U.S. patent application number 11/699175 was filed with the patent office on 2007-06-07 for stereo-examination systems and stereo-image generation apparatus as well as a method for operating the same.
This patent application is currently assigned to Carl Zeiss Surgical GmbH. Invention is credited to Michael Haisch, Christoph Hauger, Andreas Obrebski.
Application Number | 20070127115 11/699175 |
Document ID | / |
Family ID | 26010999 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070127115 |
Kind Code |
A1 |
Hauger; Christoph ; et
al. |
June 7, 2007 |
Stereo-examination systems and stereo-image generation apparatus as
well as a method for operating the same
Abstract
A stereo-examination system for imaging an object 8 is proposed,
comprising an objective arrangement 3 having an optical axis 5 and
an object plane 7 for positioning the object 8 to be imaged,
wherein the objective arrangement 3 receives an object-side beam
bundle 11 emanating from the object plane 7 into a solid angle
region 9 and converts the same into an image-side beam bundle 13, a
selection arrangement for selecting at least a pair of partial beam
bundles 19, 20 from the image-side beam bundle 13, and an image
transmission apparatus 51, 52 for generating a representation of
images of the object 8 provided by the partial beam bundles 19, 20.
The stereo-examination system is distinguished in that the
selection arrangement is provided for displacing a beam
cross-section of at least one of the two partial beam bundles 19,
20 relative to a beam cross-section of the image-side beam bundle
13, a controller 49 being provided for controlling the selection
arrangement to displace the beam cross-section of the at least one
partial beam bundle 19, 20 in circumferential direction about the
optical axis 5.
Inventors: |
Hauger; Christoph; (Aalen,
DE) ; Haisch; Michael; (Aalen, DE) ; Obrebski;
Andreas; (Dusseldorf, DE) |
Correspondence
Address: |
OSHA LIANG L.L.P.
1221 MCKINNEY STREET
SUITE 2800
HOUSTON
TX
77010
US
|
Assignee: |
Carl Zeiss Surgical GmbH
Oberkochen
DE
|
Family ID: |
26010999 |
Appl. No.: |
11/699175 |
Filed: |
January 29, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10357260 |
Feb 3, 2003 |
7180660 |
|
|
11699175 |
Jan 29, 2007 |
|
|
|
Current U.S.
Class: |
359/376 |
Current CPC
Class: |
G02B 21/22 20130101 |
Class at
Publication: |
359/376 |
International
Class: |
G02B 21/22 20060101
G02B021/22 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 4, 2002 |
DE |
102 04 431.7 |
Jan 13, 2003 |
DE |
103 00 925.6 |
Claims
1-13. (canceled)
14. A stereo-examination system, comprising: an objective
arrangement having an optical axis and an object plane, wherein the
objective arrangement is configured to receive an object-side beam
bundle emanating from the object plane into a solid angle region
and to convert the object-side beam bundle into an image-side beam
bundle; a selection arrangement for selecting a first pair and a
second pair of partial beam bundles from the image-side beam
bundle, wherein the selection arrangement is configured to displace
a beam cross-section of at least one partial beam bundle of the
first pair and the second pair of partial beam bundles relative to
a beam cross-section of the image-side beam bundle; an image
transmission apparatus for generating representations of images
provided by the first pair and the second pair of partial beam
bundles; and a controller configured to control the selection
arrangement to displace the beam cross-section of the at least one
partial beam bundle in a circumferential direction about the
optical axis, wherein the selection arrangement comprises a pulsed
light source.
15. The stereo-examination system according to claim 14, wherein
the selection arrangement comprises a reflector displaceable about
the optical axis.
16. A stereo-examination system, comprising: an objective
arrangement having an optical axis and an object plane, wherein the
objective arrangement is configured to receive an object-side beam
bundle emanating from the object plane into a solid angle region
and to convert the object-side beam bundle into an image-side beam
bundle; a selection arrangement for selecting a first pair and a
second pair of partial beam bundles from the image-side beam
bundle, wherein the selection arrangement is configured to displace
a beam cross-section of at least one partial beam bundle of the
first pair and the second pair of partial beam bundles relative to
a beam cross-section of the image-side beam bundle; an image
transmission apparatus for generating representations of images
provided by the first pair and the second pair of partial beam
bundles; and a controller configured to control the selection
arrangement to displace the beam cross-section of the at least one
partial beam bundle in a circumferential direction about the
optical axis, wherein the image transmission apparatus comprises at
least a pair of cameras, wherein each camera is allocated to a
partial beam bundle of the first pair and the second pair of
partial beam bundles to generate a representation of the image
provided by said partial beam bundle.
17. The stereo-examination system according to claim 16, wherein
the selection arrangement comprises the image transmission
apparatus, and the pair of cameras are rotatable about a rotational
axis to displace the two selected partial beam bundles relative to
the beam cross-section of the image-side beam bundle.
18. The stereo-examination system according to claim 16, wherein
the pair of cameras are fixedly positioned relative to the
objective arrangement, and the selection arrangement comprises two
controllable beam deflectors respectively allocated to the pair of
cameras to supply each of the two partial beam bundles to the
respectively allocated camera.
19. The stereo-examination system according to claim 16, wherein
the pair of cameras are fixedly positioned relative to the
objective arrangement, and the selection arrangement comprises an
optical system rotatable about a rotational axis to supply each of
the two partial beam bundles to the camera allocated thereto.
20. The stereo-examination system according to claim 19, wherein
the rotatable optical system is an image-rotating optical system
comprising a Dove prism or/and a Schmidt-Pechan prism.
21. The stereo-examination system according to claim 16, wherein a
beam dividing arrangement for supplying the image-side beam bundle
to several selection arrangements is provided, a separate image
transmission apparatus being allocated to each selection
arrangement.
22. The stereo-examination system according to claim 21, wherein
the selection arrangement comprises a rotatable stop having a
decentral aperture.
23. The stereo-examination system according to claim 21, further
comprising an illumination apparatus for illuminating the object
through the beam dividing arrangement.
24. A stereo-examination system, comprising: an objective
arrangement having an optical axis and an object plane wherein the
objective arrangement is configured to receive an object-side beam
bundle emanating from the object plane into a solid angle region
and to convert the object-side beam bundle into an image-side beam
bundle; a selection arrangement for selecting a first pair and a
second pair of partial beam bundles from the image-side beam bundle
wherein the selection arrangement is configured to displace a beam
cross-section of at least one partial beam bundle of the first pair
and the second pair of partial beam bundles relative to a beam
cross-section of the image-side beam bundle; an image transmission
apparatus for generating representations of images provided by the
first pair and the second pair of partial beam bundles; and a
controller configured to control the selection arrangement to
displace the beam cross-section of the at least one partial beam
bundle in a circumferential direction about the optical axis
wherein, in the direction of the optical axis, the selection
arrangement comprises two controllable beam deflectors and a stop,
the stop being disposed between the two controllable beam
deflectors or one of the two controllable beam deflectors being
disposed between the stop and the other one of the two controllable
beam deflectors.
25. A stereo-examination system comprising: an objective
arrangement having an optical axis and an object plane wherein the
objective arrangement is configured to receive an object-side beam
bundle emanating from the object plane into a solid angle region
and to convert the object-side beam bundle into an image-side beam
bundle; a selection arrangement for selecting a first pair and a
second pair of partial beam bundles from the image-side beam bundle
wherein the selection arrangement is configured to displace a beam
cross-section of at least one partial beam bundle of the first pair
and the second pair of partial beam bundles relative to a beam
cross-section of the image-side beam bundle; an image transmission
apparatus for generating representations of images provided by the
first pair and the second pair of partial beam bundles; and a
controller configured to control the selection arrangement to
displace the beam cross-section of the at least one partial beam
bundle in a circumferential direction about the optical axis
wherein the selection arrangement comprises a facet mirror or a
facet prism, a controllable beam deflector.
26. (canceled)
27. A stereo-examination system, comprising: an objective
arrangement having an optical axis and an object plane, wherein the
objective arrangement is configured to receive an object-side beam
bundle emanating from the object plane into a solid angle region
and to convert the object-side beam bundle into an image-side beam
bundle; a selection arrangement for selecting a first pair and a
second pair of partial beam bundles from the image-side beam
bundle, wherein the selection arrangement is configured to displace
a beam cross-section of at least one partial beam bundle of the
first pair and the second pair of partial beam bundles relative to
a beam cross-section of the image-side beam bundle; an image
transmission apparatus for generating representations of images
provided by the first pair and the second pair of partial beam
bundles; and a controller configured to control the selection
arrangement to displace the beam cross-section of the at least one
partial beam bundle in a circumferential direction about the
optical axis, wherein the image transmission apparatus comprises at
least three cameras, wherein a partial beam bundle is directed to
each camera, said partial beam bundle being fixed relative to the
other cameras, and wherein the selector arrangement selects from
the at least three cameras different pairs for generating the
representation to displace the at least one beam cross-section
about the optical axis.
28-34. (canceled)
35. A stereo-examination system, comprising: an objective
arrangement having an optical axis and an object plane, wherein the
objective arrangement is configured to receive an object-side beam
bundle emanating from the object plane into a solid angle region
and to convert the object-side beam bundle into an image-side beam
bundle; a selection arrangement for selecting a first pair and a
second pair of partial beam bundles from the image-side beam
bundle, wherein the selection arrangement is configured to displace
a beam cross-section of at least one partial beam bundle of the
first pair and the second pair of partial beam bundles relative to
a beam cross-section of the image-side beam bundle; an image
transmission apparatus for generating representations of images
provided by the first pair and the second pair of partial beam
bundles; and a controller configured to control the selection
arrangement to displace the beam cross-section of the at least one
partial beam bundle in a circumferential direction about the
optical axis, further comprising an illumination apparatus
comprising a beam coupler for superposing a cross-section of an
illumination beam to the beam cross-section of the image-side beam
bundle, the illumination apparatus being controllable such that the
cross-section of the illumination beam does substantially not
overlap with the beam cross-sections of the partial beam
bundles.
36. The stereo-examination system according to claim 35, wherein
the illumination apparatus comprises a field of a plurality of
selectively switchable mirrors.
37. A stereo-image generation apparatus for generating at least a
pair of representations of an object for observation by at least
one user, comprising: a detector arrangement for detecting
radiation emanating from a region of the object into at least two
solid angle regions and for providing radiation data corresponding
to the detected radiation, a position detection apparatus for
detecting a first position of the user relative to a fixed point in
a user coordinate system, a selection arrangement for determining
the at least two solid angle regions dependent upon an azimuth
or/and an elevation of the user position in the user coordinate
system, and a display apparatus for displaying a first
representation for a left eye of the user and for displaying a
second representation for a right eye of the user dependent upon
the radiation data.
38. The stereo-image generation apparatus according to claim 37,
wherein the detector arrangement and the selection arrangement
comprise a stereo-examination system.
39. A stereo-image generation method for generating at least a pair
of representations of an object for observation by at least one
user, comprising: detecting a first position of the user relative
to a fixed point in a user coordinate system, detecting radiation
emanating from a region of the object into at least two solid angle
regions and providing radiation data corresponding to the recorded
radiation, supplying the radiation data to a display and displaying
a first representation for a left eye of the user and displaying a
second representation for a right eye of the user, and
subsequently: detecting a second position of the user relative to
the fixed point and: if an azimuth of the second position has
changed as compared to an azimuth of the first position: displacing
at least one of the two solid angle regions azimuthally about an
axis or/and if an elevation of the second position has changed as
compared to an elevation of the first position: displacing at least
one of that the two solid angle regions elevationally with respect
to the axis.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/357,260, filed Feb. 3, 2003, which claims priority from
Germany Patent Applications No. 102 04 431.7, filed Feb. 4, 2002,
and No. 103 00 925.6, filed Jan. 13, 2003, the contents of which
are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a stereo-examination system for
imaging an object, a stereo-image generation apparatus for
generating at least a pair of images of an object and a method for
generating such images.
BACKGROUND OF THE INVENTION
[0003] An example of a conventional stereo-examination system is a
stereomicroscope. A beam path of a conventional stereomicroscope is
schematically shown in FIG. 1. The stereomicroscope 1 shown there
comprises an objective 3 with an optical axis 5 and an object plane
7 in which an object to be viewed is positioned. A beam bundle 11
emanating from the object or object plane 7 into a solid angle
region 9 around the optical axis 5 images the objective 3 to
infinity and thus converts it into a parallel image-side beam
bundle 13. Two zoom systems, each having an optical axis 17 and 18,
respectively, of its own, are positioned adjacent each other in the
parallel beam bundle 13 such that the optical axes 17 and 18 of the
zoom systems are offset parallel to the optical axis 5 of the
objective 3 and spaced apart from each other by a distance a. The
two zoom systems 15, 16 each feed a partial beam bundle 19 and 20,
respectively, out of the parallel beam bundle 13, the partial beam
bundle 19 being supplied to a left eye 21 of a user and the other
partial beam bundle 20 being supplied to a right eye 22 of the
user. To this end, a field lens 23, a prism system 25 and an ocular
27 are disposed in the beam path of each partial beam bundle 19,
20. As a result, the left eye 21 perceives the object 7 at a
viewing angle a with respect to the optical axis 5, while the right
eye 22 perceives the object at a viewing angle -.alpha. with
respect to the optical axis. As a result, the user gets a
stereoscopic, three-dimensional impression of the object.
[0004] FIG. 2 shows part of a beam path of a conventional
microscope 1 for providing a stereoscopic image of an object for
each one of two users. Similar to the microscope shown in FIG. 1,
an objective 3 produces a parallel image-side beam bundle from a
beam bundle 11 emanating from the object into a solid angle region,
with two zoom systems 15 and 16 being provided, each feeding a
partial beam bundle 19 and 20, respectively, out of the parallel
beam bundle which are supplied via field lenses 23 as well as prism
systems and oculars, not shown in FIG. 2, to the two eyes of a
first observer.
[0005] In the parallel image-side beam path, there are further
disposed two mirrors 31 which feed two further partial beam bundles
33 and 34 out of the parallel beam path and reflect the same such
that they extend transversely to the beam direction of the partial
beam bundles 19, 20. These two partial beam bundles 33 and 34 are
each supplied, via a zoom system 35 and 36, respectively, as well
as prism systems and oculars, not shown in FIG. 2, to the two eyes
of a second observer.
[0006] In order for this microscope to be used by two observers, it
is required that, while observing the object, the two observers are
constantly in a fixed spatial position relative to the microscope.
In particular, if the microscope is used as surgical microscope
during a surgical operation, this spatial limitation is obstructive
for the two observers who must operate as surgeons in the operating
field.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an object of the present invention to
provide a stereo-examination system and a stereo-image generation
apparatus which provide degrees of freedom at least for one
observer as regards his position relative to the object to be
viewed.
[0008] According to a first aspect, the invention proceeds from a
stereo-examination system for imaging an object, or an intermediate
image produced from the object, comprising an objective arrangement
with an optical axis and an object plane in which the object to be
imaged, or the intermediate image, is positioned. The objective
arrangement receives an object-side beam bundle emanating from the
object, or intermediate image, into a solid angle region and
converts the same into an image-side beam bundle. A selection
arrangement selects or feeds at least a pair of partial beam
bundles out of said image-side beam bundle which are supplied to an
image transmission apparatus to generate a representation of the
image information contained in each one of the partial beam
bundles.
[0009] The stereo-examination system is distinguished in that it
comprises a selection arrangement which is provided to displace a
beam cross-section of at least one of the two partial beam bundles
relative to a beam cross-section of the image-side beam bundle,
i.e., to change the position of the beam cross-section of the
fed-out partial beam bundle within the beam cross-section of the
image-side beam bundle.
[0010] To this end, the stereo-examination system comprises a
controller for controlling the selection arrangement such that it
displaces the beam cross-section of the at least one partial beam
bundle relative to the beam cross-section of the image-side beam
bundle in circumferential direction about the optical axis. As a
result, it is possible to eliminate and modify the fixed
arrangement, as it is known from the prior art, of the fed-out
partial beam bundle in circumferential direction about the optical
axis of the object such that representations of the object can be
supplied to the observer via the displaced partial beam bundles,
said representations being generated from different, variable
viewing angles. It is thus possible for the observer to move in
azimuthal direction about the object and, when the selection
arrangement is controlled accordingly, to view stereoscopic images
of the object at different azimuth angles.
[0011] Preferably, the selection arrangement is provided to
selectively choose only a first one or a second one of the pair of
partial beam bundles from the image-side beam bundle. As a result,
the individual partial beam bundles can be imaged, successively in
time, by the image transmission apparatus. It is thus particularly
easy to spatially separate the individual partial beam bundles from
each other. This applies, in particular, if several pairs of
partial beam bundles are fed out of the image-side beam
cross-section for several observers.
[0012] Preferably, such a selection arrangement is provided as
switchable stop which selectively transmits the first one or the
second one of the partial beam bundles or still further partial
beam bundles.
[0013] To this end, the switchable stop preferably comprises a
plurality of separately controllable stop elements, each of which
is switchable from a state in which they transmit much or
substantially all light to a state in which they transmit less
light or substantially no light. The stop elements are then
controlled such that they are light-permeable in the region of the
beam cross-section of the image-side beam bundle in which the
respective partial beam bundle is to be shaped and
light-impermeable in the remaining region of the image-side beam
bundle. Subsequently, the stop elements are then switched into the
light-permeable state in another region of the image side
beam-cross section in order for the other partial beam bundle to be
shaped there.
[0014] The switchable stop elements may be formed of liquid
crystals or mechanically displaceable stop elements.
[0015] As an alternative to the provision of the selection
arrangement as switchable stop, it can also be provided in the form
of a switchable mirror disposed in the cross-section of the
image-side beam bundle for selectively reflecting the first one or
the second one of the partial beam bundles or further beam bundles.
The beam bundles are then formed by reflection at reflection
regions of the switchable mirror. To this end, the mirror
preferably comprises separately controllable mirror members which
are switchable from a state in which the light of the image-side
beam bundle is reflected towards the image transmission apparatus
to a corresponding non-reflecting or less reflecting state.
[0016] Preferably, the mirror members comprise liquid crystals or
mechanically displaceable mirror elements.
[0017] The plurality of partial beam bundles successively fed out
of the image-side beam bundle by the selection arrangement are
preferably supplied to a common camera which is controlled by the
controller such that it generates, successively in time,
representations of the image information which is contained in the
individual partial beam bundles.
[0018] Here, it is in particular possible to generate with one
camera stereo-image pairs for several observers which are located
at different positions in circumferential direction about the
optical axis of the objective.
[0019] Alternatively, it is also provided for that, in order to
generate each stereo-image pair, a pair of cameras is provided,
each camera being allocated to a separate partial beam bundle. It
is then possible to obtain simultaneously representations of the
image information contained in the two partial beam bundles.
[0020] In this respect, it is provided for the two cameras to be
jointly displaceable together with the two partial beam bundles. To
this end, the cameras are connected to each other in rotationally
fixed position with respect to a rotational axis, but can be
jointly rotated about the same.
[0021] As an alternative thereto, it is provided for that the two
cameras are stationary relative to the objective arrangement, and
the selection arrangement comprises an optical system which is
rotatable about a rotational axis in order to supply the two
partial beam bundles which are displaceable about the optical axis
to the two stationary cameras.
[0022] Preferably, the rotational optical system is an
image-rotating optical system so that both cameras can directly
generate the respective representations in correct image
orientation.
[0023] Preferably, the rotational optical system comprises a Dove
prism or a Schmidt-Perchan prism.
[0024] If the examination system is provided for use by several
observers, it comprises preferably a beam-dividing arrangement to
divide the image-side beam bundle and to supply it to several
selection arrangements. In this case, a separate image transmission
apparatus is allocated to each selection arrangement for
respectively generating the stereoscopic representations for one
observer.
[0025] If use is made of a beam-dividing arrangement, it offers a
simple possibility to illuminate the object in that an illuminating
light beam is fed into the beam path through the beam-dividing
arrangement such that the illuminating light beam passes through
the objective and is focused by the same onto the object.
[0026] Furthermore, it is provided for that the image transmission
apparatus comprises at least three cameras, each of which receives
a portion of the image-side beam bundle in fixed spatial relation
relative to each other and generates a representation of the image
information contained in the partial beam bundles supplied to the
same. The selection arrangement then selects a pair of cameras from
the at least three cameras to combine the representations thereof
to a stereoscopic representation.
[0027] By selecting different camera pairs, partial beam bundles
are thus selected for generating the representations which are
differently positioned about the optical axis of the objective.
[0028] Preferably, the objective is provided such that it images
the image-side beam bundle substantially to infinity and thus
converts it to a substantially parallel beam bundle. However, the
objective can also image to finity and form a convergent image-side
beam bundle in which the selection arrangement is provided.
[0029] Preferably, the selection arrangement selects the partial
beam bundles at a location of the image-side beam path where a
Fourier plane is disposed.
[0030] Preferably, the image transmission comprises a display
apparatus for representing the image information contained in the
two partial beam bundles such that the image information of a first
partial beam bundle of the pair of partial beam bundles is visible
for the left eye of the observer and, correspondingly, the
representation of the image information contained in the other,
second partial beam bundle of the pair is visible for the right eye
of the observer. The image transmission apparatus may comprise a
viewing screen suitable for a stereoscopic image observation. For
example, this may be a viewing screen which presents the two
representations, successively in time, to the observer, the latter
wearing shutter spectacles which are synchronized with said time
sequence and alternately give the left eye and the right eye the
view over the display screen. It is also possible for a separate
image transmission apparatus to be allocated to each eye of the
observer which is, in particular, worn directly on the head of the
observer in front of the eye.
[0031] When necessary for a correct stereo representation, the
images are rotated by the image transmission apparatus about an
image rotation angle such that the image rotation angle increases
with increasing displacement of the partial beam bundles about the
optical axis.
[0032] Preferably, the examination system then comprises a position
detection apparatus to detect an azimuth position of the observer
relative to the objective arrangement, the controller then using
the detected azimuth position to adjust the displacement of the
cross-sections of the two partial beam bundles relative to the beam
cross-section of the image-side beam bundle in circumferential
direction about the optical axis. The examination system can then
supply stereoscopic representations to the observer from a
perspective which corresponds to the perspective from which the
observer would view the object directly, i.e., without the use of
the objective arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Embodiments of the invention will now be described in
further detail with reference to the drawings, wherein
[0034] FIG. 1 shows a beam path of a conventional
stereomicroscope;
[0035] FIG. 2 shows a part of a beam path of a further conventional
stereomicroscope for two observers,
[0036] FIG. 3 shows an embodiment of a stereo-examination system
according to the invention comprising several rotatable
cameras,
[0037] FIG. 4 is a schematically representation from the side of a
further embodiment of a stereo-examination system according to the
invention comprising several rotatable cameras,
[0038] FIG. 5 is a plan view of the stereo-examination system shown
in FIG. 4,
[0039] FIG. 6 shows an embodiment of a stereo-examination system
according to the invention with stationary camera and rotatable
optical system,
[0040] FIG. 7 shows a further embodiment of a stereo-examination
system according to the invention with rotatable cameras,
[0041] FIG. 8 shows a further embodiment of a stereo-examination
system according to the invention with stationary cameras and
rotatable optical systems,
[0042] FIG. 9 shows a still further embodiment of a
stereo-examination system according to the invention with
stationary cameras and rotatable optical systems,
[0043] FIG. 10 shows a still further embodiment of a
stereo-examination system according to the invention with
stationary cameras and rotatable optical systems
[0044] FIG. 11 is a schematic plan view of an embodiment of the
stereo-examination system according to the invention comprising an
image transmission apparatus with eight cameras,
[0045] FIG. 12 shows an embodiment of a stereo-examination system
according to the invention comprising a switchable stop,
[0046] FIGS. 13 to 16 show variants of the switchable stop shown in
FIG. 13,
[0047] FIG. 17 shows an embodiment of a stereo-examination system
according to the invention comprising a switchable mirror
arrangement,
[0048] FIG. 18 is a schematic representation of the
stereo-examination system according to the invention together with
a user,
[0049] FIG. 19 is a plan view of stereobasis of the examination
system shown in FIG. 18,
[0050] FIG. 20 shows a position detection apparatus for use in the
stereo-examination system shown in FIG. 18,
[0051] FIG. 21 shows a further embodiment of a stereo-examination
system according to the invention,
[0052] FIG. 22 shows an illumination system for use in a
stereo-examination system shown in FIGS. 1 to 19,
[0053] FIG. 23 is a cross-sectional view for illustrating the
function of the illumination system shown in FIG. 22,
[0054] FIGS. 24 to 30 show further embodiments of a
stereo-examination system according to the invention.
DETAILED DESCRIPTION
[0055] The system and the method according to the invention serve
to generate stereoscopic images and representations, respectively,
of an object such that, when viewing the images, the observer
obtains a three-dimensional impression of the object. To this end,
it is required for the left eye and the right eye of the observer
to perceive different images from different directions of view onto
the object.
[0056] An embodiment of a stereo-examination system according to
the invention is schematically shown in FIG. 3. The
stereo-examination system 1 comprises an objective 3 with an
optical axis 5 and an object plane 7. An object 8 is positionable
in the object plane 7. An object-side beam bundle 11 emanates from
the object 8 or object plane 7 into a solid angle region 9 and is
received by the objective 3 to be imaged to infinity and converted
into a parallel image-side beam bundle 13, respectively, the
optical axis 5 being disposed in a center of a beam cross-section
of the image-side beam bundle 13.
[0057] Behind the objective 3, there is positioned a beam divider
41 in the beam path comprising a semi-transparent mirror surface 43
disposed at 45.degree. to the optical axis 5. The beam divider 41
serves to divide the parallel image-side beam bundle into two
portions 13' and 13'', the beam portion 13' passing straightly
through the beam divider 41 and the beam portion 13'' emerging from
the beam divider 41 at 90.degree. to the optical axis 5.
[0058] After the beam divider 41, there are positioned two zoom
systems 15 and 16 in the beam path of the image-side beam bundle
13', each of said zoom systems 15 and 16 having an optical axis 17
and 18, respectively, of its own. The optical axes 17 and 18 of the
zoom systems 15 an 16 extend parallel to the optical axis 5.
Furthermore, the zoom systems 15 and 16 are disposed symmetrically
with respect to the optical axis 5 of the objective 3 and are
spaced apart from each other by a distance a. Due to the geometric
dimensions of the entrance lenses of the zoom systems 15, 16, only
a portion of the radiation supplied by the image-side beam bundle
13' enters the zoom systems. These partial beam bundles 19 and 20
entering the zoom systems 15 and 16, respectively, are supplied by
the zoom systems 15 and 16 to cameras 45 and 46 which are, for
example, CCD cameras. Here, the camera 45 is fixedly allocated to
the zoom system 15, and the camera 46 is fixedly allocated to the
zoom system 16.
[0059] When extending the partial beam bundles 19, 20 entering the
zoom systems 15 and 16 back to the object 8, it is evident that the
camera 46 receives an image of the object 8 as it appears upon
observation of the object 8 at a viewing angle a with respect to
the optical axis 5 of the objective. Accordingly, the camera 45
receives an image of the object 8 as it appears upon observation of
the object 8 at a viewing inclined at an angle .alpha. with respect
to the optical axis 5. However, the viewing angles of the two
images produced by the two cameras 45, 46 differ by a value of
2.alpha.. The images recorded by the cameras 45, 45 are digitally
read out by a controller 49 and either stored or directly supplied
to two displays 51 and 52, the display 51 representing the image
received from the camera 45 and the display 52 representing the
image received from the camera 46. The displays 51, 52 may be
provided in the form of head-mounted display units worn on the head
of a user, so that the display 51 is viewed by the left eye of the
user and the display 52 is viewed by the right eye of the user.
Accordingly, the left eye receives an image of the object 8 as it
is generated upon observation of the object 8 inclined at an angle
.alpha. to the optical axis 5, and the right eye of the user
receives an image of the object as it is generated upon observation
of the object 8 at a viewing angle .alpha. opposite thereto. As
images of the same object but at different viewing angles are
presented to the eyes of the user, the two images are a
stereo-image pair, i.e., a pair of images which evokes a
stereoscopic three-dimensional impression of the object 8 on the
part of the user.
[0060] The two cameras 45, 46 and the two zoom systems 15, 16 are
fixedly mounted in a common holder 53 which is rotatable about the
optical axis 5 (see angle .phi. in FIG. 3). A motor 55 driven by
the controller 49 is provided for driving the holder 53 together
with the zoom systems 15 and 16 and the cameras 45, 46. By
actuation of the motor 55, the zoom systems 15, 16 and the cameras
45, 46 are rotated about the optical axis 5 of the objective 3. As
a result, the partial beam bundles 19, 20 supplied to the cameras
45, 46 are also displaced relative to the beam cross-section of the
parallel image-side beam bundle 13'. As a result, the directions of
view onto the object 8 of the images of the object 8 presented on
the displays 51 and 52 change as well. Although the angle 2.alpha.
between the partial beam bundles imaged on the cameras 45, 46 is
maintained, the partial beam bundles supplied to the cameras 45, 46
have been displaced in azimuthal direction (see angle .phi. in FIG.
3) about the optical axis 5, i.e., a stereobasis for the
stereoscopic observation of the object has rotated about the
optical axis 5 as compared to the situation shown in FIG. 3.
[0061] Preferably, the magnifying powers of the zoom systems 15, 16
are the same.
[0062] Accordingly, the stereo-examination system 1 can present
stereoscopic image pairs to the user of the same as they are
produced upon observation of the object 8, with a circumferential
angle .phi. or azimuth of the stereobasis being freely adjustable
by the controller 49. Methods for adjusting the azimuth by the
controller 49 are described below.
[0063] The beam portion 13'' of the image-side beam bundle
extending along a mirrored optical axis 5' at 90.degree. to the
optical axis 5 of the objective 3 impinges on two zoom systems 15'
and 16' disposed parallel to the mirrored optical axis 5', said
zoom systems feeding two partial beam bundles 19' and 20' out of
the beam bundle 13'' and supplying the same to two cameras 45' and
46'. The images recorded by the cameras 45', 46' are likewise read
out by the controller 49 and presented on displays 51' and 52', one
display 51' being allocated to the camera 45' and the other display
52' being allocated to the camera 46.
[0064] The two displays 51' and 52' are provided for observation by
a further user who is different from the user observing the
displays 51 and 52.
[0065] The cameras 45' and 46', too, are mounted together with the
zoom systems 15' and 16' on a holder 53' and rotatable about the
mirrored optical axis 5'. To this end, a motor 55' controlled by
the controller 49 is provided. Accordingly, the controller 49 can
also adjust the azimuth for the stereobasis with which the further
user observes the object 8. In particular, the azimuths of the
stereobases of the two users are adjustable independently from each
other.
[0066] Preferably, the magnifying power of the zoom systems 15' and
16' is adjustable independently from the magnifying power of the
zoom systems 15 and 16.
[0067] In the following, variants of the stereo-examination system
illustrated in FIG. 3 are described. Components which correspond to
each other in structure and function are indicated by the same
reference numbers as in FIGS. 1 to 3. For the purpose of
distinction, they are, however, supplemented by an additional
letter. For the purpose of illustration, reference is taken to the
entire above description.
[0068] FIG. 4 is a side view and FIG. 5 a plan view of a further
stereo-examination system la.
[0069] The stereo-examination system la again comprises an
objective 3a with an optical axis 5a and an object plane 7a for
positioning an object 8a. A beam bundle 11a emanating from the
object 8a is converted by the objective 3a into a parallel
image-side beam bundle 20a which enters a first beam divider 41a
and is divided by a semi-reflective mirror 43a disposed at 450 to
the optical axis 5a into a beam portion 13a' extending along a
mirrored optical axis 5a' which extends at 90.degree. to the
optical axis 5a of the objective 3a and a beam portion 13a''
passing straightly through the first beam divider 41a. The beam
portion 13a'' passing through the first beam divider enters a
second beam divider 41a' and is reflected at 90.degree. by a
semi-reflective mirror 43a' disposed at 45.degree. to the optical
axis 5a so that it extends as mirrored beam portion 13a'' along a
mirrored optical axis 5a''.
[0070] The examination system la further comprises a lamp disposed
on the optical axis 5a of the objective 3a, the light emitted from
said lamp being shaped by means of a collimator 60 to form a
parallel beam bundle 61 which successively passes through the
second beam divider 41a' and the first beam divider 41a and
subsequently the objective 3a in order to be shaped by the same to
form a convergent beam for illuminating the object 8a.
[0071] The beam divider 41a (41a') is fixedly connected to a holder
53a (53a') which is supported to be rotatable about the optical
axis 5a of the objective 3a, a motor, not shown in FIGS. 4 and 5,
being provided to drive the same about the optical axis 5a.
Moreover, the holder 53a (53a') supports a pair of zoom systems
15a, 16a (15a', 16a') and a pair of cameras 45a, 46a (45a', 46a'),
each being symmetrically disposed with respect to the mirrored
optical axes 5a' (5a'').
[0072] The zoom systems 15a, 16a (15a', 16a') transmit partial beam
bundles 19a, 20a (19a', 20a') to the cameras 45a, 46a (45a', 46a')
which, in the plan view of FIG. 5, are disposed adjacent one
another and spaced apart from the mirrored optical axis 5a'
(5a'').
[0073] The zoom systems 15a, 16a, 15a', 16a' thus feed partial beam
bundles 19a, 20a, 19a', 20a' out of the parallel beam bundles 13a',
13a'', the arrangement of said partial beam bundles in the beam
cross-section of the parallel beam bundle 13a being particularly
evident from the plan view of FIG. 5. The partial beam bundles 19a,
20a and 19a', 20a' form the stereobasis for the stereoscopic
representations of the object produced by the cameras 45a, 46a and
45a', 46a', respectively, for observation by a first and a second
user, respectively. By rotating the holders 53a and 53a' about the
optical axis 5a, the stereobasis can be rotated about the optical
axis 5a for each user such that each user can observe the object
with different and individually adjustable azimuths of his
stereobasis.
[0074] A stereo-examination system 1b shown in FIG. 6 comprises an
objective 3b which converts a divergent beam bundle 11b emanating
from the object 8b into a parallel image-side beam bundle 13b. A
zoom system 15b is disposed in the parallel beam bundle 13b. After
having passed through the zoom system 15b, the parallel beam bundle
13b enters a beam divider 41b which comprises a semi-transparent
mirror 42b to divide the parallel beam bundle 13b into a parallel
beam bundle 13b' propagating further along an optical axis 5b of
the objective 3b and a parallel beam bundle 13b'' extending at
90.degree. to the optical axis 5b of the objective 3b.
[0075] The parallel beam bundle 13b' propagating further along the
optical axis 5b of the objective 3b enters an image-rotating
optical system provided as Schmidt-Perchan prism 61 and emerges
from the same again as parallel beam bundle 63. Disposed in the
beam path behind the image-rotating optical system 61, there is
disposed a pair of cameras 45b, 46b adjacent each other in the
parallel beam bundle 63, each camera feeding a partial beam bundle
19b and 20b, respectively, out of the beam bundle 63.
[0076] The two cameras 45b and 46b and the beam divider 41b are
fixedly positioned with respect to the objective 3b. However, the
image-rotating optical system 61 is disposed to be rotatable about
the optical axis 5b. When the optical system 61 is rotated by an
angle .phi. about the optical axis 5b, the beam bundle 63 emerging
from the image-rotating optical system 61 is thus rotated relative
to the parallel beam bundle 13b' entering the image-rotating
optical system by an angle 2.times..phi. about the optical axis 5b.
As a result, an azimuth of the stereobasis of the stereoscopic
representations produced by the cameras 45b, 46b can be rotated
about the optical axis 5b by rotation of the image-rotating optical
system 61 about the optical axis 5b, which rotation is caused by
means of a motor, not shown in FIG. 6, via the controller, likewise
not shown, of the examination system 1b.
[0077] A system comprising an image-rotating optical system 61' and
cameras 45b' and 46b', corresponding to the system of
image-rotating optical system 61 and cameras 45b, 46b, is disposed
along the mirrored optical axis 5b' and serves to generate
stereoscopic representations of the object 8b for a second user.
For this user, too, an azimuth of the stereobasis can be changed
for observation of the object 8b by actuation of a drive, not shown
in the Figure, to rotate the image-rotating optical system 61'
about the axis 5b'.
[0078] A stereo-examination system 1c perspectively shown in FIG. 7
again comprises an objective 3c which converts a divergent beam
bundle 11c emanating from an object 8c into a parallel beam bundle
13c. Four cameras 45c, 46c, 45c' and 46c' are disposed in the
parallel beam bundle 13c, each one of the four cameras feeding
another partial beam bundle 19c, 20c, 19c' and 20c' out of the
parallel beam bundle. The representations of the object 8c
generated by the cameras 45c and 46c are supplied to the eyes of a
first user via a controller, not shown in FIG. 7, and the images
generated by the pair of cameras 45c' and 46c' are presented to the
eyes of a further user.
[0079] The cameras of the pair of cameras 45c, 46c are fixedly
connected to each other by means of a rod 53c and cameras of the
pair of cameras 45c', 46c' are likewise fixedly connected to each
other by means of a further rod 53c'. The two cameras 45c, 46c are
supported by a sleeve 67 connected to the rod 53c, while the
cameras 45c' and 46c' are supported by a rod 68 traversing the
sleeve 67 which is connected to the rod 53c. Both the sleeve 67 and
the rod 68 are supported to be rotatable about an optical axis 5c
of the objective 3c, with toothed wheels 69 and 70 being provided
for the same to be driven on the sleeve 67 and rod 68,
respectively. The toothed wheels 69 and 70 are in engagement with a
drive, not shown in FIG. 7, to rotate the camera pairs 45c, 46c and
45c', 46c', respectively, in azimuth direction about the optical
axis 5c. The camera pairs are independently rotatable about the
optical axis 5c, the rotational angles, however, not being fully
free, but rather limited by the cameras getting in abutment against
each other.
[0080] A stereo-examination system id shown in FIG. 8 for
generating stereoscopic image pairs for two observers is similar in
construction to the examination system shown in FIG. 6. It likewise
comprises two pairs of cameras 45d, 46d and 45d', 46d',
respectively, which are fixedly positioned with respect to an
objective 3d. Image-rotating optical systems 61d and 61d' are
respectively disposed between a beam divider 41d and the camera
pairs. In contrast to the embodiment shown in FIG. 6, the
image-rotating optical system 61d, 61d' is not provided as
Schmidt-Perchan prism, but comprises a plurality of mirror surfaces
71, 72, 73 and 74 which are disposed fixedly relative to each other
and rotatably about the optical axes 5d' and 5d'', respectively.
Moreover, a stationary mirror 75 is allocated to each camera which
feeds the partial beam bundle produced by the mirror system 61d
into the respective camera. The image pairs generated by the camera
pairs are again stereo-image pairs which present the object 8d
stereoscopically to a respective observer. By actuating a drive,
not shown in FIG. 8, of the mirror systems 61d, 61d', the azimuths
of the stereobases for the respective observer are then rotatable
about the optical axis 5d.
[0081] A stereo-examination system 1e schematically shown in FIG. 9
again serves to generate stereo-image pairs for two observers. The
examination system 1e is substantially similar to the examination
system shown in FIG. 6, but differs from the same as far as the
structure of an image-rotating optical system 61e is concerned. The
latter comprises two prism systems 77 and 78 which are rotatable
relative to each other and about an optical axis 5e. The two prism
systems 77 and 78 are driven by a gear system 79 to rotate about
the optical axis 5e such that the prism system 78 rotates through
an angle of 2.times..phi., while the prism system 77 rotates
through an angle .phi.. The prism system 78 is disposed between a
beam divider 41e and the prism system 77. It comprises two prisms
79 for moving two partial beam bundles 19e and 20e, which have been
fed out of a parallel beam bundle 13e produced by an objective 3e
and are spaced apart from each other by a relatively large distance
a from the optical axis 5a, closer to the optical axis 5a. After
having passed through the prism system 78, the partial beam bundles
19e, 20e enter the prism system 77 which comprises an
image-rotating Dove prism 80. As the partial beam bundles 19e, 20e
then extend relatively close to the optical axis, the Dove prism 80
can be of relatively small size. After having passed through the
prism system 77, the partial beam bundles 19e, 20e are each
supplied to a camera 45e and 46e, respectively, via double
reflection prisms 81.
[0082] The images obtained by the cameras 45e and 46e are supplied
to displays for a left eye and a right eye, respectively, of a
first user.
[0083] A second user is supplied with images from the cameras 45e'
and 46e' which generate images of the partial beam bundles 19e' and
20e' via an optical system which is disposed along the optical axis
5e' mirrored at the beam divider 41e. The components 77', 78', 79',
80' and 81' are similar to the corresponding components of the
optical system disposed along the optical axis 5e.
[0084] A stereo-examination system 1f schematically shown in FIG.
10 again serves to generate stereo-image pairs for two observers.
The examination system 1f is similar in construction to the
examination system shown in FIG. 9. It likewise comprises two prism
systems 77f and 78f which are adapted to be driven via a gear
system 79f about an optical axis 5f such that the prism system 77f
rotates about the optical axis at twice the rotational speed as the
prism system 78f. Here, the prism system 78f also feeds two partial
beam bundles 19f and 20 out of a parallel beam bundle 13f generated
by an objective 3f. However, the prism system 78f serves to
superpose the two partial beam bundles 19f and 20f along the
optical axis 5f by means of deflecting prisms 83 and 84 and a beam
coupler 83. In contrast to the embodiment shown in FIG. 9, the
examination system 1f merely comprises a single camera 45f which is
likewise disposed on the optical axis 5f to generate
representations of the image information contained in the two
partial beam bundles 19f, 20f. In order to separate the two
representations from each other, the prism system 78f comprises a
switchable shutter 87 disposed in the beam path of the partial beam
bundle 20f as well as a further switchable shutter 88 disposed in
the beam path of the partial beam bundle 19f. The shutters 87 and
88 are liquid crystal shutters which are switchable, by means of a
controller 49f, from a state in which they transmit light to a
state in which they transmit substantially no light. The controller
49f, first, switches the shutter 87 to the light-impermeable state
and the shutter 88 to the light-permeable state so that the partial
beam bundle 19f is directed to the camera 45f. The image of the
object 8f thus produced by the camera 45f is read out by the
controller 49f from the camera 45f and represented by the same on a
display 51f for observation of the left eye of a first observer.
Subsequently, the controller 49f switches the shutter 88 to the
light-impermeable state and, correspondingly, the shutter 87 to the
light-permeable state. As a result, the other partial beam bundle
20f is supplied to the camera, and the image thus recorded by the
camera 45f is read out by the controller 49f and represented on a
further display 52f for the right eye of the user. This procedure
is then repeated so that the camera 45f alternately records the
image information of the object 8f contained in the partial beam
bundles 19f and 20f and represents the same on the displays 51f and
52f for the user's left eye and the right eye, respectively. Due to
the partial beam bundles 19f and 20f being switched alternately in
time, it is thus possible to obtain the image information contained
therein by merely one camera.
[0085] There is a corresponding optical system provided for a
second user, said optical system being disposed along an optical
axis mirrored at the beam divider 41f and having the same structure
as the optical system disposed along the optical axis extending
through the beam divider 41f. For the sake of clarity, this optical
system for the second user is not shown in full detail in FIG.
10.
[0086] FIG. 11 shows a plan view of a part of a stereo-examination
system 1g. The examination system 1g shown in FIG. 11 is similar to
the examination system shown in FIG. 7 in that it comprises more
than three cameras, namely eight cameras, which are disposed at
equal distance from an optical axis 5g, the eight cameras being
fixedly disposed spaced apart from each other in circumferential
direction about the optical axis 5g by the same distance. Each
camera feeds a partial beam bundle 19g1, . . . , 19g8 out of a
parallel image-side beam bundle 13g to generate an image of the
image information of an object contained in the respective beam
bundles 19g1, . . . , 19g8 and to supply the same to a controller
49g.
[0087] A pair of displays comprising two display apparatus 51g and
52g is connected to the controller 49g for providing a stereoscopic
display for a first observer. Correspondingly, there are two
display apparatus 51g' and 52g' connected to the controller 49g for
a second observer. The controller 49g and the cameras cooperate as
selection arrangement in that the controller 49g selects a first
pair of cameras from the eight cameras to allocate these selected
cameras to the displays 51g, 52g for the first user and to
represent the images recorded by said pair of cameras on the
corresponding displays, if applicable, after an image rotation. The
controller 49g selects a second pair of cameras to allocate the
same to the displays 51g' and 52g' for the second user and to
represent the images recorded by said pair of cameras on the
corresponding displays, if applicable, after an image rotation.
[0088] In the situation depicted in FIG. 11, the controller 49g has
allocated the camera receiving the partial beam bundle 19g1 to the
display 52g and thus to the right eye of the first user. The camera
receiving the partial beam bundle 19g2 is allocated to the display
51g' and thus to the left eye of the second user. And the camera
receiving the partial beam bundle 19g5 is allocated to the displays
51g and 52g' and thus to both the left eye of the first user and
the right eye of the second user. Accordingly, the first user
receives a stereoscopic representation of the object under
observation with a stereobasis which is indicated in FIG. 11 by a
line 91, while the second observer receives a stereoscopic
representation of the object with a stereobasis which is indicated
in FIG. 11 by a line 92. Both lines or stereobases 91 and 92 are
disposed at different azimuth angles about the optical axis 5g.
These azimuth angles of the stereobases 91, 92 are variable by the
controller 49g. For example, the stereobasis for the first observer
can be rotated about the optical axis 5g counter-clockwise in that
the controller selects, instead of the camera receiving the partial
beam bundle 19g1, the camera receiving the partial beam bundle 19g8
for allocation to the display 52g observed by the right eye of the
first user so that a stereobasis 91g' results for this user which
is shown in FIG. 11 as dotted line.
[0089] FIG. 12 schematically shows a further stereo-examination
system 1h. It serves again to present stereoscopic pairs of images
of an object 8h on displays 51h and 52h to a left eye and a right
eye, respectively, of a first user and on displays 51h' and 52h' to
a left eye and a right eye, respectively, of a second observer. To
this end, the examination system 1h further comprises an objective
3h for generating a parallel image-side beam bundle 13h from a
divergent beam bundle 11h emanating from the object 8h and an
imaging optical system 93 for transmitting the parallel beam bundle
13h to a CCD camera chip 45h so that a sharp image of the object 8h
is formed on the same.
[0090] In the beam path of the parallel beam bundle 13h, there is
provided a switchable stop 87h in a plane which corresponds to a
Fourier plane of the objective 3h with respect to the object plane
7h thereof. The stop 87h is a liquid crystal stop having a
plurality of liquid crystal elements (pixels) which are switchable
by the controller 49h from a state in which they transmit light to
a state in which they transmit less light. In the plane of the stop
87h, the controller 49h comprises selected regions 19h1, 19h2, 19h3
and 19h4 which correspond to partial beam bundles whose image
information is represented on the displays 51h to 52h' for the
observers. Here, the region 19h1 is allocated to the display 52h
and thus to the right eye of the first user, the region 19h3 is
allocated to the display 51h and thus to the left eye of the first
user, the region 19h2 is allocated to the display 51h' and thus to
the left eye of the second user, while the region 19h4 is allocated
to the display 52h' and thus to the right eye of the second
user.
[0091] The camera 45h records, sequentially in time, the image
information contained in the individual partial beam bundles for
representation on the displays 51h to 52h'. To this end, the stop
elements or pixels of the LCD stop 87h which are disposed outside
of said regions 19h1 to 19h4 are constantly switched to the state
in which they transmit less light. Of the pixels disposed in the
regions 19h1 to 19h4, merely the pixels disposed in the region 19h1
are switched, in the situation shown in FIG. 12, to the state in
which they transmit much light, while the pixels of the other
regions 19h2, 19h3 and 19h4 are switched to the state in which they
transmit little light. Accordingly, the camera records in this
switching sate the image information contained in the partial beam
passing through he cross-section of the region 19h1. The controller
49h reads this image information out of the camera 45h and presents
the same on the display 52h for the right eye of the first
user.
[0092] Subsequently, the pixels contained in the region 19h1 are
switched to the state in which they transmit less light, while the
pixels contained in the region 19h3 are switched to the state in
which they transmit much light. Accordingly, the cross-section of
the region 19h3 is exposed for transmission of the corresponding
partial beam bundle, and the camera 45h records the image
information contained in this partial beam bundle which is read out
by the controller 49h and presented on the display 51h for the left
eye of the first observer.
[0093] Subsequently, the pixels of the LCD stop 87h contained in
the region 19h3 are switched to the state in which they transmit
less light. A corresponding procedure is then carried out for the
regions 19h2 and 19h4, i.e., first, a picture of the partial beam
traversing the cross-section of the region 19h2 is taken by the
camera 45h and represented on the display 51h' and, then, a
corresponding picture is taken of the partial beam bundle
traversing the region 19h4 and presented on the display 452h' for
the right eye of the second observer.
[0094] Accordingly, the first observer obtains as stereoscopic
representation of the object 8h with a stereobasis which is
indicated in FIG. 12 by a line 91h, while the second observer
obtains a stereoscopic representation with a stereobasis which is
indicated by a line 92h.
[0095] Herein the images recorded by the camera are rotated in
their image planes by the controller before transmission to the
displays 51h, 52h and 51h', 52h', respectively, such that they are
displayed to the observer in their correct orientation. This is, in
particular, the case, if a direction of the stereobasis 19h1 and
19h2 is a horizontal direction in the displayed images.
[0096] By use of the switchable stop 87h as selector for selecting
the individual partial beam bundles to be imaged, particular
degrees of freedom are obtained for the adjustment of the
stereobases 91h, 92h for the individual users. It is not only
possible to displace the stereobases azimuthally about an optical
axis 5h in that the controller 49h selects regions which are
displaced with respect to the regions 19h1 to 19h4 in
circumferential direction about the axis 5h to switch the same,
successively in time, into their light-permeable state, which
results into the stereobases 91h, 92h being rotated about the
optical axis 5h. Rather, it is also possible to change the lengths
of the stereobases in that the distance between the regions 19h1
and 19h3 and 19h2 and 19h4, respectively, is reduced. Moreover, it
is also possible to displace the stereoscopic bases 91h and 92h in
parallel. This results in that the respective observer perceives
the object 8h at the same azimuth but at a different elevation.
[0097] The individually controllable liquid crystal switching
elements of the stop 87h can be disposed periodically in a field in
two directions (X,Y) extending orthogonally to each other.
[0098] A variant thereof is schematically shown in FIG. 13. A
swichtable stop 87h comprises a plurality of liquid crystal
elements which are individually switchable. These elements comprise
triangular elements 95, 96, 97 and 98 as well as arcuate segments
99 defining a segmented circle. The segments 95, 96, 97, 98 and 99
are combined such that, together, they form a circular switchable
stop. In order to open the stop allowing a partial beam bundle 19h
to pass therethrough, a plurality of the elements are switched by
the controller into the sate in which they transmit much light, as
it is shown in FIG. 13 by the hatched elements, while all other
elements are switched to the state in which they transmit little
light.
[0099] A further variant of a switchable stop 87h is shown in FIG.
14. This switchable stop 87h, too, is of circular shape, the
switchable elements being each of square shape and are distributed
in circumferential direction about the optical axis 5h in three
annular rings. FIG. 14 shows two switchable elements in hatched
outline which is to indicate that they are switched to the state in
which they transmit much light in order to allow a partial beam
bundle 19h to pass therethrough, while all other switchable
elements are switched to the state in which they transmit little
light.
[0100] A further variant of a switchable stop 87h is illustrated in
FIGS. 15 and 16. The stop 87h shown in plan view in FIG. 15
comprises a plurality of switching elements 96 which are
mechanically switchable between a state in which they are permeable
to light and a state in which they are impermeable to light. Each
switching element 96 comprises a sector-shaped lamella 101 which is
supported in a bearing 105 to be rotatable about a rotational axis
103 and is driven by means of an actuating drive 107 controlled by
the controller 49h to rotate about the axis 103. The plurality of
lamellas 101 is disposed in circumferential direction about the
optical axis 5h, the rotational axis 103 of each lamella 101 being
oriented radially with respect to the optical axis 5h, as it is
shown in FIG. 15. The drives 107 of the lamellas 101 can change the
orientation thereof about the axis 103 from a first position in
which the lamellas 101 lie flat in the paper plane of FIG. 15 to a
second position in which the lamellas 101 are oriented
perpendicular to the paper plane of FIG. 15. In the fist position,
the lamellas substantially prevent light from passing through, and
in the second position, they substantially allow light to pass
through. In FIG. 15, a region 104 is shown in hatched outline in
circumferential direction in which the lamellas 101 are in their
second light-transmitting position, while all other lamellas 101
are in the first position in which they prevent light from passing
through. Accordingly, the partial light bundle 19h can freely pass
through the region 104. The controller can thus define different
regions in circumferential direction for the passage of a partial
beam bundle and switch the same, successively in time, to the
light-permeable state so that the camera 45h can record the image
information contained in this partial beam bundle.
[0101] In order to select the partial beam bundles imaged on the
camera, the stereo-examination system shown in FIG. 12 comprises a
switchable transmission device, namely the switchable liquid
crystal stop. However, it is also possible to provide a similar
system with a switchable reflection device, as it is illustrated in
FIG. 17. In the stereo-examination system 1i schematically shown in
this Figure, a parallel image-side beam bundle 13i is deflected
through 90.degree. C. at a polarizing beam divider 109 and impinges
as polarized parallel beam bundle 3i' on a switchable mirror 111.
The switchable mirror 111 comprises a plurality of individual
switchable mirror elements which are formed as liquid crystal
elements. In a first switching state, the liquid crystal elements
reflect the impinging radiation of the beam bundle 3i' with a
polarization such that the reflected radiation passes through the
polarizing beam divider 109, while it reflects the radiation with
another polarization in a second switching state so that the
reflected radiation does not pass through the polarizing beam
divider 109.
[0102] In the state shown in FIG. 17, a controller 49i has
determined two regions 19i1 and 19i2 of the mirror 111 which are
alternately switched from the first switching state to the second
switching state. All other regions of the mirror 111 remain
permanently in the second switching state. In FIG. 17, a situation
is shown in which the region 19i1 is switched to the state in which
the radiation reflected in this region passes through the
polarizing beam divider 109 as partial beam bundle 19i1' and
exposes a camera 45i.
[0103] A method for adjusting a stereobasis of the
stereo-examination system will now be described in further detail
with reference to FIGS. 18 and 19.
[0104] FIG. 18 shows an operating room. An operating table 132, on
which a patient 133 lies on whom a microsurgery is being performed
by a surgeon 135 is fixedly mounted on the floor 131 of the
operating room. A microscope 138 is mounted to a stand 137 fixedly
attached to the floor 131 of the operating room such that it
records images of an operating field 139 and visibly represents the
same for the surgeon 135. To this end, the surgeon 135 wears a
head-mounted display apparatus 141 comprising two displays 51, 52
which together present stereoscopic images to the left eye and the
right eye of the surgeon. The images to be represented are
transmitted wireless as data from the microscope 138 mounted on the
stand to the display apparatus 141. A preset fixed point 151 of the
microscope 138 is defined as point of origin of a polar coordinate
system. Moreover, at the display apparatus 141 of the surgeon,
there is defined a reference point 153, the position of which
relative to the fixed point 151 is determined as an azimuth .phi.
and an elevation u by a position detection apparatus 161 of the
examination system which is attached to the microscope 138 near the
fixed point 151 and shown in detail in FIG. 20.
[0105] An arrangement of a stereobasis 91 for the stereo-images
provided for the surgeon 135 is shown in plan view onto the
XY-plane of the operating room in FIG. 19. The fixed point 151 at
the microscope 138 is selected such that, in plan view onto the
XY-plane, it coincides with the optical axis 5 of the microscope
138. The stereobasis for the surgeon 135 shown as line 91 is
oriented azimuthally such that a connecting line between the
reference point 153 of the surgeon 135 and the fixed point 151
extends orthogonally to the line 91. If the surgeon 135 moves in
the operating room and, in so doing, changes his position .phi.1
relative to the fixed point 151 in circumferential direction about
the optical axis 5, the controller 49 readjusts the stereobasis
correspondingly such that the stereobasis continues to be disposed
orthogonally to the connecting line between the surgeon 135 and the
optical axis 5. The surgeon 135 thus gets a stereoscopic image
impression of the operating field 139 via the display apparatus 141
which corresponds substantially to an image impression which the
surgeon 135 would obtain if he viewed through a stereomicroscope
shown in FIGS. 1 and 2 onto the operating field 139. However, the
surgeon 135 is now no longer obstructed in his freedom of movement
around the operating field 139 by the position of oculars of the
stereomicroscope.
[0106] In particular, the examination system 1 can likewise obtain
a stereoscopic representation of the operating field 139 for a
second surgeon, whose azimuthal position is indicated by 153' in
FIG. 19, via a display apparatus worn by the same, with a
stereobasis 92 for the stereoscopic representation supplied to the
second surgeon being adapted to the azimuthal position .PHI..sub.2
of the same in that the stereobasis 92 also extends orthogonally to
a connecting line between the position 153' of the second surgeon
and the optical axis 5.
[0107] With reference to FIG. 20, the position detection apparatus
161 is disposed symmetrically with respect to the optical axis 5 on
the microscope 138. It detects positions of one or more surgeons in
the operating room in the polar coordinate system .PHI., .theta.
having its point of origin at the fixed point 151. The position
detection apparatus 161 comprises a conical mirror 163 which
reflects radiation impinging on the mirror 163 from an angular
range .+-..gamma. with respect to a horizontal plane 165 onto an
optical system 167 which images said radiation on a CCD chip
169.
[0108] The surgeon 135 who carries a light source on his head is
locatable in the operating room by the apparatus 161 because his
azimuthal position about the axis 5 as well as his elevation with
respect to the plane 165 in a range .+-..gamma. can be determined
by evaluating the image of the CCD chip 169. If several surgeons
are present in the operating room, each surgeon may carry a light
source, the light intensity of which changes time-dependently, a
different characteristic time pattern of the light intensity being
provided for each surgeon. By evaluating the image of the camera
169 and taking into consideration the detected time patterns, it is
thus possible to determine the positions of the individual
surgeons. The image of the camera 169 is evaluated by the
controller 49 which changes, corresponding to the detected position
of the respective surgeon, the stereobasis 91, 92 of the same in
azimuthal direction about the optical axis 5 of the microscope
138.
[0109] The controller 49 can also react to changes in the elevation
.theta. of the surgeon in that it shifts the stereobases in
parallel, as it has been described with reference to the embodiment
shown in FIG. 12.
[0110] It is also possible to position the observer remote from the
object under observation if, for example, there is only space for a
few people at the operating table and further persons, for example,
students wish to observe the operation directly "flesh-and-blood".
These person can then be positioned outside of the operating room.
A fixed point and an orientation of his user coordinate system in
space can be determined for each one of these persons so that, when
viewing their head-mounted display, they get the impression as if
the region of the patient under observation were disposed around
this very, namely, their personal fixed point.
[0111] FIG. 21 is a schematic representation of a further
stereo-examination system 1j. Again, it comprises a microscope
objective 3j with an optical axis 5j and an object plane 7j for
positioning an object. The objective 3j images the object to
infinity so that a conic beam bundle emerging from the object plane
7j at the optical axis 5j is converted into a parallel beam bundle.
It impinges on a mirror 181 disposed behind the objective 3j, said
mirror comprising a mirror surface 183 which intersects the optical
axis 5j at a point 185. The mirror 181 is pivotal about this point
185 into two spatial directions, a drive 187 being provided for
pivoting the mirror 181.
[0112] The radiation reflected at the mirror surface 183 impinges
on a stop 189 with a central stop aperture 191.
[0113] If the mirror 181 is in the position shown in continuous
outline in FIG. 21, the stop aperture 191 is traversed by a partial
beam bundle 19j' which is generated from a partial beam bundle 19j
after reflection at the mirror surface 183. The partial beam bundle
19j is the partial beam bundle, the central beam of which emanates
from the object 8j at an angle .alpha. with respect to the optical
axis 5j.
[0114] The partial beam bundle 19j' impinges on a further mirror
193, the mirror surface 195 of which is disposed symmetrically to
the mirror surface 183 of the mirror 181, the mirror surface 195
being pivotal about a point 197 in two spatial directions. The
point 197 disposed is symmetrically to the point 185 with respect
to the plane of the stop 189. In order to pivot the mirror 193, a
drive 199 is provided which is shown merely symbolically in FIG.
21.
[0115] After having been reflected at the mirror surface 195, the
partial beam bundle 19j' passes through an imaging optical system
201 and impinges as conic partial beam bundle 19j'' on a
light-sensitive surface 45j of a camera, the optical imaging system
201 being provided such that the object 8j in the object plane 7j
is imaged on the light-sensitive surface 45j.
[0116] In the pivot position of the mirrors 181 and 193 shown in
FIG. 21, the camera 45j thus records an image of the object 8j
viewed at an angle .alpha. to the optical axis.
[0117] The dotted lines in FIG. 21 show pivot positions of the
mirror surfaces 183 and 195 in which a partial beam bundle 20j
which is different from the partial beam bundle 19j images the
object 8j on the camera 45j. A central beam of the partial beam
bundle 20j is inclined at an angle -.alpha. to the optical axis
5j.
[0118] The drives 187 and 199 are driven by a controller not shown
in FIG. 21. By pivoting the mirror surfaces 183 and 195, this
controller can thus adjust within an adjustment range arbitrary
viewing angles at which the object 8is imaged on the camera 45j.
The controller can thus sequentially read an image out of the
camera 45j at a first viewing angle and then change the position of
the mirrors 181 and 193 and read an image out of the camera 45j at
a second viewing angle. The images taken at the first and the
second viewing angles are then supplied to the left eye and the
right eye, respectively, of the user, so that he gets a
stereoscopic impression of the object 8j.
[0119] In the variant shown in FIG. 24, the distance and the pivot
angles of the pivotal mirrors 181, 193 are adjusted to each other
such that the first pivotal mirror 181 always directs the partial
beam bundle 191', 201' on a central region of the second pivotal
mirror 193, and the second pivotal mirror 193 only images this
central region as partial beam bundle 191'', 201'' on the camera
451. To this end, the stop 189 is positioned between the second
pivotal mirror 193 and the camera 451.
[0120] In contrast to the above-described embodiment, in the
embodiment shown in FIG. 25, the first pivotal mirror is replaced
by a stationary facet mirror 180. The facets 182, 184 of the facet
mirror 180 are arranged in pairs inclined at an angle relative to
each other which corresponds to the pivot angle .delta. of the
pivotal mirror 193.
[0121] As a result, partial beam bundles 19m', 20m' are always
directed from every mirror facet 182, 184 to the second mirror 193
provided as pivotal mirror which, depending on its pivotal
position, selects one partial beam bundle from said plurality of
partial beam bundles 19m', 20m' and reflects the selected partial
beam bundle 19m'' and 20m'', respectively, in the direction of the
camera 45m, while the other partial beam bundles 20m'' and 19m'',
respectively, are absorbed by the stop 189m.
[0122] A further variant of the above-described embodiment is
illustrated in FIG. 26. Instead of the facet mirror, this
embodiment comprises a prism arrangement 186 disposed in beam
direction behind the objective. The prism arrangement 186 consists
of a ring of individual prisms 188, 190 each of which deflects a
partial beam bundle 19n', 20n' in axial direction. On the optical
axis 5n, there is again disposed a pivotal mirror 193n which
directs, in its different pivot positions, one of the partial beam
bundles 19n'' into the direction of the camera 45n, while the
partial beam bundles 20n'' are absorbed by the stop 189n positioned
between the mirror 193n and camera 54n.
[0123] Further, FIG. 27 shows a variant of the two above-described
embodiments, wherein, instead of the one pivotal mirror 193n and
the one camera 45n, there are disposed two of the kind. Here, the
facets 182, 184 of the facet mirror 180 (or, in a variant not
shown, the prisms of a prism arrangement) are provided such that
facets 182, 184 (or prisms) disposed opposite each other, each
direct their partial beam bundle 19p' and 20p', respectively, to
different pivotal mirrors 193p', 193p'' and thus to different
cameras 45p', 45p''. Each of the two pivotal mirrors 193p', 193p''
selects, according to its pivotal position, a partial beam bundle
19p' and 20p' from the facets 182 and 184 (or prisms) respectively
allocated thereto so that each of the cameras 45p', 45p'' always
receives a partial beam bundle 19p', 20p' for generating
corresponding representations. The facets 182, 184 allocated to the
two pivotal mirrors 193p', 193p'' are, moreover, positioned in
alternate configuration in circumferential direction of the facet
mirror 180. The variant shown in FIG. 27 comprises a facet mirror
with 6 pentagonal facets which are disposed about a central
hexagon. The four of the six facets which do not lie in the plane
of the three mirror centers are each slightly bent upwards towards
the center. The other two opposed facets lie approximately in a
plane with the central hexagon. Each one of these flatly disposed
facets is allocated, together with the two diagonally opposite,
upwardly bent facets, to one pivotal mirror 193p', 193p'',
respectively. These pivotal mirrors 193p' and 193p'' each select,
depending on the pivotal position, one of three facets and reflect
the respective partial beam bundle 19', 20' in the direction of the
camera 45p' and 45p'' respectively allocated thereto.
[0124] In a further variant, not shown, the two individual movable
pivotal mirrors 193p', 193p'' are replaced by a single rotatable
polyeder mirror in the form of an irregular truncated pyramid.
Depending on the rotational position, said truncated pyramid
provides two opposite mirror surfaces in the plane of the optical
axis, each of which directs one of the two selected partial beam
bundles to a camera.
[0125] In FIGS. 24 to 27, the respective controllers of the pivotal
mirror drives are not shown.
[0126] In the embodiments comprising a plurality of cameras, the
latter can also by formed by different regions of a light-sensitive
elements of a single camera.
[0127] Finally, FIG. 28 shows an embodiment wherein one of the
partial beam bundles 19q'' and 20q'' is fed out by a turnable
double stop 203 having two stop apertures 205', 205''. The rotation
of the double stop 203 is effected by a drive 207 which is
controlled by a controller 221. Moreover, this embodiment comprises
a rotating chopper wheel 209 with an uneven number of open sectors
223, here shown with three sectors. The chopper wheel 209 is driven
by the drive 211 which is likewise controlled by the controller
221. By rotation of the chopper wheel 209, the two stop apertures
205', 205'' alternately overlap with the open sectors 223 of the
chopper wheel 209. As a result, one of the partial beam bundles
19q' and 20q' is alternately supplied to the camera 45q and
detected there so that the camera 45q alternately receives images
of a region 8q of the object 7q.
[0128] In order for the camera 45q being maintained in correct
synchronization when the double stop 203 is rotated, a marking hole
213 is furthermore provided in the double stop 203. A reference
beam bundle 217 emanating from the object 7q passes through said
hole, provided that an open sector of the chopper wheel 209 is
currently in a corresponding angular position, impinges on the
deflecting mirror 215 connected to the double stop 203 and is
detected by the photo diode 219 disposed on the optical axis 5q.
Accordingly, the output signal of the photo diode 219 is modulated
with a frequency which is dependent upon the rotational speed and
the number of sectors of the chopper wheel 209, the phase of said
modulation being dependent upon the difference between the phases
of the chopper wheel 209 and the double stop 203. The output signal
of the photo diode 219 is supplied to the controller 221, and the
controller 221 controls the drive 211 of the chopper wheel 209 such
that a constant modulation phase is maintained. As a result, the
camera is correctly synchronized with the chopper wheel 209 in
every rotational position of the double stop 203 and thus provides
a correctly alternating image sequence.
[0129] A further variant of a selection arrangement for selecting
different partial beam bundles to image the object on a camera can
be provided by a stop which is rotatable about an axis and
comprises a decentral stop aperture. The rotational axis of the
stop coincides with the optical axis of a microscope objective and,
by rotating the stop about the optical axis, an azimuth angle of
the partial beam bundle can then be selected which is imaged on a
camera. As a result, a first camera image of the object can be
recorded in a first rotational position of the stop about the
optical axis, and a second camera image can be recorded in a
different rotational position of the stop about the optical axis.
The two camera images are then supplied to the left eye and the
right eye, respectively, of the observer so that he gets a
stereoscopic impression of the object.
[0130] A similar embodiment of the stereo-examination system is
shown in FIG. 29. Here, a mirror prism 225, driven by a drive 227,
rotates about a rotational axis which coincides with the optical
axis 5r. As a result, the prism 225 always feeds with mirror
surfaces 225' and 225'' another partial beam bundle 19r' out of the
object-side beam bundle and passes it on to the camera 45r. The
selection of specific partial beam bundles 19r'' is effected here
by a pulsed light source 229, the timing of which can be controlled
by the observer by means of the controller 221r. For example, a
stroboscope lamp arrangement is provided as controllable pulsed
light source 229. The lamp arrangement 229 is caused to effect a
flash sequence of double the prism rotary frequency for each
observer; the camera images corresponding to a flash sequence are
alternately allocated to the two stereo-images for the respective
observer. The phase position between the different flash sequences
determines the angular difference between the stereobases for the
observers.
[0131] As against this, FIG. 30 shows an embodiment wherein a
camera 45s, 46s, 45s', 46s'' is allocated to each one of the two
eyes of two observers. The selection of the appertaining partial
beam bundles is effected here by dividing the beam bundle up
between the two observes by the cross beam divider 41s; the latter
furthermore causes the beam bundle to be divided into the two
partial beam bundles for the two eyes of the first observer. The
division of the other beam portion for the two eyes of the second
observer is effected by the beam divider 41s'. Each one of the four
cameras 45s, 46s, 45s', 46s' is associated with a stop 235s, 236s,
235s', 236s' which is rotatable about the optical axis 4s and has a
selection region 237s, 238s, 237s', 238s', respectively. The stops
235s, 236s and 235s', 236s' respectively allocated to an observer
are each coupled such that they allow oppositely disposed partial
beam bundles 19s and 20s to pass therethrough. The rotational
positions of the stops 235s, 235s' and 236s, 236s' respectively
allocated to different observers, however, are freely selectable.
The camera optics 15s, 16s, 15s' and 16s' focus the partial beam
bundles 19s'' and 20s'' respectively fed out. Each one of the
observers can adjust the pair of stops 235s, 236s and 235s', 236s'
respectively allocated to the same by means of a controller, not
shown, such that the desired stereoscopic representation of the
object 8s is made available to him.
[0132] FIG. 22 shows, by way of example, an advantageous embodiment
of an illumination for a stereo-examination system of the invention
on the basis of an embodiment which is similar to the embodiment
shown in FIG. 3. Light from a light source 211 is shaped by an
optical system 231 to form a parallel beam 215 which impinges on a
field 217 of symbolically represented micromirrors 219. The
micromirrors 219 are controllable by a controller 49k which
likewise causes cameras 45k and 46 to rotate about an optical axis
5k of an objective 3k to supply a stereoscopic representation of an
object 8k positioned in the object plane 7k of the objective 3k to
a left eye and a right eye of a user via displays 51k, 52k. To this
end, the camera 45k feeds a partial beam bundle 19k out of the
complete beam bundle which emanates from the object 8k inclined at
an angle .alpha. to the optical axis 5k and is further processed by
the objective 3k. Equally, the other camera 46k feeds out a
corresponding partial beam bundle 20k which is inclined at an angle
-.alpha. to the optical axis 5k.
[0133] The micromirrors 219 are selectively switchable by the
controller 49k from a first switching state to a second switching
state. In the first switching state, they reflect the light of the
light source 211 contained in the parallel beam 215 through
90.degree. so that it is fed into the beam path of the microscope
via a mirror surface 43k of a beam divider 41k and focussed onto
the object 8k via the objective 3k. In the second switching state,
the micromirrors 219 each reflect the light of the beam 215 such
that the beam is not fed into the beam path of the microscope and,
accordingly, the radiation of the lamp 211 does not reach the
object 8k.
[0134] The controller 49k controls the micromirrors 219 such that
not the light of the entire cross-section of the beam 125 is used
for illuminating the object 8k. This is illustrated in further
detail with reference to FIG. 23 which shows a cross-section
through the objective 3k and an arrangement of the cross-sections
of the partial beam bundle 19k and 20k in the plane of the
objective 3k. The cross-sections of the partial beam bundles 19k
and 20k occupy only a portion of the entire cross-section of the
objective 3k. Those regions of the objective 3k which are disposed
outside of the cross-sections of the partial beam bundles 19k and
20k are occupied by regions 225 which are traversed by the
radiation used to illuminate the object 8k. This is achieved by
appropriately controlling the micromirros 219. In the regions
disposed outside of the regions 225 of the cross-section of the
objective 3k, no radiation of the light source 211 passes through
the objective 3k. By this spatial separation of the cross-sectional
regions of the objective 3k used for the illumination of the object
8k and the imagining of the same, disturbing reflections caused by
the illumination in the images of the object 8k recorded by the
cameras 45k and 46k are eliminated.
[0135] The beam guidance for the illumination illustrated with
reference to FIGS. 22 and 23 can be applied to any other of the
above-described examination systems to reduce reflections caused by
the illumination radiation in the recorded images.
[0136] A variant of the stereo-examination system shown in FIGS. 4
and 5 can reside in that, instead of the cameras 45a, 46a and 45a',
46a', respectively, oculars are provided for direct observation by
two observers. The observers then do not view the imaged object via
separate displays, such as viewing screens, but in a similar way as
described with reference to the conventional stereomicroscope shown
in FIG. 2. However, an accordingly modified stereo-examination
system is advantageous in so far as each observer can rotate his
pair of oculars freely about the optical axis and thus is no longer
obstructed by the fixed arrangement in circumferential direction
about the optical axis as it is the case with the conventional
stereomicroscope shown in FIG. 2.
[0137] In this respect, it is possible to provide separate zoom
systems in a beam path between the respective beam divider and the
oculars so that each observer can select his own zoom position. The
objective can then be an objective with variable working
distance.
[0138] In the embodiment described above with reference to FIGS. 18
and 19, the fixed point 151 for the user coordinate system lies on
the optical axis. This is appropriate if the user is to perform
directly manipulations on the object 133 under observation, as it
applies to the case of the surgeon 135 in the operating room as
shown in FIG. 18.
[0139] However, it is also possible for the user to be positioned
remote from the object under observation so that the fixed point of
the user coordinate system does not coincide with the region of the
object under observation. An example for such an application would
be a telesurgical method wherein the surgeon is positioned distant
from the patient and performs the operation on the patient by means
of a remote-controlled robot. In this case, an image is defined
between an azimuth of the user in the user coordinate system and an
azimuth of the stereobasis about the optical axis of the microscope
is defined. By moving the head, the user can then likewise obtain
impressions of the object under observation from different
perspectives.
* * * * *