WO2013004687A1

WO2013004687A1 - Imaging optical unit and optical system having such an imaging optical unit

Info

Publication number: WO2013004687A1
Application number: PCT/EP2012/062895
Authority: WO
Inventors: Markus Sesselberg; Jan Buchheister; Marco Pretorius
Original assignee: Carl Zeiss Ag
Priority date: 2011-07-05
Filing date: 2012-07-03
Publication date: 2013-01-10
Also published as: DE102011078693B4; WO2013004687A8; DE102011078693A1

Abstract

A camera system (1) has an imaging optical unit (2) for imaging an object field (3) into an image field (5). The imaging optical unit (2) has at least one variation optics module (19) having at least two refractive optical variation components (20, 21). The latter are configured such that they can be offset with respect to one another for the purposes of a targeted change of imaging properties. The variation components (20, 21) simultaneously guide an illumination beam path (13) for illuminating the object field (3) and an imaging beam path (14). Entry surfaces (25) and exit surfaces (26) of the variation components (20, 21) are oriented in the beam path (13, 14) such that illumination light (8) reflected at these optical surfaces (25, 26) is not reflected into the imaging beam path (14). At least one of the optical surfaces (25, 26) is configured as a freeform surface. The result is a camera system, the imaging optical unit of which allows targeted changing of imaging properties and is also free from undesired incident-light reflections.

Description

Imaging optics and optical system with such an imaging optics

The invention relates to an imaging optics for imaging an object field in an image field. Furthermore, the invention relates to an optical system with such imaging optics.

Such an imaging optics and such an optical system are known from DE 103 16 416 A1, DE 10 2008 040 944 A1, US Pat. No. 4,415,239 and US Pat. No. 4,730,910. An imaging optics with incident illumination and eyepieces is known from EP 1 510 847 A. There are known optical systems with incident illumination, which include optical components whose optical surfaces are enforced by both an illumination beam path and an imaging beam path.

It is an object of the present invention to provide an imaging optics for an optical system equipped therewith, which on the one hand enables a targeted change in imaging properties and on the other hand is free of unwanted reflected light reflections, that is, free of unwanted reflections of illumination light in the imaging beam path.

This object is achieved by an imaging optics with the features specified in claim 1.

The use of at least one free-form surface makes it possible to avoid reflection by corresponding orientation of the entry and exit surfaces, in particular of the variation components, so that during a displacement path of the variation components no risk of reflection occurs. used displacement position of the variation optical module annoying reflected light reflections arise. The variation components are those components of the imaging optics which are designed to be able to be displaced relative to one another for the purpose of deliberately changing imaging properties. Those optical components whose distance from each other can be variably predetermined represent the variation components, even if in one specific embodiment only one of the two variation components is actually displaced. The variation optical module is an assembly containing the optical variation components for selectively changing imaging properties. A reflection prevention by appropriate orientation of the entry and exit surfaces of the additionally optionally existing rigid optical components can be ensured by the use of at least one free-form surface.

Such free-form surfaces can not be described by a mathematical function which is rotationally symmetrical about an excellent axis, which is a normal to a surface section of the optical surface. In particular, such free-form surfaces can not be described by a conic section-aspherical equation and require at least two independent parameters for the description of the optical surface. Such free-form surfaces can be described by a mathematical surface representation, which is characterized by a reference axis. With regard to the characterization of an optical surface as a free-form surface, the form of a boundary of the optically effective optical surface does not matter. Of course, optically effective surfaces are known from the prior art, which are not bounded rotationally symmetrical. Such optically effective surfaces are nevertheless writable by a rotationally symmetric function, wherein a non-rotationally symmetrical Bound cutout of this optical surface is used. Examples of free-form surface designs can be found in DE 10 2008 033 342 AI. The at least one free-form surface can be designed in such a way that imaging deviations, which are generated by the incident-light reflection-avoiding orientation of the variation components or also one of the other optical components of the imaging optics used jointly for guiding the illumination beam path and the imaging radiation path, are transmitted via the Design of free-form surface to be compensated. The variation optical module of the imaging optics may have more than one free-form surface. For example, each of the variation components may have at least one free-form surface. All optical surfaces of the variation optical module can also be designed as free-form surfaces. Finally, it is also possible to design additional optical components, which are provided in addition to the variation optical module in the imaging optics, with at least one free-form surface. Only one of the optical surfaces of these further components can be designed as a free-form surface. Alternatively, it is also possible here to design several or all of the optical surfaces of these further components as free-form surfaces. The displaceability of the variation components of the variation optical module can be used for focusing, ie for adapting an object distance of the object to be imaged to the imaging optics. Alternatively or additionally, the displaceability of the variation components of the variation object module can be used to vary a size of an image detail, that is to say to vary an enlargement of the imaging optics. The displacement of the variation components against each other can be done by a displacement drive. When shifting the variational components against each other Both variation components can be displaced, or only one of the two variation components can be displaced. The variation components can in turn be made up of a plurality of optical elements or subcomponents. The imaging optics can be used where incident light illumination is needed, for example in a surgical microscope, in a fundus camera or in a microscope. The imaging optics can be designed such that a central object point is imaged into a center of the image field or near a center of the image field relative to one another, regardless of a relative position of the optical variation components of the variation optical module. A deviation of an image of the central object point from the center of the image field can be made smaller than 10% of a typical field size. The imaging optics may be part of a varioscope, wherein the variation optics module is designed as a zoom optics. All optical surfaces of optical components of the imaging optical system which simultaneously guide the illumination beam path and the imaging beam path, thus oriented in the beam path, ie in particular tilted, can be such that illumination light reflected at these optical surfaces is not reflected in the imaging beam path. As a freeform surface, one of the components used jointly for guiding the illumination beam path on the one hand and the imaging beam path on the other hand is implemented. In particular, at least one of the optical surfaces of at least one of the optical variation components can be embodied as a free-form surface.

A tilt according to claim 2 allows the avoidance of reflected light reflections. Alternatively or additionally, the variation components can also be arranged decentered in relation to the main beam of the central object field point. The tilt manifests itself in one non-zero angle of the reference axis characterizing the freeform surface to the principal ray of the central optic field point. The decentering describes the distance of an origin of a local reference coordinate system characterizing the free-form surfaces from the main beam of the central object field point. The reference axis, which characterizes the at least one free-form surface, thereby represents an axis of this reference coordinate system. Alternatively or additionally, the other optical surfaces of the imaging optical system, ie those optical surfaces which do not belong to the variation components, can also be used as Freeform surfaces be executed. In this case, there may be a reference axis characterizing the at least one free-form surface of this optical component not belonging to the variation components, which is tilted or decentered against a main ray of a central object field point.

A tilt according to claim 3 in two mutually perpendicular excellent planes, z. B. a tilting of one of the at least two optical surfaces in an optical axis or a reference axis for mathematical description of the optical surfaces containing first reference plane and another of the at least two optical surfaces in a direction perpendicular to the first reference plane and the optical axis or the reference axis also containing second reference plane of the imaging optics, distributes the effects of this tilting on the imaging properties of the imaging optics and thus facilitates the compensation of deviations and in particular a correction of image errors on a corresponding interpretation of at least one free-form surface. An aperture element according to claim 4 facilitates blocking or discharging unwanted main light reflections.

An embodiment according to claim 5 can be used to compensate for imaging deviations. Image deviations that result from the displacement along the main beam of the central object field point can be compensated for at least partially by the displacement perpendicular thereto, so that the additional compensation effect that is placed on the design of the at least one free-form surface is not so great without the relative displacement with the two mutually perpendicular direction components.

An embodiment according to claim 6 facilitates a mechanical design of the imaging optics. The two variation components are each shifted along exactly one direction component. Such a displacement with two degrees of freedom makes it possible to image a central object field point in a central image field point, independently of a displacement of the variation components of the variation optical module. Alternatively, it is possible to design the image such that a deviation of the image of a central object field point from the center of the image field is less than 10% of the field size. This facilitates a measurement evaluation. The advantages of an optical system according to claim 7 correspond to those which have already been explained above with reference to the imaging optics according to the invention. The camera module can be designed as a stereo camera. The camera module can be designed to be rotatable. As an alternative to a camera module, a monoscopic or stereoscopic shear visual insight, eg. B. by a tube according to claim 8, may be provided.

An optical system according to claim 9 does not require an external light source due to the included illumination module.

Embodiments of the invention will be explained in more detail with reference to the drawing. FIG. 1A shows an optical system with an imaging optic for. FIG

Illustration of an object field in an image field, which is detected by a camera module, and with a schematically illustrated illumination module for illuminating the object field, wherein optical components of the imaging optics are shown in a meridional- section and wherein a beam path of the imaging beams between the object field and an entrance pupil of the camera module is shown; FIG. 1B shows the optical system according to FIG. 1A, wherein the illumination module is shown in greater detail and an illumination beam path is shown by way of example; a further embodiment of an imaging optics, which can be used instead of the imaging optics of Figure 1, also in a meridional section and shown with a relative position of the optical components "long working distance". Fig. 3 in a similar to Fig. 2 representation of the imaging

Optics of Figure 2, also in the meridional section, shown in the relative position after "average working distance" of the optical components.

FIG. 4 shows, in a representation similar to FIG. 2, the components of the imaging optics according to FIG. 2 in the relative position "small working distance"; FIG. 5 to 7 show the components of the imaging optics according to FIG. 2 in the relative positions according to FIGS. 2 to 4, illustrated in a sagittal section;

FIG. 8 enlarges the optical in a meridional section

Components in the relative position of Figures 2 and 5;

FIG. 9 enlarges the optical in a meridional section

Components in the relative position of Figures 4 and 7;

Fig. 10 increases in a sagittal section, the optical

Components in the relative position of Figures 2 and 5;

Fig. 1 1 increases in a sagittal section, the optical

Components in the relative position of Figures 4 and 7; Fig. 12 to 21 in a similar to Figs. 2 to 1 1 representation of another embodiment of an imaging optics, which can be used instead of the imaging optics in FIG.

An imaging optical system 1 according to FIG. 1 (FIGS. 1A and 1B) comprises an imaging optical unit 2 for imaging an object field 3 in an object plane 4 into an image field 5 in an image plane 6. The imaging optical system 1 is subsequently connected as far as it is concerned is described with a camera module, also referred to as a camera system.

The imaging system 1 comprises a camera module 7 for detecting an intensity distribution of imaging light 8 over the image field 5. The (8a) imaging light 8 emanating from the object points is guided via a front pupil opening 9 into the interior of the camera module 7 towards the image field 5. Optical components between the pupil opening 9 and the image field 5 are not shown. The pupil opening 9 is arranged in a pupil plane 10 of an imaging beam path of the imaging light 8. The pupil opening 9 simultaneously represents an aperture diaphragm. The pupil plane 10 also lies in the xy plane. In the camera module 7, the imaging light 8 falls on a coincident with the image field 5 portion of a spatially resolving detection element 10a, for example, a CCD array.

Instead of the camera module 7, a tube 10b indicated by dashed lines may be provided with a tube optics (not shown). The detection element 10a then drops away. About the tube 10b is a visual insight for subjective image capture possible. The imaging system 1 further includes an illumination module 1 1 having a light source I 1 a for generating illumination light 1 lb (see FIG. 1B). A beam direction of the illumination light 1 lb is indicated in FIG. 1B by an arrow 11c.

An illumination beam path 13 and an imaging beam path 14 are illustrated in FIG. 1B and in FIG. 1A on the basis of seven selected object field points. Shown are, as far as the imaging beam path 14 is concerned, in each case the courses of main beams 15 and edge beams 16, 17 which originate from the respective object field points. 1A shows the imaging beam path 14. FIG. 1B shows, by way of example, a possible illumination beam path 13. An object-side numerical aperture of the illumination beam path 13 is smaller than the object-side numerical aperture detectable by the camera module 7. An embodiment of the illumination beam path is also possible, in which the entire detectable object-side numerical aperture is also illuminated. An embodiment of the illumination beam path is also possible, in which the object-side numerical aperture of the illumination beam path 13 is greater than the object-side numerical aperture detected by the camera module 7.

To explain the description of positional relationships of the components of the imaging system 1, a Cartesian xyz coordinate system is used below. The x-axis is perpendicular to the plane of FIG. 1 and into it. The y-axis goes up. The z-axis extends to the right and parallel to the main beam 15 _{Z of} the central object field point.

The illumination light 1 lb emanating from the light source 1 la passes through a schematically indicated illumination optics 12 and is shown in the figure below. bildungsstrahlengang 14 via a beam splitter 18 coupled. This is tilted by about 45 ° with respect to a main ray 15 _{z of} a central object field point about an axis of rotation perpendicular to a first yz-eferenzebene (drawing plane of FIG. 1). The beam splitter 18 reflects at least a part of the illumination light 1 1b and leaves at least part of the imaging light 8 returning from the object field 3, so that in the imaging beam path after the beam splitter 18 the imaging light 8 entering the camera module 7 is decoupled from the illumination beam path 13.

A maximum angle of incidence of imaging rays on the pupil plane 10 may be less than 40 °, less than 20 °, less than 10 °, or less than 5 °. In the embodiment of the imaging optical system 2, this maximum angle of incidence is approximately 8 °.

The imaging optics 2 has a variation optical module 19 with two refractive optical variation components 20, 21. The variation component 21 lies in the imaging beam path 14 between the object field 3 and the variation component 20. The variation component 20 is designed as a lens doublet. The variation component 21 is implemented as a single meniscus lens. The two variation components 20, 21 of the variation optical module 19 are designed to be able to be displaced relative to each other along a direction of displacement, which is indicated by a double arrow 22 in FIG. 1 in order to selectively change the imaging properties of the imaging optical system 2. The displacement direction 22 runs parallel to the main beam 15 _{z of} the central object field point. The displacement leads to a corresponding displacement of the object plane 3 in the z direction, which is indicated by a further double arrow 22a. The displacement of the variation component 20 via a schematically indicated in FIG. 1 displacement drive 20a.

Between the variation optical module 19 and the beam splitter 18, the imaging optic 2 has two further refractive optical components 23, 24, which are rigid, that is, not displaceable along the displacement direction 22. The optical component 24 is the first optical component in the imaging beam path 14 after the variation optical module 19. The optical component 23 is arranged between the optical component 24 and the beam splitter 18.

The optical components 23, 24 are likewise refractive optical components. The optical component 24 is again designed as a lens doublet. The optical component 23 is designed as a meniscus lens.

The optical components 20, 21, 23 and 24, ie in particular the variation optical module 19, simultaneously guide the illumination beam path 13 and the imaging beam path 14. Entry surfaces 25 and exit surfaces 26 of the optical components 20, 21, 23 and 24, as seen from the object field 3, are oriented in the imaging beam path 14 and in the illumination beam path 13 in such a way that illumination light 1 1b reflected on these optical surfaces 25, 26 is not reflected in the imaging beam path 14, that is, if it is not incident on the pupil opening 9 of the camera module 7. Also, reflexes that arise on cement surfaces, such as doublets, may also not enter the pupil opening 9 of the camera module 7. The illumination beam path 13 is folded in the yz plane adjacent to the pupil opening 9 via the beam splitter 18. The object plane 4 and the image plane 5 run parallel to the xy plane. The entry surfaces 25 and the exit surfaces 26 of the two optical components 21 and 23 are tilted about tilt axes parallel to the x-axis, ie, as shown in Fig. 1, in the first reference plane (yz plane) tilted. The entry surfaces 25 and the exit surfaces 26 of the two optical components 20 and 24 are tilted about tilt axes parallel to the z axis, ie tilted within a second reference plane (xz plane).

At least one optical surface of the optical components 20, 21, 23, 24 is designed as a free-form surface. The free-form surfaces are marked in FIGS. 2 et seq. By a dashed line running perpendicular to the surface. Thus, at least one of the entry surfaces 25, at least one of the exit surfaces 26 or, in the case of the doublets 20, 24, an intermediate surface 27a may be designed as a freeform surface. The intermediate surface 27a may be designed as a cemented surface. Also, several of these optical surfaces and in particular all of these surfaces can be designed as freeform surfaces. Alternatively, all entry surfaces 25 or all exit surfaces 26 may be designed as free-form surfaces.

On the edge side, one of the optical components 20, 21, 23, 24 can be designed as a diaphragm opening and thus as an aperture element for limiting a peripheral profile of the imaging beam path 14. This can be used for targeted absorption or dissipation of illumination light which is reflected at the tilted surfaces of the optical components 20, 21, 23, 24 and should not reach the image field 5. A further embodiment of an imaging optic 27 will be described below with reference to FIGS. 2 to 11, which may be used instead of the imaging optics 2 in the imaging system 1.

Components which correspond to those already explained above with reference to FIG. 1 carry the same reference numerals and will not be discussed again in detail. The imaging optics 27 has in the imaging beam path 14 between the object field 3 and the pupil opening 9 a total of three optical components, namely two variation components 28, 29 of a variation optical module 30 and dashed lines between the variation optical module 30 and in FIG indicated beam splitter 18, another, rigid optical see component 31. The object field 3 facing variation component 29 is designed as a lens doublet with two meniscus lenses. The variation component 28 is also designed as a lens doublet with a biconcave lens and a biconvex lens. The optical component 31 is designed as a single meniscus lens.

In the imaging optics 27 are an entry surface 25 of the variation component 29, an exit surface 26 of the variation component 29, an exit surface 26 of the variation component 28 and an entrance surface 25 of the optical component 31 designed as free-form surfaces. The other optical surfaces of the imaging optics 27 are designed as rotationally symmetrical surfaces.

The components 28, 29, 31 of the imaging optics 27 are refractive optical components. Fig. 2 and in an enlarged detail the Fig. 8 show the imaging optics with a displacement position of the two variation components 28, 29 for realizing a large working distance between see the pupil plane 10 and the object plane 4. The variation component 28 is in positive z-direction so far in the direction of the variation component 29 to move that touch the two variation components 28, 29 practically. 3 shows the relative position of the two variation components 28, 29 for realizing an average working distance between the object plane 4 and the pupil plane 10.

FIG. 4 and in a detailed enlargement the FIGS. 9 show a relative position of the variation components 28, 29 for realizing a small working distance between the field plane 4 and the pupil plane 10.

Between the relative positions according to FIGS. 8 and 9, the variation component 28 is displaced so far in the negative z direction that in the relative position according to FIG. 9 there is only a small distance between the variation component 28 and the optical component 31 is present. At the same time, the variation component 29, starting from the position according to FIG. 8, is displaced in FIG. 9 by a displacement path Ay in the positive y-direction.

The displacement position "average working distance" of FIG. 3 represents an intermediate position on the displacement path of the variation components 28, 29 between the displacement positions of FIGS. 8 and 9. A relative displacement of the two variation components 28, 29 relative to each other thus takes place with a z direction component along the main ray 15 _{z of} the central object field point and at the same time with a y direction component perpendicular thereto. The relative displacement is such that one of the two components of the variation optical module 30, namely the variation component 28, in the z-direction and the other of the two components of the variation optical module 30, namely the variation component 29, perpendicular thereto is displaced in the y-direction.

The displacement of the variation component 28 takes place via a displacement drive 28a shown schematically in FIG.

The displacement of the variation component 29 takes place via a displacement drive 29a, which is also schematically indicated in FIG. 9. The two variation components 28, 29 of the variation optical module 30 form, together with the optical component 31, the object plane 3 to infinity. A further imaging optical system 32 will be described below with reference to FIGS. 12 to 21, which likewise can be used instead of the imaging optical system 2 in the imaging system 1 according to FIG. Components and functions which correspond to those which have already been explained above with reference to FIGS. 1 to 1 1 bear the same reference numerals and will not be discussed again in detail.

The imaging optical system 32 consists exclusively of components of a variation optical module 33. The components of the variation optical module 33 image the object plane 3 to infinity. In this The variation optical module 33 corresponds to the variation optical module 30 according to FIGS. 2 to 11, including the optical component 31. The function of the variation optical module 33 otherwise corresponds to that of the variation optical module 19 or 30 described above in connection with FIGS Fig. 1 to 1 1 have already been explained. A variation component 34 facing the object field 3 comprises two sub-components, namely a meniscus lens 35 facing the object field 3 and a lens doublet 36. A further variation component 37 of the variation optical module 33 facing the pupil opening 9 comprises a biconvex lens 38, which faces the pupil opening 9, and a lens doublet 39.

In the imaging optical system 32, therefore, exactly one lens group, namely the variation component 34 with the two optical components 35, 36, is displaced.

An entrance surface 25 of the meniscus lens 35, an exit surface 26 of the lens doublet 36, an exit surface 26 of the lens doublet 39 and an exit surface 26 of the lens 38 are designed as free-form surfaces. The other optical surfaces of the imaging optical system 32 are designed as rotationally symmetrical surfaces.

FIG. 12 and in an enlarged detail FIG. 18 show the imaging optics 32 in a displacement position of the variation optics module 33 for realizing a large working distance between the object plane 4 and the pupil plane 10. FIG. 13 shows the imaging optic 32 in a displacement position of the variation optics module 33 for realizing an average working distance between the object plane 4 and the pupil plane 10. FIG. 14 and in detail enlarged FIG. 19 show a displacement position of the variational components 34, 37 of the variation optical module 33 for realizing a small working distance between the object plane 4 and the pupil plane 10. To shift the variation optical module 33 between the displacement positions shown in FIGS. 12 to 14, the object field 3 facing variation component 34 in positive z-direction towards the object field 3 shifts. When adjusting the working distance of the imaging optics 32, none of the optical components 35, 36, 38, 39 is displaced in the x or the y direction.

The joint displacement of the two optical elements 35, 36 of the variation component 34 takes place via a displacement drive 34a schematically indicated in FIG.

The free-form surfaces of the imaging optics 27, 32 can be described by the following surface formula, which is designated in the following tables for describing the exemplary embodiments as "surface type: KXY":

In this case, x and y denote the coordinates on the optical surface, starting from a coordinate origin which is defined as the penetration point of a z-axis in the local xyz coordinate system of the freeform surface. This puncture point can theoretically also lie outside the used optical surface. z denotes the arrow height of the freeform surface. The coefficients cvx and cvy describe the curvatures of the free-form surface in the xz and yz sections. The coefficients ccx and ccy are conic parameters.

The free-form surface formula has a leading biconical term and a subsequent xy polynomial with coefficients α_μ. In the following tables, the embodiment is described, which is based on the figures 2 to 1 1. Described in Table 1 is the variant in the relative position which belongs to the "small working distance" and which is shown in Fig. 4. Unrequited constants α _ω (alpha_k, 1) are equal to 0. In addition: RDX = 1 / cvx; RDY = 1 / cvy The information "xyz" designates the local systems of the different surfaces with respect to the local system to surface 1; the unit is millimeters. The words "exx exy exz" denote the direction of the x-unit vector of the respective area in coordinates of area 1. The words "eyx eyy eyz" denote the direction of the y-unit vector of the respective area in coordinates of area 1. The words "ezx ezy ezz "denotes the direction of the z-unit vector of the respective area in coordinates of area 1. Area 1 corresponds to the pupil opening 9. The indication of the medium to a surface is to be understood that the light beam in the specified medium, as soon as he the area has passed through "Medium" given abbreviations such as "N-PK 52A" refer to the optical glass types used in the embodiment and are taken from the current catalog of optical glasses Schott AG (issued May 201 1). For example, it is available online at http://www.schott.com/advanced_optics/english/download/schott_optical_ glass_pocket_catalogue_may_201_en.pdf.

Table 1: exemplary embodiment

Surface No. 1 Surface type: Plan

Medium: AIR Manufacturer:

x y z

0 0 0

exx exy exz

1 0 0

eyx eyy eyz

0 1 0

ezx ezy ezz

0 0 1

Surface No. 2 Area Type: Sphere

Medium: N-PK52A Manufacturer: SCHOTT x y z

0 0 44

exx exy exz

1 0 0

eyx eyy eyz

0 0.9837756334423198 0.1794031857163143 ezx ezy ezz

0 -0.1794031857163143 0.9837756334423198

RDY -170.102121

Surface No. 3 Surface type: KXY

Medium: AIR Manufacturer:

x y z

0 -0.6554149999999999 48.5

exx exy exz

1 0 0

eyx eyy eyz

0 0.9651804487793452 0.2615849791064122 ezx ezy ezz

0 -0.2615849791064122 0.9651804487793452

RDX -239.709649

RDY -85.1 18363

CCX 0.000000 CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 -3.316327e-03

0 2 1.1 14535e-03

2 1 -4.073101 e-05

0 3 -3.212235e-05

4 0 3.459538e-07

2 2 2.616513e-07

0 4 1.061355e-07

4 1 9.628452e-09

2 3 8.393582e-09

0 5 5.169824e-10

Surface No. 4 Surface type: KXY

Medium: N-PK51 Manufacturer: SCHOTT

x y z

0 -1,171 132 57.5

exx exy exz

1 0 0

eyx eyy eyz

0 0.960081276469539 -0.279721 1872072273

ezx ezy ezz

0 0.279721 1872072273 0.960081276469539

RDX 454.525309

RDY -932.327343

CCX 0.000000

CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 4.883200e-03

0 2 6.242278e-03

2 1 -1.541434e-05

0 3 -1.152281 e-05

4 0 4.948645e-07

2 2 7.134341 e-07

0 4 2.516236e-07

4 1 1.021739e-08

2 3 7000242e-09

0 5 -3.892305e-10

Surface No. 5 Surface type: Sphere

Medium: N-SF66 Manufacturer: SCHOTT

x y z

0 0 68.87026400000001

exx exy exz

1 0 0

eyx eyy eyz

0 0.9714574300770291 -0.2372139573215162

ezx ezy ezz

0 0.2372139573215162 0.9714574300770291

RDY -667.057684 Surface No. 6 Surface type: Spherical

Medium: AIR Manufacturer:

x y z

0 -0.6437169999999998 71.87026400000001

exx exy exz

1 0 0

eyx eyy eyz

0 0.9642794713636933 -0.2648869591 100254

ezx ezy ezz

0 0.2648869591 100254 0.9642794713636933

RDY 607.709944

Surface No. 7 Surface type: KXY

Medium: N-LASF44 Manufacturer: SCHOTT

x y z

0 3.025698000000001 103.3

exx exy exz

1 0 0

eyx eyy eyz

0 0.9594740962691601 -0.2817968392095241 ezx ezy ezz

0 0.2817968392095241 0.9594740962691601

RDX 331.598751

RDY -386.412156

CCX 0.000000

CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 8.640401 e-04

0 2 4.815790e-03

2 1 -4.930274e-05

0 3 -3.066782e-05

4 0 1.071602e-06

2 2 1.388790e-06

0 4 3.954612e-07

Area No. 8 Area Type: Sphere

Medium: N-SF66 Manufacturer: SCHOTT

x y z

0 5.139174294071431 1 10.4960557220187

exx exy exz

1 0 0

eyx eyy eyz

0 0.9304059959727887 -0.3665306026212314

ezx ezy ezz

0 0.3665306026212314 0.9304059959727887

RDY 53.498204

Surface No. 9 Surface type: KXY

Medium: AIR Manufacturer: xyz

0 6.689056909723814 1 15.7731632514991

exx exy exz

1 0 0

eyx eyy eyz

0 0.9434375517996789 -0.3315502765105595

ezx ezy ezz

0 0.3315502765105595 0.9434375517996789

RDX 48.589505

RDY 53.218455

CCX 0.000000

CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 -3.305736e-03

0 2 -2.034866e-03

2 1 -2.465846e-05

0 3 -1.002891 e-05

4 0 2.750502e-07

2 2 2.656296e-07

0 4 3.738444e-09

4 1 -5.496640e-09

2 3 -1.358851 e-08

0 5 -5.793797e-09

Surface No. 10 Surface type: Plan

Medium: AIR Manufacturer:

x y z

0 0 122

exx exy exz

1 0 0

eyx eyy eyz

0 1 0

ezx ezy ezz

0 0 1

RDY 0.000000

Surface No. 1 1 Surface type: Plan

Medium: AIR Manufacturer:

x y z

0 0 324

exx exy exz

1 0 0

eyx eyy eyz

0 1 0

ezx ezy ezz

0 0 1

RDY 0.000000 The variant for the relative position "average working distance" for the exemplary embodiment from FIG. 3 is obtained if the following changes are made in Table 1 above:

Embodiment of Fig. 3rd

Average working distance

Surface no.

x

0 77.677814

Surface no.

x

0 89.048078

Surface no.

xY

-0.6437169999999998 92.048078

Surface No. 7

x y z

0 0.247319 103.3

Surface No. 8

x y

0 2.360795294071431 1 10.4960557220187

Surface No. 9

x y

3.910677909723813 1 15.7731632514991

Surface no.

x z

0 479

The variant for the relative position "large working distance" for the embodiment of FIG. 2 is obtained by making the following changes in Table 1 above:

Embodiment of FIG. 2

Large working distance

Surface No. 4 x Y z

0 -1 .171 132 88.48288199999999

Surface No. 5

x Y z

0 0 99.853146

Surface No. 6

x Y z

0 -0.6437169999999998 102.853146

Surface No. 7

x y z

0 -0.916638 103.3

Surface No. 8

x y z

0 1 .196838294071431 1 10.4960557220187

Surface No. 9

x y z

0 2.746720909723813 1 15.7731632514991

Surface no. 1 1

x y z

0 0 635

In the following tables, the embodiment is described, which is based on the figures 12 to 21. Described in Table 2 is the variant in the relative position which belongs to the "small working distance" and which is shown in Fig. 14. Non-specified constants α _ω (alpha-k, 1) are equal to 0. In addition: RDX = 1 / cvx; RDY = 1 / cvy. The indications "xyz" designate the local systems of the different areas with respect to the local system to area 0; the unit is millimeters. The words "exx exy exz" denote the direction of the x-unit vector of the respective area in coordinates of area 0. The words "eyx eyy eyz" denote the direction of the y-unit vector of the respective area in coordinates of area 0. The statements "ezx ezy ezz "denote the direction of the z-unit vector of the respective area in coordinates of area 0. Area 0 corresponds to the pupil opening 9. The indication of the mea- The surface of a surface is to be understood as meaning that the ray of light passes through the specified medium as soon as it has passed through the surface. The under

Refer to "Medium" given abbreviations such as "N-PK 53"

refer to the optical glass types used in the embodiment and are taken from the current catalog of optical glasses Schott AG (May 201 1 edition 1). This is for example online at

http://www.schott.com/advanced_optics/english/download/schott_optical_ glass_pocke t_catalogue_may_201 l_en.pdf available.

Table 2: exemplary embodiment

Surface No. 0 Surface type: Plan

Medium: AIR Manufacturer:

x y z

0 0 0

exx exy exz

1 0 0

eyx eyy eyz

0 1 0

ezx ezy ezz

0 0 1

Surface No. 1 Surface type: KXY

Medium: P-PK53 Manufacturer: SCHOTT

x y z

0 -0.540959 44

exx exy exz

1 0 0

eyx eyy eyz

0 0.9659258262890683 -0.2588190451025207

ezx ezy ezz

0 0.2588190451025207 0.9659258262890683

RDX -436.305672

RDY 244.871562

CCX 0.000000

CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 2.305089e-03

1 1 -1.961383e-04

0 2 -1.086664e-03

3 0 -2.866679e-05 2 1 -1.471717e-05

1 2 -3.605414e-05

0 3 9.567453e-07

4 0 -5.264173e-07

3 1 7.786697e-07

2 2 1.907950e-07

1 3 1.094817e-06

0 4 3.674618e-07

5 0 8.238225e-09

4 1 1.932793e-08

3 2 2.458507e-08

2 3 -1.702729e-10

1 4 1.190706e-08

0 5 -2.056332e-08

6 0 2.976716e-10

5 1 -3.734873e-10

4 2 2.555383e-10

3 3 -1.004882e-09

2 4 1.340956e-10

1 5 -7.447032e-10

0 6 2.224027e-10

Surface No. 2 Area Type: Sphere

Medium: AIR Manufacturer:

x y z

0 0.7531362255126037 48.82962913144534

exx exy exz

1 0 0

eyx eyy eyz

0 0.9659258262890683 -0.2588190451025207

ezx ezy ezz

0 0.2588190451025207 0.9659258262890683

RDY -399.651627

Surface No. 3 Surface type: KXY

Medium: P-PK53 Manufacturer: SCHOTT

x y z

1.063939 0 52.6

exx exy exz

0.9659258262890683 0 -0.2588190451025207

eyx eyy eyz

0 1 0

ezx ezy ezz

0.2588190451025207 0 0.9659258262890684

RDX -101.500447

RDY -62.171332

CCX 0.000000

CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 1.067386e-02 1 1 2.298249e-04

0 2 1.409776e-02

3 0 3.385375e-05

2 1 1.241867e-05

1 2 4.235964e-05

0 3 -1.432995e-06

4 0 8.643002e-07

3 1 -7.497370e-07

2 2 8.521928e-07

1 3 -1.055672e-06

0 4 3.033558e-07

5 0 -1.735162e-09

4 1 -1.527084e-08

3 2 -1.346266e-08

2 3 3.765862e-09

1 4 -8.840041 e-09

0 5 2.594443e-08

6 0 -1.682484e-10

5 1 2.341912e-10

4 2 -2,236,872e-10

3 3 6,301 172e-10

2 4 -1.086680e-10

1 5 5.545305e-10

0 6 -1.448558e-10

Surface No. 4 Surface type: Sphere

Medium: N-SF66 Manufacturer: SCHOTT x y z

2.875672315717645 0 59.36148078402348 exx exy exz

0.9659258262890683 0 -0.2588190451025207 eyx eyy eyz

0 1 0

ezx ezy ezz

0.2588190451025207 0.9659258262890684 RDY -301.616778

Surface No. 5 Surface type: Sphere

Medium: AIR Manufacturer:

x z

3.80742087808672 0 62.83881375866412 exx exy exz

0.9659258262890683 0 -0.2588190451025207 eyx eyy eyz

0 1 0

ezx ezy ezz

0.2588190451025207 0.9659258262890684 RDY 1593.163604

Surface No. 6 Surface type: KXY Medium: N-SSK8 Manufacturer: SCHOTT

x y z

0 0 99

exx exy exz

0.9659258262890683 0 -0.2588190451025207

eyx eyy eyz

0 1 0

ezx ezy ezz

0.2588190451025207 0 0.9659258262890684

RDX -264.972629

RDY -280,951 194

CCX 0.000000

CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 -1.170631 e-03

1 1 1.337185e-04

0 2 -1.860734e-03

3 0 -3.575536e-06

2 1 -8.794331 e-06

1 2 1.1 12212e-05

0 3 -1.827406e-05

4 0 1.079125e-06

3 1 -2.313551 e-07

2 2 1.659866e-06

1 3 1.937796e-08

0 4 9.103396e-07

5 0 -1.541027e-08

4 1 1.955001 e-08

3 2 -3.391982e-08

2 3 2.808398e-08

1 4 -2.017594e-08

0 5 1.552720e-08

6 0 -1.081426e-10

5 1 -3.971836e-10

4 2 -1.756341 e-1 1

3 3 -4.764189e-10

2 4 -3.338145e-10

1 5 -8.977737e-1 1

0 6 -2.865713e-10

Surface No. 7 Surface type: Sphere

Medium: N-SF6 Manufacturer: SCHOTT

x y z

0.6729295172665557 0 101.51 14071483516

exx exy exz

0.9659258262890683 0 -0.2588190451025207

eyx eyy eyz

0 1 0

ezx ezy ezz

0.2588190451025207 0 0.9659258262890684 RDY 104.243682

Area No. 8 Area Type: Sphere

Medium: AIR Manufacturer:

x y z

1.759969506697143 0 105.5682956187657

exx exy exz

0.9659258262890683 0 -0.2588190451025207

eyx eyy eyz

0 1 0

ezx ezy ezz

0.2588190451025207 0 0.9659258262890684

RDY 547.488988

Surface No. 9 Surface type: Sphere

Medium: N-SK5 Manufacturer: SCHOTT

x y z

0 0 1 19

exx exy exz

1 0 0

eyx eyy eyz

0 0.9659258262890683 -0.2588190451025207

ezx ezy ezz

0 0.2588190451025207 0.9659258262890684

RDY 267.198663

Surface No. 10 Surface type: KXY

Medium: AIR Manufacturer:

x y z

0 1 .294095225512604 123.8296291314454

exx exy exz

1 0 0

eyx eyy eyz

0 0.9659258262890683 -0.2588190451025207

ezx ezy ezz

0 0.2588190451025207 0.9659258262890684

RDX -125.906960

RDY 53.408079

CCX 0.000000

CCY 0.000000

k I coefficient alpha_k, l to (x ** k) * (y ** l)

2 0 8.264826e-03

1 1 1.708655e-04

0 2 -5.749938e-03

3 0 -2.927335e-05

2 1 -4.629718e-06

1 2 -9.138780e-06

0 3 -1.454081 e-05

4 0 1.677784e-06

3 1 -5.333602e-07 2 2 2.366516e-06

1 3 -5.920024e-08

0 4 1.280144e-07

5 0 -2.232395e-08

4 1 3.665385e-08

3 2 -3.904649e-08

2 3 4.653573e-08

1 4 -2.056444e-08

0 5 1.936619e-08

6 0 8.816679e-1 1

5 1 -5.245902e-10

4 2 3.663081 e-10

3 3 -1.015639e-09

2 4 3.799061 e-1 1

1 5 -4.972656e-10 0 6 -1.417384e-10

Surface No. 1 1 Surface type: Plan

Medium: AIR Manufacturer:

x y z

0 0 322.0

exx exy exz

1 0 0

eyx eyy eyz

0 1 0

ezx ezy ezz

0 0 1

Surface No. 12 Surface type: Plan

Medium: AIR Manufacturer:

x y z

0 0 322.

exx exy exz

1 0 0

eyx eyy eyz

0 1 0

ezx ezy ezz

0 0 1

The variant for the relative position "average working distance" for the exemplary embodiment from FIG. 13 is obtained if the following changes are made in Table 2 above:

Exemplary embodiment for FIG. 13 (average working distance)

Surface No. 6 xyz

0 0 78.719403

Surface No. 7

x y z

0.6729295172665544 0 81.23081014835158

Surface No. 8

x y z

1.759969506697141 0 85.28769861876567

Surface No. 9

x y z

0 0 98.71940300000001

Surface No. 10

X y z

0 1 .294095225512604 103.5490321314454

Surface no. 1 1

X y z

0 0 477.

Surface no. 12

X y z

0 0 477.

The variant for the relative position "large working distance" for the embodiment of FIG. 12 is obtained by making the following changes in Table 1 above:

Exemplary embodiment for FIG. 12 (large working distance)

Surface No. 6

x y z

0 0 69

Surface No. 7

x y z

0.6729295172665541 0 71.51 140714835158

Surface No. 8

x y z

1.759969506697141 0 75.56829561876567

Surface No. 9

xyz 0 0 89.

Surface No. 10

x y z

0 1 .294095225512604 93.82962913144536

Surface no. 1 1

x y z

0 0 632.0

Surface no. 12

x y z

0 0 632.0

The local xyz coordinate system of the free-form surface described in each case is also designated with canceled coordinates x 'y' z 'in order to distinguish it from the global xyz coordinate system of the imaging optics 27, 32. At x '= 0 and y' = 0, a reference axis which characterizes the free-form surface in accordance with this surface formula runs along the z'-direction. This reference axis is also referred to below as z'-axis. The coordinates of this z-axis with respect to the coordinate system of the pupil aperture 9 of the camera module 7 are indicated in Table 1 with ezx, ezy and ezz. The reference axis z 'is tilted in the freeform surface components of the imaging optics 27 and 32 against the z direction of the main beam 15 _{z of} the central object field point. Some of the z 'axes are shown by way of example in FIGS. 18 to 21. It should be emphasized that the z 'axes are not assigned to one of the optical components but to one of the optical surfaces in each case, since they belong to the local x' y 'z' coordinate system describing the respective free-form surface.

As an alternative to a tilting of the free-form reference axis z 'to the z direction of the main ray 15 _{z of} the central object field point, the free-form reference axis z' can also lead to the course of the main ray 15 _z. be centered, so that the free-form reference axis z 'parallel to the main beam 15 _Z and spaced from this runs.

The free-form surfaces can be described by other surface shapes in the case of variants of imaging optics which are not shown and which can be used instead of the imaging optics 2, 27 and 32 in the imaging system 1. An example of this is the following area formula:

z = ar _k - [(l - ap _k ) - x ² + (l + ap _k ) - y ² ] ⁺

In this case, x and y denote coordinates on the optical surface, starting from the z reference axis. z denotes the arrow height of the free-form optical surface, p _x or p _y the curvature in the x or y direction. κ _χ and K _y are conic constants, and ar _K and ap _K are coefficients.

Another surface formula for describing alternative free-form surfaces, which can be used in other variants of imaging optics instead of the imaging optics 1, 27 and 32, is the following:

where:

(m + n) ² + m + 3n.

J = - + 1

2 Z is the arrow height of the freeform surface at point x, y. The following applies: x 2 + y 2 = r ² . c is a constant corresponding to the vertex curvature of a corresponding asphere, k corresponds to a conic constant of a corresponding asphere. C _j are the coefficients of the monomials X ^m Y ⁿ . The order of the monomial, m + n, can be varied. A higher-order monomode can lead to a design of the imaging optics with better image aberration correction, but is more complicated to calculate, m + n can, for. For example, take values between 3 and more than 20.

Free-form surfaces can also be mathematically described by Zernike polynomials, which are explained in the manual of the optical design program CODE V ^® , for example. Alternatively, freeform surfaces can be described using two-dimensional spline surfaces. Examples include Bezier curves or non-uniform rational base splines (NU BS). For example, two-dimensional spline surfaces may be described by a mesh of points in an xy plane and associated z-values or by these points and their associated slopes. Depending on the particular type of spline surface, the complete surface is obtained by interpolating between the mesh points using e.g. As polynomials or functions that have certain properties in terms of their continuity and differentiability won. Examples of this are analytical functions.

The camera module 7 can be designed as a stereo camera, in particular as a rotatable stereo camera. An axis of rotation runs perpendicular to the Level of the pupil opening 9 and can pierce the pupil plane centrally between the used part of the pupil.

The imaging optics 2, 27 and 32 may for example be part of a stereomicroscope of the type described in DE 2004 052 253 A.

The imaging optics 2, 27 and 32, with the exception of the beam guide 18, can be designed exclusively using refractive optical elements. Alternatively, the imaging optics 2, 27, and 32 may also include other optical elements, such as diffractive optical elements (DOE).

Claims

claims

1. imaging optics (2; 27; 32) for imaging an object field (3) into a field of view (5),

with at least one variation optical module (19, 30, 33) having at least two refractive optical variation components (20, 21, 28, 29, 35, 36, 38, 39),

Which are designed to be able to be displaced relative to one another for the targeted alteration of imaging properties,

- At the same time an illumination beam path (13) for illuminating the object field (3) and an imaging beam path (14) lead and

- whose entrance surfaces (25) and exit surfaces (26) in the beam path (13, 14) are oriented, that at these optical surfaces (25, 26) reflected illumination light (8) is not reflected in the imaging beam path (14), wherein at least one the optical surfaces (25, 26) of at least one of the optical components (20, 21, 23, 24, 28, 29, 31, 35, 36, 38, 39) of the imaging optics (2, 27, 32) is designed as a free-form surface ,

2. Imaging optics according to claim 1, characterized in that the variation components (20, 21, 28, 29, 35, 36, 38, 39) have a the at least one free-form surface characterizing reference axis (ζ '), which is directed against a main beam (15 _z ) of a central object field point is tilted.

3. Imaging optics according to claim 1 or 2, characterized in that a tilting of at least two optical surfaces (25, 26) the variation components (20,21; 28,29; 35,36,38,39) are made in mutually perpendicular excellent planes (xz, yz).

Imaging optics according to one of claims 1 to 3, characterized by an aperture element for limiting a maximum angle of incidence in an exit pupil plane (10) of the imaging optics (2; 27; 32).

Imaging optics according to one of claims 1 to 4, characterized

by an embodiment of the variation optical module (30) such that a relative displacement of the two variation components (28, 29) relative to each other with a directional component (z) along the main beam (15 _z ) of the central object field point and additionally with a directional component (y) done perpendicular to this.

6. Imaging optics according to claim 5, characterized by an embodiment of the variation optical module (30) such that the Relatiwer- storage of the one (28) of the two variation components (28, 29) with the directional component (z) along the main beam (15 _z ) of the central object field point and the relative displacement of the other (29) of the two variation components (28, 29) with the direction component (y) perpendicular to the main beam (15 _z ) of the central object field point.

Optical system (1)

with an imaging optic (2; 27; 32) according to one of claims 1 to 6,

with a camera module (7) for image acquisition.

8. Optical system (1)

with an imaging optic (2; 27; 32) according to one of claims 1 to 6,

with a tube (10b) to provide visual insight for image acquisition.

9. An optical system according to claim 7 or 8, characterized by an illumination module (1 1) for illuminating the object field (3) via the illumination beam path (13).