U.S. patent application number 10/359396 was filed with the patent office on 2003-06-19 for 3-d viewing system.
Invention is credited to Takahashi, Susumu.
Application Number | 20030112509 10/359396 |
Document ID | / |
Family ID | 17797786 |
Filed Date | 2003-06-19 |
United States Patent
Application |
20030112509 |
Kind Code |
A1 |
Takahashi, Susumu |
June 19, 2003 |
3-D viewing system
Abstract
A 3-D viewing system is disclosed that enables multiple
operators to share a common objective element while readily
adjusting the orientation of images that are displayed to one or
more moveable display units. The orientation of images that are
displayed at a movable display unit can be made to automatically
depend on the position/orientation of the display unit. Thus,
greater freedom in viewing postures is provided than previously
available in 3-D viewing systems that share a common objective
element, and each operator may view a 3-D image with proper
perspective for his position/orientation. In order to reduce the
number of optical components, the need to adjust optical
components, and reduce costs, images from at least two different
optical perspectives may be time-division multiplexed onto a single
optical detecting device. Moreover, wide-angle, electronic color
displays are disclosed which demodulate time-multiplexed image
signals having two different parallaxes in a manner that dispenses
with the need for wearing polarized glasses in order to experience
a wide-angle, 3-D viewing experience. An electronic image display
unit demultiplexes image data using left and right LED sets that
are energized in sequence to emit up to three color light beams
toward the left and right eyes of a viewer, at a frequency higher
than 30 times per second. The light beams are then modulated with
the image data for that color component using one or more
high-speed, image modulators. Such modulators may be formed of
transmissive or reflective liquid crystals in a known manner, or by
an array of DMD's that are controlled in a binary fashion to
reflect light for a given pixel within or outside an exit pupil of
the display. If DMD's are used as the modulator, the duty cycle for
a given pixel may be controlled in order to provide gradation of
the display brightness for that pixel.
Inventors: |
Takahashi, Susumu;
(Iruma-shi, JP) |
Correspondence
Address: |
Arnold International
P.O. BOX 129
Great Falls
VA
22066
US
|
Family ID: |
17797786 |
Appl. No.: |
10/359396 |
Filed: |
February 7, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10359396 |
Feb 7, 2003 |
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09686976 |
Oct 12, 2000 |
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6525878 |
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Current U.S.
Class: |
359/466 ;
359/462 |
Current CPC
Class: |
G02B 21/361 20130101;
G02B 21/0012 20130101; G02B 21/22 20130101; G02B 2027/0187
20130101; H04N 13/324 20180501; H04N 13/32 20180501; G02B 21/18
20130101; G02B 30/24 20200101; H04N 13/302 20180501; G02B 27/017
20130101; G02B 27/0093 20130101; G02B 30/34 20200101; H04N 13/346
20180501; H04N 13/365 20180501; G02B 2027/0132 20130101; H04N
13/218 20180501; G02B 2027/014 20130101; G02B 27/0176 20130101;
G02B 27/0172 20130101; G02B 2027/0138 20130101 |
Class at
Publication: |
359/466 ;
359/462 |
International
Class: |
G02B 027/22 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 1999 |
JP |
H11-293675 |
Claims
What is claimed is:
1. A 3-D viewing system with which multiple viewers can view
electronic display images of an object while sharing an optical
objective, and wherein at least one of said multiple viewers may
change his position or head orientation while maintaining a
moveable electronic display unit in position for viewing, said
system comprising: an optical objective that is shared among
operators of the 3-D viewing system; an image detecting unit; a
moveable electronic image display unit that displays images which
have been captured by the image-detecting unit; and means to change
images that are displayed by the moveable electronic image display
unit in response to a change in location or orientation of the
moveable electronic image display unit.
2. The 3-D viewing system of claim 1, wherein the means to change
images comprises: an arm that is rotatable about the optical axis
of the optical objective, said arm supporting the moveable
electronic image display unit, a beam-splitting prism, and two
apertures that select light which has been reflected from a surface
of the beam-splitting prism, said two apertures passing light to
the image detecting unit.
3. The 3-D viewing system of claim 2, wherein: said two apertures
are left and right apertures in an aperture plate that is rotatable
about an axis; the moveable electronic image display unit may be
tilted about an axis that is parallel to the axis about which the
aperture plate is rotatable; and the aperture plate is linked to
the moveable electronic image display unit so that tilting the
display unit rotates the aperture plate.
4. The 3-D viewing system of claim 2, wherein the means to change
images comprises: a detecting means for detecting the location or
orientation of the moveable electronic image display unit; and a
changing means for changing the location or orientation of the
image detecting unit in response to a change in location or
orientation of the moveable electronic image display unit.
5. The 3-D viewing system of claim 4, wherein: the moveable
electronic image display unit is separated from the image detecting
unit; and the detecting means uses remote sensing by a navigation
unit to detect the location and orientation of the moveable
electronic image display unit.
6. The 3-D viewing system of claim 5, wherein the moveable
electronic image display unit is head-mounted.
7. The 3-D viewing system of claim 1, wherein the image detecting
unit includes two image detecting devices.
8. The 3-D viewing system of claim 1, wherein the image detecting
unit consists of a single image detecting device and images from
two light paths having different optical perspectives are
time-division multiplexed onto the optical detecting device using a
switching means that is synchronized in operation with the capture
of image data by the optical detecting device.
9. The 3-D viewing system of claim 8, wherein wavelength selective
devices having a characteristic that is controlled as a function of
time are provided in the two light paths in order to time-division
multiplex color image data onto light beams transiting these paths
before the light beams are incident onto the image detecting
device.
10. The 3-D viewing system of claim 1, wherein the images that are
displayed on the moveable electronic image display unit are
monochrome images.
11. The 3-D viewing system of claim 1, wherein color images are
displayed on the moveable electronic image display unit.
12. The 3-D viewing system of claim 1, wherein said moveable
display unit may be moved to a selected one of three angular
positions about the optical axis of said shared optical objective,
said 3-D viewing system including: two image detecting units that
share said optical objective; two optical imaging systems, each
located in optical paths positioned between the shared optical
objective and a respective one of said image detecting units, each
optical imaging system including means to time-multiplex two light
beams that have passed through different apertures onto an optical
path; and means to selectively display image pairs whereby detected
images from four apertures are selectively displayed in pairs on
the moveable electronic image display unit, depending on its
position.
13. The 3-D viewing system of claim 12, wherein: the moveable
electronic image display unit includes left and right eye display
panels; a rotation angle of a rotatable arm that supports the
moveable electronic image display unit is monitored; and the means
to selectively display image pairs selects the inputs to these left
and right display panels depending on the rotation angle of the
arm.
14. The 3-D viewing system of claim 13, wherein the means to
selectively display image pairs includes means to selectively
rotate certain images that are displayed, depending on the rotation
angle of the arm so that the images that are displayed are
displayed with a proper vertical orientation with respect to the
viewer.
15. The 3-D viewing system of claim 9, and further comprising:
means to demultiplex color encoded images from different
perspectives, said means to demultiplex including LED sets and at
least one image modulator that are sequentially energized, in
time-sequence, in order to form image-modulated light beams that
are separately directed to the left and right eye of a viewer, to
thereby enable the viewer to view wide-angle images without
polarized glasses that are perceived as wide-angle, 3-D color
images.
16. The 3-D viewing system of claim 15, wherein said at least one
image modulator is formed of a transmissive, two-dimensional,
liquid crystal array.
17. The 3-D viewing system of claim 15, wherein said at least one
image modulator is formed of a reflective, two-dimensional, liquid
crystal array.
18. The 3-D viewing system of claim 15, wherein said at least one
image modulator is formed of a reflective, two-dimensional, DMD
array.
19. The 3-D viewing system of claim 18, wherein pixel intensity
gradation is provided by controlling the duty cycle that a given
pixel reflects light to the eye during the period that an LED is
energized.
Description
BACKGROUND OF THE INVENTION
[0001] Three-dimensional (3-D) viewing units and electronic image
display units according to the prior art have been described in
Japanese Laid Open Patent Applications H5-107482 and H9-511343. As
described in Japanese Laid Open Patent Application H5-107482,
surgical microscopes that image light fluxes, convert the images
into electrical signals, and then display the images are
advantageous in that a weaker light can be used to illuminate
ophthalmic operations. The weaker illuminating light not only
presents less of a problem if directed directly into a patient's
retina, but it also reduces surface evaporation due to the light at
the illuminated surface being converted into heat. Thus, less
saline solution is needed during an operation to prevent the
operation site from drying out. However, prior art surgical
microscopes using electronic displays retain the following
obstacles to increased usage.
[0002] 1) They provide less freedom to the main operator in his
viewing position and head orientation (hereinafter viewing position
and head orientation will be termed, for convenience, viewing
posture). Further, the assistant operator is provided with very
limited viewing postures, namely, either directly opposite the
operator facing the operator or at the operator's side facing a
direction that makes a right angle to the forward direction of the
operator.
[0003] 2) When the operator and assistant share a common optical
system, the prior art devices require too much adjustment. For
example, when the operator and assistant take side-by-side
positions, they share an optical viewing system between them. Three
optical zoom systems are usually provided in order to offer the
user a selection of magnifications with which to view the
operation. However, it is very difficult to adjust the optical
axis, magnification, and co-focus of the three optical zoom systems
for multiple viewers. Thus, it is desired for surgical microscopes
using electronic displays to provide more freedom in terms of
viewing posture of the operator and assistant without requiring
complex adjustments of the optical system.
[0004] 3) In order that multiple users, such as both the operator
and assistant, can have an independent observation capability,
prior art surgical microscopes that use electronic displays provide
each viewer with an individual imaging system and individual
optical viewing system. However, this results in an increase in
size of the surgical microscope, more difficulty in adjustment, and
greater cost as compared to the present invention.
[0005] In prior art surgical microscopes that provide wide-angle,
3-D images, the viewers must wear polarized glasses as they view a
large display monitor that displays wide-angle images. If polarized
glasses are not used, the left eye receives not only the images
displayed on the monitor intended for the left eye, but also the
images having different parallax that are intended for the right
eye. Similarly, the right eye also sees double images. Thus, rather
than experiencing wide-angle, 3-D images, the viewer experiences
only blurred 2-D images if polarized glasses are not worn. Further,
both wide-angle images and proper eye relief may not be realized at
the same time in prior art devices.
[0006] Prior art devices relating to problems (1), (2), and (3)
above are discussed in more detail below.
[0007] Japanese Laid Open Patent Application H 9-511343 describes a
method to reduce the number of optical zoom systems. However, no
consideration is given to the limited viewing postures available to
the operator and assistant or of giving these viewers more freedom
of viewing posture.
[0008] Japanese Laid Open Patent Application H5-107482 describes an
example of a 3-D viewing system according to the prior art, wherein
two viewers view an operation site from positions that are opposed
to each other. This example is described with reference to FIGS.
20-22. FIG. 20 is a schematic front elevation view of such a
device. FIG. 21 is a side view of the device shown in FIG. 20, and
FIG. 22 is a partial, top view which illustrates the opposed
directions in which the two pairs of monitors are directed. A
microscope body 106' (FIG. 20) comprising an optical system and
imaging section is provided with a viewing section supporting
member 138 (FIG. 21). The viewing section supporting member 138 is
provided with rotation axes 134, 134' for rotationally supporting
the back of viewing sections 130, 130', as well as a first left
monitor 131 for the left eye (FIG. 20) having an eye shade 131a and
a first right monitor 132 for the right eye having an eye shade
132a. These side-by-side monitors are connected to the viewing
section 130' by a rotation supporting member 133 (FIG. 20).
Similarly, a second left monitor 137 for the left eye (FIG. 22) and
a second right monitor 136 for the right eye are provided to the
viewing section 130'. As shown in FIG. 22, the monitors 131, 132
display to the left in the figure and the monitors 136, 137 display
to the right in the figure.
[0009] Therefore, by orienting the detecting devices that are fixed
within the microscope body so that the left and right parallax
images that are detected are displayed with a correct vertical
orientation for the user, each operator is provided with a 3-D
viewing experience using the viewing sections 130, 130'. In this
case, the operators do not need to wear polarized glasses. Rather,
a monitor is provided for each eye, each eye views only its
monitor, and no obstacles to viewing, such as the wearing of
polarized glasses, are present. However, a wide-angle 3-D image is
not obtained and the viewing positions are limited to the opposed
positions illustrated. Viewing at the side of the operator is not
available. Because a user has little freedom in choice of viewing
postures, the viewing experience may be tiresome.
[0010] As mentioned previously, the field of view is limited in
systems that use two display units (for instance the left and right
monitors 131, 132) in order to provide images to the left and right
eyes, respectively. In order to display wide-angle images, both the
left and right display panels would need to be enlarged. However
this would cause the two display panels to physically interfere
with each other. In addition, in this prior art device, each
imaging section is provided with an optical zoom system. Enlarging
these optical zoom systems would likely lead to adjustment problems
and oversized systems.
[0011] Japanese Laid Open Patent Application H5-107482 also
describes another prior art device of a 3-D viewing system, wherein
the operator and assistant view at right angles to each other. This
embodiment is described with reference to FIGS. 23-25. FIG. 23 is a
schematic side view of a prior art 3-D viewing system that shows
how two side-by-side viewers view 3-D images while facing 90
degrees to each other. FIG. 24 is a block diagram of the microscope
body and electric wiring of this device. FIG. 25 is a top view
showing the locations of optical paths P, Q, R (each passing light
of different perspective relative to the operation site) which are
detected by solid-state image detecting devices positioned within
the microscope body 199. As shown in FIG. 23, the microscope body
(not separately labeled in this figure) is fixed to a supporting
arm 156 which is provided with liquid crystal monitors 193, 194.
Being supported so as to be spatially movable, the microscope body
199 (FIG. 24) is provided with an illumination system (not shown),
an objective lens 110, three magnifying systems 161a, 161b, 161c,
and relay lenses 162a, 162b, 162c. Further, a solid-state image
detecting device 200, 201, or 202 is positioned in the optical
paths P, Q, or R (FIG. 25), respectively, with the solid-state
image detecting device 202 having an orientation that is rotated
counter-clockwise 90.degree. relative to the orientation of the
solid-state image detecting device 201.
[0012] In this prior art device, in 3-D image circuit 185A, an
internal switching circuit (not shown) alternates in time sequence
picture signals F1 and picture signals A as input signals to create
time-multiplexed image signals which are output to a liquid crystal
monitor 193. A liquid crystal driving circuit (not shown) drives
electrodes attached to the back surface of the liquid crystal
monitor 193 so as to rotate the polarization of the displayed
images in synchronism with the switching of the switching circuit.
Thus, at the liquid crystal monitor 193, the time-multiplexed
picture signals A detected from the optical path Q and the picture
signals F1 detected from the optical path P are displayed with
different polarizations. By wearing polarized glasses (not shown),
cross-talk between these images is avoided, thereby enabling the
left eye of the viewer to see only those images captured from a
left perspective optical path, and the right eye of the viewer to
see only those images captured from a right perspective optical
path. Thus, a viewer experiences a 3-D viewing sensation of the
operation site 111. In a similar manner, the 3-D image circuit 185B
and the liquid crystal monitor 194, display picture signals F2 on
the optical path P and the picture signals C on the optical path R,
in a time-division manner, with different polarizations. Polarized
glasses worn by the other viewer prevent the images intended for
that viewer's right eye (i.e., the images from a right perspective
optical path) from entering the viewer's left eye, and vice-versa.
Thus, each viewer perceives 3-D images of the operation site 111.
According to this prior art device, three optical viewing paths are
used. One path is observed by one operator, one path is observed by
the other operator, and one path is shared so as to be observed by
both operators. The images on the path they share are processed so
as to present a correct vertical orientation to each operator. Each
operator is provided with two images (one for each eye) having
different parallax, with the display images having a proper
vertical orientation for each viewer's position relative to the
operation site so as to create the perception of viewing a 3-D
image with proper orientation for that viewer's position. In
addition, more free space is available to the operators because the
circuit parts are all stored within tables and the microscope body
may be small, since the optical objective 110 is shared. However,
in this prior art device, the operator and assistant view can only
view from positions such that the directions of view are at a right
angle to each other; thus, the viewing postures are again limited.
In this prior art device, no consideration is given to providing a
pair of liquid crystal monitors that may be adjusted about the axis
of the microscope body so that the monitors are easier to view or
so that the operator's viewing posture may be varied. Furthermore,
an optical zoom system must be provided for each image detecting
device, which makes adjustment troublesome and the size of the
microscope larger. Furthermore, this device requires the operators
to wear polarized glasses, which is inconvenient.
[0013] Japanese Laid Open Patent Application H9-511343 also
describes prior art electronic image input and output techniques
that employ time-multiplexing and demultiplexing. First, the
electronic image input technique in this publication will be
described. A zoom lens is shared in the image input section, and
the left and right images are input in a time-division manner. This
will be described with reference to FIGS. 26 and 27. FIG. 26 is a
schematic diagram showing an improvement in inputting and
outputting electronic images. FIG. 27 is a top view of an optical
path switching element of the prior art device. As shown in FIG.
26, right and left optical paths 101a, 101b and a rotation switch
element 103a are provided. As shown in FIG. 27, the rotation switch
element 103a is structured on a thin glass plate (disk) 105. One of
the major characteristics of the optical paths 101a, 101b is that
the distances along both paths from the object (at the operation
site) to optical zoom system 113 are the same. Similarly, the
distances along both paths from the object to image detecting
device 109 are equal. This results from the symmetry of the two
mirrors 138a, 138b about the center axis of main objective lens
108. Images are captured by the image detecting device 109 in a
time-division manner using the rotation switch element 103a. Next,
the electronic image output technique that is disclosed in this
publication for demultiplexing these time-multiplexed left and
right images will be discussed.
[0014] FIG. 28 is a horizontal sectional view illustrating the
configuration of a device disclosed in the above-mentioned
publication that demultiplexes the two time-multiplexed images. As
shown in this figure, the images are displayed on a single display
which alternately feeds light from the display into to two ocular
lens paths 101c and 101d in synchronism with the displayed images.
In this device, equal length optical paths are realized using a
prism. An optical path switching element 103a allows alternate
images from the display to be transferred to the ocular paths 101c,
101d in a time-division manner. Thus, the left eye of a viewer will
receive only images having a left perspective and the right eye of
a viewer will receive only images having a right perspective if the
motor that drives the optical path switching element 103a is
properly synchronized with the alternately displayed left and right
images on the single monitor. In this manner, a color 3-D viewing
experience may be provided that does not require the viewer to wear
polarized glasses. However, this prior art device can not realize
both a wide-angle field of view and have a large eye relief.
Further, this publication does not disclose, when using
multiplexing/demultiplexing of the images, how two operators (e.g.,
an operator and the assistant) can view an object while sharing a
common optical objective, or how they may change their viewing
postures and have the images that are presented automatically be
adjusted in orientation for the new viewing posture. Therefore, a
surgical microscope which is desirable for operators as described
above is not realized.
BRIEF SUMMARY OF THE INVENTION
[0015] The purpose of the present invention is to provide a 3-D
viewing system for surgical microscopes wherein light flux images
at different locations (i.e., having different parallax) are
transformed into electronic images, which are then displayed on one
or more electronic display units, and in which:
[0016] (1) the operator and assistant are given more freedom in
selecting viewing postures, and there is less adjustment required
by the viewer as a result selecting a different viewing
posture;
[0017] (2) despite there being more freedom in selecting viewing
postures, it is unnecessary to enlarge the microscope body,
resulting in cost savings; and
[0018] (3) an electronic image display unit is provided that
enables wide-angle, color or black and white, images to be viewed
so that wide-angle, 3-D images may be perceived without wearing
polarized glasses.
[0019] Thus, the microscope viewing system of the present invention
is easier to use while providing more freedom of viewing postures
than prior art devices. Further, the microscope viewing system of
the present invention is safer for the patient than microscope
viewing systems that do not use electronic display units.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention will become more fully understood from
the detailed description given below and the accompanying drawings,
which are given by way of illustration only and thus are not
limitative of the 3-D viewing system of the present invention,
wherein:
[0021] FIG. 1 is a side, sectional view of the entire surgical
microscope of Embodiment 1;
[0022] FIG. 2 shows the relationship between electronic display
panels positioned before the left and right eye of a viewer and the
left and right apertures of the surgical microscope of Embodiment
1, as well as of additional embodiments to be discussed below;
[0023] FIG. 3 is a schematic diagram of Embodiment 2 which shows
only the structures which differ from Embodiment 2;
[0024] FIG. 4 is a side, sectional view of a main portion of the
surgical microscope of Embodiment 3;
[0025] FIG. 5 shows, in greater detail and from a different
perspective, the optical system of an image detecting unit that is
used in Embodiment 3;
[0026] FIG. 6 is a side, sectional view of a main portion of the
surgical microscope of Embodiment 4;
[0027] FIG. 7 shows a modified image detecting unit of Embodiment
5;
[0028] FIGS. 8A and 8B show curves of the transmittance t versus
wavelength .lambda. of the devices 29 and 29', respectively, of
Embodiment 5;
[0029] FIG. 9 is a side, sectional view of the entire surgical
microscope of Embodiment 6;
[0030] FIG. 10 is a side, elevation view of the entire surgical
microscope of Embodiment 7;
[0031] FIG. 11 is a side, elevation view of the entire surgical
microscope of Embodiment 8;
[0032] FIG. 12 is a side, sectional view of the entire surgical
microscope of Embodiment 9;
[0033] FIGS. 13A and 13B show the relationship between the display
panels and the images displayed in the surgical microscope shown in
FIG. 12, with FIG. 13A being a top view of the surgical microscope
shown in FIG. 12 and FIG. 13B illustrating the relationship between
the display panels and the images displayed in the surgical
microscope shown in FIG. 12;
[0034] FIG. 14 is a horizontal cross-sectional view of the display
panel of Embodiment 10;
[0035] FIG. 15 is a side, sectional view of the display panel of
Embodiment 11;
[0036] FIG. 16 is a horizontal sectional view of the display unit
shown in FIG. 15;
[0037] FIG. 17 is a horizontal sectional view of the display panel
of Embodiment 12;
[0038] FIG. 18 is a horizontal sectional view of the display panel
of Embodiment 13;
[0039] FIG. 19A is a sectional, side view of the display panel of
Embodiment 14;
[0040] FIG. 19B is a front elevation view of the display panel
shown in FIG. 19A;
[0041] FIG. 20 is a schematic front elevation view of a prior art,
3-D viewing system;
[0042] FIG. 21 is a side view of the system shown FIG. 20,
illustrating how two viewers can view 3-D images in directions that
are opposed to each other;
[0043] FIG. 22 is a partial, top view of the system shown in FIG.
20, illustrating the two opposed directions of the monitor display
surfaces;
[0044] FIG. 23 is a side view of a prior art, 3-D viewing system
showing how two side-by-side viewers can view 3-D images while
facing 90 degrees to each other;
[0045] FIG. 24 is a schematic diagram of a microscope body and the
associated wiring of components of a prior art 3-D viewing
system;
[0046] FIG. 25 is a top view showing the locations of three optical
paths within the microscope body of the prior art 3-D viewing
system shown in FIG. 24;
[0047] FIG. 26 is a schematic diagram showing an improvement in
inputting and outputting electronic images;
[0048] FIG. 27 is a top view of an optical path switching element
of the prior art; and
[0049] FIG. 28 is a horizontal sectional view of a prior art
display that demultiplexes, to left and right oculars, the
time-multiplexed signals displayed on a single electronic image
display device.
DETAILED DESCRIPTION
[0050] The present invention is an improvement in a 3-D viewing
system of a microscope which includes a single optical objective
section that is shared among all users of the microscope, an
optical imaging section, an image detecting unit that detects
images of an object from at least two perspectives, and one or more
electronic display units, wherein optical images that are acquired
by at least one image detecting device in the image detecting unit
are transformed into electrical signals which are then displayed on
one or more electronic display units so as to create a 3-D viewing
experience. The 3-D viewing system is especially useful in viewing
surgical procedures.
[0051] The improvement involves providing the 3-D viewing system
with:
[0052] (a) a moveable electronic image display unit that displays
images which have been captured by the image-detecting unit;
and
[0053] (b) means to change images that are displayed by the
moveable electronic image display unit in response to a change in
location or orientation of the moveable electronic image display
unit.
[0054] The image detecting unit and electronic image display unit
may be mechanically linked so that the image detecting unit is
re-positioned in real time when the electronic image display unit
is re-positioned so as to remain before an observer as the observer
changes viewing postures. Also, the location detecting unit may
employ remote sensing using a prior art navigation system, as will
be discussed below. A selection mechanism, such as a mechanical
clutch or electric switch, may be provided to select among either a
mechanically linked mode or a mode wherein the location of the
electronic image display unit and the location of the image
detecting unit are not mechanically linked. The electronic image
display unit(s) may be separated from the image detecting unit. For
instance, head-mounted image display units which are separated from
the surgical microscope itself, but receive input data via cable or
wireless means from the microscope, may be used. A beam splitter,
(e.g., one formed of a pair of joined prisms, a mirror, a
polarizing beam splitter, and so on), is provided on the optical
path of the optical viewing system. An image detecting unit is
provided on each divided optical path created by the beam splitter.
The beam splitter and the image detecting unit are rotated as a
unit around the optical axis of an optical viewing system.
Furthermore, each image detecting unit conveys images to be
captured that have passed either through a left aperture and a
right aperture, or have been reflected by a left mirror and a right
mirror which similarly confine the light to light bundles having
different perspectives. Images, detected using light from different
perspectives, may be modulated by a modulation device having a
characteristic property, such as its transmission as a function of
wavelength, that is changed sequentially in time in a repeating
fashion.
[0055] Alternatively, four apertures may be provided on one side of
an optical system. Images are then captured from the light passing
these four apertures. Among the captured images, two are selected
and displayed per observer, each after being adjusted in
orientation if needed, in order for the observer to experience 3-D
images that correspond automatically to the view that would be seen
from the observer's position.
[0056] An electronic image display unit may display left and right
images on respective left and right electronic displays,
sequentially on a single, wide-angle, electronic display, or
sequentially on multiple electronic displays arranged either
side-by-side horizontally or stacked vertically for wide-angle
viewing.
[0057] The present invention may employ image modulators selected
from among the following types:
[0058] (1) digital micro mirror devices (hereinafter termed DMD's),
in which tens to hundreds of thousands of micro mirrors, sized from
several microns to several tens of microns, are arranged, for
example, in a two-dimensional matrix. The orientation of the DMD's
may be controlled among two different angles, such as 5.degree. and
15.degree., as determined by the phase of an alternating current
used to drive the DMD's. The micro mirror arrays, preferably, are
driven by an a-c current having a frequency of at least 30 cycles
per second; however, the minimum frequency depends on the
application and may be much higher;
[0059] (2) reflective liquid crystal display units, and/or
[0060] (3) transmission liquid crystal display units.
[0061] Further, the present invention also employs DMD's as an
optical path switching means, for example, to convey light having
two different perspectives to a single image detecting device in a
time-division manner so as to reduce the number of optical
components and decrease cost. By decreasing the number of optical
components, fewer adjustments of optical components are needed.
[0062] For each image display panel, a magnifying lens having a
large aperture may be positioned on the side of the viewer from the
display panel. An eye shade may be provided at the periphery of the
magnifying lens. Eye relief may vary from 10 mm to 100 mm. Left and
right illumination sources, of three different wavelength ranges or
of a single wavelength range, may be energized in synchronism with
left and right images that are displayed by one or more image
modulators in response to image signals received from the image
detection unit(s) so as to produce color or monochrome images.
[0063] Various embodiments of the present invention will now be
described with reference to the figures.
[0064] Embodiment 1
[0065] FIG. 1 is a side, sectional view of the entire surgical
microscope of Embodiment 1 of the 3-D viewing system according to
the present invention. An optical viewing system and an optical
illumination system are provided in the microscope body. The
optical viewing system comprises variable objective lenses 1 and an
optical zoom system 2. In the optical illumination system, light
from a light source (not shown) passes through a light guide 3 and
illuminates the surface of an object via a half mirror 5 after
being adjusted to a desired convergence angle via an illumination
lens 4. Two beam splitters 6, 6 are provided, one for each viewer
(operator and assistant) on the optical axis of the optical zoom
system 2 within the optical viewing system. At least one of the
beam splitters 6,6 (the lower one in this figure) is integrally
fixed within an arm 10. Arm 10 is mounted so as to be rotatable
around the optical axis of the zoom system 2, which substantially
corresponds with the axis of the cylindrical microscope body. Thus,
the lower beam splitter 6 is rotationally mounted relative to this
axis. However, both beam splitters can be mounted so as to be
rotatable about this axis. An aperture plate, having apertures L, R
(see FIG. 2) which pass light for left and right images,
respectively, is provided on the separate optical paths created by
reflection from the beam splitters 6,6. In this embodiment, a
separate image detecting device 7 is provided on each left and
right optical path following each aperture.
[0066] The image detecting devices 7 are electrically connected to
respective, left and right, image display panels (i.e., monitors)
8,8 positioned in front of the viewer's left and right eyes,
respectively, through a cable 9. An operator views electronic
images captured by these pairs of image detecting devices 7. An
image detecting device 7 is positioned in each light path following
each aperture L, R. The captured images are then displayed on the
left and right display panels, with the image data being input to
these display panels through the cable 9. An image detecting device
7' is also provided in the transmitted light path of the
beamsplitters 6,6 (i.e., on the optical path above the two beam
splitters 6, 6) so that a third person can view an electronic image
of the operation site. The light guide 3 used in this embodiment
has a silicon core and fluoroplastic-coated monofilament cladding.
This yields less transmission loss and is advantageous in terms of
brightness because the core of this type of light guide has a
larger effective area as compared with the summation of the
effective areas of the cores of fiber-bundle type light guides.
[0067] As mentioned above, in this embodiment, the moveable arm 10
to the right in this figure, by reason of its design, automatically
aligns the direction of the beam splitter 6 within it, as well as
the left and right apertures within it, with the location of a
viewer about the operation site, so long as the viewer repositions
the arm 10 so as to remain in front of his head as he repositions
himself to a new position. This automatic realignment of the
display images to a proper orientation for the new position of the
viewer occurs as a result of the beamsplitter 6 and display panels
8,8 being integrally mounted within the arm 10 so that they move,
in synchronism with the arm, around the optical axis of the optical
zoom system 2. In this way, when the operator to the right in the
figure changes his viewing position from the illustrated position
opposite the operator on the left to a new position, such as a
position facing the plane of the figure, the operator on the right
will automatically be presented with images appropriate for his new
position. Since the left and right apertures as well as the lower
prism 6 will rotate about the optical axis of the microscope body
as the movable arm rotates about the axis of the microscope body,
the images that are detected will continue to have an appropriate
orientation for the new position.
[0068] Further, the display panels 8,8, on each arm can be tilted,
as illustrated by the arrows in FIG. 2. This allows for greater
viewer comfort, as well as providing a different perspective view
to the object, as will now be discussed. The left and right
apertures L, R are in an aperture plate that is rotationally
mounted about a center axis. Similarly, the left and right display
panels 8,8 are rotationally mounted so as to be rotatable about an
axis that is parallel to the center axis of the aperture plate. The
display panels 8,8 and the left and right apertures are connected
to each other through wires 11 so that a rotation of the display
panels 8,8 causes a rotation of the apertures L, R. The viewer can
select if the wires 11 connect the display panels 8, 8 to the
apertures in order to synchronize their rotation. When they are
connected to each other, the viewer can obtain left and right
images having different parallaxes according to the tilt of the
display panels in front of him.
[0069] Even in the case where one arm 10 is fixed in relation to
the microscope body, both operators (i.e., a main operator and an
assistant), can view electronic images having a perspective
appropriate for each's position. Moreover, each operator can change
his viewing posture, such as the tilt of his head. By merely
repositioning the tilt of the display unit before him to correspond
to his head tilt, the images that are displayed are automatically
adjusted for the new orientation. Thus, the operators can change
their viewpoint to the object without visual confusion because the
images for each operator correspond in perspective to that
operator's position and head orientation. In this embodiment, an
optical focusing system (not shown) is provided after the left and
right apertures for obtaining the left and right images. Because a
common optical zoom system is provided in this embodiment, the left
and right co-focus, magnification, and focus adjustments are easier
than with prior art 3-D viewing systems.
[0070] Embodiment 2
[0071] FIG. 3 is a schematic diagram that illustrates only those
portions of Embodiment 2 that differ from Embodiment 1. In this
embodiment, rather than a common optical zoom system being provided
in the microscope body, individual zoom systems are provided in
each optical path following a left or right aperture. Consequently,
a total of four optical zoom systems are provided for the operator
and assistant. Just as in Embodiment 1, the beam splitter 6 can be
rotated around the optical axis according to the viewer position.
The imaging section in which the left and right optical zoom
systems 2 are mounted can also be rotated around the center axis of
the left and right apertures. In this way, just as was shown for
Embodiment 1, a main operator and an assistant can view images as
if seen from their own position without changing the microscope
body, even if they move their position or change their viewing
posture. As before, the operators can change their viewpoint to the
object without visual confusion because the images are
automatically correlated to the position and orientation of each
operator.
[0072] Embodiment 3
[0073] FIG. 4 is a side, sectional view of a main portion of the
surgical microscope of Embodiment 3 of the 3-D viewing system
according to the present invention. This embodiment is a modified
version of Embodiment 2 shown in FIG. 3. Once more, only the
structure that is different from-that discussed previously is
illustrated. This embodiment comprises, in order from a viewed
object: a half mirror 5, variable objective lenses 1, a beam
splitter 6, image detecting units 14 (each with an optical coupling
means 12 for coupling the optical paths from the left and right
apertures in a time-division manner), an optical zoom system 2, an
optical imaging system 13, an image detecting device 7 (integrally
mounted), and two display panels for the left and right eyes (not
shown). As in FIG. 1, a common objective system 1 and an image
detecting device 7' are provided. As before, the beam splitter 6
for the right viewer is integrally fixed to the arm together with
the display panels (not shown) of image detecting unit 14. The beam
splitter 6 is mounted on the microscope body so as to be rotatable
around the optical axis of the variable objective lenses 1.
However, this embodiment is provided with a DMD array 15 and two,
left and right, mirrors 16 which, as will be described in detail
below with reference to FIG. 5, are used with a DMD array 15 for
coupling the optical paths from the left and right mirrors 16
(which here serve as left and right apertures) in a time-division
manner. The micro mirrors of the DMD are controlled in unison by an
external voltage source to change their inclination angles between
two positions at a high frequency. Thus, the DMD array 15 here
serves as a fast optical path switching means. FIG. 5 is a
schematic diagram showing the configuration of the optical elements
in the image detecting unit 14 according to this embodiment.
[0074] In the image detecting unit 14, the light flux from the beam
splitter 6 is reflected by left and right mirrors 16, 16 onto DMD
15, which acts as a switch to selectively reflect either the light
from the left mirror 16 or the right mirror 16 to the image
detecting device 7 via the optical zoom system 2 and optical
imaging system 13. The micro mirror angles are changed according to
the plus or minus phase of an alternating current power source (not
illustrated) that drives the DMD array in synchonism with
activating the image detecting device 7 to output a detected image.
In this way, the light from one of the left and right light mirrors
16 is alternately guided to the image detecting device 7 and output
to electronic displays (not illustrated in FIG. 4).
[0075] The main operator and the assistant are each provided with
an image detecting unit 14 as shown in FIG. 5. The detected left
and right images, which are detected in a time-division manner by
the image detecting device 7, are displayed on the left and right
display panels by synchronizing the display panel inputs with the
left and right images that are sequentially output by the image
detecting device 7. The frequency of the A-C current driving the
DMD array and the image detecting device 7 is preferably such that
at least 30 images per second are detected by the image detecting
device 7. In a known manner, this enables each display to display
images so that image flicker is not bothersome. The DMD 15 and
image detecting device 7 can be driven at a much higher frequency
than described above, in which case the viewer will never perceive
any image flicker. With this embodiment, as is shown in Embodiment
1, a main operator and an assistant can view images correlated to
their own positions without changing the microscope body when they
move positions. In addition, the operators can change their viewing
postures and the images that are viewed by each will be correlated
to their new viewing postures automatically. Thus, visual confusion
is minimized. Furthermore, with this embodiment, the left and right
co-focus, magnification, and focus adjustments are easier because
only a single optical zoom system is necessary for each operator.
The size and cost are reduced as compared to prior art devices
because only one imaging system 13 and one optical zoom system 2
are necessary for each operator. Cross talk between images intended
for the left and right eyes does not occur because the left and
right images having different parallaxes are displayed on separate
monitors for the left and right eyes.
[0076] Embodiment 4
[0077] FIG. 6 is a side, sectional view of the main portion of the
surgical microscope of Embodiment 4 of the 3-D viewing system
according to the present invention. This embodiment is a modified
version of Embodiment 3, and comprises, in the order from the
viewed object: a half mirror 5, variable objective lenses 1, an
optical reflective member (e.g., a right-angle prism) 17, lower and
upper optical beam splitters 6, 6, and lower and upper image
detecting units 19, 18 on the divided optical paths for the
operator and assistant. In this figure, the upper beam splitter 6
and image detecting unit 18 to the right are integrally mounted to
the right microscope arm and rotate around the optical axis of the
optical viewing system of the microscope body. Each of the image
detecting units 18, 19 is rotated around the optical axis of the
beam splitters 6, 6. The image detecting devices 7 in each of the
image detecting units 18, 19 are connected to two, left and right,
display panels through a cable 9 and the images which are detected
by the image detecting device are displayed on the display panels.
In this figure, the left and right display panels (not shown), the
image detecting unit 18, and the upper beam splitter 6 are integral
to the right arm and thus are rotated with it around the optical
axis of reflected light from the optical reflective member 17.
Thus, when the operator rotates the right arm to a new position,
since the upper beam splitter 6 as well as the left and right
apertures are integral to the right arm, the upper beam splitter 6
and left and right apertures are accordingly rotated, allowing the
operator to view properly oriented left and right images at the new
position.
[0078] As before, when the display panels (not shown in this
figure), are tilted, the image detecting units 18, 19 can be
rotated around the optical axis of light beams that are reflected
by the beam splitter 6 in order to properly orient the displayed
image to the orientation of the display panels. A mechanical or
electrical clutch can be used to engage or release a linkage
between the movements of the display panel and the image detecting
unit. In the imaging units 18, 19, respective optical imaging
systems 20, 21 for changing magnification are provided, as well as
respective image detecting devices 7. The left imaging unit 19
modulates and merges the light from the left and right apertures as
four polarized components after they pass a reflective prism 22 and
polarized beam splitter 23 to direct them into the optical imaging
system 21 for changing magnification. In the optical imaging system
21 for changing magnification, a twisted nematic liquid crystal
cell 24 is provided in order to rotate the polarized light
direction by 90.degree.. This angle is switched between 0.degree.
and 90.degree. by a control means (not shown) using an electric
voltage from an external source. If the liquid crystal cell 24 is a
ferro electric liquid crystal cell, it can be driven at a higher
speed. The imaging unit 19 can thus detect the left and right
images in a time-division manner by driving the liquid crystal cell
24 from the external source synchronously with outputs from the
image detecting device 7.
[0079] As illustrated in FIG. 6, the right imaging unit 18 has a
different configuration from the left imaging unit 19. In the
imaging unit 18, shutter devices 25, 25 are provided on the optical
paths from the left and right apertures. The shutter devices are
controlled by a controller (not shown) so as to be repeatedly
switched between a transmission verses a blocking (i.e., shading)
state so that either one of the left and right images is guided
into a common optical system 20 without being mixed. The shutter
devices 25, 25 are synchronized with the image detecting device 7
so that the image detecting device 7 transmits the left and right
images in an alternate manner. A reflective mirror 26 is positioned
on one of the optical paths from the left and right shutter devices
25, 25 and a beam splitter 27 (which here serves as a beam
combiner) is positioned on the other optical path. In this way, the
left and right light fluxes are guided into one and the same
optical path. In this figure, the operator and assistant have an
optical system with different configurations in their imaging
units. This is merely for the purpose of explanation of multiple
structures that may be selected. As will be apparent to those of
ordinary skill in the art, both the operator and the assistant may
instead be provided with imaging units having the same
configuration. With this Embodiment, just as with Embodiment 1, the
operators (a main operator and an assistant) can view respective
images as is seen from their own position without changing the
microscope body when they move to the opposite position or to the
side position. In addition, the operators can change their
viewpoint to the object without creating confusion as to what they
are viewing because the images that are displayed properly coincide
in orientation with the images as seen from the new viewpoint.
[0080] Furthermore, with this embodiment, as is in Embodiment 3,
the left and right co-focus, magnification, and focus adjustments
are easier because an optical zoom system is provided for each
operator. However, the size and cost are reduced because only one
imaging device and one optical zoom system are needed for each
operator. Cross talk does not occur between the left and right
images because these images are switched in a time-division
manner.
[0081] Embodiment 5
[0082] FIG. 7 is a schematic diagram illustrating Embodiment 5 of
the 3-D viewing system according to the present invention. This
embodiment provides a modified version of the imaging units. The
imaging units of this embodiment include wavelength selective
devices 29, 29' provided at the left and right apertures, which
vary the wavelength of the light that is transmitted in a
time-division manner among three time periods. Thus, the color
components which pass the left and right optical paths via
wavelength selective devices 29, 29' are subject to repeated change
from blue B, to green G, to red R, and back to blue B in a
repeating sequence while they go through the devices 29, 29'. The
wavelength selective devices may be made in many ways apparent to
those of ordinary skill in the art, the easiest solution being
using three different color transmitting filters mounted in a
rotating disk. The detected image signals from the image detecting
device 7 are stored on the memory 30.
[0083] FIGS. 8A and 8B are diagrams showing that the devices 29,
29', respectively, have different transmittances at a given point
in time. The transmittance of the devices 29 and 29' is changed in
a repeating time sequence, as indicated by the arrows, during the
time periods (1), (2) and (3) so that the viewer sees a 3-D view.
For instance, during time period (1) the wavelength transmitted by
the wavelength selective device 29 is the color B and the
wavelength transmitted by the wavelength selective device 29' is
the color G. As a result, the light rays passing along the left and
right optical path via the devices 29, 29' differ from each other
in color during each of the time periods (1), (2), and (3), as
illustrated.
[0084] The imaging unit 28 of this embodiment merges the light
fluxes from the left and right optical paths via a reflective prism
22 and a beam splitter 27 after they have passed the devices 29,
29'. The merged light flux is then imaged onto the image detecting
device 7 via the optical zoom system 2 and optical imaging system
13. The image detecting device 7 may be formed of a color (R, G, B)
CCD array or other known device that captures color images. With
the imaging unit of this embodiment as described above, the merged
left and right images which have been captured by the image
detecting device 7 are reconstructed for each color so as to obtain
left and right display images in full color, as is known in the
art. Thus, both left and right images can be displayed at once,
rather than in a time-division manner as in the Embodiment
above.
[0085] Embodiment 6
[0086] FIG. 9 is a side, sectional view of the entire surgical
microscope of Embodiment6 of the 3-D viewing system according to
the present invention. In this Embodiment, a beam splitter 31 is
positioned behind variable objective lenses 1. An image detecting
unit 32 is positioned on each of the transmission path (left) and
reflective path (right). Optical reflective system 33 is positioned
on the reflective path of the beam splitter 31. In each image
detecting unit 32, a polarized beam splitter 23 is positioned in
each of the left and right image optical paths. The polarized beam
splitters are used in order to modulate the light fluxes on the
left and right optical paths as two linearly polarized light beams
which share a common optical path. The right polarized beam
splitter 23 in each image detecting unit 32 can be replaced by a
reflective member (for instance, a reflective mirror, reflective
prism, or beam splitter) which deflects the optical path to the
left polarized beam splitter 23. In each image detecting unit 32,
an optical zoom system 2 and an optical imaging system 13 are
positioned as components of the common optical system 21 and are
used to adjust the magnification and for imaging, respectively. In
the common optical systems 21, a respective polarized liquid
crystal cell 24 is mounted and is controlled using an external
voltage source to chronologically switch its polarized direction
between 0.degree. and 90.degree.. Each image detecting device 7 is
positioned on the optical path from the common optical system 21.
The image detecting device 7 is synchronized with the switching of
the polarization direction of the polarized liquid crystal cell 24
in order to capture the left and right images in a time-division
manner. The resulting signals are then demultiplexed and displayed
on the left and right display panels. In the figure, only one of
the left and right display panels for each operator is visible in
this side view. The other left and right display panels are
obscured, because they are located behind the plane of the figure.
In this embodiment, rotation motors 34, 34 having encoders for
encoding the rotation of the respective image detecting units 32,
32 are provided for each image detecting unit 32,32. One end of the
arms 39, 39 for the main operator and assistant, respectively, is
rotationally connected to the microscope body 35 through a
respective encoder 36 for detecting the rotational position of the
display panels 8(8) in relation to the microscope body. A display
unit 40 having left and right display panels 8(8) is rotationally
connected to the other end of the arm 39 by its lower part through
the respective encoder 37 for detecting the inclination of the
display panels 8(8) in relation to the lengthwise direction of the
arm.
[0087] The microscope body 35 is provided with a controller 38
which is connected to the image detecting devices 7,7, rotation
motors 34, 34 with encoders 36, 36, 37, 37 through the cables 41,
41, 42, 42, 43, 43, 9, 9, respectively. When the operator (viewer)
rotates the arm 39 in relation to the microscope body 35 to change
the position of the left and right display panels, the encoder 36
detects the position and signals to the controller 38 through the
cable 43. When the display unit 40 having the display panels 8, 8
is rotated in relation to the arm 39 to incline the left and right
display panels, the encoder 37 detects the inclined angle and
signals to the controller 38 through the cable 9. Then, the
controller 38 calculates the rotation of the rotation motor 34 with
encoders based on the rotation direction and angle of the left and
right display panels and rotates the image detecting unit 32 in
response thereto using the rotation motor 34. The image detecting
device 7 in the image detecting unit 32 alternately detects the
left and right images at the rotated position and sends the image
data to the controller 38 through the cable 41. The controller 38
sends the image data to the display panels 38 through the cable 9
and the display panels 8 display this data as images. In this way,
when the operator changes the rotational angle or display panel
inclination in relation to the microscope body, the data on the
rotation and/or inclination is sent to the controller in a
real-time manner. The controller then directs the motors for the
image detecting units to capture images corresponding to the
position. Therefore, images having viewpoints which correspond to
those of the operator are obtained. With this embodiment, as in
Embodiment 1, the operators (a main operator and an assistant) can
obtain images as seen from their own position without changing the
microscope body when they move to the opposite position or the side
position. In addition, by detecting the viewing position of the
operator, by changing the direction of the image detecting unit,
and by appropriately linking the viewing position and the direction
of the image detecting unit, an operator can view images that are
oriented properly for his position automatically.
[0088] Embodiment 7
[0089] FIG. 10 is a side elevation view of the entire surgical
microscope of Embodiment 7 of the 3-D viewing system according to
the present invention. In this Embodiment, unlike Embodiment 6, the
display panels are provided separately from the microscope body.
For instance, as illustrated, they may be independently hung from
the ceiling. The microscope body 35 includes structure as was
illustrated for Embodiment 6 (FIG. 9) but, for clarity of
illustration, is not repeated in FIG. 10, such as the variable
objective lenses, beam splitter, optical reflective system, and two
image detecting units for two viewers. Just as before, the two
viewers can view from positions that vary in location about the
optical axis of the microscope body 35. The rotational directions
of those two image detecting units are controlled independently and
externally through a controller (not shown) provided in the
microscope body 35. As is shown in FIG. 10, the microscope body 35
is suspended from a ceiling 45 through an arm 44. The joints 44a,
44b of the arm 44 which support the microscope body 35 are each
provided with an encoder (not shown).
[0090] The encoders detect the position (inclination, location,
height, and so on) of the microscope body 35 and signal the
position to a controller (not shown) in the microscope body 35. A
display unit 40 for each operator is suspended from the ceiling 45
through an arm 39. The joints 39a, 39b, 39c of the arm 39 which
support the display unit are provided with encoders (not shown).
Those encoders detect the position (inclination, location, height,
and so on) of the display panels 8,8 mounted in the display unit 40
and signal a controller (not shown) in the microscope body 35
through the cable 46. The controller within the microscope body 35
computes, using the data from the encoders in the joints of the
arms 44 and 39 which support the microscope body 35 and the data
from the encoders in the arms which support the display panel
holding member 40, the direction from a particular display panel to
the object being viewed by the microscope. The proper orientation
of the image detecting unit is then determined and corrected in a
real-time manner. The image detecting units can be driven
independently for the operator and assistant. Therefore, two
operators can view at their desired positions while having the
images they each see on the electronic displays automatically
corrected to the proper orientation. Instead of being supported
from the ceiling, the display units 40 can be supported from other
structures, such as a wall, the floor, or an operating table. The
other components of this embodiment are the same as in Embodiment 6
(shown in FIG. 9).
[0091] Embodiment 8
[0092] FIG. 11 is a side elevation view of the entire surgical
microscope of Embodiment 8 of the 3-D viewing system according to
the present invention. This embodiment is a modified version of
Embodiment 7. For clarity, many items are omitted, in that they do
not differ from that of Embodiments 6 and 7. For example, the
microscope body 35 includes, as was illustrated for Embodiment 6
shown in FIG. 9: variable objective lenses, a beam splitter, an
optical reflective system, and two image detecting units for two
viewers that can be rotated around the optical axis of the
microscope body 35 (not shown in FIG. 11). In Embodiment 8, the
display units 47 are separate from the microscope body and are worn
by the operators. With this type of display unit, the operator is
free to move about because the display units are entirely
independent from the microscope body 35. In addition, the arms
which connect the display panels to the microscope are eliminated,
providing more open space. Further, in this embodiment, the means
for detecting the operator viewing position and orientation
consists of, instead of encoders, three light emitting elements 48,
48, 48 fixed on the display unit 47 and navigation units 49, 49
which are mounted on the microscope body 35 to monitor the position
of the light emitting elements using a television camera. The
navigation unit 49 is programmed to detect the operator's viewing
position and head orientation by monitoring the location of the
light emitting elements 48, 48, 48 using a television camera.
Furthermore, if light emitting elements 50, 50 are provided around
the viewed object and monitored by a television camera, the
location of the microscope body 35 can also be also detected. A
similar navigation system is disclosed in U.S. Pat. No. 6,081,367,
the disclosure of which is incorporated herein by reference. As
another navigation system, reflective balls to reflect light can be
used in lieu of using the light emitting elements. Infrared rays
are emitted from the microscope body 35 to the display unit 47 and
the location of the reflective balls which reflect the infrared
rays are monitored by two television cameras so as to detect the
operator's viewing position. In this way, the same effect is
obtained as is described above for the two preceding
embodiments.
[0093] Using the navigation unit 49, the angular positions of the
head-mounted display surfaces relative to the microscope body 35
are monitored. Based on the angular positions obtained, the image
detecting unit can be controlled by being rotated through a driving
member, such as a motor mounted in the microscope body 35, so that
the two separated images that are detected have a parallax
orientation that corresponds to that of the head-mounted display
surfaces. In this way, even if the display units are not held on
the microscope body or an arm as in Embodiment 1, the operators
(main operator and assistant) can obtain images appropriate to
their own position using a single microscope body without changing
the microscope settings. With the benefit of having a means for
detecting each operator's angular position relative to the
microscope body, and a means for changing the angular position of
the image detecting unit in response to that operator's angular
position, each operator (i.e., a main operator and an assistant)
can view images that are automatically oriented properly for the
viewer's position.
[0094] Embodiment 9
[0095] FIG. 12 is a side-sectional view of the entire surgical
microscope of Embodiment 9 of the 3-D viewing system according to
the present invention. In this Embodiment, two optical systems are
actually included within the microscope body 51; however, for
clarity of illustration, only the optical system nearest the reader
is illustrated. Each optical system includes an optical zoom system
2, an imaging lens 13, and an image detecting device 7. These are
positioned sequentially on the optical path of the light flux that
has been merged by the optical path merging means 12. Light fluxes
from the optical path merging means 12 are imaged onto the image
detecting device 7 via the optical zoom system 2 and imaging lens
13. Each optical system also includes variable objective lenses 1,
as well as an illumination system formed of a light guide 3, an
illumination lens 4, and a prism 52. Two apertures, one for the
light that will form the image directed to the left eye, and one
for the light that will form the image directed to the right eye,
are provided for each optical system. Thus, in all, the microscope
body 51 contains four apertures that pass light from the object to
the two image detecting devices 7. The optical path merging means
12 consists of a DMD 15 and two mirrors 16,16 that are positioned
on the object side of the optical zoom system 2. The optical path
merging means 12 guides alternate, left and right images having
different parallaxes to the optical zoom system 2 in a
time-division manner. Thus, the two optical systems allow four
images having different parallaxes to be imaged using two image
detecting devices 7,7. In this embodiment, two mirrors 16, 16 for
each optical system are fixed in position so that, using the two
optical systems, two assistants can view images at predetermined
viewing positions that are at 90.degree. or 180.degree. to the
direction in which the main operator looks to view the operation.
However, no images at positions intermediate to these positions are
available. However, this embodiment provides a significant
improvement to that of the prior art devices, in that two viewing
positions relative to the viewing position of the operator are
provided, namely, opposite the operator or at the side of the
operator, without changing or adjusting the microscope body. In
FIG. 12 the arm 53, which holds the display unit 40 having the
display panels 8(8) for the operator (i.e., the arm on the right
side of the figure), is fixed to the microscope body 51. Thus, the
right display panels 8, 8 are at the fixed location in relation to
the axis of the microscope body.
[0096] FIG. 13A is a schematic diagram of the components of the
microscope body of this embodiment as viewed from above, with the
illustrated components having the same reference numerals as those
shown in FIG. 12. Thus, a separate description of these components
will be omitted.
[0097] FIG. 13B is an illustrative diagram of the cylindrical
microscope body (item 51 of FIG. 12) as seen from above. For ease
of description, the circle in FIG. 13B representing the microscope
body as seen in cross-section will be momentarily considered as
representing instead the face of a clock. Thus, the display unit
(represented by a rectangle) positioned at the top of the figure
will be termed the display at the 12 o'clock position. Similarly,
the display unit represented by the rectangle to the left in the
figure will be termed the display unit at the 9 o'clock position,
and the display unit represented by the rectangle at the bottom of
the figure will be termed the display at the 6 o'clock
position.
[0098] Within the circular area of the microscope body, FIG. 13B
accurately relates the positions of the four mirrors 16 shown in
FIG. 13A (each mirror receiving light flux having different
parallax due to the differing positions of the four mirrors 16), to
the light fluxes A, B, C, D shown within the circular microscope
body illustrated in FIG. 13B. This can be verified by noting the
one-to-one correspondence between the four positions of the mirrors
16 in FIG. 13A within the circular microscope body and between the
four positions of the light fluxes A, B, C, D within the circular
microscope body shown in FIG. 13B. However, in the event the light
fluxes A, B, C, D are detected using image detecting devices that
are oriented with "up" facing the 12 o'clock position, it is
apparent that the direct outputs of the pairs of image detecting
devices will yield left and right images having proper "up"
orientation only in the case of detecting the light fluxes C and D,
which light flux images are displayed on monitors C and D located
at the 6 o'clock position.
[0099] If data from the image detecting devices that detect light
fluxes A and C is fed to a display unit positioned at the 9 o'clock
position or if data from the image detecting devices that detect
light fluxes A and B is fed to a display unit positioned at the12
o'clock position as illustrated in FIG. 13B, the display images at
the 9 o'clock and 12 o'clock positions would be oriented
improperly. Thus, it is apparent that these display images need to
be reoriented in rotation relative to the detected light fluxes in
order to yield a proper view of the scene for a person standing or
sitting and facing the display units.
[0100] Thus, the display images at the 9 o'clock position need to
be rotated clockwise 90 degrees and the display images at the 12
o'clock position need to be rotated 180 degrees in order to present
a proper orientation of the operation being viewed. Of course, all
the image-detecting units need not be aligned in a single
direction. In fact, the most desirable arrangement, in terms of
reducing the number of display images that need to be rotated, is
to have the "up" direction of the image detecting devices that
detect light fluxes A and B be reversed to that discussed above. In
this case, only the images for the display unit at the 9 o'clock
position need to be rotated, but in this case the rotation
direction is no longer 90 degrees clockwise for both display
images, as discussed above. Rather the left display image needs
instead to be rotated 90 counter-clockwise.
[0101] In this manner, display images having the proper orientation
and parallax for the position from which they are viewed are
automatically obtained for the present embodiment as follows. The
arm 54 (FIG. 12) which provides support for the display panels 8, 8
for the operator on the left side of FIG. 12 is coupled to the
microscope body 51 through rotational encoder 55. The rotational
encoder 55 detects the permissible rotational positions for this
embodiment (0.degree., -90.degree. or +90.degree.) of the arm 54
relative to the microscope body 51 and signals the detected
position to a controller 56. If a rotational position (0.degree.)
of the arm 54 is detected, indicating that the assistant is
positioned at the 6 o'clock position of FIG. 13B with the arm 54
(FIG. 12) directly opposite the operator (fixed arm 53 as
illustrated in FIG. 12), the controller 56 sends the image
information to the display panels 8, 8 so as to display the images
as shown in bottom part of FIG. 13B (i.e., the left and right
images are derived directly from image detectors C, D,
respectively).
[0102] On the other hand, if a rotational position (-90.degree.) is
detected, the controller 56 sends the image information to the
display panels 8,8 shown at the 9 o'clock position in FIG. 13B,
using image detectors A, C. In order to obtain proper orientation
of the images for this observation site, the images A, C are first
stored to a memory (not shown) and the detected data is read out so
that the images A, C, are rotated 90.degree. so as to display a
properly oriented image, as discussed above. The controller 56 also
sends the image information to the display panels 8, 8 located at
the 12 o'clock position (i.e., the stationary position of arm 53
(FIG. 12). Thus, the controller serves to select the image
information to be sent to the left and right display panels and to
control the rotation angle and direction of the images to be sent
to the left display panels in order to provide images having
different, left and right parallaxes, and with the proper
orientation. In this embodiment, two sets of time-division
multiplexing optical systems, each formed of a DMD array, a mirror,
and having a zoom capability, are provided. The captured images are
selected and, if necessary, properly rotated before being displayed
in accordance with signals which are sent by the means for
detecting the position of the display panels. Thus, an assistant
and an operator can obtain 3-D images displayed with proper
orientation at his position using a single microscope body, and
proper images for a different position can be obtained
automatically when the assistant moves to the opposed position or
to a side position. Furthermore, cross talk does not occur between
the two displayed images because they are displayed in a
time-division manner.
[0103] If an optical path merging system consisting of a DMD array
and a mirror is provided in addition to the two sets of optical
path merging systems 12,12 to merge the optical paths for a main
operator and an assistant, it is possible that light fluxes
including four different parallaxes are passed through a single
optical zoom system in a time-division manner. Controllers can be
used to store the images, select the desired images, and adjust the
orientation of the images, if needed, so that they are displayed
with proper orientation on the display panels.
[0104] Embodiments 10 to 14, to be discussed in detail later,
involve modifications which relate to various types of display
panels. In Embodiments 10 to 14, a large aperture lens is used
which conveys left and right images having different parallax to
the left and right eyes, respectively, of the user. In Embodiment
10 (FIG. 14) a single display panel is used in lieu of separate
display panels, as described above. However, prior art display
units of this type either do not provide sufficient eye relief, or,
do not provide wide-angle views. Thus, wide-angle display units
which are easy to view were not obtained. The reason for this is
because either the eye relief is insufficient, or the left and
right optical paths are mixed, resulting in cross-talk between
images intended for the left and right eyes. In the prior art, the
left and right images are displayed in a time-division manner on a
display panel and the operator must wear a pair of polarized
glasses in order to insure that the images intended for the left
and right eyes, respectively, do not reach the other eye. However,
wearing polarized glasses is cumbersome, and portions of the
display may actually be obscured by the frames of the glasses.
Embodiments 10 to 14 provide 3-D viewing for an operator and
assistant(s) that yield wide-angle images and a large eye relief
without need for wearing polarized glasses. In addition, the 3-D
viewing system is compact and relatively inexpensive.
[0105] Embodiment 10
[0106] FIG. 14 is a horizontal cross-sectional view of the display
panel of Embodiment 10 of the 3-D viewing system according to the
present invention. As mentioned above, this embodiment uses a
single display panel 57 formed using a two-dimensional array of
DMD's 58, with each individual micro mirror being controllable
between two angular positions. One the two positions for each DMD
reflects incident light rays, for a given light source, so as to be
viewable by the observer. The other of the two positions reflects
incident light rays, for a given light source, so as to not be
viewable by the observer. On the DMD panel 57, the images for the
left and right eyes are displayed alternately in a time-division
manner using the output of an image detecting unit (not shown). In
front of the DMD's 58, a large lens system 59 having a large
aperture is positioned for magnifying the images. On the left and
right sides of the large lens system 59 are provided: a focusing
lens 60; blue B, green G, and red R light source LED's 61; and, in
front of the LED's 61, a diffusion plate 62. All of these face
toward the DMD panel 57. The DMD panel 57 operates as follows. The
image intended for the right eye is displayed on the DMD panel 57
at a certain point in time, during which time the controller 38
turns on the LED's 61 for the right eye (for instance, the LED's 61
on the right side in the figure). The LED's 61 illuminate the
entire display surface of the DMD panel 57 through the diffusion
panel 62 and the focusing lens 60. The DMD's 58 are driven by the
control signals from the controller 38 to reflect the incident
illumination light received via the focusing lens 60 toward the
large aperture lens system 59 (formed of lenses 59a, 59b) so as to
form an image nearly at the right eye point. Consequently, when the
viewer's right eye is precisely in a region near the right eye
point, the viewer sees a bright display image. In fact, nearly all
of the emitted light that is reflected by the display surface
enters the viewer's right eye and is imaged onto the retina. Thus,
the image may be too bright. In order to provide a wider exit
pupil, and at the same time to reduce the intensity of the image
that is seen by the viewer, a diffusion plate 62 is used. With it,
bright images having an even illumination can be viewed with ease,
since the wider exit pupil no longer requires the observer's right
eye to be precisely aligned near the right eye point. Therefore,
the viewer can view images without a sudden change in brightness
even when the viewer moves his head relative to the right eye
point.
[0107] During the following time-division sequence, the image for
the left eye is displayed on the DMD panel 57. LED's 61 for the
left eye (for instance, those on the left side in the figure) are
energized and the inclination angle of the micro mirrors of the DMD
58 is switched so that the light is directed only toward the left
eye of the viewer. The LED's 61 for the left eye and the micro
mirrors of the DMD 58 are controlled by the controller 38 in the
same way as for the right eye. Thus, both the left-eye images and
the right-eye images are displayed on the same display. By the
repeated, high-speed switching of the LED's on both sides of the
display and by the rapidly controlled inclination angles of the
micro mirrors of the DMD, 3-D images are perceived due to the left
eye and right eye displays providing images having different
parallax. Since the LED's and DMD's can be operated at high
frequencies, no flicker of the images is perceived despite the
images being presented in a time-division manner. Not only is there
no flicker, there is also no interference or cross talk between the
left and right images. In this manner, a single display panel is
used and it is viewed through a large aperture lens so that
wide-angle images are achieved. Since the left and right images are
displayed on the display panel in a time-division manner,
overlapping of the light paths for the left and right eyes, as is
present in prior art displays that provide a large eye relief, is
avoided. Thus, with this embodiment, a microscope display having
both a wide-angle of view and a large eye relief is realized.
[0108] However, if too large an eye relief is selected, the
microscope may become oversized. Thus, a lesser eye relief may be
desirable; for example, one having an eye relief in the range from
10 mm to 100 mm. In this embodiment, when the image for one of the
eyes (for instance, the right eye) is displayed on the display
panel by the controller 38, each color B, G, R of the LED's 61 is
energized in synchronization with the respective B, G, R image
components being displayed on the display panel. For intensity
gradation of the displayed images, the duration during which the
micro mirrors of the DMD reflect the rays to a desired eye point
may be adjusted for each pixel, for example, while the LED's 61
emit the color B. Because the DMD's 58 can be operated at a very
high frequency, switching control of the micro mirrors enables
control of gradation of the displayed color images. The large
aperture lens 59 of this embodiment is a combination of a plastic
Fresnel lens 59a and a glass lens 59b. This enables both a thinner
and lighter design. A Fresnel lens is also used for the diffusion
panel 62 at each side of the illumination system. More than one
color of the LED's 61 may be energized at a given time. This, in
turn, enables a larger exit pupil to be used, which makes viewing
even easier. An eye shade 63 is provided around the large aperture
lens 59 of the display unit in this embodiment. The eye shade 63 is
similar to a flange and its purpose is to prevent light sources
behind the viewer's head from being incident on the display and
then reflected into the viewer's eyes. With such a configuration,
an electronic image display unit can be realized according to the
present invention wherein both an operator and an assistant can
view wide-angle, 3-D images having a large eye relief from
arbitrary positions, while using a common microscope objective
portion which reduces the cost and size of the 3-D viewing
system.
[0109] Embodiment 11
[0110] This embodiment is a modified version of Embodiment 10. FIG.
15 is a side, sectional view of the display panel of Embodiment 11
of the 3-D viewing system according to the present invention. FIG.
16 is a horizontal sectional view of the display unit shown in FIG.
15. In this embodiment, two sets (left and right) of red R, green
G, blue B LED's 61,61 and diffusion plates 62, 62 are provided
above a DMD display panel 57 in order to create images for the left
and right eyes, respectively. A curved mirror 64 is provided above
a large aperture lens 59 for reflecting the light from the two sets
of LED's 61,61 (FIG. 16) and the two diffusion plates 62,62 to the
DMD display panel 57. The light emitted from a set of the LED's 61
is diffused by a respective diffusion plate 62, reflected on the
mirror 64, and is then directed to the DMD display panel 57. The
light from the sequentially energized left and right sets of LED's
61 is then reflected on the DMD's 58 in order to be modulated with
image information upon reflection and pass, via the large aperture
lens 59 to the viewer's right and left eyes, respectively. As is
shown in FIG. 16, the diffusion plate 62 allows imaging using a
larger pupil. In this embodiment, the DMD panel 57 displays the
right eye image when the right eye LED's 61 (those on the left side
in FIG. 16) are energized, and it displays the left eye image when
the left eye LED's 61 (those on the right side in FIG. 16) are
energized. By performing this alternate display and switching at a
high speed, an electronic image display for a surgical microscope
can be realized wherein wide-angle, 3-D images are displayed
without flicker on a display having a large eye relief. In this
Embodiment, the micro mirrors of the DMD 58 are driven to change
their inclination angles in a binary manner at a high frequency in
order to direct the light incident thereon from the left and right
LED's 61 to the upper and lower part of the magnifying lens 59. The
magnifying lens 59 focuses the light guided onto its upper and
lower parts onto the viewer's left and right pupils, respectively.
The large aperture lens 59 in this embodiment is formed of a
plastic Fresnel lens. Unlike Embodiment 10, this embodiment uses a
mirror 64, instead of a focusing lens 60, to illuminate the DMD's.
The micro mirrors of the DMD are driven so as to reflect the light
either upward and downward. Furthermore, the large aperture lens
once again allows the use of a compact DMD display panel 57. Other
features of this embodiment do not differ from those in Embodiment
10.
[0111] Embodiment 12
[0112] FIG. 17 is a horizontal sectional view of the display panel
of Embodiment 12 of the 3-D viewing system according to the present
invention. In this embodiment, a display panel 65 is formed using a
reflective liquid crystal display. Two rows of red, green and blue
LED's 61,61, each followed by a diffusion panel 62, are provided on
the same side of the display panel 65. In front of the diffusion
panel 62, an aperture plate 66 having apertures for passing light
directed to a respective eye of the viewer is provided. Further, a
single Fresnel lens 67 is provide which gathers the light fluxes
restricted by these apertures and focuses them so as to illuminate
the entire surface of the display panel 65. A polarized beam
splitter 68 is positioned in front of the Fresnel lens 67. The
polarized beam splitter 68 reflects predetermined polarized
components of the light which has passed through the Fresnel lens
67 in order to illuminate the front surface of the display panel
65, and transmits other predetermined polarized components of the
light reflected from the display panel 65 in order to guide the
light to the large aperture imaging lens 59.
[0113] The large aperture imaging lens 59 then images the light
onto the viewer's left and right eye's. In this embodiment, the
reflective liquid crystal of the display panel 65 can rotate the
polarized direction of the incident light by 0 or 90 degrees. The
left and right LED's 61 are controlled so as to be energized
sequentially in a time-division manner. Therefore, among the left
and right light beams which have been reflected on the polarized
beam splitter 68 and reached the display panel 65, only those
pixels in which the direction of polarization has been selectively
rotated by the display panel 65 can be pass the polarized beam
splitter 68 and reach the viewer's eyes. Although not illustrated,
the display panels 65 are controlled by electrical signals so as to
display images received from one or more image detecting devices in
a time-division fashion, so that 3-D image color images are
perceive by the viewer without wearing polarized glasses.
[0114] The operation of the display unit of this embodiment will
now be described. The left and right images are switched by the
polarized beam splitter 68. The R, G, B LED's 61 are illuminated
sequentially, giving different color properties for the left and
right images. Being synchronous with the LED's, images for the left
and right eyes are displayed by the reflective liquid crystal 65
for each color. As for gradation, the reflective duration of each
pixel of the reflective liquid crystal in the display panel is
controlled to adjust gradation while each color of the LED's 61 is
illuminated. With this embodiment, using the reflective display
panel and the left and right light sources, the left and right
images are displayed on a single display in a time-division manner.
Polarized glasses are not needed, and a compact 3-D display that
provides wide-angle views and a large eye relief is achieved. The
display panel 65, instead of being formed of a reflective-type
display as described above, may instead be an R, G, B matrix
structure, in which case, LED's 61 would preferably all emit white
light. In this embodiment the light sources are provided
side-by-side. However, the same effects can be obtained when they
are stacked vertically.
[0115] Embodiment 13
[0116] FIG. 18 is a horizontal sectional view of the display panel
of Embodiment 13 of the 3-D viewing system according to the present
invention. In this embodiment, a transmissive liquid crystal
display panel is used in lieu of the reflective liquid crystal
display panel that was used in Embodiment 12. Left and right sets
of R, G and B LED's 61 are provided, as well as a diffusion panel
62, a focusing lens 69, and the transmissive liquid crystal display
panel 70. A large aperture lens system 71 is provided that is
formed of a large aperture imaging lens and, closer to the eyes, a
large aperture magnifying lens. The imaging lens focuses the images
from the left and right sets of LED's 61 onto the left and right
eyes, respectively. The illumination is effectively gathered into
the pupils of the observer and thus bright images are formed.
Further, cross talk is prevented in that light intended for the
left eye does not reach the right eye and vice versa. The left and
right sets of LED's 61 are energized by a controller 38. In
synchronism with the LED's being energized, left and right image
information is input to the display panel 70 so that the incident
light is modulated by the display panel 70. High speed switching of
the left and right LED's 61 and image displays on the display panel
70 enables the images to be displayed without flicker. When the
transmission-type display panels are used as in this embodiment,
the display panels themselves can have R, G, B color mosaics, in
which case all the LED's 61, preferably, are selected to emit white
light.
[0117] Embodiment 14
[0118] FIG. 19A is a sectional, side view of the display unit of
Embodiment 14 of the 3-D viewing system according to the present
invention, and FIG. 19B is a front elevation view of the display
panels shown in FIG. 19A. The display unit of this embodiment can
employ a DMD display panel, a reflective-type liquid crystal
display panel or a transmissive-type liquid crystal display panel.
This embodiment differs from those presented earlier in that three
horizontally-elongated display panels 72.sub.1, 72.sub.2, and
72.sub.3 are used with respective large aperture lenses 73.sub.1,
73.sub.2 and 73.sub.3.
[0119] Here, the LED's, diffusion panels, and so on, are not
illustrated for clarity of explanation of the operation of the
components that are illustrated. In this embodiment, the
horizontally elongated display panels 72.sub.1, 72.sub.2 and
72.sub.3 illuminate respective large aperture lenses 73.sub.1,
73.sub.2 and 73.sub.3 so as to create images that are stacked
vertically. This arrangement, as shown in FIGS. 19A and 19B,
provides a large eye relief as well as a wide-angle of view. In a
known manner, the electical signals input to the horizontally
elongated display panels 72.sub.1, 72.sub.2 and 72.sub.3 are such
that the upper third of the image is input to display panel
72.sub.1, the middle third of the display image is input to display
panel 72.sub.2 and the lower third of the display image is input to
display panel 72.sub.3. If the upper and lower display panels
72.sub.1 and 72.sub.3 project fluxes to the eye of the viewer
having a diameter that allows the pupil of the eye to remain within
these light fluxes even as the eyeball rotates in its socket as the
observer looks upward or downward, the observer can view not only
images of wide angle in the horizontal direction, but also images
of wide angle in the vertical direction.
[0120] The invention being thus described, it will be obvious that
the same may be varied in many ways. Such variations are not to be
regarded as a departure from the spirit and scope of the invention.
Rather the scope of the invention shall be defined as set forth in
the following claims and their legal equivalents. All such
modifications as would be obvious to one skilled in the art are
intended to be included within the scope of the following
claims.
* * * * *