U.S. patent number 3,895,854 [Application Number 05/407,536] was granted by the patent office on 1975-07-22 for chromatic method and apparatus for conducting microscopic examinations at a plurality of magnifications.
This patent grant is currently assigned to Coulter Electronics, Inc.. Invention is credited to Garret Francis Ziffer.
United States Patent |
3,895,854 |
Ziffer |
July 22, 1975 |
Chromatic method and apparatus for conducting microscopic
examinations at a plurality of magnifications
Abstract
A chromatic method and apparatus for conducting microscopic
examinations at a plurality of magnifications provide for
illuminating a microscopic object with a plurality of colors of
light, conducting the light transmitted by the object along
different paths for different colors, and producing different
degrees of magnification along the different paths.
Inventors: |
Ziffer; Garret Francis (Natick,
MA) |
Assignee: |
Coulter Electronics, Inc.
(Hialeah, FL)
|
Family
ID: |
23612488 |
Appl.
No.: |
05/407,536 |
Filed: |
October 18, 1973 |
Current U.S.
Class: |
359/372;
359/629 |
Current CPC
Class: |
G02B
27/1006 (20130101); G02B 21/18 (20130101) |
Current International
Class: |
G02B
21/02 (20060101); G02B 21/06 (20060101); G03B
21/20 (20060101); G02b 021/00 () |
Field of
Search: |
;350/33,20,171,172,173 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lawrence; James W.
Assistant Examiner: Church; C. E.
Attorney, Agent or Firm: Silverman & Cass, Ltd.
Claims
What is claimed is:
1. A chromatic method of conducting microscopic examinations of an
illuminated object at a plurality of magnifications, in which
neither the object nor any magnifying lenses are required to be
moved, which comprises the steps of:
illuminating the object with a plurality of different colors of
light,
conducting the light transmitted by said object along different
paths for said different colors, and
producing different degrees of magnification along said different
paths.
2. A method according to claim 1 wherein said step of illuminating
said object is accomplished by employing selectively light of
different colors, and including the step of conducting the light
from said paths to a common terminal path.
3. A method according to claim 2 wherein said step of conducting
includes the step of regulating the intensity of the light of said
different colors to be substantially the same intensity when
supplied to said common terminal path.
4. A method according to claim 1 including the step of generating
said different paths by color differentiation.
5. Chromatic apparatus for conducting microscopic examinations of
an illuminated object at a plurality of magnifications, in which
neither the object nor any magnifying lenses are required to be
moved, which comprises, in combination:
a color differentiating element adapted to be disposed in the path
of light transmitted by the illuminated object, said color
differentiating element transmitting light of different colors in
different directions therefrom and along first and second separate
light paths, and
a magnifying means disposed in at least one of said separate paths
for producing different degrees of magnification along said
different light paths from the illuminated object.
6. Apparatus according to claim 5 further including an objective
lens adapted to be disposed in the path of light between the
illuminated object and said differentiating element.
7. Apparatus according to claim 5 including magnifying lenses
having different magnifying powers disposed in different ones of
said separate paths.
8. Apparatus according to claim 5 wherein said differentiating
element is a color filter adapted to pass at least one color and
reflect at least one different color.
9. Apparatus according to claim 8 further including a second color
filter disposed in the light path for said reflected color and
adapted to pass said reflected color while blocking passage of any
reflected components of said passed color.
10. Apparatus according to claim 5 further including means for
converging said first and second light separate paths into a common
terminal path.
11. Apparatus according to claim 10 wherein said converging means
includes reflecting means disposed in at least one of said separate
paths.
12. Apparatus according to claim 11 wherein said reflecting means
includes a color filter adapted to pass at least one color and
reflect at least one different color.
13. Apparatus according to claim 10 further including means for
delivering to said terminal path light of said colors having
substantially the same order of intensity.
14. Apparatus according to claim 13 wherein said delivery means
includes a beam splitter.
15. Apparatus according to claim 5 wherein said separate paths are
equal in length.
16. Apparatus according to claim 5 further including means for
illuminating said object selectively by light of different
colors.
17. Apparatus according to claim 5 including a sensor disposed at
the end of each of said separate light paths for receiving two
different magnifications of the illuminated object.
18. Apparatus according to claim 5 which includes color selecting
structure which causes said color differentiating element to
receive simultaneously at least two different colors from the
illuminated object.
19. Apparatus according to claim 5 in which said color
differentiating element, said separate light paths, magnifying
means and the object are stationary at least during the production
of the different degrees of magnification.
20. Apparatus according to claim 5 which includes a second color
differentiating element positioned in one of said separate light
paths for directing at least one color along a third separate light
path.
21. Apparatus according to claim 20 which includes color selecting
structure for selectively causing the light transmitted from the
object to said color differentiating elements to be more than of
two colors, each color being directed to a different one of said
light paths.
22. Apparatus according to claim 20 including a sensor disposed at
the end of each of said separate light paths for receiving
different degrees of magnification of the illuminated object.
23. Apparatus according to claim 22 in which said color selecting
structure causes at least one of said color differentiating
elements to receive simultaneously at least two different colors
from the illuminated object.
Description
BACKGROUND OF THE INVENTION
This invention relates to a chromatic method and apparatus for
conducting microscopic examinations at a plurality of
magnifications.
Efficient operation of computerized automatic or semi-automatic
equipment for microscopy necessitates an ability to change the
degree of magnification rapidly during examination of microscopic
objects, and a rapid change in magnification cannot be accomplished
in a practical manner by changing the objective or the eyepiece.
Consequently, a need exists for a method and apparatus suited for
making a change in magnification rapidly and in a practical
manner.
SUMMARY OF THE INVENTION
The invention provides a chromatic method of conducting microscopic
examinations at a plurality of magnifications which includes the
steps of illuminating a microscopic object with a plurality of
colors of light, conducting the light transmitted by the object
along different paths for different colors, and producing different
degrees of magnification along the different paths.
The invention also provides chromatic apparatus for conducting
microscopic examinations at a plurality of magnifications which
includes a color differentiating element adapted to be disposed in
the path of light transmitted by an illuminated object, said
element transmitting light of different colors in different
directions therefrom, means providing separate light paths for
different colors transmitted from the element, and a magnifying
lens disposed in at least one of the separate paths for producing
different degrees of magnification along different light paths from
an illuminated object. A preferred embodiment of the apparatus
includes an objective lens adapted to be disposed in the path of
light between an illuminated object and the differentiating
element.
Employing further preferred embodiments of the method and
apparatus, the object is illuminated selectively by light of
different colors, and the light from the separate paths is
conducted to a common terminal path, so that images of the several
different degrees of magnification may be transmitted in turn to
the same receiving point for purposes of examination. Employing
still further preferred embodiments, light of substantially the
same order of intensity for each of the several colors is delivered
to the common terminal path.
The chromatic method and apparatus are adapted for effecting rapid
changes of magnification by changing the color of illumination of
an object. It is within the scope of the invention, in addition or
alternatively, to illuminate an object simultaneously with a
plurality of light colors, for obtaining a plurality of
simultaneous readings at different degrees of magnification.
Employing the new method and apparatus, there need be no movement
of microscope lenses for changing the degree of magnification. The
remaining apparatus employed for magnification also can be mounted
fixedly and compactly. Consequently, wear is minimized, thereby
preserving the high degree of accuracy required in microscopic
analysis.
BRIEF DESCRIPTION OF THE DRAWING
The attached drawing is a diagrammatic representation of apparatus
according to a preferred embodiment of the invention, and also
illustrates a preferred manner in which the method of the invention
can be carried out.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawing, the preferred embodiment of the invention
is illustrated in its application to the examination of an object
or specimen on a microscope slide 10. The slide 10 is mounted
adjacent to and between a condenser lens 12 beneath the slide and
an objective lens 14 above the slide. The condenser 12 can be
mounted on a microscope stage, not shown. In the particular
arrangement illustrated, an object on the slide 10 is illuminated
by a lamp 16 and a sub-stage mirror 18 which serves to reflect
light rays from the lamp at right angles to the incident path and
in the direction of the axis 20 of the condenser lens 12 and the
objective lens 14. It will be understood that the light source can
be disposed in other arrangements, such as on the axis 20, with
elimination of the mirror 18.
A conventional microscope can include structure similar to the
foregoing, including one or more objective lenses, and an eyepiece
or eyepieces. The objective lens and/or the eyepiece can be changed
or adjusted, to change the degree of magnification of the object on
the slide 10. The present invention especially is adapted for use
of a fixed lens system, without need for changing or adjusting a
lens when the degree of magnification is to be changed.
Consequently, the time lag required for such lens changes is
eliminated, and there is no wear in apparatus required for making
such changes with resulting decrease in accuracy. It will be
apparent that, nevertheless, one or more lenses can be mounted for
movement or be changeable, if desired, for additional versatility
and adptability.
The object on the slide 10 is illuminated with light of different
colors, and the color of the illumination determines the resulting
degree of magnification. For this purpose, a source of illumination
selectively with light of different colors is provided, and in the
illustrative embodiment, it includes a color filter wheel 22
interposed between the lamp 16 and the sub-stage mirror 18. The
filter wheel is divided into sections embodying different color
filters, for transmitting light of different colors or ranges of
wavelengths from different sections to the mirror 18. For example,
in the illustrative embodiment, the filter wheel 22 includes: one
section transmitting both green and orange colored light having
wavelength bands in the regions of 500 and 600 nm. (nanometers)
respectively; and one section transmitting yellow-green colored
light having a wavelength band in the region of 565 nm. The color
of the transmitted light can be changed very rapidly, operating the
filter wheel in a conventional manner, preferably by rotating the
wheel in step-wise fashion to change the color. It will be apparent
that, alternatively, any of various other suitable arrangements for
providing and rapidly changing light of different colors can be
employed.
Light of the desired color is transmitted from the filter wheel 22
to the sub-stage mirror 18, from whence it is transmitted by
reflection to the condenser 12 and to the object on the slide 10.
Light transmitted by the object passes through the objective lens
14, and an image of the object is produced that is magnified
according to the power of the lens. The degree of magnification
produced by the lens 14 can be, for example, forty times.
Light is transmitted from the objective lens 14 in the direction of
the lens axis 20 in a common initial light path 24 provided in the
apparatus. The initial light path 24 terminates at a first color
differentiating element 26. In the illustrative embodiment, the
element 26 is constructed to function as an interference color
filter which passes a light band of a certain color, and also as a
folding (plane) mirror (reflector), which reflects light of one or
more other colors. The plane of the reflective surface 26a on the
element 26 is disposed at a preferred angle of 45.degree. to the
lens axis 20 and the initial light path 24 coincident with the
axis. In the illustrative embodiment, the differentiating element
26 is adapted to pass the orange light of 600 nm. wavelength and to
reflect the green and yellow-green light of 500 and 565 nm.
wavelength. It will be understood, however, that the properties of
a color filter, such as are obtained by applying a proper coating
to a light-transmitting substrate, are such that less than 100
percent of the light of the selected wavelength band at 600 nm. is
transmitted through the differentiating element 26. At times,
depending upon the quality of the element 26, a minor quantity of
such light is reflected from the surface 26a of the element.
The light passing through the differentiating element 26 is
transmitted therefrom in the direction of the lens axis 20, and
follows an angular, separate first light path 28 having a first
section 28a extending in the direction of the axis 20 and a second
section 28b extending at right angles thereto. In the illustrative
embodiment, orange colored light follows the first path 28, and it
is magnified by an eyepiece having a field lens 32 in the first
section 28a and an eye lens 34 in the second section 28b of the
path. The degree of magnification produced by the eyepiece can be,
for example, five times, and yielding a total exemplary
magnification of 200. An aerial image is formed as indicated by a
broken line at 36. The angularity of the first light path 28 is
achieved by disposing a folding mirror 38 in the path following the
field lens 32, with the plane reflective surface 38a of the mirror
disposed at an angle of 45.degree. to the lens axis 20 and the
first section 28a of the path.
The light transmitted by reflection from the reflective surface 26a
of the differentiating element 26 is conducted along first and
second sections 30a and 30b of an angular, separate second light
path 30, the path sections being at right angles to each other. The
reflected light, including either the green light of 500 nm.
wavelength or the yellow-green light of 565 nm. wavelength, and any
reflected minor proportion of orange light of 600 nm. wavelength,
is transmitted to a blocking color filter 40 disposed in the first
path section 30a perpendicularly thereto. The blocking filter 40 is
adapted to block the orange light and pass a preponderating amount
of the remaining colors of light. Alternatively, with a more nearly
perfect differentiating element 26, i.e., which reflects at most an
insignificant amount of light of 600 nm. wavelength, the blocking
filter 40 can be eliminated.
In the illustrative embodiment, the first section 30a of the second
light path 30 terminates at a second color differentiating element
42 having a plane reflective surface 42a disposed at an angle of
45.degree. to the direction of the first path section 30a. The
second differentiating element 42 is similar in function to the
first differentiating element 26, and is constructed to pass the
green light of 500 nm. wavelength, and to reflect the yellow-green
light of 565 nm. wavelength. The light passed by the second element
42 follows a separate third light path 44, which extends in the
same direction as and beyond the first section 30a of the second
path 30. The reflected light follows the second path section 30b of
the second path 30.
A second blocking color filter 46 is disposed in the second section
30b of the second light path 30 perpendicularly to the section. The
second blocking filter 46 is adapted to block passage of any green
light of 500 nm. wavelength, which is reflected in a minor amount
by the second differentiating element 42 rather than being passed
thereby, and to pass a preponderating amount of the reflected
yellow-green light of 565 nm. wavelength. As in the case of the
first differentiating element 26, the use of a second
differentiating element 42 of sufficiently high color separating
ability will enable the elimination of the second blocking filter
46.
A second eyepiece 48 is disposed in the second section 30b of the
second light path 30, so that the path section follows the axis of
the second eyepiece. The second eyepiece can produce a
magnification of 25.times., for example, which together with an
objective lens 14 having a magnification of 40.times., produces an
overall magnifying power of 1,000. An aerial image is formed as
represented by a broken line at 50.
The sections 28a, 28b, 30a and 30b of the separate light paths 28
and 30 form the sides of a rectangle. The separate paths 28 and 30
thus are equal in length, and they converge at a beam splitter 52
having a reflective layer 52a. The reflective layer 52a is adapted
to reflect a major portion of the light incident to either its
front surface or its back surface, and to pass a minor proportion
of such light. Thus, the layer 52a is adapted to reflect most of
the yellow-green colored light of 565 nm. wavelength from the
second section 30b of the second light path 30, and to pass the
balance. The layer 52a is at an angle of 45.degree. to the second
path section 30b, so that the light rays are reflected at an angle
of 90.degree. to the second path section 30b, and are conducted
along a terminal path 54 leading to a first sensor 56. The passed
light follows a path 58, the light from which is dissipated.
The layer 52a of the beam splitter 52 also is adapted to pass a
minor proportion and reflect the balance of the light rays from the
second section 28b of the first separate light path 28. The passed
light from the latter section 28b follows the terminal path 54, and
the reflected light from the latter section follows the dissipation
path 58. In this manner, beam splitter 52 serves to equalize the
intensity of the light reaching the terminal path 54 from the
separate paths 28 and 30, and delivers light of substantially the
same order of intensity to the sensor 56. In the illustrative
embodiment, about 8 percent of the light from the second path
section 28b of the first path 28 is passed to the terminal path 54,
and about 92 percent is reflected to the dissipation path 58.
Similarly, about 92 percent of the light from the second path
section 30b of the second path 30 is reflected to the terminal path
54, and about 8 percent is passed to the dissipation path 58.
The illustrative arrangement of different paths leading from the
slide 10 to the sensor 56 via the separate paths 28 and 30 allows
an examination to be made at one magnification at a time, employing
the appropriate setting of the color filter wheel 22, i.e., at the
500 and 600 nm. setting, or at the 565 nm. setting. In each case,
an examination is made by the same agency or at the same point,
i.e., by the sensor 56, which can be a television camera, for
example. It will be apparent, however, that, alternatively,
provision can be made for separate light paths that do not
terminate in a common path, such as the terminal path 54, but lead
to separate sensors. In such case, it is possible to make
examinations at two different magnifications at the same time,
while illuminating the slide 10 with light of two or more colors at
the same time. This manner of operation is illustrated by reference
to the third separate light path 44.
The light of 500 nm. wavelength which is passed by the second
differentiating element 42 and follows the third separate path 44
terminates in a second sensor 60 serving any desired purpose.
Consequently, when the color filter wheel 22 is adjusted to
transmit light of 600 and 500 nm. wavelength together, light of the
respective wavelengths is transmitted simultaneously along separate
paths and at different magnifications to the respective sensors 56
and 60, which can operate simultaneously to perform separate
functions. Similarly, if desired, light of 500 nm. wavelength might
be transmitted together with light of 565 nm. wavelength, for
simultaneous examinations by the sensors 56 and 60. It will be
noted that in either of the foregoing alternatives, the image
reaching the second sensor 60 has been magnified but once, by the
objective lens 14, so that the magnification at the second sensor
is 40.times.. The illustrative system thus provides three different
degrees of magnification.
In the event that it is not desired to provide for a simultaneous
second examination, the sensor 60 is eliminated, and the
appropriate section of the filter wheel 22 can be constructed so as
to transmit only light of 600 nm. wavelength, and not light of 500
nm. wavelength. There is no need then for an element to pass 500
nm. light to the sensor 60, so that the second differentiating
element 42 can be replaced by a folding mirror similar to the
previously described folding mirror 38, for reflecting the 565 nm.
light. The second blocking filter 46 can be eliminated, since its
function is to prevent passage of 500 nm. light, no longer
transmitted.
While preferred embodiments of the method and apparatus of the
invention have been described and illustrated, it will be apparent
that various changes and modifications can be made therein within
the spirit and scope of the invention. It is intended that such
changes and modifications be included within the scope of the
appended claims.
* * * * *