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Description  |
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TECHNICAL FIELD
The present invention relates to radiant energy illumination and light
controls for viewing systems such as microscopes, cameras, object
detecting systems, etc., wherein illumination and/or viewing can be
changed.
DESCRIPTION OF THE PRIOR ART
The prior art as exemplified in U.S. Pat. Nos. 2,516,907, 3,161,717,
3,561,876, 3,628,848, 3,646,608, 3,658,405, 3,851,949, 3,846,009,
4,127,318 and No. 4,148,552, contains a number of microscopes wherein one
or more elements are adjustable or changeable to vary the illumination or
viewing properties of the microscope. However, such microscopes usually
require some mechanical or physical part to be moved or replaced to effect
the change. This greatly increases the mechanical complexity of the
apparatus. Various prior art illumination techniques such as transmissive
illumination, incident illumination, darkfield illumination, bright field
illumination, oblique illumination, differentially shaded illumination,
phase contrast illumination, differential polarization illumination, etc.,
have been employed for improving the visibility of various objects being
examined by microscopes, cameras, and other devices.
A liquid crystal diaphragm arrangement for a photographic camera is
illustrated in U.S. Pat. No. 3,955,208. The diaphragm is formed by two
superimposed cells containing concentric ring-shaped electrodes with an
electronic control circuit for selectively changing the area of
transmissivity through the diaphragm.
An electro-optic device for portraying closed ring images is illustrated in
U.S. Pat. No. 3,588,225 wherein semicircular electrodes forming
complementary arcuate portions of the rings are located in respective
superimposed liquid crystal cells.
Liquid crystal display devices utilizing resistive electrodes for producing
variable patterns in light transmitted therethrough are disclosed in U.S.
Pat. Nos. 3,675,988 and No. 4,139,278. These disclosures include
individual devices with resistive electrode patterns for generating rings,
wedges, spot, sectors, and other configurations.
U.S. Pat. No. 2,388,858 discloses a stereo trainer employing a Wollaston
prism in front of an objective for dividing the image into two images
polarized at right angles to each other. Polarizing filters oriented
mutually at right angles to each other are positioned in front of the
respective right and left eyepieces to pass only the respective images and
produce a stereoscopic view. The similarity of the operation of Wollaston
prism to a Ronchon prism and to a single birefringent crystal of quartz or
calcite is also disclosed.
A comparison viewer illustrated in U.S. Pat. No. 3,450,480 discloses a
mechanism which can be manipulated to provide either stereoscopic or
monoscopic viewing through a binocular eyepiece arrangement.
SUMMARY OF THE INVENTION
The present invention is summarized in an apparatus for a viewing or
electronic detecting system including an electrically controlled light
transmission unit interposed in a path of light in an illumination system
for an object station and/or in the path of light from the object station
to enhance an image or portion thereof for viewing or electronic
detection. Electrical control means selectively operates the light
transmission unit or units.
An object of the invention is to construct an illumination apparatus for a
viewing or electronic sensing system wherein one of a plurality of
illumination conditions, such as transmissive illumination, incident
illumination, oblique illumination, differentially shaded illumination,
darkfield ilumination, bright field illumination, phase contrast
illumination, differential polarization illumination, color or spectral
illumination, etc., can be selected by an electronic control system.
Another object of the invention is to construct an illumination apparatus
for a viewing or electronic detector which produces substantially new and
different illumination and/or viewing or detecting of an object.
One advantage of the invention is that an illumination condition is
selected by electrical controls, and thus versatile electrical control
circuits can be employed for selectively operating the illumination
system.
Other objects, advantages and features of the invention will be apparent
from the following description of the preferred embodiment taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic sectional view of a microscope with an
illumination control constructed in accordance with the invention.
FIG. 2 is a cross-section view of a broken-away portion of one light
control cell in an electrically controlled light transmission unit of the
microscope of FIG. 1.
FIG. 3 is a plan view of an electrode arrangement in one light control cell
of a light transmission unit of FIGS. 1 and 5 for producing a portion of a
ring pattern.
FIG. 4 is a plan view of an electrode arrangement in another cell of a
light transmission unit of FIGS. 1 and 5 for producing a portion of a ring
pattern complementary to the ring portion of FIG. 3.
FIG. 5 is a block diagram of an electrical control circuit and an
electrically controlled light transmission unit of the microscope of FIG.
1.
FIG. 6 is a plan view of an electrode structure in a polarization control
cell of the light transmission unit of FIG. 5.
FIG. 7 is a plan view, enlarged relative to FIG. 6, of an electrode
structure in a ray selecting control cell of the light transmission unit
of FIG. 5.
FIG. 8 is a plan view of an electrode arrangement in a spot selecting
control cell which could be alternatively included in the light
transmission unit of FIG. 5.
FIG. 9 is a diagrammatic sectional view of a modified broken-away portion
of a microscope in accordance with the invention.
FIG. 10 is a diagrammatic sectional view of a second modified broken-away
portion of a microscope constructed in accordance with the invention.
FIG. 11 is a block diagram of a portion of a modified electrical control
circuit for operating a light transmission unit in a microscope according
to the invention.
FIG. 12 is a plan view of a birefringent plate in the modified microscope
of FIG. 10 illustrating the displacement of the light ray image of one
polarization.
FIG. 13 is a diagram of a third modification which can be included in a
microscope in accordance with the invention.
FIG. 14 is a diagrammatical sectional view of a further modified microscope
in accordance with the invention.
FIG. 15 is a block diagram of a variable phase adjusting cell in the
modified microscope of FIG. 14.
FIG. 16 is a schematic of a portion of an electrical circuit variation
which can be used in the control circuits of the microscopes of the
invention.
FIG. 17 is a schematic of a portion of another electrical circuit variation
which can be used in the control circuits of the invention.
FIG. 18 is a block diagram of a portion of an electrical circuit variation
for controlling the phase adjusting cell of FIG. 15.
FIG. 19 is a diagram of a variation of an illumination control station in a
microscope in accordance with the invention.
FIG. 20 is a block diagram of a variable phase adjusting and pattern
filtering unit suitable for substitution for the variable phase adjusting
unit of FIGS. 14 and 15.
FIG. 21 is a cross-sectional view of a modified pattern selecting cell
which can be used in the invention.
FIG. 22 is a plan view of one electrode arrangement in the cell of FIG. 21.
FIG. 23 is a diagram of a transmission unit employing the cell of FIGS. 21
and 22 and a driving circuit for the transmission unit.
FIG. 24 is a diagram of one pattern generated by the transmission unit and
circuit of FIG. 23.
FIG. 25 is a diagram of a second pattern generated . by the transmission
unit and circuit of FIG. 23.
FIG. 26 is a diagram of a third pattern generated by the transmission unit
and circuit of FIG. 23.
FIG. 27 is a diagram of a fourth pattern generated by the transmission unit
and circuit of FIG. 23.
FIG. 28 is a plan view of a variation of the electrode arrangement of FIG.
22.
FIG. 29 is a diagram of a still further modified broken-away portion of a
microscope in accordance with the invention.
FIG. 30 is a diagrammatical perspective view of a pattern select cell in
the microscope of FIG. 29.
FIG. 31 is a diagrammatical side view of a variable phase adjusting device
in the microscope of FIG. 29.
FIG. 32 is a diagram of a modified circuit for operating the cell of FIG.
30.
FIG. 33 is a diagram of a modified pattern select cell arrangement for
substitution in the microscope of FIG. 29.
FIG. 34 is a wave form diagram of electrical signals used to operate one of
the cells in FIG. 33.
FIG. 35 is a diagram of a broken-away portion of a pattern generated by the
operation of one of the cells of FIG. 33 by the electrical signals of FIG.
34.
FIG. 36 is a diagram of a variation of the microscope portion of FIG. 29.
FIG. 37 is a diagrammatical perspective view of a pattern select unit in
the variation of FIG. 36.
FIG. 38 is a diagram of a modification of the variation of FIG. 36.
FIG. 39 is a view, partly in perspective, of embodiment of an illumination
control device designed for insertion in a microscope in acordance with
the invention.
FIG. 40 is a plan view of a broken-away portion of an electrical controller
of the control device of FIG. 39.
FIG. 41 is an exploded view of an assembly forming an optical cell module
for the control device of FIG. 39.
FIG. 42 is an exploded view of an LCD assembly unit of the module of FIG.
41.
FIG. 43 is a plan view of a pair of superimposed LCD cells of the unit of
FIG. 42 superimposed for forming circular or semi-circular patterns.
FIG. 44 is a plan view of a joystick of FIG. 40 illustrating joystick
positions to select different patterns and different modes.
FIG. 45 is a diagram of several possible patterns which can be formed by
the cells of FIG. 43 during a first mode wherein each of the patterns is
illustrated in a position generally corresponding to the joystick position
producing such pattern.
FIG. 46 is a diagram similar to FIG. 45 but of a second mode of operation
of the illumination control device.
FIG. 47 is a diagram similar to FIG. 45 but of a third mode of operation of
the illumination control device.
FIG. 48 is a diagram similar to FIG. 45 but of a fourth mode of operation
of the illumination control device.
FIG. 49 is a functional block diagram of an electrical circuit in the
electrical controller of FIG. 39.
FIG. 50 is a detailed electrical schematic of a first portion of an
electrical circuit in accordance with FIG. 49.
FIG. 51 is a detailed electrical schematic of a second portion of an
electrical circuit in acordance with FIG. 48.
FIG. 52 is a flow diagram of a program for operating a microprocessor in
the electrical circuit of FIGS. 49-51.
FIG. 53 is a flow diagram of a normal routine employed in the program of
FIG. 52.
FIG. 54 is a flow diagram of a save routine employed in the program of FIG.
52.
FIG. 55 is a flow diagram of a voltage output routine employed in the
program of FIG. 52.
FIG. 56 is a diagram of a modified arrangement forming an illumination
control for a microscope.
FIG. 57 is a diagram of a modified microscope with illumination control in
accordance with the invention.
FIG. 58 is a diagram of another modified microscope with illumination phase
control in accordance with the invention.
FIG. 59 is a diagram of a light phase control unit or arrangement employed
in the microscope of FIG. 58.
FIG. 60 is a diagram of an alternative phase control unit or arrangement
for the microscope of FIG. 58.
FIG. 61 is a cross sectional view of a second phase control cell variation
suitable for use in the microscope of FIG. 58.
FIG. 62 is a cross sectional view of a third phase control cell variation
suitable for use in the microscope of FIG. 58.
FIG. 63 is a diagram of still another modified microscope with illumination
phase control.
FIG. 64 is a schematic of an electrical circuit modification for
controlling light intensity in the control of the invention.
FIG. 65 is a waveform diagram showing output of the circuit of FIG. 64 and
associated electro-optic cell response periods.
FIG. 66 is a waveform diagram of a waveform response when employing high
speed material in the electro-optic cell.
FIG. 67 is a diagram of a microscope including light color controls in
accordance with the invention.
FIG. 68 is a sectional view of a color control cell in the microscope of
FIG. 67.
FIG. 69 is a sectional view of an alternative color control cell for the
microscope of FIG. 67.
FIG. 70 is a sectional view of another alternative color control cell for
the microscope of FIG. 67.
FIG. 71 is a perspective view with portions cut away of an alternative
light control which is electrostatically operated.
FIG. 72 is an enlarged perspective view of a broken-away portion of the
light control switch of FIG. 71.
FIG. 73 is a perspective exploded view of another variation of the
electrostatic light control.
FIG. 74 is a perspective exploded view of a modified electrode structure
for the electrostatic light control of FIG. 73.
FIG. 75 is a sectional view of a lens-reflector system for use in devices
in accordance with the invention.
FIG. 76 is a sectional view of a variation of the lens-reflector system of
FIG. 75.
FIG. 77 is a sectional view of another variation of the lens-reflector
system.
FIG. 78 is a sectional view of an electronic focus control in accordance
with the invention.
FIG. 79 is a perspective view of a variation of the focus control of FIG.
78.
FIG. 80 is a sectional view of still another focus control variation.
FIG. 81 is a block diagram of a video camera system employing a composite
electrically controlled illumination system in accordance with the
invention.
FIG. 82 is a block diagram of an electronic circuit for differentiating
successive electronic video signals in a modification of the system of
FIG. 81.
FIG. 83 is a block diagram of another modification of the system of FIG.
81.
FIG. 84 is a block diagram illustrating one application of the video system
of FIGS. 81 and 83.
FIG. 85 is an illustration of a portion of an object illuminated by a first
light unit in a system in accordance with FIG. 84.
FIG. 86 is an illustration similar to FIG. 85 but with illumination from a
second light unit.
FIG. 87 is an illustration similar to FIG. 85 but with illumination from a
third light unit.
FIG. 88 is an illustration similar to FIG. 85 but with illumination from a
fourth light unit.
FIG. 89 is an illustration of a differential image formed by the system of
FIG. 84 from successive electronic video images taken during the
respective illumination conditions of FIGS. 85, 86, 87 and 88.
FIG. 90 is an illustration of another possible differential image of the
object of FIGS. 85-88.
FIG. 91 is a diagram of variations of the oblique-illumination of an object
in the illustrated microscope or camera system.
FIG. 92 is a diagram similar to FIG. 91 of another variation of the oblique
illumination.
FIG. 93 is a diagram of still another variation of the differentiating
circuit for video signals for a modified illumination system.
FIG. 94 is a perspective view of a video camera with an electronic
illumination system in accordance with the invention.
FIG. 95 is a diagrammatic exploded prospective view of an illumination
module in the illumination system of FIG. 94.
FIG. 96 is a sketch showing illumination of an object by electronic
spectrum control.
FIG. 97 is a representation of an image of the object of FIG. 96
illuminated with light of one spectral content.
FIG. 98 is a representation similar to FIG. 97 but with the object
illuminated with light of a second spectral content.
FIG. 99 is a representation similar to FIGS. 97 and 98 but with the object
illuminated with light of a third spectral content.
FIG. 100 is a perspective view of a modification of the video camera with
electronic illumination control in accordance with the invention.
FIG. 101 is an exploded side elevational view of the light control devices
in an illuminating control module of FIG. 100.
FIG. 102 is a front diagrammatic view of one pattern control cell in the
module of FIG. 101.
FIG. 103 is a front diagrammatic view of a second pattern control cell in
the module of FIG. 101.
FIG. 104 is a front diagrammatic view of a third pattern control cell in
the module of FIG. 101.
FIG. 105 is a block diagram illustrating a color video system employing a
conventional black and white camera.
FIG. 106 is a variation of the video system of FIG. 105.
FIG. 107 is a diagram of further modification of a color video system.
FIG. 108 is a diagram of a detector system employing illumination control
in accordance with the invention.
FIG. 109 is a perspective view of a two dimensional variation of the
detector array of FIG. 108.
FIG. 110 is a diagram illustrating another application of the system of
FIG. 108.
FIG. 111 is a diagram in perspective of a variation of.. the system in FIG.
108.
FIG. 112 is a perspective view of another detector variation.
FIG. 113 is a sectional view of the detector variation of FIG. 112.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown diagrammatically in FIG. 1, a microscope including an illumination
control in accordance with the invention includes an electrically
controlled light transmission unit indicated generally at 20 and mounted
in an illumination condenser system for the microscope together with an
electrical control circuit indicated generally at 22 for operating the
transmission unit 20 which selectively changes and passes light to
illuminate an object 24. The microscope as illustrated includes both a
substage illumination system 26 and a superstage illumination system 28;
however, the microscope could include only one of the substage and
superstage illumination systems. An electrically controlled light
transmission unit 20 is included within each of the illumination systems
26 and 28. Respective control circuits 22 are illustrated for operating
the units 20; however, the control circuits 22 could be combined into a
single control circuit for operating both units 20. Conventional light
sources 29 produce the light which is transmitted through the units 20 and
directed toward the object 24. Preferably the units 20 are mounted between
the field lens 25 and condenser lens 27 in the condenser systems of
otherwise conventional microscopes without making other major changes to
the housing and lens systems of the microscopes of their manufacturing
processes.
The microscope includes a conventional housing 30 in which is mounted an
objective 32 and a pair of eyepieces 34 and 36. An arrangement of a
half-transmissive reflector 40 and reflector 46 is provided for reflecting
one-half of the light from the objective 32 toward the eyepiece 36 while
an arrangement of reflectors 44 and 42 is provided to reflect the
remaining light from the objective 32 toward the other eyepiece 34. For
superstage or incident illumination, the telescope includes a partly
transmissive reflector 52 for directing the incident light from the
condenser system 28 through the objective to the object 24. The reflectors
40, 42, 44, 46 and 52 can be prism devices, mirror devices, and/or any
other suitable conventional light deviating devices. Generally, either
substage or superstage illumination can be used to provide both dark field
and bright illumination as well as oblique illumination. As an alternative
to passing incident illumination through the objective of the microscope,
oblique incident illumination may be produced, as shown in FIG. 56, by one
or more external light sources 29 controlled by light transmission units
20 or, alternatively, simple electro-optic light switches, or more
elaborate pattern, color, phase, and/or polarization control units.
In one possible embodiment, each of the electrically controlled light
transmission units 20 is designed to selectively modify one or more
variable characteristics,. such as pattern, color, and/or polarization, of
the light passing therethrough from the source 29 and iluminating the
object 24 in response to the electrical control circuit 22. One example of
an electrically controlled light transmission unit is illustrated in FIG.
5. The unit 20 includes a plurality of superimposed pattern selecting
cells 60, 62 and 64 positioned between polarizers 66 and 68 together with
a polarization control cell 70 positioned on the exit side of the
polarizer 68 which in turn is positioned on the exit side of the
superimposed pattern selecting cells 60, 62 and 64 all secured together by
holding means 72. If the light source 29 is selected to generate polarized
light, then the input polarizer 66 can be eliminated. Each of the cells
60, 62, 64 and 70 are formed, as shown in FIG. 2, from a layer of
electro-optic liquid crystal material such as a conventional nematic fluid
76 between transparent electrodes 78 and 80 which are configured into
desired patterns on transparent substrates 82 and 84. The liquid crystal
material 76 is selected to be anisotropic, i.e., to rotate the plane of
polarization of light passing transversely therethrough, when a voltage is
applied across the material 76 by the electrodes 78 and 80. When the
electrodes 78 and 80 are unenergized, the liquid crystal material is
isotropic, i.e., the plane of polarization of light passing therethrough
is not rotated, or at least substantially less anisotropic. The polarizers
66 and 68 are shown oriented with their directions of polarization
crossing at right angles so that light passes through the unit 20 only
when one or more of the electrodes of the cells 60, 62 and 64 are
energized. Alternatively, the polarizers can be oriented in the same
direction so that light passes freely through the unit 20 when the cells
60, 62 and 64 are unenergized, and light is selectively blocked or shaded
when one or more of the electrodes on the cells 60, 62 and 64 are
energized. Also, the liquid crystal can be selected to be isotropic, or
less anisotropic, when energized and anisotropic when unenergized; the
relative orientation of the polarizers is reversed to produce selected
passage or blockage of light.
As an alternative to nematic or liquid crystal material, the electro-optic
material may be iron garnet, PLZT (lead lanthanum zirconate titanate), or
any other material which has voltage, magnetic, or thermal dependent
anisotropic and/or isotropic states or by use of other electro-optic
techniques, such as electrostatic light switches described herein.
Generally, electro-optic cells using nematic materials have white light
contrast ratios, i.e., the ratio of light intensity passed when in the
fully on or light transmissive state to the light passed when in the fully
off or dark state, in the range from 10:1 to 20:1. When optimized for a
single color, the contrast ratio of the nematic cells can be increased to
100:1 for light of that color. Even higher contrast ratios are possible
from iron garnet (1000:1) and PLZT (10,000:1) so these materials can be
used in applications where high contrast ratios are required.
Variation of voltages applied across electro-optic materials can be used to
vary intensity, color, and/or phase. In some instances, the degree of
rotation of the polarity of the transmitted light varies in accordance
with the variation of the voltage. In an arrangement of the polarizers 66
and 68 and the pattern cells 60, 62 and 64 selected to pass maximum light
intensity at a selected voltage, the application of voltages above and
below the selected voltage will result in passage of reduced light
intensity since a portion of the light, which has its polarity rotated to
a different angle, will be blocked by the polarizer 68. Also,
electro-optic materials generally rotate the polarity of different
frequencies of light, i.e., different colors, by different degrees. Where
the light to be transmitted is white, it is conventional to utilize a
thickness of electro-optic material, polarizers, and voltages which
minimize color selectivity. Conversely, the electro-optic material,
polarizers and voltages can be selected to maximize color selectivity; and
in this case, the variation of voltage can be used to select the color of
the transmitted light. The phase of the light transmitted through
electro-optic cells is also changed by changing the applied voltages; this
phase change may result from a change in refraction or in the path of
light through the electro-optic materials due to the voltage change.
In some variations of the microscope the light source 29 is monochromatic
and the light transmission unit 20 is optimized for the light frequency of
the light source. For example, the light source 29 may be filtered to
produce only blue light and the unit 20 optimized to control blue light.
With use of monochromatic light, higher contrast ratios with nematic
electro-optic material and greater intensity control by voltage variations
with reduced color change are possible.
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