 2 «The distance between P and P _? to the vertices P- and P, the raised rear-view mirror B and B ₀ is d "

The distance between the vertices Pj- and Pg - .. · of the correction lenses F- and F ₂ and the points P ^ ^ and P is d. The thickness of the correction lines F and F _n is dr- that of the lenses -C- and C ₀ is a _r , which

15. the lenses D and D _? The thickness of the air gap between the lenses CD- and CpDp is d ~. The design data of three design examples are given below, normalized to the focal length of the half-lens of f x = 100 mm and for a numerical aperture of. 0.12 are determined. »

Radii of curvature distances u »thicknesses refractive indices for

s = s · = 39,746. n _e (= 546 nm) ng (= 436nm).

^r 1 ⁼ °° ^ ₁ = 12.719) 1.51859 1.52658

r ₂ = ω d _g = 44.035).

d ₃ = 3Q532

, d ₄ = 32,785

^ 81.754 d ₅ = 19.873). 1.73430 · 1.76206

r ₆ = + 56.958 dg = 0.762)

r _{? B +} 65.685 d _? =, 7.949) ^ ₄₈₉₁₅ ^ 49598 r ₈ = -298 _s 825 e = 1.590)

Outer diameter d * annulus 0 = 95.39 fA =

Inner diameter d * annulus 0 ^ = 85.85 f = 1724.38

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Curvature radii distances u · thickness s = s' = 45.337

^r r

00

r ₅ = + 87.713 r ₆ = + 184 ₅ 207 r _? = + 71.384 r ₈ = + 87.931

d _{1 =} ; 10.135) > d ₂ = 38.938) d ₃ = 36.116 d ₄ = 28.187 d ₅ = 14.508) d ₆ = 8.1.61)) d ₇ = 1.200) d ₈ = 9.067) e = 1.813) Refractive indices for

= 436nm). 1? 52658 ·

n _e (= 546 nm) .n

1.51859

1,51859 1,72794

1.51859

1.52658 1.74803

1.52658

Outer diameter d 0 = _e annulus 107.90

^f H ⁼

Inner diameter of circular ring 0. = 97.02 f '= 1266.24

^r 1 ^{= 00} I rp = oo

r ₃ = -147,792 r ^ = »206,774 r ₅ = + 90,967 r ₆ = + 250,522 r ₇ = + 72,293 r ₈ = + 95,504 r _g = ~ 248 ₅ 1b4

s = s' = 35.625 d _{1 =} 17.402) d ₂ = 50.099) d ₃ = 37.048 d ₄ = 28.417 d ₅ = 15.671) d ^ = 6.004) 1.671 8.0y 2 η (= 546 nm) 1.51859

^d 8 = 1.62410 1.70445 1.51859

e = 1, 740)

Outer diameter of circular ring 0 = 102.75

Inner diameter d., Iireisrings 0. ~ 92,32

1.52658

1.64204 1.72942 1.52658

f j =. f '= 1370.22

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? B 'S 11 i 9 7 3 "" - H1-' a ^ - ^

Claims (1)

Inventions claims: 1. A mirror lens objective with a telecentric beam path and a circular pupil without central shading, which consists of two symmetrical halves to a plane of symmetry (E) and for imaging a circular ring (K) in the object plane (0) at a scale of 1: 1 into an image plane (0 ^f ), characterized in that. each of the halves of the objective consists of a concave mirror (A-; Ap) with a central through-hole, a raised rear-view mirror (B-; Bp) and a lens system of at least two lenses of opposite refractive power (C., D ^; C ₂₅ Dp), which are located within the -durchbohrung des'Hohlspiegel, aufget aut is. Ci " Mirror lens according to item -1, characterized in that the value of the focal length of half. Lens (f-i ·) between 90% and 110% of the outer annulus diameter C0_), the ratio of the radii the mirror surface (^ -ηί * ^1. ) lies between the values 1.35 and 1.50, the distance d ~ (see Pig _e 2) between the mirror surfaces between 24% and 26% of the radius of the concave mirror (* "* ) and the focal length of the lens system (ff) is 1> 8, up to 2 times larger than the focal length (ft) of half the lens « 3c mirror lens objective according to item 2, characterized in that the focal length of the total system (f) is greater than 10 times, but less than 20 times, the outer circular diameter ((0 _a ) . and that all the lenses of the objective are displaceable in a common fit parallel to the optical axis of the objective relative to the fixed mirrors *. '.' ... 3469 11 '- 91' * 4 * mirror lens according to item 3, characterized in that the raised rear-view mirror (B.,; B ₂ ) are each attached to a plane-parallel Platt © optical glass, 5 ' mirror lens according to point 4 characterized' characterized in that in the plane of symmetry (E) is provided a circular aperture whose diameter is variable '*  6. Mirror lens objectively marked according to point 4-TO draws through the data of design example 1 «   , , 7. mirror lens according to item 4 characterized by the structural data of the construction example 2.. 8, mirror lens objective to 'point; 4' marked by the constructive data of construction example 3 3469