Microscope for two or more operators

A microscope adapted for use by two or more operators during surgical operations has a main objective lens and at least two mutually independent stereoscopic observation beam paths. Each stereoscopic observation beam path has a magnification system and a focusing system disposed therein. Pupil displacement systems are provided in modular construction of different mechanical lengths but of equal optical path lengths. This modular construction allows individual and customized configurations of the microscope for adaptation to meet the needs and requirements of various operating conditions and the various operating disciplines.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to a microscope and more 
specifically relates to a microscope adapted for use by two or more 
operators during surgical operations and having a main objective and 
downstream optical systems for changing the level of magnification and for 
adjusting the plane of focus. 
2. Description of the Prior Art 
Microscopes are used, for example, in microsurgical operations within the 
clinical sector. As a result of progressively more complex surgical 
operating methods, it is often necessary for more than one operator to be 
able to work simultaneously at a surgical operating site. Moreover, in the 
various surgical operating disciplines, it is also often necessary for 
surgical operators to individually arrange their working posture and 
position in working relation to the subject patient. 
A surgical operating microscope for two surgeons is disclosed, for example 
in DE 2,949,429. This patent discloses a surgical operating microscope 
having a main objective and three separately executed observation beam 
paths downstream of the main objective for two observation tubes. In order 
to construct two stereoscopic observation beam paths, one of the three 
beam paths is used jointly. As a result, it is not possible to 
independently adjust the image magnification of one stereoscope 
observation beam path without simultaneously adjusting the image 
magnification of the other stereoscopic observation beam path. 
DE 3,333,471 discloses a surgical operating microscope wherein the 
observation beam paths are capable of individual settings. This is 
accomplished by two separate microscopes that are disposed at a right 
angle relative to each other with each microscope exhibiting an objective, 
a magnification changing device and a binocular tube. By means of a mirror 
that is partially transparent and disposed at 45.degree., the light coming 
from the object is directed via the two objectives into the respective 
separate observation beam paths. Accordingly, while advantageous from the 
perspective of independent magnification control, this construct 
nevertheless suffers from a particular disadvantage stemming from the use 
of a partially transparent mirror that reduces the light available for 
observation by 50%. 
DE 3,602,095 and DE 3,523,639 also disclose operating microscopes for use 
by two surgical operators. In both microscopes, there is a common main 
objective and observation beam paths that are executed separately from one 
another. In order to permit both operators to have the same view of the 
object field to be investigated, irrespective of the particular location, 
one of the stereoscopic beam paths is rotated about the optical axis of 
the main objective using additional optical means. Both stereoscopic beam 
paths exhibit zoom objectives to alter the image magnification. In 
addition to the considerable mechanical complexity, these microscopes 
suffer from a further disadvantage in that it is not possible to carry out 
independent focusing of the individual observation beam paths. 
U.S. Pat. No. 4,138,191 discloses a surgical operating microscope for use 
by two operators, in which two separate stereoscope observation beam paths 
are formed using a common main objective. This reference also discloses 
the possibility of using an additional separate beam path for making 
photographic exposures. This microscope, however, also suffers from the 
disadvantage of lacking the capability of independently focusing the two 
stereoscopic observation beam paths. 
DE 3,202,075 discloses an optical system with variable intercept length and 
focal length for surgical operating microscopes with a main objective of 
fixed focal length. The internal focusing provided in this microscope 
includes a zoom system with a plurality of lens groups that is capable of 
movement along the optical axis of the main objective in order to retain 
the stereoscopic observation image in the course of focusing and in the 
course of the changing of the image magnification with concurrent movement 
perpendicular to the optical axis of the main objective. The curved 
movement resulting from this gives rise to a high degree of mechanical 
complexity in the precise guiding and coupling of the lens elements. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a 
microscope that can be used simultaneously by at least two operators in a 
manner such that in any given object field at least one operator can 
adjust his or her own individual level of magnification and plane of focus 
independently of and without affecting the other operator's level of 
magnification and plane of focus. 
It is a further object of the present invention to provide a surgical 
operating microscope adapted for use by two or more operators such that 
within an object field that is to a large extent the same, each operator 
can set an individual magnification and an individual plane of focus. 
The present invention is directed to a novel microscope for use by two or 
more operators and represents a vast improvement and a completely novel 
approach for satisfying and meeting the needs, requirements and criteria 
for effective and useful microscopic viewing without the problems and 
disadvantages of the prior art methods in a safe and cost effective manner 
and without complex and complicated construction. 
A particular advantage of the present invention is realized and achieved 
due to the fact that by use of the microscope of the present invention in 
differing operating disciplines, each operator can independently adjust 
their own working posture as well as their working distance from the 
operating site or from the object according to their own particular needs 
and requirements. 
Additional objects and advantages of the present invention will be set 
forth, in part, in the description that follows and, in part, will be 
obvious from the description or may be learned by practice of the 
invention. The objects and advantages of the invention may be learned by 
and attained by means of the instrumentalities, combinations and 
configurations particularly pointed out in the appending claims. 
Additionally, the teachings of the patents previously noted above are 
incorporated herein by reference. 
To achieve the foregoing objects and in accordance with the purpose of the 
present invention, as embodied and broadly described herein, the 
microscope of the present invention comprises a main objective lens having 
an optical axis; at least two mutually independent stereoscopic 
observation beam paths; a lens system disposed in each stereoscopic 
observation beam path in parallel with the optical axis of the main 
objective lens; the lens system having magnification means for selecting a 
magnification level; the magnification means including a first pair of 
lenses disposed below a second pair of lenses in overlapping 
configuration; at least one of the lens systems having focusing means for 
adjusting a focus plane of an object image; the focusing means including a 
first pair of overlapping, rotatable wedges disposed between a first lens 
of the first pair of lenses and the main objective lens and a second pair 
of overlapping, rotatable wedges disposed between a second lens of the 
first pair of lenses and the main objective lens. 
In an alternate embodiment of the present invention, the focusing means 
includes a first pair of overlapping, rotatable wedges disposed between a 
first lens of the first pair of lenses and a first lens of the second pair 
of lenses and a second pair of overlapping, rotatable wedges disposed 
between a second lens of the first pair of lenses and a second lens of the 
second pair of lenses. 
The first pair and/or second pair of lenses of the magnification means may 
be movably and adjustably disposed above the main objective lens in 
overlapping manner. 
There may further be provided a pupil displacement system within one or 
more stereoscopic observation beam path above the lens system. Each pupil 
displacement system may be provided in modular unit construction so as to 
be easily and quickly interchangeable. Each pupil displacement system may 
be provided in varying and different lengths, and the variance in such 
length may be equalized using prisms so that the effective optical path 
length of each pupil displacement system is uniform and equal. 
The focusing means may further comprise a pair of lower and upper rotatable 
mounts for each pair of overlapping rotatable wedges; the upper rotatable 
mount having a wavy profile top rim; the lower rotatable mount and the 
upper rotatable mount being operatively engaged by a bevel gear for 
rotation in mutually opposite directions; the bevel gear being operatively 
associated with a rotary drive shaft; a mount movable along and in 
parallel with the optical axis of the main objective lens and disposed 
above the upper rotatable mount and holding a first lens of the first lens 
system; and a control element integral with the mount holding the first 
lens and operatively associated with the top rim of the upper rotatable 
mount, wherein the mount holding the first lens is operatively moved by 
rotation of said upper rotatable mount, and the upper rotatable mount is 
operatively rotated by rotation of the rotary drive shaft. 
Each rotary drive shaft may be operatively associated with a drive gear 
wheel, and each drive gear wheel may be associated with a common drive 
gear wheel. The common drive gear wheel may be operatively associated with 
a driver, e.g., a motor. 
Overall, the microscope of the present invention allows at least two 
operators to simultaneously use the microscope and comprises a main 
objective having an optical axis and a fixed focal length for all beam 
paths, and at least two mutually independent stereoscopic optical beam 
paths extending parallel with the optical axis of the main objective, 
wherein at least one of the stereoscopic optical beam paths may be focused 
independently of the other stereoscopic optical beam path. In operation, 
the microscope may be initially focused for stereoscopic viewing by 
adjusting by displacement of the entire microscope apparatus along the 
optical axis 100 of the main objective relative to the object image in 
order to focus one of the stereoscopic beam paths with the other 
stereoscopic beam path being focused for stereoscopic viewing of the 
desired focal plane using the focusing means. 
The use of rotating optical wedges in the stereoscopic observation beam 
paths ensures the alignment of any convergent or divergent beams parallel 
to the optical axis of the respective stereoscopic observation beam path, 
thereby ensuring that the stereoscopic viewing is not compromised. 
There may be a plurality of stereoscopic observation beam paths provided 
around the optical axis of the main objective lens. One or more or all of 
these paths may be provided with lens systems that allows individual 
focusing of the desired focal plane of the object image. Moreover, one or 
more or all of these paths may be provided with lens systems that allow 
individual magnification of the desired object image. 
Additionally, with the use of pupil displacement systems that may be 
provided in modular unit form for quick and easy interchangeability, the 
distance of the operator relative to the object image may be suitably made 
to meet the needs and requirements of the operator. 
It is to be understood that both the foregoing general description and the 
following detailed description are exemplary and explanatory only and are 
not restrictive of the invention as claimed. 
The accompanying drawings, that are incorporated in and constitute a part 
of this specification, illustrate an embodiment of the present invention 
and together with the description, serve to explain the principles of the 
invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Reference will now be made, in detail, to a preferred embodiment of the 
present invention, an example of which is illustrated in the accompanying 
drawings. Whenever possible, the same reference numbers will be used 
throughout the drawings to refer to the same or like parts. 
Referring to FIG. 1 and in accordance with the invention, it may be seen 
that there is provided two separately executed stereoscopic observation 
beam paths 1, 2 in an operating microscope (not shown). A common, 
stationary main objective lens 3 is removably and exchangeably disposed in 
the observation beam paths 1 and 2. Proceeding in observation beam path 1 
from objective lens 3, two pairs of rotating wedges 4, 5 are provided in 
the stereoscopic beam path 1. In each instance, a lens system 6, 7 with 
individual lens groups 6a, 6b; 7a, 7b is disposed downstream of the pairs 
of rotating wedges 4, 5, respectively. In conjunction with the pairs of 
rotating wedges 4, 5 the lens groups 6a, 7a permit an alteration of the 
intercept length or focal plane of the main objective lens 3, and in 
conjunction with the downstream lens groups 6b, 7b, are employed as 
magnification means, i.e., they permit an alteration or changing of the 
level of magnification of the object image. 
For deflection of beam path 1 into binocular tubes (not shown), a common 
deflecting prism 8 is provided. A further pair of lens system 59a, 12a; 
59b, 14a that form individual telescopes 9, 10 are provided for the lens 
systems 6, 7, respectively. The plane represented by reference number 60 
marks the tube bearing surface. 
In a similar manner to stereoscopic observation beam path 1, a second 
observation beam path 2 extends through main objective lens 3 partially in 
parallel with observation beam path 1 and then through a pair of lens 
systems 15, 16 with individual lens groups 15a, 15b; 16a, 16b. These lens 
systems 15, 16 are employed as magnification means, i.e., to alter the 
image magnification in observation beam path 2. Beam paths 1 and 2 extend 
entirely separately and independently of each other and are disposed 
symmetrically about the optical axis 100 of the main objective 3. 
Accordingly, it is to be understood that in FIG. 1, it is solely for 
reasons of representation in a drawing that these beam paths 1, 2 appear 
superimposed in the region of the lens systems 7 and 15. 
In a manner similar to beam path 1, a deflecting prism 17 as well as a 
further pair of lens system 59c, 12b; 59d, 14b that form individual 
telescopes 18, 19, respectively, are provided in the stereoscopic beam 
path 2 for beam deflection into binocular tubes (not shown). In this case, 
the plane of the tube bearing surface is identified by reference symbol 
66. 
For the sake of clarity, it is to be understood that the two pairs of lens 
systems 59a, 59b; 59c, 59d shown in FIG. 1 are between the two prisms 8, 
17 and the lens systems 12a, 14a; 12b, 14b, respectively. In FIGS. 7a and 
7b, the deflecting prisms 8, 17 of FIG. 1 are represented by an altered 
arrangement of prism systems as shown and will be described. 
Referring now to FIG. 2, focusing means is shown for focusing the pair of 
individual optical wedges 4a and 4b disposed one above the other, i.e., 
overlapping configuration, as well as the lens 6a. The wedges 4a, 4b are 
seated in separately rotatable cylindrical mounts 26, 27, respectively, 
with a circulating conical toothing arrangement 28 formed between mounts 
26, 27. Operatively engaging the conical toothing arrangement 28 is a 
bevel gear 29 that is connected to a rotary drive shaft 30. Rotary 
movement of drive shaft 30 imparts rotary movement to bevel gear 29 and is 
transmitted to cylindrical mounts 26 and 27, and cylindrical mounts 26 and 
27 are moved in mutually opposite directions about optical axis 101. 
Lens 6a shown in FIG. 2 is seated in a mount 32 that is designed to be 
movable along axis 101. Control element 33 is fixedly disposed on mount 32 
and is supported on mount rim 34 of rotatable cylindrical mount 27. 
The mount rim 34 is shown in greater detail in FIG. 3 and exhibits a wavy 
profile. The mount rim 34 exhibits two profile maxima and two profile 
minima with each maxima situated opposite the other maxima and each minima 
situated opposite the other minima. Control element 33 is operatively 
associated with mount rim 34, so that a rotary movement of cylindrical 
mount 27 effects a linear movement of lens system mount 32 along axis 101 
over a distance equal to the difference in profile height between the 
profile maxima and profile minima of mount rim 34. 
FIG. 4 shows a synchronously operating mechanical coupling for two pairs of 
rotating wedges 4 and 5, disposed in stereoscopic observation beam path 1, 
using a common drive unit 44. As has already been stated with reference to 
FIG. 2, the pairs of optical wedges 4, 5 are designed to be rotatable by 
means of bevel gears 29 in the observation beam path. The two bevel gears 
for the pairs of optical wedges 4, 5 are connected to drive shafts 30 and 
35, respectively. Each drive shaft 30, 35 is connected to a corresponding 
gear wheel 36 and 38, respectively, which are in turn connected to a 
common drive gear wheel 37. The common drive gear wheel 37 is operatively 
associated with a driver 43 via a drive coupling having a shaft 39, 
additional bevel gears 40 and 41 and a further shaft 42 such that rotary 
movement of driver 43 is synchronously transmitted to the two pairs of 
rotating wedges 4 and 5. The direction of motor rotation and the 
individual rotational direction of gear wheels 36, 37, 38 resulting 
therefrom are shown by arrows in FIG. 4. 
FIG. 5 shows a stepped magnification changing device 50, that may replace, 
for example, the lens systems 15 and 16 that are illustrated in FIG. 1. 
The changing device 50 exhibits fixedly associated lens combinations 51 
and 52, that are disposed on a rotatable revolver 54 and can be rotated 
into the path of the optical axis 101. Such a changing device 50 can be 
provided pairwise in the observation beam path 2 so that differently 
defined and coordinated changes to the image magnification can be 
undertaken. 
FIGS. 6a-6c show a continuously displaceable magnification changing device 
or unit 55, that is equipped with differing lens groups 56, 57 and that 
additionally supplements, for example, the lens systems 6, 7; 15, 16 of 
FIG. 1. As a result of a movement of the lens groups 56, 57 along the 
optical axis, the image magnification may be continuously displaced or 
altered even when using a stationary main objective lens 3. 
FIGS. 7a and 7b show variants for the individual alteration of the working 
distance between the tube bearing surface 60, 66 and the optical axis 100 
of the main objective 3. 
In the observation beam path 1, proceeding from the lens group 6b (c.f., 
FIG. 1), FIG. 7a shows the lens 59, a pupil displacement system 67 of 
short overall length with a folding prism 61 with four reflections, a 
pentaprism 62 as well as the lens system 12. 
In contrast to FIG. 7a, FIG. 7b shows a pupil displacement system 63 of 
greater overall length, in which the lens 59, the pentaprism 62, a 
plane-parallel plate 64 to extend the length, a Bauernfeind prism 65 and 
the lens system 14 are disposed in the observation beam path 2. Lenses 14 
and 12 form the telescope 18, 19 and 9, 10, respectively, as shown in FIG. 
1. The bearing surface for the binocular tube is designated by reference 
number 66. 
In spite of their differing mechanical overall lengths, the pupil 
displacement systems 67 and 63 shown in FIGS. 7a and 7b, respectively, 
exhibit equal optical path lengths, so that the beam paths are not 
influenced by the differing mechanical overall lengths. 
FIGS. 8a-8d show the various possible combinations of the pupil 
displacement systems 67, and 63 (c.f., FIGS. 7a -7b) for an operating 
microscope for two operators. The pupil displacement systems 67 and 63 are 
disposed in separate housings 48 and 49 for the individual alteration of 
the working distance between the tube 70 with the eye piece and the 
optical axis 100. The observation tubes 70 shown are set onto the surfaces 
60, 66 by means of a respective rotary joint 74, and exhibit respective 
joints 69, by means of which the tube can be pivoted. The overall lengths 
of the housing 48 and 49 along the axis 100 are coordinated with one 
another. As a result of this, it is possible to achieve any selectable 
combinations of pupil displacement systems 67, 63 on a single operating 
microscope, and the differing operating disciplines can thus be 
implemented using an individually adapted microscope. Furthermore, the 
magnification systems and focusing systems may be disposed in separately 
exchangeable housings 71; 72; 71a; 72a, so that--as has already been 
stated in relation to the pupil displacement systems--individual changes 
in the configuration of the microscope can be effected. 
In FIG. 8a, two pupil displacement systems 63 of long construction are 
combined with one another, while in FIG. 8b, two systems 67 of short 
construction are shown. The combination of a pupil displacement system 67 
with a system 63 is shown in FIGS. 8c and 8d. 
The main objective lens 3 is shown in FIG. 8d, with a bayonet mount 24 so 
that the objective lens can be easily and quickly replaced or switched 
with another lens. 
Such operating microscopes are usually secured so as to pivot on a stand. 
The differing pupil displacement systems 67, 63 permit, in accordance with 
the example of FIG. 8d, an individual adaptation of the working distance 
when the microscope is tilted. 
The mode of operation of the operating microscope for two operators with 
the possibility of being able to set differing object planes is explained 
in greater detail below. The entire microscope is secured on a stand (not 
shown) in a manner known per se and is focused by altering the distance 
between the main objective lens 3 and the object site. Referring to FIG. 
1, the observation beam path 2 has been designed to be focused in 
accordance with this measure. 
An object site image by main objective lens 3 may be seen stereoscopically 
only if the latter appears behind the lens system 6, 7 or 15, 16 at the 
same angle of view. In observation beam path 2, when using a focal 
magnification systems 15, 16, this is the case only for object points in 
the front focal plane of the main objective lens 3. In the observation 
beam path an object site is not situated in the front focal plane of the 
main objective 3. The light beams proceeding from such an object point 
form at the entry aperture of the pairs of rotating wedges 4, 5 frusta of 
cones that run together or apart and having axes that do not extend 
parallel. 
These cone axes are aligned parallel by means of the pairs of rotating 
wedges. In addition to this, as has already been stated in relation to 
FIGS. 2-4, a synchronous rotation of the pairs of wedges 4, 5 is 
undertaken. The result of this rotation is that the sum of the angles of 
the wedge surfaces in relation to the optical axis 101 of the lens systems 
6, 7 is altered and a variable deflection is achieved thereby. 
As a result of displacement of the lens groups 6a, 7a along the optical 
axis of the lens systems 6, 7, the light beams penetrating the pairs of 
rotating wedges 4, 5 are focused in the focal plane of the lens groups 6b, 
7b so that the object site appears behind the lens systems 6, 7 at the 
same angle of view and can be seen stereoscopically. Without altering the 
position of the operating microscope, it is possible in this manner to 
select an individual object plane for the observation beam path 1. 
It is, of course, within the scope of the invention if such focusing 
systems are additionally disposed also in the observation beam path 2. In 
this manner, the beam path 2 may also be independently focused, without in 
this case altering the position of the entire microscope in relation to 
the object. 
If the intention is, in addition to the focusing plane, to select an 
individual magnification as well, then the lens systems 6, 7 and 15, 16, 
respectively, can be exchanged, for example, for the lens systems shown in 
FIG. 5 or FIGS. 6a-6c. According to FIG. 5, fixed alterations of the image 
magnification are selected, while in FIGS. 6a-6c a continuous displacement 
or alteration of the magnification is achieved. In this case, the lens 56, 
57 (FIGS. 6a-6c) are displaced along axis 101 (FIG. 2). In order to carry 
out focusing, the lens 6a is disposed so as to be displaceable along axis 
101. The displacement of the lens 6a is selected so that the set object 
plane is imaged by the lens 6a in a stationary position. As a result of 
this, the elements of a magnification changing device following lens 6a 
are independent of the focusing means. 
It will be apparent to those skilled in the art that various modifications 
and variations can be made in the microscope of the present invention 
without departing from the scope or spirit of the present invention. Other 
embodiments of the invention will be apparent to those skilled in the art 
from consideration of the specification and practice of the invention 
disclosed herein. It is intended that the specification and examples be 
considered as exemplary only, and that the present invention cover the 
modifications and variations of this invention provided they come within a 
true scope and spirit of the appended claims and their equivalents.