U.S. patent number RE33,883 [Application Number 07/367,300] was granted by the patent office on 1992-04-14 for split-image multi-power microscopic image display system and method.
This patent grant is currently assigned to National Biomedical Research Foundation. Invention is credited to Robert S. Ledley.
United States Patent |
RE33,883 |
Ledley |
April 14, 1992 |
Split-image multi-power microscopic image display system and
method
Abstract
A split-image, multi-power microscopic image display system and
method wherein the image of an object positioned on a slide is
split into two optical paths, and is magnified to a varying degree
in each optical path, the resulting respective magnifications being
displayed on respective monitor devices. The initial optical path
includes an objective and a splitter; the path of lower
magnification includes a converging lens, diverging lens, reduction
lens, bending prism, TV camera and TV monitor; the path of higher
magnification includes a trinocular microscope head, TV camera, and
TV monitor. Further features of the invention includes the
following: provision of a microcomputer with data entry means, and
respective mixers disposed between the TV cameras and their
monitors for insertion of identifying information into the video
signal and subsequent display on the monitors of the identifying
information and the image of the object being microscopically
viewed; provision of a photographic printer for producing a
hardcopy record of the image viewed; and provision of a lens
switching arrangement for selection of various objectives without
the necessity of refocusing after a lens is switched into
position.
Inventors: |
Ledley; Robert S. (Silver
Spring, MD) |
Assignee: |
National Biomedical Research
Foundation (Washington, DC)
|
Family
ID: |
27003744 |
Appl.
No.: |
07/367,300 |
Filed: |
June 16, 1989 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
697930 |
Feb 4, 1985 |
04673973 |
Jun 16, 1987 |
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Current U.S.
Class: |
348/79; 348/335;
359/368; 359/372; 359/381 |
Current CPC
Class: |
G02B
21/00 (20130101); G02B 21/361 (20130101); H04N
7/18 (20130101); G02B 21/367 (20130101); G02B
21/365 (20130101) |
Current International
Class: |
G02B
21/00 (20060101); G02B 21/36 (20060101); H04N
7/18 (20060101); H04N 007/18 () |
Field of
Search: |
;358/93,101,225,227,107
;350/504,505,519,520 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Britton; Howard W.
Attorney, Agent or Firm: Seeber; Joseph G.
Claims
I claim:
1. A method for displaying magnified images of an object having
different respective magnifications, comprising:
providing an objective, characterized by a given magnification,
through which the image of the object passes to produce an
objective optical output having the given magnification;
splitting the objective optical output into first and second
optical outputs for passage through respective first and second
optical paths;
providing said first optical output to a first camera in said first
optical path, said first camera producing a first video output;
.[.bending.]. .Iadd.providing .Iaddend.said second optical output
to .[.direct it toward.]. a second camera in said second optical
path, said second camera producing a second video output; and
processing said first and second video outputs to display first and
second images, respectively, of the object;
wherein the method comprises the further step of adjusting the
magnification of at least one of the first optical output in said
first optical path and the second optical output in said second
optical path so that the magnification of the object in the first
.Iadd.optical .Iaddend.path differs from the magnification of the
object in the second optical path;
whereby to display the first and second images of the object
magnified in accordance with the different respective
magnifications.
2. The method of claim 1, wherein .Iadd.one of .Iaddend.the
.[.bending step comprises passing.]. .Iadd.first optical output and
the second optical output comprises an inverted image of the
object, said method comprising the step of further inverting said
one of the first optical output and .Iaddend.the second optical
output .[.through a prism.]..
3. The method of claim 1, wherein the processing step comprises
mixing at least one of said first and second video outputs with
analog representations of operator-entered information so as to
display the operator-entered information with corresponding at
least one of the first and second images of the object.
4. The method of claim 1, comprising the additional step of
producing a hardcopy record of at least one of the first and second
images of the object.
5. The method of claim 1, wherein the step of providing an
objective comprises selecting one of a plurality of objectives, and
wherein each objective comprises a negative-diopter lens with a
superimposed positive-diopter lens.
6. The method of claim 1, wherein said objective is a lithography
lens.
7. The method of claim 1, wherein .[.said.]. .Iadd.the
.Iaddend.adjusting step comprises reducing the magnification of the
second optical output in said second optical path to produce a
third optical output characterized by a magnification different
from said given magnification.
8. The method of claim .[.7.]. .Iadd.1.Iaddend., wherein the
.[.reducing.]. .Iadd.adjusting .Iaddend.step comprises converging
the second optical output to produce a converged optical output,
diverging the converged optical output to produce a diverged
optical output, and passing the diverged optical output through a
reducing lens.
9. A system for displaying magnified images of an object having
different respective magnifications, comprising:
objective lens means for magnifying an image of the object passing
therethrough to produce an objective optical output having a given
magnification;
splitting means for splitting the objective optical output into
first and second optical outputs for passage through respective
first and second optical paths;
a first camera disposed in said first optical path for producing a
first video output;
a second camera disposed in said second optical path.[.; bending
means.]. for .[.bending the second optical output to direct it
toward said second camera, said second camera.]. producing a second
video output; and
display means responsive to said first and second video outputs for
displaying first and second images, respectively, of the
object;
said system further comprising adjusting means for adjusting the
magnification of at least one of the first optical output in said
first optical path and the second optical output in said second
optical path so that the magnification of the object in the first
optical path differs from the magnification of the object in the
second optical path;
whereby to display the first and second images of the object
magnified in accordance with the different respective
magnifications.
10. The system of claim 9, wherein .Iadd.one of .Iaddend.the
.[.bending means comprises a prism disposed at an end of.].
.Iadd.first optical output and the second optical output comprises
an inverted image of the object, said system comprising inverting
means for further inverting said one of the first optical output
and .Iaddend.the second optical .[.path and adjacent to said second
camera.]. .Iadd.output.Iaddend..
11. The system of claim 9, wherein said objective lens .Iadd.means
.Iaddend.comprises a lithography lens.
12. The system of claim 9, comprising photographic printer means
operatively associated with said display means for producing a
hardcopy record of at least one of the first and second images of
the object.
13. The system .[.f.]. .Iadd.of .Iaddend.claim 9, comprising
photographic printer means operatively associated with at least one
of said first and second cameras for receiving a direct optical
output therefrom, and for producing a hardcopy record of at least
one of the first and second images of the object.
14. The system of claim 9, .[.furthr.]. .Iadd.further
.Iaddend.comprising mixing means connected to at least one of said
first and second cameras for mixing at least one of said first and
second video outputs with analog representations of
operator-entered information so as to display the operator-entered
information with corresponding at least one of the first and second
images of the object.
15. The system of claim 14, further comprising operator input means
for inputting the operator-entered information, and processing
means for processing the operator-entered information so as to
provide the operator-entered information to said mixing means.
16. The system of claim 9, wherein said objective lens means
comprises a plurality of objective lenses of varying
magnifications, said system further comprising selecting means for
selecting one of said plurality of objective lenses through which
the image of the object passes.
17. The system of claim 16, wherein each of said plurality of
objective lenses comprises a negative-diopter lens and a
superimposed positive-diopter lens.
18. The system of claim 9, wherein said adjusting means comprises a
reducing arrangement disposed in said second optical path for
reducing the magnification of the second optical output so as to
produce a third optical output characterized by a magnification
different from the given magnification.
19. The system of claim .[.18.]. .Iadd.9.Iaddend., wherein .[.the
reducing arrangement.]. .Iadd.said adjusting means
.Iaddend.comprises a converging lens for converging the second
optical output to produce a converged optical output, a diverging
lens for diverging the converged optical output to produce a
diverged optical output, and a reducing lens for reducing the
diverged optical output. .Iadd.20. The method of claim 2, wherein
said further inverting step comprises bending said one of the first
optical output and the second optical output to direct it toward a
corresponding one of said first and second cameras. .Iaddend.
.Iadd.21. The system of claim 10, wherein said inverting means
comprises bending means for bending said one of the first optical
output and the second optical output to direct it toward a
corresponding one of said first and second cameras. .Iaddend.
.Iadd.22. The system of claim 21, wherein said bending means
comprises a prism disposed at the end of a corresponding one of the
first and second optical paths. .Iaddend. .Iadd.23. A method for
interactively viewing in detail a selected portion of an object,
comprising the steps of:
(a) providing an optical image input corresponding to the object to
be viewed;
(b) splitting the optical image input into a first optical input
and a second optical input;
(c) providing the first optical input to a first optical path, at
an output end of which a first camera is disposed for receiving a
first optical output, corresponding to a first image of the object,
from the first optical path;
(d) providing the second optical input to a second optical path, at
an output end of which a second camera is disposed for receiving a
second optical output, corresponding to a second image of the
object, from the second output path;
(e) operating the first camera to provide a first video output,
corresponding to the first optical output, to a first display
screen; and
(f) operating the second camera to provide a second video output,
corresponding to the second optical output, to a second display
screen;
wherein the method further comprises the step of providing at least
one optical element in at least one of the first optical path and
the second optical path for adjusting the magnification of at least
one of the first image of the object in the first optical path and
the second image of the object in the second optical path so that
the second optical output from the second optical path represents
an image of the object which appears magnified relative to the
first image of the object. .Iaddend. .Iadd.24. The method of claim
23, wherein one of the first optical output and the second optical
output comprises an inverted image of the object, said method
comprises the step of further inverting said one of the first
optical output and the second optical output. .Iaddend. .Iadd.25.
The method of claim 24, wherein said further inverting step
comprises bending said one of the first optical output and the
second optical output to direct it toward a corresponding one of
said first and second cameras. .Iaddend. .Iadd.26. A system for
interactively viewing in detail a selected portion of an object,
comprising:
splitter means for splitting an optical image input into first and
second optical inputs, and for providing the first optical input to
a first optical path and the second optical input to a second
optical path;
first camera means disposed at an output end of the first optical
path for receiving a first optical output corresponding to a first
image of the object in the first optical path, and for providing a
first video output corresponding thereto;
second camera means disposed at an output end of the second optical
path for receiving a second optical output corresponding to a
second image of the object in the second optical path, and for
providing a second video output corresponding thereto; and
displaying means connected to said first camera means for receiving
said first video output and responsive thereto for displaying the
first image of the object, and connected to said second camera
means for receiving said second video output and responsive thereto
for displaying the second image of the object;
wherein said system further comprises optical means disposed in at
least one of the first optical path and the second optical path for
adjusting the magnification of at least one of the first image of
the object in the first optical path and the second image of the
object in the second optical path so that the second optical output
from the second optical path represents an image of the object
which appears magnified relative to
the first image of the object. .Iaddend. .Iadd.27. The system of
claim 26, wherein one of the outputs of the first optical path and
the second optical path comprises an inverted image of the object,
said system comprising inverting means for further inverting said
one of the outputs of the first optical path and the second optical
path. .Iaddend. .Iadd.28. The system of claim 27, wherein said
inverting means comprises bending means for bending said one of the
outputs of the first optical path and the second optical path to
direct it toward a corresponding one of said first and second
cameras. .Iaddend. .Iadd.29. The system of claim 28, wherein said
bending means comprises a prism disposed at the end of a
corresponding one of the first and second optical paths. .Iaddend.
Description
TECHNICAL FIELD
The present invention relates to a split-image, multi-power
microscopic image display system for use in viewing simultaneously
two images of the same object or specimen, each image having a
different magnification with respect to the other.
BACKGROUND ART
In certain microscopic viewing applications, such as microscopic
examination of chromosomes, it is necessary for the technician to
view a relatively large area of the specimen under a lower
magnification power in order to locate a particular smaller area to
be viewed, and then to switch magnifications and refocus in order
to view the smaller area of concern under a larger magnification.
Much time is wasted performing these manipulations, and it is quite
inefficient and inconvenient for the technician to have to refocus
the microscope after switching to a higher magnification.
Accordingly, it would be considered highly desirable to provide a
split-image microscopic image display system and method having
multiple magnification powers, and it would especially be desirable
to provide such a system with the capability of simultaneously
viewing and displaying on two monitors both the larger area of
general interest and the smaller area of specific interest.
Moreover, it would also be considered desirable to provide such a
system with the capability of producing, on operator command, a
hardcopy of the images displayed on either of the monitors (the
high-power monitor or the low-power monitor).
In some applications, it might be desirable to provide such a
split-image, multi-power microscopic image display system and
method with a type of lens switching apparatus whereby lenses of
varying physical characteristics can be manually and yet easily
employed as the objective lens in the microscopic image display
system and method. However, as mentioned previously, the technology
of the prior art is such as to require a refocusing of the
microscope each time a new lens is switched into place for use as
the objective. Therefore, it is considered desirable to provide a
lens switching arrangement wherein refocusing is not required each
time a new lens is switched into position.
The following patents are generally pertinent to the present
invention: U.S. Pat. Nos. 2,527,719; 2,699,092; 2,950,649;
3,030,861; 3,057,259; 3,353,891; 3,459,464; 3,488,104; 3,503,684;
3,871,741; 3,895,854; 4,218,112; and 4,440,475.
DISCLOSURE OF INVENTION
The present invention relates to a split-image, multi-power
microscopic image display system and method.
Specifically, the present invention relates to a microscopic image
display system and method wherein the optical image of a specimen
is, as a result of the employment of a splitter, directed along two
optical paths. A first optical path includes a trinocular
microscope head for operator viewing of the specimen during initial
microscopic setup, in combination with a first TV camera to which
the image is presented as an optical input and a first TV monitor
connected to the first camera for producing a visual image of the
specimen magnified in accordance with a first magnification power.
The second optical path includes a combination of lenses and a
bending prism for presenting to a second TV camera, as an optical
input thereto, an image of the specimen magnified in accordance
with a second magnification power, and a second TV monitor
connected to the second TV camera for presenting a visual image
thereof.
Preferably, the microscopic image display system and method of the
present invention includes a microcomputer having an operator input
means (such as a keyboard) for inputting information pertaining to
the specimen being viewed, in combination with a mixer connected
between the microcomputer and the TV camera(s), on the one hand,
and the TV monitor(s), on the other hand, for displaying on the TV
screen, as an inset, the information pertinent to the particular
specimen being viewed. As a further preference, the microscopic
image display system and method includes a slave monitor or
monitors, each slave monitor being connected to an output of a
respective one of the TV monitors, the system and method further
including one or more respective photographic printers, each
photographic printer being connected to a respective one of the
slave monitors for producing a hardcopy record of the image being
displayed at a particular time.
In accordance with a further feature of the invention, the
microscopic image display system and method is provided with an
objective lens switching apparatus by means of which the operator
can switchably employ two or more lenses of varying characteristics
as the objective lens of the microscopic image display system and
method. However, in accordance with this feature of the present
invention, each time the operator switches the lens into position,
it is not necessary for the operator to refocus the microscope.
Therefore, it is a primary object of the present invention to
provide a split-image, multi-power microscopic image display system
and method.
It is an additional object of the present invention to provide a
microscopic image display system and method having at least two
optical paths, each optical path providing a visual image of a
specimen magnified in accordance with a respective magnification
power.
It is an additional object of the present invention to provide a
microscopic image display system and method employing at least two
TV cameras and at least two respectively associated TV monitors for
viewing the respective magnified images of the specimen.
It is an additional object of the present invention to provide a
microscopic image display system and method having the capability
of producing a hardcopy record of the specimen being viewed.
It is an additional object of the present invention to provide a
microscopic image display system and method wherein information
relevant to the particular specimen being viewed can be
electronically inserted into the TV signals so that it can be
viewed simultaneously with the magnified image of the specimen.
It is an additional object of the present invention to provide a
microscopic image display screen and method having a lens switching
apparatus for providing the operator with the capability of
switching various lenses into place without the need for refocusing
after each lens switching operation.
The manner in which these and other objects are accomplished by the
present invention will become clear from the following detailed
description of a preferred embodiment.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a front view of the microscopic image display system of
the present invention.
FIG. 2 is a top view of the microscopic image display system of the
present invention.
FIG. 3 is a side view of a portion of the microscopic image display
system of FIG. 1, as viewed along the arrow D in FIG. 1.
FIG. 4 is a block diagram further disclosing the microscopic image
display system of the present invention.
FIGS. 5A and 5B are a top view and a section view (along line B--B'
of FIG. 5A), respectively, of a lens switching arrangement employed
in accordance with the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
The invention will now be described in more detail with reference
to the figures of the drawings.
FIG. 1 is a front view of the microscopic image display system of
the present invention, while FIG. 2 is a top view of the
microscopic image display system. As seen therein, the system 10
comprises a stage 12, specimen slide 14, objective lens 16,
splitter 18, trinocular microscopic head 20, first camera 22, first
TV monitor 24, converging lens 26, diverging lens 28, reduction
lens 30, bending prism 32, neutral density filter 33, second TV
camera 34, and second TV monitor 36.
The objective 16 is preferably a 100X microscope objective having a
high numerical aperture (1.3-1.4). Moreover, the optical output of
the objective 16 must be characterized by a 15.degree.
divergence.
In accordance with a preferred embodiment of the invention, the
amount of image provided as an optical output of the objective 16
covers an area of approximately 700 microns, but an image area of
only 350 microns is desired for display on the monitor 36;
moreover, the image area of 350 microns preferably fills the entire
display area of the monitor 36. This is accomplished by proper
design choice of the following parameters: (1) the distance between
the objective 16 and the converging lens 26; (2) the distance
between the converging lens 26 and the lens 38 of camera 22; and
(3) the reduction factor, that is, the ratio of the focal length of
reduction lens 30 to the focal length of diverging lens 28.
Converging lens 26 is preferably a 61 mm. double-convex lens
measuring 16 (.+-.5) diopters. As is well-known, a diopter is the
inverse of the focal length.
Diverging lens 28 is preferably a 102 mm. compound lens, such as a
projection lens, which takes converging light (emanating from the
converging lens 26) and converts it to parallel light.
Reduction lens 30 is preferably a 28 mm. lens, such as is typically
employed in a 35 mm. camera, for reducing the parallel light image
coming from the diverging lens 28.
Bending prism 32 is any conventional light-bending prism employed
for the purpose of bending the light coming from reduction lens 30
so as to direct it toward camera 34. In this regard, it is to be
noted that a first inversion of the image of the specimen takes
place as a result of bending by the splitter 18, whereas a second
inversion of the image takes place as a result of bending by the
prism 32. It is to be further noted that the camera 34 is disposed
in an inverted manner, with its top facing downward (in FIG. 1),
whereas the monitor 36 is disposed on its side (as also shown in
FIG. 1).
As a result of the latter arrangement, the image viewed on monitor
36 corresponds precisely, in orientation, to that viewed through
the microscope directly (via the trinocular microscope head 20).
Moreover, the arrangement is such that movement of the slide 14
(and its specimen) in a given direction will result in a movement
of the image on monitor 36 in the corresponding direction on
monitor 36. Finally, the placement of monitor 36 on its side
results in vertical orientation of the scan lines of the monitor,
thus facilitating viewing by the user.
Neutral density filter 33 (preferably, a Kodak Wratten No. 96) is
disposed at some point in the optical path to the camera 34,
preferably between prism 32 and camera 34 (FIG. 2), to compensate
for an increase in light intensity occurring due to reduction in
the second optical path.
FIG. 3 is a side view of a portion of the system of the present
invention, as viewed along the line D in FIG. 1. As seen in FIG. 1,
and as confirmed in FIG. 3, the camera 22 is preferably oriented
with its top facing to the left in FIG. 1, while the monitor 24 is
disposed on its side. As a result, the specimen as viewed through
the trinocular microscope head 20 will correspond precisely in
orientation to the view of the specimen displayed on the monitor 24
and viewing is facilitated. As best seen in FIG. 3, the trinocular
microscope head 20 provides the user with the capability of viewing
the fully magnified (100X) image of the specimen directly, that
image being conveyed via the objective 16, splitter 18, further
splitter 40 in the trinocular microscope head 20, and binocular
viewing arrangement 42. The trinocular microscope head 20 is a
conventional item available in the marketplace; for example, such a
trinocular microscope head is manufactured by Olympus of Japan.
In order to provide the system with the aforementioned viewing
capability, the present invention calls for the mounting of the
trinocular microscope head 20, by suitable means, on the end of the
camera 22 such that the distance B+C from the objective 16 to the
binocular viewing arrangement 42 equals the distance A from the
objective 16 to the camera 22 (specifically, the input lens 38
thereof).
Referring to FIGS. 1, 2 and 3, the operation of the system is as
follows. The specimen to be viewed is placed on the slide 14, and
the slide 14 is placed on the stage 12. The technician then adjusts
the slide 14, using the trinocular microscope head 20 or the
monitor 36 to view the specimen on slide 14. As mentioned
previously, the arrangement is such that movement of the slide 14
in a given direction will result in precisely the same movement of
the specimen on the monitor 36.
Once the specimen is properly positioned, the technician views the
specimen under a lower magnification power (for example, 20X) on
monitor 36 and under a higher magnification power (for example,
100X) on monitor 24. This simultaneous viewing of the specimen
under lower and higher magnification powers is achieved without the
need for switching of lenses and without any need for
refocusing.
FIG. 4 is a block diagram further disclosing the system of the
present invention. As seen therein, the system comprises the
previously discussed cameras 22 and 34 and monitors 24 and 36, and
further comprises a microcomputer 50, keyboard (or other input
means) 52, mixers 54 and 60, slave monitors 56 and 62, and
photographic printers 58 and 64.
In operation, in the course of positioning a specimen on the slide
14 (FIG. 1), the technician uses the keyboard 52 to enter
information relevant to the specimen into the microcomputer 50, the
microcomputer 50 being appropriately programmed and configured to
provide analog representations of the entered information to the
mixers 54 and 60. As an example, the microcomputer 50 can be
configured to include a Video Memory Board MFB-512-8-4-M and an
A/D, D/A board MFB-512-8-1-M, manufactured by Imaging Technology,
Inc. of Woburn, Mass., for the purpose of generating analog
representations of information entered via keyboard 52.
The mixers 54 and 60 are conventional analog mixing devices,
available in the marketplace, for mixing the analog video signals
from the cameras 22 and 34, respectively, with the analog
representations of operator-entered information provided by
microcomputer 50, so as to generate a mixed video signal for
provision to the monitors 24 and 36, respectively. As a result,
monitors 24 and 36 display both the operator-entered information
and the image of the specimen.
The system further provides the capability, via photographic
printers 58 and 64, of producing a hardcopy record of the image
displayed on the monitors 24 and 36, respectively. This can be
accomplished in either one of two alternate ways: first, the
cameras 22 and 34 can provide a direct optical output to the
photographic printers 58 and 64, respectively; or second, slave
monitors 56 and 62 can be connected to the output of monitors 24
and 36, respectively, so as to produce appropriate inputs to the
photographic printers 58 and 64, respectively. The photographic
printers 58 and 64 are, by way of example, implemented by an
automatic print processor such as the "47th Street Photo Speed
Printer" manufactured by the 47th Street Darkroom Center of New
York, N.Y.
FIGS. 5A and 5B are top and sectional views, respectively, of a
lens switching arrangement which can be employed with the system of
the present invention. As seen in the figures, the lens switching
arrangement comprises a frame member 160 in which a rotatable,
circular disclike member 162 is positioned, member 162 being
rotatable within the member 160. The member 162 includes
receptacles in which are disposed respective lens arrangements 164,
165 and 166.
More specifically, each of the lens arrangements 164, 165 and 166
has a different magnification power so that, by rotating the member
162 within the frame member 160, lens arrangements of different
magnification powers can be moved into position in the optical
path, thus providing variable magnification of the object being
viewed.
In the prior art, it is well-known to provide a lens switching
arrangement wherein lenses of differing magnification may be
rotated into position in the optical path. However, a significant
drawback to such prior art arrangements resides in the fact that,
after rotating each lens into position, it is necessary to refocus
the microscope with which the lens switching arrangement is being
used.
In accordance with a feature of the present invention, there is no
necessity to refocus the microscope when a new lens is switched
into position in the optical path. This is due to the fact that, in
accordance with the invention, and as seen in FIG. 5B, each lens
arrangement 164, 165 and 166 includes a pair of lenses 164a and
164b, 165a and 165b, and 166a and 166b, respectively. More
specifically, the present inventor has discovered that, by
superimposing positive diopter lenses 164b, 165b and 166b on top of
the negative diopter lenses 164a, 165a and 166a, respectively, and
by arranging for a predetermined distance to be established between
the negative diopter lens and its superimposed positive diopter
lens, refocusing of the microscope after each switch to a new lens
arrangement is unnecessary.
Accordingly, referring to FIGS. 1, 5A and 5B, in accordance with a
further feature of the invention, a lens switching arrangement as
shown in FIGS. 5A and 5B can be substituted for the objective lens
16 of FIG. 1. This will provide the microscopic image display
system with the capability of switching objective lenses, thus
providing the user with further flexibility in the establishment of
split-image, multi-power displays.
It is to be understood that the split-image, multi-power
microscopic image display system and method of the present
invention must comply with the Koler technique (well-known in the
art) in order to avoid focusing of the filament. In brief, every
microscope has a filament which generates light which passes
through the objective and is focused by one or more lenses in an
objective plane. It is possible, in certain arrangements, to obtain
a spurious image resulting from focusing of the filament. In order
to avoid this problem, Koler developed lens arrangements and
procedures so that the filament image was positioned quite a
distance away, and thus was out of focus insofar as the microscopic
viewer was concerned.
While preferred forms and arrangements have been shown in
illustrating the invention, it is to be understood that various
modifications can be made without departing from the spirit and
scope of this disclosure.
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