DE19504427A1 - Multiple observer stereo-microscope for e.g. micro-surgery - Google Patents

Abstract

The three observation (or documentation) lenses stereo-optically focus the primary and secondary objective light beams (I,II). A rotatable beam splitting element (4), positioned after the main objective lens (2), has two beam splitting surfaces (4.1, 4.2) with identical transmission and reflection characteristics. The beam splitting surfaces (4.1, 4.2) transmit or reflect defined proportions of light from the object (1) to the primary and secondary objective light beams (I,II). The beam splitting element (4) turns on an axis (13) coincident with the optical axis of the stereoscopic paths of the primary and secondary objective light beams.

Description

The present invention relates to a stereomicroscope at least three observation and / or documentation Beam paths including a suitable beam splitter element, which is a variable orientation of the observation and / or documentation beam paths in a defined Angular range enabled.

When using stereomicroscopes in the micro surgery is next to an observation facility for a main observer often has another observation possibility for a second surgeon or assistant staff needed. There are a number of Approaches.

It is known from DE 12 17 099 and DE 36 02 095 the orientation of the primary observation beam path of the Main observer relative to the secondary observation to vary the beam path of a co-observer.

The rotating beam used in these devices divider elements with which a division of the object coming light towards the main and co-observer Observation beam path occurs, but have certain Disadvantages. So build the beam proposed there divider elements relatively voluminous. On the one hand, this has Consequence that relatively long glass paths for those passing through Partial beam paths result. With the slope of the glass paths however, the effort required for optical corrective measures in the respective beam splitter element. In addition, a larger number are undesirable This results in reflections in this component. Furthermore results with a voluminous beam splitter of this type element also a correspondingly voluminous structure of the  entire surgical microscope, d. H. an undesirable Increasing the working distance between the binoculars tubus and the field of view. The result is unfavorable ergono mixed working conditions for the operating surgeon.

The beam splitter element from DE 36 02 095 used results from varying the observation directions from Main and co-observers also the undesirable consequence that when the partial beam paths of main and co overlap observe a reduction in the perceived Object brightness for the main observer. The optical observation quality thus varies in terms of the perceived object brightness for the main observer and affects his perception of what is being viewed Field of view in an undesirable manner.

Furthermore, there are also solutions in which one such variable adjustment of the angle between main and co-observers is not provided, but rather a fixed or constant orientation of primary and secondary observation beam paths in 180 ° - or 90 ° - Orientation to each other takes place. In particular, observation directions of Main and co-observers are the requirements in the modern microsurgery no longer does it justice. Rather, a variable option is desired optional orientation of the observation directions of Main and co-observer.

The same problem also arises when a conventional stereomicroscope does not have the usual binocular tubes for direct viewing of an object points, but is designed as a video stereo microscope. In this case are in place of the usual binocular tubes electro-optical image recorders such. B. CCD arrays in the corresponding documentation beam paths in stereo  microscope provided. The same applies to a mixed one Interpretation, d. H. a surgical microscope with one possible for immediate viewing including documentation Beam paths with such electro-optical image takers.

The object of the present invention is a stereo microscope to create a variable orientation of the Observation directions of a main and at least one Co-observer in a defined angular range enables and the mentioned disadvantages of the prior art Technology avoids. The beam splitter used for this element in the stereo microscope should be sufficient Offer light economy for main and co-observers. Further the stereomicroscope is said to be both conventional and Wise direct viewing through binocular tubes enable as well as designed as a video stereo microscope can be.

This task is solved by a stereomicroscope with the Features of claim 1.

Advantageous embodiments of the stereo according to the invention microscopes can be found in the subclaims. The subject of claim 14 is a suitable beam divider element for such a stereomicroscope.

According to the invention, a beam is now in the stereomicroscope divider element used, which has the same proportion of dated object to be observed light coming towards Primary and secondary observation beam path transmitted and reflected. Here is both Transmission as well as the reflection in the beam splitter element or the corresponding surfaces of the beam splitter element spectrally and in terms of intensity for all beam paths to be chosen identically, d. H. all as beam splitter surfaces  acting surfaces are in terms of these properties as identical as possible.

Furthermore, the beam splitter element can be rotated about an axis, that with one of the optical axes of the stereoscopic Partial beam paths of the primary and secondary observation Beam paths coincide.

In comparison to the known prior art results now due to the dimensioning of the invention Beam splitter element both a smaller construction volume than also an improved observation or imaging quality for the stereo microscope.

The smaller construction volume of the beam splitter element in turn has an essential due to the shorter glass paths lower optical correction effort. Further there are no problems with multiple reflections, such as double images or the like. Furthermore, this can entire stereomicroscope according to the invention thus smaller be constructed, which in turn is favorable for the Ergonomics when used as operations microscope is.

Finally occur in the stereomicroscope according to the invention when varying the directions of observation and thus the Rotation of the beam splitter element no fluctuations in terms of the perceived object brightness, it also results in intermediate positions partially superimposed observation beam paths consistently perceived object brightness in all Observation beam paths or documentation beams gears.

Furthermore, the stereomicroscope according to the invention enables now a variable relative orientation of a main and  of a co-observer beam path in a defined Angular range to each other.

The stereomicroscope according to the invention can also be used as usual stereomicroscope with binocular tubes for immediate visible observation by the observers be used. Alternatively, it can also be used as a pure Video stereo microscope can be designed in which in the Documentation beam paths suitable electro-optical Image recorders are arranged.

Further advantages and details of the invention Stereomicroscope result from the following Description of exemplary embodiments using the enclosed drawings.

It shows

Fig. 1 shows an embodiment of the stereomicroscope according to the invention in a schematic illustration;

Figure 2 is a perspective view of the beam splitter element used from the embodiment example of FIG. 1.

Figures 3a-3c. Respectively the plan view of the beam splitter element in FIG. 2 tationspupillen in different angular positions inclusive of the shared observation and / or Dokumen in the primary and secondary observation beam path.

In Fig. 1, a first embodiment of the stereomicroscope according to the invention is shown schematically.

The light coming from the object under consideration ( 1 ) passes through a main objective ( 2 ) shared by both stereoscopic observation beam paths to a magnification-changing device ( 3 ), which is only indicated schematically in the illustration in FIG. 1. As a magnification change device, for. B. a known Pankrat system can be used.

In the illustrated embodiment, one of all Observation beam paths shared, unique Enlargement change facility provided, then also a corresponding optical diameter required to to include all observation beam paths.

As an alternative to the arrangement shown in FIG. 1, it is also possible to arrange the respective magnification changing device ( 3 ) only after the beam splitter element ( 4 ) in the observation beam paths of the main and co-observers. Known stereo pan rates with two partial beam paths in each of the observation beam paths can then be used for this.

In the exemplary embodiment shown in FIG. 1, the beam splitter element ( 4 ) follows in the parallel beam path behind the magnification changing device ( 3 ), two partially reflecting and partially transparent surfaces ( 4.1 , 4.2 ) being visible in this illustration. These surfaces ( 4.1 , 4.2 ) are designed to be partially transparent or partially reflective in the exemplary embodiment shown, so that half of the light reaching them is transmitted in the direction of the primary observation beam path (I), while the other half in the direction of the secondary observation beam path (II ) is reflected. Identical observation conditions in the primary and secondary beam path are thus realized. As far as possible, both surfaces should be interpreted identically with regard to their reflection and transmission characteristics.

For the specific structure and the mode of operation of the beam splitter element ( 4 ) used and possible alternative embodiments, reference is made to the following description of FIGS. 2 and 3.

It can be seen in the illustration of Fig. 1 further comprises an element at the beam splitter suppressed (4) arranged absorbent element (4.3), the undesirable multiple reflections in the optical system of the stereomicroscope according to the invention, in particular in the beam splitter element (4). As a suitable absorbing element ( 4.3 ), for example, a neutral glass filter with high absorption can be selected, which absorbs light in the visible wavelength range and z. B. is cemented to the beam splitter element ( 4 ). Such filters are e.g. B. available from Schott.

When choosing a suitable absorbent element, it should also be ensured that the refractive indices of the adjoining materials of the beam splitter element ( 4 ) and the absorbent element are as identical as possible in order to suppress any reflections that would otherwise occur at the boundary layer.

In the two stereoscopic partial beam paths of the primary observation beam path (I), optical elements ( 5 a, 5 b) follow, which provide an intermediate image of the object under consideration ( 1 ) in one plane, where electro-optical image recorders ( 6 a, 6 b) are arranged. Known CCD arrays come into question as suitable electro-optical image recorders ( 6 a, 6 b).

The exemplary embodiment of the stereomicroscope according to the invention shown in FIG. 1 is accordingly designed as a video stereomicroscope. Alternatively, however, it is also possible to arrange the beam splitter element ( 4 ) with the known observation optics of a binocular tube with eyepiece and tube lenses in the primary and secondary observation beam paths (I, II), which allow an observer to observe the object directly ( 1 ) enable. Such a binocular tube is known, for example, from DE 26 54 778 by the applicant.

A combination can also be implemented in such a way that that a known one in the primary observation beam path Observation optics for direct viewing of the Object is provided while in secondary observation beam path arranged electro-optical image sensor and vice versa.

An optical element ( 7 a) is also provided in the left stereoscopic partial beam path of the secondary observation beam path (II), which is visible in this illustration, via which the reflected portion of the light coming from the object ( 1 ) in the direction of an electro-optical image sensor ( 9 a) is redirected. Furthermore, a deflection element ( 8 ) in the form of a deflection mirror is provided in this stereoscopic partial beam path of the secondary observation beam path (II). Possibly. a prism can also be used as a deflecting element ( 8 ).

In the illustrated embodiment of the stereomicroscope according to the invention, the orientation of the primary observation beam path (I) is now fixed, while the orientation of the secondary observation beam path in an angular range between 90 ° and 180 ° relative to the orientation of the primary observation beam path (I) can be varied. This means that the secondary observation beam path can be rotated by a total of 90 ° relative to the primary observation beam path (I). For this purpose, the beam splitter element ( 4 ) is arranged in the stereomicroscope so as to be rotatable about an axis of rotation. This axis of rotation is defined by a shared observation pupil of the primary and secondary beam path in the beam splitter element or its optical axis.

The arranged in the secondary observation beam path (II) optical elements ( 7 a, 8 , 9 ) are firmly connected to the rotatable beam splitter element ( 4 ) and thus also rotatable relative to the main objective ( 2 ) and the magnification changing device ( 3 ) arranged. The optical elements ( 5 a, 5 b; 6 a, 6 b) in the primary observation beam path (I), on the other hand, are fixed to the main objective ( 2 ) and the magnification changing device ( 3 ).

As an alternative to the fixed arrangement of the primary observation beam path (I) and the variable arrangement of the secondary observation beam path (II) as in the exemplary embodiment shown in FIG. 1, it is also possible at any time, for example also the secondary observation beam path (II ) to be fixed to the housing of the stereomicroscope, while the primary observation beam path is arranged in a defined angular interval relative to it. Even with such an alternative arrangement, a magnification changing device, which is used by all the stereoscopic partial beam paths, is used, arranged as in FIG. 1.

With reference to FIG. 2, the beam splitter element guide, for example as used in this out is described (4) and operates in the following.

The beam splitter element ( 4 ) shown in perspective in Fig. 2 consists of three separate prisms ( 4 a, 4 b, 4 c), with between two prisms ( 4 a, 4 b) with cube-shaped cross section, which abut with one edge , a third prism ( 4 c) inserted in a form-fitting manner, preferably cemented on. The areas ( 4.1 , 4.2 ) on which the three prisms ( 4 a, 4 b, 4 c) collide serve as divider areas ( 4.1 , 4.2 ) on which the incident light is transmitted or reflected in a 50:50 ratio becomes. It is important here that the two divider surfaces ( 4.1 , 4.2 ) are as identical as possible in terms of the transmission and reflection properties.

Alternatively, if different intensity ratios are desired in the primary and secondary observation beam path, it is also possible to choose other intensity distribution ratios, such as 70:30, etc. It is only important again, for both divider surfaces ( 4.1 , 4.2 ), if possible choose largely identical division ratio between reflected and transmitted intensity.

It is now possible to do a number of different things To provide beam splitter elements that are different Have division ratios and as needed in stereo microscope according to the invention can be used. E.g. could be realized in primary observation rays to provide a greater transmitted intensity than for example in the secondary observation beam path, etc.

The perspective view of FIG. 2 also clearly shows the absorbing element ( 4.3 ) arranged on the beam splitter element ( 4 ), which serves to suppress undesired reflections already described above. The absorbing element ( 4.3 ) is arranged on the surface of the prism ( 4 a) where there is no deflection of the light in the direction of the secondary observation beam path. In the direction of the secondary observation beam path, only the portion that reaches the other divider surface ( 4.2 ) is reflected.

In addition, it is possible to seal the beam part element ( 4 ) used on its underside by means of a cover glass (not shown in FIG. 2) in order to prevent the edge from being exposed to external influences in the course of time. For this purpose, it is also possible to design the divider surfaces ( 4.1 , 4.2 ) so that they do not reach all the way to the upper edge of the beam splitter element ( 4 ), but rather end already inside the beam splitter element ( 4 ) and thus against the outside Influences such as air humidity etc. are largely isolated.

The mode of operation of the beam splitter element ( 4 ) used is explained below with reference to FIGS . 3a-3c. The beam splitter element ( 4 ) has three observation and / or documentation pupils ( 10 , 11 , 12 ) for the stereoscopic partial beam paths of the primary and secondary observation beam paths, one of these pupils ( 13 ) always from both the primary - and is also used simultaneously by the secondary observation beam path.

As already mentioned above, the beam splitter element ( 4 ) can be rotated about the optical axis ( 13 ) of the shared pupil ( 13 ) in the stereomicroscope.

In FIGS. 3a-3c is respectively marked on the hatched marked in recorded pupil fixedly oriented observation direction of the main or primary observer. In the exemplary embodiment shown, this is oriented such that the connecting line of the two pupils ( 10 , 11 ) runs in the direction of the transverse axis of the sheet. The two observer pupils ( 11 , 12 ) can now be rotated by 90 ° to achieve this fixed orientation. A corresponding rotation of the beam splitter element ( 4 ) about the axis ( 13 ) by 45 ° in each case, including the resulting orientations of the primary and secondary observation beam paths or pupils, is shown in FIGS . 3b and 3c. It is clearly recognizable here how the orientation of the observation direction of the co-observer can be changed by a total of 90 °, while the observation direction of the main observer remains unchanged.

In order for this rotation of the beam splitter element (4) has a sufficient optical quality in the two observation beam paths to ensure the beam splitting element used must satisfy (4) specific optical requirements.

On the one hand, the effective beam splitter surfaces ( 4.1 , 4.2 ) must be designed with regard to their reflection and transmission properties in such a way that both spectrally and intensively sufficiently identical conditions in reflection and transmission exist for both beam splitter surfaces ( 4.1 , 4.2 ).

Furthermore, it must be ensured that the edge ( 15 ) at the point where the three half-cube prisms ( 4 a, 4 b, 4 c) meet when rotating the beam splitter element ( 4 ) in the pupils of the main and observer not visible is. This edge ( 15 ) traverses in intermediate positions (not shown) of the beam splitter element ( 4 ) a pupil ( 10 ) of the main observer and must not lead to an impairment in the actual image. This is ensured in the stereomicroscope according to the invention in that the beam splitter element ( 4 ) is arranged in the parallel beam path, the edge not being in the immediate vicinity of an intermediate image plane. Otherwise, the edge could be imaged by the optical system of the stereomicroscope and the edge could have a disturbing effect when the main observer passed through the pupil.

If the stereomicroscope according to the invention is used as a pure video Stereomicroscope designed, are also suitable Provide displays or monitors on which a stereo Skopical representation of the pictures taken from each viewed object is possible. This can be known in about ter way about the sequential representation stereo scopic drawing files and accordingly synchro nized shutter glasses.

Claims (14)

1. Stereo microscope with at least three observation and / or documentation pupil (10, 11, 12), the stereoscopic primary and secondary observation beam paths (I, II) and define one of the main objective (2) downstream rotatable beam splitting element (4 ) that has at least two beam splitter surfaces ( 4.1 , 4.2 ) that transmit or reflect a defined proportion of the light coming from the object to be observed ( 1 ) to the primary and secondary observation beam paths (I, II) and both beam splitter surfaces ( 4.1 , 4.2 ) have largely identical transmission and reflection properties, the beam splitter element ( 4 ) being rotatable about an axis ( 13 ) which coincides with one of the optical axes of the stereoscopic partial beam paths of the primary and secondary observation beam paths (I, II). 2. Stereomicroscope according to claim 1, wherein three observation and / or documentation pupils ( 10 , 11 , 12 ) are provided and the observation and / or documentation pupil ( 11 ) about which the beam splitter element ( 4 ) is rotatable in each rotation Position can be used jointly by a stereoscopic partial beam path of the primary and secondary observation beam path (I, II). 3. Stereomicroscope according to claim 2, wherein the beam splitter element ( 4 ) consists of two prisms with a half-cube-shaped cross-section ( 4 a, 4 b) which abut one edge ( 15 ) and a third prism ( 4 c) between the other two is arranged positively and the boundary surfaces between the prisms ( 4 a, 4 b, 4 c) act as beam splitter surfaces ( 4.1 , 4.2 ) and the beam splitter element ( 4 ) is further arranged in the stereomicroscope in the parallel beam path. 4. Stereomicroscope according to claim 3, wherein all beam splitter surfaces ( 4.1 , 4.2 ) of the beam splitter element ( 4 ) have spectrally and intensity-identical reflection and transmission properties. 5. Stereomicroscope according to claim 4, wherein all beam splitter surfaces ( 4.1 , 4.2 ) cause a division between reflected and transmitted beam portions in a 50:50 ratio. 6. Stereo microscope according to claim 3, wherein the beam splitter element ( 4 ) is rotatable by 90 °. 7. Stereomicroscope according to claim 3, wherein the beam splitter element ( 4 ) has a light-absorbing element ( 4.3 ) on the side facing away from the secondary observation beam path (II). 8. Stereomicroscope according to claim 7, wherein the light-absorbing element ( 4.3 ) is designed as a neutral glass filter, which has an identical refractive index as the adjacent prism ( 4 a). 9. Stereomicroscope according to at least one of the preceding claims, wherein in the primary and secondary observation beam paths (I, II) electro-optical image recorders ( 6 a, 6 b, 9 a) are arranged. 10. Stereomicroscope according to at least one of the preceding claims, wherein the beam splitter element ( 4 ) imaging optics ( 5 a, 5 b, 7 a) for generating an intermediate image in the stereoscopic primary and secondary observation beam paths (I, II) are arranged according to and the imaging optics ( 7 a) in the secondary observation beam path (II) are firmly connected to the rotatable beam splitter element ( 4 ). 11. Stereomicroscope according to at least one of the preceding claims, wherein for all stereo scopic observation beam paths (I, II) common magnification change device ( 3 ) between the beam splitter element ( 4 ) and a common objective for all stereoscopic observation beam paths ( 2 ) arranged is. 12. Stereo microscope according to at least one of the first outgoing claims, with magnification change Devices arranged downstream of the beam splitter element the primary and secondary observation beam paths are arranged. 13. Stereomicroscope according to at least one of the first outgoing claims, used as a surgical microscope. 14. beam splitter element for a stereomicroscope with at least three observation and / or documentation pupils ( 10 , 11 , 12 ), which define stereoscopic primary and secondary observation beam paths (I, II) and the beam splitter element is arranged after a shared main objective ( 2 ) , The beam splitter element ( 4 ) has at least two beam splitter surfaces ( 4.1 , 4.2 ) which transmit or reflect a defined proportion of the light coming from the object to be observed ( 1 ) to the primary and secondary observation beam paths (I, II) and both beam splitter surfaces ( 4.1 , 4.2 ) have largely identical transmission and reflection properties and the beam splitter element ( 4 ) is arranged so as to be rotatable about an axis ( 13 ) which is aligned with one of the optical axes of the stereoscopic partial beam paths of the primary and secondary observation beam paths (I, II) coincides.