DE102016211743A1 - Optical arrangement and method for operating in two modes - Google Patents

Abstract

The optical arrangement (2) comprises an objective (OL) which is designed to detect radiation which impinges on the objective (OL) from a field of view of the objective (OL), wherein the detected radiation by means of the objective (OL) into a Beam path (4) of the optical arrangement (2) is guided, an imaging optics (TL, OL) for generating a map detected radiation of a nominal object field as a nominal image field in an image plane (B1), wherein the nominal object field is a section of the field of view and Radiation detected as marginal rays (RS) from outside the nominal object field before reaching the image plane (B1) is removed from the beam path (4) by trimming the beam path (4). The optical arrangement (2) is characterized in that an optical unit (E) is provided which can be reversibly inserted between the objective (OL) and the image plane (B1) in the beam path (4) and the optical unit (E) in such a way is formed, that the trimming of the beam path (4) is reduced or canceled, so that at least a portion of the marginal rays (RS) in addition to the originating from the image radiation in the image plane (B1) is imaged or imaged.

Description

The invention relates to an optical arrangement according to the preamble of claim 1 and a method for operating the optical arrangement in two modes.

Imaging techniques in which a portion of an object, surface or space, such as a sample, the atmosphere or the universe is to be imaged, typically require the steps of locating an object field to be imaged (hereafter also nominal object field) and the image of the selected object field in sufficient quality.

Conventionally, a lens with a low magnification, ie with a long focal length, or with a separate viewfinder is used to locate (localize) the image to be imaged. After a section has been located and the cutout and the optical axis of the microscope, for example, have been aligned relative to one another, a higher-quality objective, for example a lens, is produced by means of a lens change mechanism. B. a lens with high magnification (short focal length), brought into the beam path of the microscope. In astronomy, the separate high-quality optics are often used for the actual recordings.

A change of the lens is disadvantageous because of the required mechanism and its potential susceptibility to interference. In addition, a lens change requires a considerable effort for the control operations and z. As the effort for a par-focal alignment. There is a risk of damage to the sample or the lens with a lens change and there are also several lenses vorzuhalten, which causes additional costs and requires an increased space requirement. Last but not least, a change of objective can lead to undesired changes in the positions of the elements of an optical arrangement relative to one another. A reproducible lens position is therefore only with considerable effort to ensure. In addition, if an immersion medium is used, it must be renewed after a lens change.

From the prior art, optical lenses are known which directly in front of a detector, for. As a camera, or instead of the eyepiece are used and an object field magnified or reduced in the image plane. For example, Barlow lenses are used for image magnification, by means of which the focal length is extended. In contrast, Shapley lenses, also referred to as "reducers", serve to shorten the focal length and thus to reduce the image.

The invention has for its object to propose an optical arrangement by means of the lens without changing both a localization of a part of the object to be imaged and a high-quality image is possible. A further object of the invention is to propose a method for locating and imaging the detail of the object.

The object is achieved with regard to the optical arrangement by the subject matters of independent claim 1. With regard to the method, the object is achieved by a method according to claim 15. Advantageous developments and refinements are specified in the dependent claims.

The object is achieved by means of an optical arrangement, wherein these
comprises an objective which is designed to detect radiation which impinges on the objective from a field of view of the objective, the detected radiation being guided by the objective into a beam path of the optical arrangement,
and an imaging optics for generating a map of detected radiation of a nominal object field as a nominal image field in an image plane, wherein the nominal object field is a portion of the field of view and as peripheral rays detected radiation from outside the nominal object field before reaching the image plane by trimming the beam path are removed from the beam path.

According to the invention, an optical unit is provided which can be introduced reversibly between the objective and the image plane into the beam path. The optical unit is designed such that the trimming of the beam path is reduced or canceled, so that at least a portion of the marginal rays in addition to the radiation originating from the nominal object field can be imaged or imaged in the image plane.

Lenses, in particular microscope objectives, are specified and optionally corrected for a defined nominal image field in which an associated nominal object field having a desired imaging quality is imaged.

The nominal object field is a section of the field of view of the objective. In the context of this description, a field of vision is understood to be the entire field from which radiation can be collected through the objective. In the following, for simplicity, a section of the field of view is also referred to as a field of view, if this section is not identical to the nominal object field or if another meaning is not explicitly stated.

Rays that are detected by the lens from the field of view but coming from outside the nominal object field are referred to as marginal rays for simplicity.

Detected radiation is the entirety of the radiation collected by the objective.

As reversible in the beam path can be introduced, an optical unit is considered if it is possible without dismantling or without (re) assembly of the optical arrangement, in particular a housing in which the beam path extends.

An optical unit can not be introduced reversibly into a beam path, for example if the housing of the optical arrangement has to be screwed or unfolded at least in sections or if, for example, the objective must be temporarily removed from the optical arrangement.

As trimming is here any intentional and / or inevitable technical measure understood that prevents reaching the image plane by marginal rays.

The invention is based on the observation that, with a high magnification lens, also rays from far outside the nominal object field, typically to infinity, can be imaged, albeit at a reduced quality. Normally, rays from outside the nominal object field do not contribute to the imaging of the nominal object field in the nominal image field. These marginal rays usually do not affect the imaging optics, but are shielded for example by diaphragms in the beam path. Edge beams are also prevented by sockets of other elements of the optical arrangement and by a housing of the optical arrangement of an impact in the image plane.

For example, in fluorescence microscopy, it is often difficult to find a fluorescent object by "scanning" a region under high magnification. For this task of finding an optically poor quality picture is sufficient.

It is essential to the invention that the optical element is arranged as close as possible to the objective or can be arranged. It is less a physical proximity to the lens, but on a portion of the beam path after the lens in which no or only a small proportion of the marginal rays are cropped.

By means of the optical element, it is possible to also image edge rays by means of the imaging optical system on the image plane. An extensive avoidance of the cut of the marginal rays in the aforementioned sense is essential to the invention. A mere reduction of the image of the detected radiation is not sufficient to solve the problem.

Although the quality of the image with the marginal rays can be significantly worse than the quality of the image of the nominal object field, for example the central field of view. For tasks such. However, the quality of this figure is sufficient, for example, the localization of areas of interest in an object plane.

The beams of the marginal rays have large relative angles to the optical axis and are trimmed in the infinity beam path of the optical arrangement by the finely dimensioned elements of the optical arrangement and / or by an existing enclosure of the optical arrangement, so that these marginal rays only to a very small extent or at all do not contribute to the generated nominal image field (hereinafter also referred to as image). This may even be desirable because of the reduced quality in imaging these marginal rays. The inferior portions of the detected radiation for a mapping are sometimes even selectively cropped by using a field stop.

• 1. Auskopplung der erfassten Strahlung aus dem primär zur Bildgebung verwendeten Strahlengang der optischen Anordnung (Primärstrahlengang) in einen alternativen Strahlengang (Sekundärstrahlengang) und Abbildung sowie Detektion in einer in dem alternativen Strahlengang befindlichen Bildebene, so dass ursprünglich beschnittene Randstrahlen umgelenkt werden und zum erzeugten Bild (nominales Bildfeld) beitragen.
• 2. Modifizierung des Primärstrahlengangs, so dass ursprünglich beschnittene Randstrahlen so innerhalb des Strahlengangs umgelenkt werden, dass diese zum erzeugten Bild beitragen können.

Basically, there are two ways to map the marginal rays:

• 1. decoupling the detected radiation from the beam path of the optical arrangement (primary beam path) used primarily for imaging into an alternative beam path (secondary beam path) and imaging as well as detection in an image plane located in the alternative beam path, so that originally trimmed edge beams are deflected and the image produced (nominal field of view).
• 2. Modification of the primary beam path, so that originally trimmed edge beams are deflected within the beam path so that they can contribute to the generated image.

Both principles can be realized such that the nominal field of view thus produced either maps a larger nominal object field or the size of the nominal object field remains the same but depicts another section of the field of view. In further possible embodiments of the optical arrangement and in further possible embodiments of the method, combinations of the aforementioned principles are also possible.

• 1. ein größerer Chip oder ein Scanner mit größerer Winkelauslenkung verwendet werden,
• 2. ein Detektor verwendet werden, der eine eigene verkleinernde abbildende Optik beinhaltet, z. B. eine Kamera mit Frontlinse, die ein größeres Bild auf einen kleineren Chip abbilden kann,
• 3. der vorhandene, zu kleine Sensor an eine andere Stelle des erzeugten Bildes verschoben wird oder
• 4. durch eine umlenkende Optik, beispielsweise mindestens einen verstellbaren Spiegel oder eine Linse, ein frei wählbarer Teilbereich des erzeugten Bildes auf dem Detektor dargestellt werden.

If the generated image depicts a larger nominal object field, then it may be that the Image of a detector arranged in the image plane is no longer completely detected. For example, the image thus enlarged may be larger than the chip of the camera used as a detector or larger than the area detectable by a scanner used as a detector. In this case can

• 1. a larger chip or a scanner with greater angular excursion are used
• 2. a detector may be used which includes its own demagnifying imaging optics, e.g. B. a front-lens camera that can image a larger image on a smaller chip,
• 3. the existing, too small sensor is moved to another location of the generated image or
• 4. be represented by a deflecting optics, for example, at least one adjustable mirror or lens, a freely selectable portion of the image generated on the detector.

Alternatively, the optical element can be designed so that in addition to the imaging of the detected radiation including the marginal rays a reduced image of the field of view or a section of the field of view is generated so that the field of view or the section can be recorded with the existing detector.

In all embodiments, the engagement takes place close behind the objective acting as a detection objective, since here the marginal rays from the outer regions of the field of view are not yet cropped and still accessible. Due to the effect of the optical element, marginal rays are no longer or only partially cropped and can be imaged in the image plane and detected by means of the detector.

The detector can be for example a camera, in particular with a chip such as a CCD chip or a CMOS chip or a scanner.

The objective serves as a detection objective and may, for example, be formed by a single optical lens or by a group of optical lenses.

By way of example, the optical element can be designed in such a way that the detected radiation of both the nominal object field and the field of view is modified, as a result of which an image of the field of vision is generated or can be generated.

Advantageous embodiments of the optical arrangement are given, for example, if the imaging optical system is reversibly replaceable by the optical unit and the optical unit is designed to image the radiation originating from the nominal object field and the marginal rays into the image plane. In such an embodiment, the number of optics present in the beam path is not or only slightly increased in a first operating mode of the optical arrangement with the imaging optical system and in a second operating mode of the optical arrangement with the optical element.

Also possible is an embodiment in which the imaging optical system is optically replaceable by the optical unit. For example, the function of the imaging optics is wholly or partly taken over by the optical unit.

The imaging optics may be designed to be changeable. In this case, a substantial reduction (for example more than 2 times) of the nominal image field can be effected with regard to its dimensions in the image plane. The change of the imaging optics can be done mechanically and / or motorized, for example by means of a motor, in particular a stepping motor.

Alternatively, the imaging optics can also be designed to be movable from the beam path or along the beam path. The imaging optics may also be replaced by a corresponding lens or optical group at another (optical) location for generating the image (primary image).

The optical unit can be formed with effect for the marginal rays as a focus unit, by the effect of the marginal rays are guided at relative angles to the optical axis in the beam path, in which no or a reduced cropping occurs. The relative angles were in the application with the file number DE 10 2016 002 460 referred to as the departure angle.

It is also possible that the optical unit has at least one first beam-directing element for coupling the radiation out of the beam path into the alternative beam path and a second beam-directing element for re-coupling the coupled-out radiation from the alternative beam path into the beam path. Beam-directing elements are, for example, mirrors or partially mirrored prisms, which can be designed to be partially transparent. Recoupling may occur before or after the imaging optics.

It is possible that both the complete additional optics and / or optomechanics is moved or that only the beam-directing elements and possibly arranged in the alternative beam path optical components are eigeschoben, folded or rotated in the beam path.

• A) eine Kombination einer konkaven und einer konvexen Linse oder die Kombination eines konvexen Hohlspiegels (z. B. verspiegelte Kugeloberfläche) mit einem konkaven Hohlspiegel;
• B) eine Kombination mehrere bikonvexer oder plankonvexer Linsen;
• C) wie B) mit der Erzeugung eines dem Primärbild vorgelagerten Zwischenbildes, wenn in der zweiten Betriebsart beispielsweise ein 4f-System eingesetzt wird.

The optical unit can be designed, for example, in one of the following variants:

• A) a combination of a concave and a convex lens or the combination of a convex concave mirror (eg mirrored spherical surface) with a concave concave mirror;
• B) a combination of several biconvex or plano-convex lenses;
• C) as B) with the generation of an intermediate image preceded by the primary image, if, for example, a 4f system is used in the second operating mode.

The objective pupil visible by the imaging optical system and the object field imaged on the detector (or in the eye) are magnified by the action of the optical element, ie an object reduction on the detector is achieved compared to the first operating mode. It is additionally possible to introduce at least one, optionally variably adjustable, pupil diaphragm in an aperture plane in order thus to increase (at the expense of the light intensity) the imaging quality by suppressing aberrated beams.

The alternative beam path may be formed in further embodiments as a telescope.

Further possible embodiments are listed below.

If several image fields may overlap (at the expense of the light intensity), image fields can be superimposed by a suitable choice of the angles. To find, for example, GFP-stained cells (GFP = green fluorescent protein), a superimposed image field can thus be useful, in particular if sub-beams can be dimmed when moving. This can be realized in particular in combination with the 0.5x Optovar. Arrangements are also possible which generate the (partial) superposition of the different image fields by means of a small slider using semitransparent mirrors.

It is also possible to create an arrangement which allows to "search" the maximum possible field of view (field of view) in the environment. For this purpose, the execution according to the 13 and 14 construct and use a variable wedge as follows: take a plano-convex and a plano-concave lens with the same radius of curvature, add it, optionally with a lubricating medium (eg oil-based) of the same refractive index, together. By twisting you can change the wedge angle and scan without object movement a larger field of view. It would be possible to use two small knobs, which are mounted directly on the outside of the optical element.

A slider, the z. B. in the Bertrand lens position or (better) is introduced in the DIC slider position, consists only of a carrier material (eg., Glass) on which a diffraction grating, for example, a crossed diffraction grating is inscribed. The grating can be an amplitude but (preferably) also a phase grating. The various diffraction orders of the grating simultaneously realize the effect of many different wedges similar to 13 and 14 , The grid can z. By an iterative Fourier transform algorithm similar to the description in Abrahamsson, S. et al. ( Abrahamsson, M. McQuilken, SB Mehta, A. Verma, J. Larsch, R. Ilic, R. Heintzmann, CI Bargmann, AS Gladfelter, R. Oldenbourg, Optics Express 23, 7734-7754, 2015 ) be optimized so that z. B. nine diffraction orders of almost constant strength arise. However, one can also use a conventional cross grid. It can also be advantageous in the case of both grating types to form the grating as a hexagonal grating, so that an isotropic image field increase is achieved. By selecting the lattice constant, the relative effective image shift can be adjusted. The grid effectively results in a series of overlapping image fields, all simultaneously imaged through the eyepiece in the eye or on the camera. Nevertheless, a skilled microscopist can appreciate that there is an interesting (eg, GFP stained) cell or other region of interest near the current sample position.

The arrangement described here will result in chromatic blurring in all orders except the direct (zero order) beam. This has the advantage of being able to view the smeared object (eg, a cell smeared only slightly "to the right" = plus first right order), where it is in comparison to the desired central visual field. The otherwise considered disadvantageous spectral smearing is therefore a surprising advantage.

Another advantage is that such an optical element formed as a drawer or slider can be constructed very simply and is very error-prone. EWeiterhin a slight user-operable rotation about the optical axis may also be useful to facilitate the assignment to the correct overlapping field of view.

Analogously to the aforementioned embodiment, a slot (optical element) is introduced at the DIC slider position or at the Bertrand lens position. Here is a similar multi-wedge effect can be achieved, however, without large caused by the grid chromatic aberrations. It uses a very small multi-faceted prism that divides the pupil into several parts or areas, each with a wedge of different pitch and direction. This has a not inconsiderable light and also Loss of resolution results, but is still useful and sufficient to find interesting areas or objects in the field of view. A prism causes far fewer chromatic aberrations than a grating. By using grisms (prism grid combinations), the resulting chromatic smearing can be further reduced.

Another possibility is to use several wedge-shaped birefringent materials attached in succession analogous to Wollaston prisms. This can also be used to superimpose many shifted images. The result is a loss of light, but the resolution remains largely intact.

In order to achieve a simultaneous very efficient superimposition of several image fields, it is also possible to introduce a multifaceted prism at a position approximately halfway between the pupil plane and the tube lens (imaging optics). Each prism surface is responsible both for a part of the enlarged total field of view, which is normally outside of the limited by the camera or the eyepieces (and ultimately through the tube lens) field of view, to steer by the prism modified beam tilting on the tube lens and by the beam tilting the image field in one for the camera, the eye, or more generally: the detector to move visible range. This will only be partially successful, since centering leads to overcompensation, but by accepting a pruning of the pupil, ie, designing this prism with slightly smaller spacings, it is possible to achieve an image field multiplication.

It is also possible that the optical element is designed as a beam expander, by the effect of the edge beams are guided at relative angles in the beam path, which allow imaging in the image plane.

In one embodiment, the beam expander can have a plurality of reflection surfaces which are arranged relative to one another such that detected radiation is guided into the beam path after multiple, in particular cascaded, reflections.

The optical element may be formed in a further embodiment of the optical arrangement as a wedge, by the effect of edge beams are guided in the beam path.

The wedge may have an integrated diffractive grating, so that advantageously occurring dispersions of the radiation are compensated.

Furthermore, it is possible that the optical element is designed as at least one mirror, by the effect of which edge beams are guided into the beam path.

Also, an embodiment of the optical element as a Fresnel mirror or a diffraction grating, in particular a blazed diffraction grating is possible. A blazed diffraction grating is optimized for high diffraction efficiency with respect to a diffraction order in one wavelength.

The optical arrangement may, in another embodiment, comprise an optical element as a carrier of an optically conductive material. The optical element has at least one Fresnel zone and / or a diffraction grating, wherein detected radiation coupled out of the beam path by means of the Fresnel zone and / or the diffraction grating is guided in the carrier by means of total reflection.

In a further embodiment, the optical element is designed as a faceted arrangement of semitransparent mirrors.

The optical element may be rotatably controlled in further embodiments or in combination with a described embodiment about an optical axis of the optical arrangement controlled.

Retrofitting an optical device with an optical element can advantageously be done at a slider position that is normally used for inserting Bertrand lenses. Retrofitting may alternatively or additionally be done at an insertion position normally used for DIC prisms.

It is also possible for the optical element to be designed in such a way or adapted to the optical properties of the objective and / or the optical arrangement that aberrations occurring in the second operating mode are reduced and / or corrected.

In other embodiments, the optical element may have a second objective with a small focal length and a third objective with a relatively longer focal length. The second lens can be arranged reversed in the beam path, whereby in cooperation with the third lens, a real image is again imaged to infinity.

The second lens is in one possible embodiment identical to the serving as a detection objective lens.

Furthermore, the second lens may have a focal length which is about the ratio of Refractive indices (object-side refractive index and refractive index between the two introduced lenses) is changed so that the Abbe sine condition and the Herschel condition can be fulfilled approximately both.

The second and third lenses may be manufactured as an optical component. The realized principle can again be: creation of a real intermediate image and long focal length imaging.

In other embodiments, the optical arrangement can have a deflection unit, by means of which the detected radiation with a short focal length tube lens or an inverted lens is directed onto the detector in the second operating mode.

In a further embodiment, it is possible for the detected radiation to be deflected towards the primary objective (detection objective) and guided back onto the detector behind the imaging optics by a beam-directing element.

In a further embodiment, an image of the pupil plane of the objective is achieved by one or more optical components in the alternative beam path in the second mode.

In a further embodiment, the optical arrangement has at least two imaging optics which can be used optionally in the first and in the second operating mode.

If the imaging of the field of view is achieved, a possible reduction of minor importance. In principle, the field of view can also be imaged by using a larger detector or by shifting the detector accordingly.

A decoupling into the alternative beam path and to a separate detector does not have to be image-reducing, as long as a correspondingly large detector is present.

If the separate detector has its own optical system, it merely has to be ensured that the intermediate image produced can be recorded by the detector over the entire desired area.

The object is further achieved by a method for operating the optical arrangement, wherein the optical arrangement is operated alternately in the first operating mode and the second operating mode, wherein
in the first operating mode, an image of detected radiation of a nominal object field is generated as a nominal image field in an image plane, wherein the nominal object field is a section of the field of view and radiation detected as marginal rays from outside the nominal object field before reaching the image plane by trimming the beam path be removed from the beam path and,
In a second operating mode, the optical unit is introduced into the beam path and, in addition to the radiation originating from the nominal object field, the marginal rays are imaged in the image plane.

The optical arrangement may advantageously be used or arranged in a microscope, a telescope, a pair of binoculars, a camera or a camera.

A first operating mode is understood to mean a mode (imaging mode) of the optical arrangement in which a nominal image field of the highest possible quality is produced with the objective in the image plane.

A second operating mode is understood to be a mode (localization mode) of the optical arrangement in which an image of the field of view takes place in the image plane. The second mode is used for finding an object to be examined or a part of the object to be examined.

One or more pictures can be taken in the first or in the second operating mode before changing to the other operating mode.

The quality of optical imaging in the second mode of operation will often not be ideal because the high magnification lens has been optimized for only a particular nominal field of view. For the stated task "localization of an object of interest", the optical quality of the image is secondary, especially in the edge region.

The invention will be explained in more detail with reference to embodiments and figures. Show it:

1 a schematic representation of a first embodiment of the optical arrangement according to the invention;

2 a schematic representation of a second embodiment of the optical arrangement according to the invention;

3 a schematic representation of a third embodiment of the optical arrangement according to the invention;

4 a schematic representation of a fourth embodiment of the optical arrangement according to the invention;

5 a schematic representation of a fifth embodiment of the optical arrangement according to the invention;

6 a schematic representation of a sixth embodiment of the optical arrangement according to the invention;

7 a schematic representation of a seventh embodiment of the optical arrangement according to the invention;

8th a schematic representation of an eighth embodiment of the optical arrangement according to the invention;

9 a schematic representation of an optical arrangement;

10 a schematic representation of a ninth embodiment of the optical arrangement according to the invention;

11 a schematic representation of a tenth embodiment of the optical arrangement according to the invention;

12 a schematic representation of an eleventh embodiment of the optical arrangement according to the invention;

13 a schematic representation of a twelfth embodiment of the optical arrangement according to the invention;

14 a schematic representation of an embodiment of a wedge assembly;

15 a schematic representation of a thirteenth embodiment of the optical arrangement according to the invention;

16 a schematic representation of a fourteenth embodiment of the optical arrangement according to the invention in a central field of view output configuration;

17 a schematic representation of the fourteenth embodiment of the optical arrangement according to the invention with marginal rays

18 a schematic representation of the fourteenth embodiment of the optical arrangement with central field of view and marginal rays according to the invention;

19 a schematic representation of a fifteenth embodiment of the optical arrangement according to the invention;

20 a schematic representation of a sixteenth embodiment of the optical arrangement according to the invention;

21 a schematic representation of an embodiment of a faceted optical element;

22 a schematic representation of a seventeenth embodiment of the optical arrangement according to the invention;

23 a schematic representation of an eighteenth embodiment of the optical arrangement according to the invention;

24 a schematic representation of a nineteenth embodiment of the optical arrangement according to the invention and

25 a schematic representation of a twentieth embodiment of the optical arrangement according to the invention;

The following embodiments are shown schematically and not to scale. Like reference numerals denote like elements unless expressly stated otherwise.

The 1 puts a microscope 1 with an optical arrangement according to the invention 2 dar. Along an optical axis 3 the optical arrangement 2 are an object Obj, designed as a detection objective lens OL, a reversible (symbolized by the double arrow) in the beam path 4 the optical arrangement 2 insertable optical element E, an optional imaging optical system TL and a detector D arranged. The beam path 4 coincides with the optical axis 3 together. By means of the imaging system thus simplified, an image of a nominal object field in an image plane B ₁ (FIG. 2 to 5 . 7 to 13 . 15 to 20 . 22 to 25 ) can be generated on the detector D. Due to the effect of the optical element E, the image on the detector D is reduced, so that the overall system in the illustrated second operating mode of the optical arrangement 1 can be used to find an interesting region of the object Obj. In this case, it is generally immaterial whether the optical axis E is the optical axis 3 in the beam path 4 or in an alternative beam path 5 (please refer 3 . 6 . 7 and 8th ) is decoupled or not.

Will instead of the microscope 1 For example, if a Gallileo telescope is used, the objective OL would correspond to the first (objective) lens and the imaging optics TL would correspond to one short-focal concave lens (eyepiece) together with the optics of the eye, which produces the image on the retina.

It should be noted that the optics can also be designed in each case as a lens system and not only as individual lenses. Furthermore, it should be noted that the objective OL can also directly generate an image ("primary image") on the detector D without the need for further imaging optics TL. In this case, then also the optical element E directly generates an image. But it is also possible that the primary image is reproduced by the (optional) imaging optics TL again.

The optical arrangement 2 is in a microscope 1 available.

In the 2 is exemplarily the imaging optics of a modern microscope 1 shown with infinite beam path in a first mode, ie for a selected and specified lens OL. An object plane B ₀ is imaged to infinity by the lens OL, typically a lens system obeying the Abbe sine condition. The object-side and image-side focal distances are designated f _OL . Simplified here only paraxial rays are drawn and the schematic lenses are in the simplified 1 to 8th coincides with the reference planes (symbolized by vertical broken lines). On the image side, the pupil P _{1 of} the objective OL follows in a focus distance f _OL after the objective OL. The imaging optical system TL, which is designed as a tube lens, generates a real image of the object plane B ₀ in the image plane B ₁ after the distance f _TL . The optical arrangement shown here 2 is for clarity's sake in 4f arrangement ("confocal", so the respective foci of the lenses are superimposed) drawn, even if many existing real microscope systems deviate from it and shorten the distance of the imaging optical system TL to the lens OL. Furthermore, the magnification is chosen to be quite small for clarity. In an actual system, this is usually many times greater.

The 3 shows analogously to 2 the optical situation after insertion of the optical element E in the beam path 4 , The optical element E is surrounded by a dashed box and shows that here a beam deflection unit is inserted, which detects a detected radiation from the beam path 4 in an alternative beam path 5 decoupled and back into the beam path 4 couples. The optical element E has two planar mirrors arranged perpendicular to one another as a first beam-directing element S ₁ and a second beam-directing element S ₂ . The beam directing elements S1, S2 can also be realized in each case by an externally mirrored prism. The pupil P ₁ is located in the alternative beam path 5 behind (here below) the first beam steering element S ₁ , as well as an intermediate image plane B _E. The alternative beam path 5 Now a 4f-system (2 times f _E1 and 2 times f _E2 ) happens which is formed by two lenses E ₁ and E ₂ . The radiation is formed by two further designed as a mirror beam steering elements S3 and S4, the z. B. can also be implemented as total reflection in a prism, reflected and by means of the second beam steering element S ₂ back into the beam path 4 coupled. By a suitable choice of the total length of the telescope even the position of the exit pupil P _{E of} the telescope, which is also entrance pupil of the imaging optics TL, as approximately indicated here, with the original pupil position P ₁ (see 2 ) are optically matched. However, such a matching of the pupils P ₁ and P _E is not necessarily necessary for a good imaging. It may also be useful to the lens E ₂ elsewhere, z. B. between the beam steering elements S ₃ and S ₄ to arrange.

Like in the 3 2, the optical element E can be used to reverse the image in comparison to the first mode of operation (without the optical element E in the beam path 4 ) to lead. This can be remedied either by optical components such as image rotation prisms, or by an appropriate software in the data acquisition with a computer, so that no confusion in terms of the required movement of the object Obj for localization and centering of an interesting and to be examined region with a user of the object Obj arises.

The lenses E ₁ , E ₂ are uniformly represented by elliptical, biconvex symbols regardless of their actual configuration in the figures of this description.

The 4 shows a fourth embodiment of the optical arrangement 2 in which the optical element E is directly on the original optical axis 3 is realized. The lens E ₁ is formed as a short focal length concave lens and the lens E ₂ is a longer focal length convex lens. This allows an image with the same orientation as in the first mode, but the image-side pupil planes do not match in both modes.

5 shows an optical element E with two lenses E ₁ and E ₂ to reduce the overall magnification. The first lens E ₁ has a short focal length and z. B. with the high magnification lens OL be identical. It is the other way around in the beam path compared to the lens OL 4 introduced and creates a small real picture. The second lens E ₂ , however, has a relatively longer focal length, which to the desired Image reduction in the image plane B ₁ leads. If the objective OL has a very high numerical aperture in the first operating mode, then a significant portion of the detected radiation is often not collected by the second objective E ₂ , which can lead to a loss of brightness. Nevertheless, even in such cases, the low-magnification localization mode (second mode) can be used to find an object region or object Obj.

6 shows the introduction of a beam deflection as close to the lens OL. The beam deflection produces an image in the image plane being reflected _B'1 via a tube lens with short focal length E. ₁ In this being reflected image plane _B'1 can directly localization camera 6 (Also, for example, with a small pixel pitch) can be accommodated, which is useful in locating and setting a desired object position. The short focal length tube lens E ₁ can also be a lens itself. For some applications it can, especially with a localization camera 6 with very small pixels, be an advantage, even if here a to the lens OL identical lens is arranged in the reverse transmission direction.

In the 7 a seventh embodiment is shown, in which the same detector D is usable in both the first mode (imaging mode or normal mode) and in the second mode (localization mode). Here, the imaging optical system TL by the introduction of the optical element E, comprising the beam directing elements S ₁ and S ₂ in the form of mirrors, bypassed and replaced by a short focal length lens E ₂ close to the detector D. The lens E ₁ is introduced here in 2f to 2f, so that it directly produces an equally large image of the pupil P ₁ at the location of the pupil P _E.

An eighth embodiment of the optical arrangement 2 is in the 8th shown. By changing the beam path 4 in the first mode, a visually advantageous simple switching between the first mode and the second mode is possible. In this case, use is made of the fact that in the first operating mode (normal operation, image generation optics TL with a focal distance f _TLN of normal operation), the beam path has a (long) beam path 4 describes and in the second mode (localization) a tube lens TLL with substantially shorter focal length f _TLL is used. For this purpose, upon introduction of the optical element E, the detected radiation is coupled out after the objective OL by means of the beam-directing element S ₁ , in the alternative beam path 5 directed with the short focal length tube lens TLL and by means of the beam directing element S ₂ back into the beam path 4 coupled in front of the image plane B ₁ .

The 9 shows the beam path 4 a microscope 1 , The imaging optics TL in the form of a tube lens, which converts the infinity beam path into an image, has an extent that would allow transmission of the marginal rays RS. In real constructions, this is not the case, since the marginal rays RS shown would be trimmed, for example, by the versions of the imaging optical system TL shown as dashed boxes and do not contribute to the image.

The 10 shows the same microscope 1 which is extended by an optical element E in the form of a lens system of two lenses. This optical element E is a beam expander (or beam expander) made of two lenses with an additional 3-fold beam expansion / image reduction.

This beam expansion has two effects: a) It leads to a reduction in the relative angle of the peripheral rays RS, which is why they make the tube lens of the imaging optical unit TL more central and therefore would not be trimmed even with a smaller (tube) lens and thus contribute to the image (magnification the field of view). b) At the same time, the beam expansion leads to a reduction of the image scale, so that the larger field of view can still be imaged on a detector D of unchanged size.

To the optical arrangement according to the invention 2 on existing microscopes 1 easy to retrofit, it would be advantageous if the required space could be reduced compared to the telescope solution described above. For this purpose, mirror optics are suitable, which make it possible the beam path 4 to fold back in and thus significantly reduce the required length.

Such a solution is in principle in the 11 shown. The beam expander is arranged like a reflector telescope, which has the consequence that part of the beam path 4 folded back into itself, whereby a smaller overall length is achieved.

The overall length can be drastically reduced by the beam expansion over multiple cascaded reflections is achieved. This is in 12 shown by a beam expansion in a compact binoculars. After entering the optical element E, which is formed in the form of a carrier TR of an optically conductive material, a reflection with angular deflection is achieved at the back by a Fresnel zone FF1 or a diffractive grating FF1 down. Optionally, this zone can also have a lens effect. Further reflections in the optical element E are achieved by total reflection, so that the entrance surface of the detected radiation at its second impact as a mirror surface acts. After a cascaded reflection with beam expansion, a further reflection with angular deflection and optional lens action takes place on a surface FF2. By using two such carriers TR, the resulting lateral beam offset can be reversed again, so effectively a beam expansion in the beam path 4 similar to the one in 10 shown is achieved, however, with significantly less space.

Such an embodiment can be made so short that they are in existing slider positions of the microscope 1 , z. B. in which for the insertion of a Bertrand lens of often only 1 cm in size can be introduced.

The 13 shows a variant by a wedge 7 changed the angle of all radiation beams of the detected radiation. At a constant magnification, this results in edge beams RS being guided through the imaging optical system TL and being imaged in the image plane B ₁ , while the central beam bundles are now trimmed. This results in that another area of the field of view is imaged on the detector D.

By turning the wedge 7 Other areas of the field of view can be addressed, so that, for example, by six rotational positions sequentially the complete field of view can be detected, which in 14 is shown schematically. The rotation of the wedge 7 can also be realized in that several correspondingly rotated wedges 7 are arranged side by side, which can be exchanged by a linear movement. A wedge 7 near the pupil shifts a section of the field of view, which is outside the nominal object field, into the center of the image plane B ₁ (see, for example, FIG. 13 ). By rotation of the wedge 7 For example, a 3-times larger section of the field of view can be recorded.

Chromatic aberrations due to the dispersion of the wedge 7 or by the wedges 7 formed prism are negligible, but can by a combination with one in the wedge 7 integrated gratings are compensated.

The described effect of the angle change could also be realized by suitably arranged mirrors as an alternative to the wedge solution.

The 15 shows a schematic representation of a thirteenth embodiment of the optical arrangement according to the invention 1 , The optical arrangement 1 is designed for parallel displacement of edge beams RS. A central region of the detected radiation remains unchanged.

The 16 and 17 show a double mirror arrangement, which on the optical arrangement 1 according to 15 builds. This double mirror arrangement of the beam directing elements S5 and S6 leads to an offset of the pupil corresponding to the edge region. The associated ray bundles are no longer cropped and can be imaged, but the pupil offset does not lead to an image offset, so that the central region and an edge region with the marginal rays RS are imaged together as an enlarged field of view. In order to image an extended field of view, the arrangement of the beam directing elements S5 and S6 must be about the optical axis 3 be rotated.

An optional reduction of the resulting image can be done later by a suitable optics, which no longer truncates the beams thus offset. For example, a shrinking tube lens is arranged. Other edge regions of the field of view can be addressed by the illustrated double mirror from the beam directing elements S5 and S6 about the optical axis 3 is turned. In a continuous rotation, the entire enlarged field of view can be displayed integrating, for example on a camera sensor or in the eyepiece. The slightly darker edge areas can be displayed brighter by appropriate image editing. Instead of a rotation similar to the solution according to 13 and 14 Different mirror combinations of different orientations are placed side by side and addressed by linear displacement.

The illustrated principle of the parallel offset of the marginal rays RS can be extended, so that several edge regions are made accessible at the same time. A rotation of the mirror optics is then no longer necessary. The opposite edge regions are made accessible by using two further beam-directing elements S7 and S8 arranged symmetrically to the beam-directing elements S5 and S6, for example as mirrors, which make the new edge regions accessible, as in FIG 18 shown. Since the illustrated rays penetrate, or are obstructed by the mirrors S5 and S8 required for the respective other edge images, these must be implemented as semitransparent mirrors. Part of the detected radiation is lost as a result, resulting in a darker image of the peripheral areas, which can later be digitally corrected.

In 19 the double mirrors, the beam directing elements S5 to S8, are arranged at a slightly different angle. The beam path (shown for clarity as an enlarged excerpt) between two beam-steering elements S5 and S6 or S7 and S8, thus does not run more perpendicular to the optical axis 3 but slightly back towards object Obj (not shown). A course in the other direction would be possible in a further embodiment as well. As a result, beam directing elements such as ordinary mirrors can be used.

However, in this example, the rays of the central field of view are now blocked. This can be avoided if the beam-directing elements S5 and S8 are formed semitransparent.

Another possibility for realizing the parallel beam offset is the deflection of the beams with Fresnel zones or diffraction gratings instead of mirrors and the guidance of the beams within the carrier substrate TR of the Fresnel zones / grating FF1 (for a better overview as an enlarged excerpt in FIG 20 shown). This principle of the deflection is similar to that of the extraction in 19 , However, a second Fresnel zone / grid leads here to a deflection in the original beam direction, so that the principle of the beam offset from 15 to 18 is satisfied.

If the grids FF1 are produced as volume holograms, then it can be achieved that the deflection takes place angle-selectively only for the marginal rays RS, but the central bundles can continue to propagate unhindered.

By further copies of the semitransparent mirror arrangement upon rotation about the optical axis 3 Edge areas under other orientations can also be detected simultaneously. Such a faceted system of partially transparent mirrors is in 21 shown schematically. Shown are two elements, an interior mirror assembly 8th and an outside mirror assembly 9 , each consisting of six partially reflecting surfaces. The enclosed inside areas are free, ie completely transparent. The continuous arrows show an example of a desired parallel beam offset, the dotted lines show the unwanted partial reflections. An incoming beam hits one of the partially reflective surfaces of the outside mirror assembly 9 is through one of the partially reflective surfaces of the interior mirror assembly 8th through and meets a further, opposite surface of the inner mirror assembly 8th , from which the beam continues parallel to the optical axis 3 is reflected. There occurs a beam offset.

For decoupling detected radiation from the beam path 4 For example, a beam steering element disposed at an angle of about 45 °, such as a mirror, may be used. Other possibilities are the use of a small mirror, which covers only slightly more than the size of the regular objective pupil P ₁ . This then couples only a few beams, so only a portion of the still available behind the lens OL detected radiation from. The decoupled bundles of detected radiation and thus also the bundles associated field of view cut-outs can by a displacement of the mirror perpendicular to the optical axis 3 will be realized. Integral results after the image on the detector D then the entire field of view.

It is also possible to use a Fresnel mirror or a (blazed) diffraction grating instead of an ordinary mirror. This also reduces the overall length of the element so that it can be integrated in a slider. Optionally, there is still an image reduction to adapt to the size of the detector D after the coupling out of the microscope 1 possible.

The 22 to 25 show various embodiments for decoupling detected radiation by means of optical elements E in the form of carriers TR having Fresnel zones or diffraction gratings with simultaneous guidance by total reflection in the material of the carrier TR. A second Fresnel zone / grid leads to a deflection in the original beam direction, so that the principle of the beam offset (see, for example, FIG. 15 ) is realized.

If the grids are manufactured as volume holograms, it is achieved that the deflection takes place in an angle-selective manner only for the marginal rays RS, but the central bundles can continue to propagate unhindered.

LIST OF REFERENCE NUMBERS

1

 microscope

2

 optical arrangement

3

 optical axis

4

 beam path

5

 alternative beam path

6

 location camera

7

 wedge

8th

 Interior mirror arrangement

9

 Exterior mirror assembly

Obj

 object

TL

 Imaging optics

OIL

 lens

P _E

 pupil

P ₁

 Pupil of the lens

D

 detector

e

 optical element

f _OL

 focus distance

f _TL

 distance

S1

 beam-directing element

S2

 beam-directing element

S3

 beam-directing element

S4

 beam-directing element

S5

 beam-directing element

S6

 beam-directing element

S7

 beam-directing element

S8

 beam-directing element

TLL

 tube lens

f _E1

 distance

f _E2

 distance

f _TLL

 Focal length tube lens TLL

E ₁

 lens

E ₂

 lens

B ₀

 object level

B ' ₁

 Image plane (mirrored)

B ₁

 real picture / picture plane

B _E

 Intermediate image plane

FF1

 Fresnel zone / diffractive grating

FF2

 Fresnel zone / diffractive grating

TR

 carrier

RS

 marginal rays

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102016002460 [0035]

Cited non-patent literature

• S. Abrahamsson, M. McQuilken, SB Mehta, A. Verma, J. Larsch, R. Ilic, R. Heintzmann, CI Bargmann, AS Gladfelter, R. Oldenbourg, Optics Express 23, 7734-7754, 2015 [0044]

Claims (15)

Optical arrangement ( 2 ), comprising - a lens (OL), which is designed to detect radiation which impinges on the objective (OL) from a field of view of the objective (OL), wherein the detected radiation is directed into a beam path by means of the objective (OL). 4 ) of the optical arrangement ( 2 ) Is guided, - an imaging lens (TL, OL) for forming an image of detected radiation from a nominal object field as a nominal image field in an image plane (B _1, B _'1), wherein the nominal object field is a section of the field of view and (as marginal rays RS) detected radiation from outside the nominal object field before reaching the image plane (B ₁ ) by trimming the beam path ( 4 ) from the beam path ( 4 ), characterized in that - an optical unit (E) is provided, the reversible between the lens (OL) and the image plane (B ₁ ) in the beam path ( 4 ) can be introduced and - the optical unit (E) is formed such that the trimming of the beam path ( 4 ) is reduced or canceled, so that at least a portion of the marginal rays (RS) in addition to the originating from the object field radiation in the image plane (B ₁ ) is imaged or mapped. Optical arrangement ( 2 ) according to claim 1, characterized in that the imaging optics (TL) is reversibly replaceable by the optical unit (E) and the optical unit (E) for imaging the radiation originating from the nominal object field and the marginal rays (RS) in the image plane ( B ₁ ) is formed. Optical arrangement ( 2 ) according to claim 1 or 2, characterized in that the optical unit (E) for the marginal rays (RS) is designed as a focus unit, by whose effect the marginal rays (RS) in the beam path (RS) ( 4 ) are guided. Optical arrangement ( 2 ) according to claim 1 or 2, characterized in that the optical unit (E) at least one first beam-directing element (S1) for coupling out the radiation from the beam path ( 4 ) in an alternative beam path ( 5 ) and a second beam-directing element (S2) for the re-coupling of the coupled-out radiation from the alternative beam path (US Pat. 5 ) in the beam path ( 4 ) having. Optical arrangement ( 2 ) according to claim 4, characterized in that the alternative beam path ( 5 ) is a telescope. Optical arrangement ( 2 ) according to claim 1, characterized in that the optical element (E) is designed as a beam expander, by the effect of the edge beams (RS) in the beam path ( 4 ) are guided. Optical arrangement ( 2 ) according to claim 6, characterized in that the beam expander has a plurality of reflection surfaces, which are arranged in such a way that detected radiation after multiple reflections in the beam path ( 4 ) is guided. Optical arrangement ( 2 ) according to claim 1, characterized in that the optical element (E) as a wedge ( 7 ) is formed by the effect of edge beams (RS) in the beam path ( 4 ) are guided. Optical arrangement ( 2 ) according to claim 8, characterized in that the wedge ( 7 ) has an integrated diffractive grating, so that occurring dispersions of the radiation are compensated. Optical arrangement ( 2 ) according to claim 1, characterized in that the optical element (E) as at least one mirror (S1) is formed by the effect of edge beams (RS) in the beam path ( 4 ) are guided. Optical arrangement ( 2 ) according to claim 1, characterized in that the optical element (E) is designed as a Fresnel mirror or a blazed diffraction grating. Optical arrangement ( 2 ) according to claim 11, characterized in that the optical element (E) as a support (TR) of an optically conductive material comprising at least one Fresnel zone and / or a diffraction grating (FF1) is formed, wherein by means of the Fresnel zone and / or the diffraction grating (FF1) from the beam path ( 4 ) coupled out detected radiation in the carrier (TR) is guided by total reflection. Optical arrangement ( 2 ) according to claim 1, characterized in that the optical element (E) is formed as a faceted arrangement of semi-transparent mirror. Optical arrangement ( 2 ) according to one of claims 6 to 10, characterized in that the optical element (E) about an optical axis ( 3 ) of the optical arrangement ( 2 ) is rotatably controlled. Method for operating an optical arrangement ( 2 ) according to one of claims 1 to 14, wherein the optical arrangement ( 2 ) is alternately operated in a first mode of operation and a second mode of operation, wherein in the first mode of operation an image of detected radiation of a nominal object field generates as a nominal image field in an image plane (B ₁ ) is, wherein the nominal object field is a section of the field of view and as edge rays (RS) detected radiation from outside the nominal object field before reaching the image plane (B ₁ ) by trimming the beam path ( 4 ) from the beam path ( 4 ) and, in a second mode, the optical unit (E) in the beam path ( 4 ) and, in addition to the radiation originating from the nominal object field, the marginal rays (RS) are imaged in the image plane (B ₁ ).

Images