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`US005585967A
`5,585,967
`[11] Patent Number:
`United States Patent
`Monroe
`[45] Date of Patent:
`Dec. 17, 1996
`
`
`[19]
`
`[54] THREE DIMENSIONAL VIRTUAL IMAGE
`SYSTEM
`
`[75]
`
`Inventor: Marshall M. Monroe, Glendale, Calif.
`-
`.
`-
`[73] ASSlgnee'
`'é‘ngaltmsney Company, Burbank
`'
`
`[21] Appl. No.: 118,384
`,
`Filed:
`
`[22]
`
`Sep. 7, 1993
`
`4,799,765
`11/1989 Ferrer ...................................... 350/174
`
`11/1989 Ber-man .. .. 358/242
`4,879,603
`4,900,133
`2/1990 Berman ......
`2.. 350/346
`
`4,971,312 ““990 Wélmelch -------------- 272/8
`
`..
`4,973,951
`11/1990 Slugeta et a1.
`340/717
`.
`4,987,410
`1/1991 Berman et a1.
`340/705
`
`2/1991 Vetter ................... 352/69
`4,991,955
`
`.. 353/31
`4,995,718
`2/1991 Jachimowicz ..
`
`3/1993 Watanabe et a1.
`5,190,286
`
`3/1993 Yajima ................'. 359/54
`5,191,450
`
`6/1993 Dote ............. 273/85
`5,221,083
`
`5,264,881
`11/1993 Brooke
`...... 353/94
`
`4/1994 Dolgoff ..
`5,300,942
`...... 345/32
`11/1995 Gale ........................................ 353/119
`5,467,154
`
`OTHER PUBLICATIONS
`»
`Scientific American, v61, 254, Jun. 1986, Jearl Walker, “The
`Amateur Scientist; Mirrors Make a Maze SO Bewilden'ng
`That The Explorer Must Rely On A Map,” pp. 120—126.
`Primary Examiner—Georgia Y. Epps
`Assistant Examiner—Ricky Mack
`Attorney, Agent, or Firm—Hecker & Ham'man
`
`'
`_
`.5
`Int' CL """""""""""""" G02B 27/14’ G033 21,32"
`G03B 21/26; G03B 21/28
`[52] US. Cl. .......................... 359/629; 359/636; 359/630;
`,
`359’633; 352/86; 353/94; 353/98? 353/99
`[58] Fleld of Search .................................. 352/69, 70, 57,
`352/86; 353/947 98’ 99’ 6! 7’ 10; 354/112,
`113, 117; 359/462, 464, 466, 471, 629,
`633, 634, 636, 618, 630
`
`[51]
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`[57]
`
`ABSTRACT
`
`4,084,194
`4,129,365
`4,189,145
`4,232,968
`4,306,768
`4,378,955
`4,403,216
`4,535,394
`4,568,080
`4,589,659
`4,641,918
`
`358/254
`. ..
`4/1978 Hector
`
`12/1978 Aversno ........... 353/99
`
`”1930 sulbben Eta]
`273/313
`
`11/1980 Kempf ........
`.. 356/393
`12/1981 Egging .............
`350/174
`
`4/1983 Bleha, Jr. et a1,
`.. 350I334
`
`
`9/1983 Yokoi
`...............
`340/705
`8/1985 Dngre ......
`362/231
`
`2/1986 Yokoi
`.........
`273/}
`
`5/1986 Yokoiet al.
`273/1
`.
`2/1987 Moffatt ...................................... 352/69
`
`A method and apparatus for display of a three dimensional
`virtual image is provided. The present invention allows one
`or more objects, real
`images and virtual
`images to be
`displayed at one or more of an arbitrary number of depth
`-
`1
`-
`-
`-
`-
`levels along a v1ewer 8 km of SIght. The present Invennon
`“565 f“ plurality °.f bear.“ Splitter? :rganized as an 01m.“
`labynnth to combme 8. Images wit
`the. proper perspective
`and parallax to result In a three dlmenswnal image.
`
`28 Claims, 6 Drawing Sheets
`
`106
`
`704
`
`
`
`Cirque du Soleil My
`Cirque du Soleil My
`Call, L.L.C.
`Call, L.L.C.
`Ex. 1004
`EX. 1004
`
`Page 1 of 14
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`US. Patent
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`Dec.17, 1996
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`Sheet 1 of 6
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`5,585,967
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`US. Patent
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`Dec. 17, 1996
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`Sheet 2 of 6
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`5,585,967
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`US. Patent
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`Dec. 17, 1996
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`Sheet 3 of 6
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`5,585,967
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`FIG. 3/1
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`F/G. 35’
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`US. Patent
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`Dec. 17, 1996
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`Sheet 4 of 6
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`402
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`502
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`403
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`470
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`404
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`FIG. 4
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`US. Patent
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`Dec. 17, 1996
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`Sheet 5 of 6
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`5,585,967
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`US. Patent
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`Dec. 17, 1996
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`Sheet 6 of 6
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`5,585,967
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`F/G. 8
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`FIG. 9
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`

`1
`THREE DEVIENSIONAL VIRTUAL IMAGE
`SYSTEM
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates to virtual image systems.
`2. Background Art
`It is diificult to display three dimensional images on most
`present display devices. Images may be displayed on a two
`dimensional display device such as a CRT, and the images
`may be displayed in perspective so as to give the appearance
`of three dimensions. However,
`the image size must be
`adjusted to provide perspective. Portions of an image
`intended to appear more distant must be reduced in size
`relative to portions intended to appear closer. While two
`dimensional images in perspective may have the correct
`proportions to simulate three dimensional images, they do
`not provide parallax. Without the proper parallax, a viewer
`can easily distinguish a two dimensional image in perspec-
`tive from a true three dimensional image.
`Other approaches have been used to provide parallax as
`well as proportion. Mirror mazes or labyrinths have been
`constructed to provide the illusion of hallways, rooms and
`other objects in locations where they did not actually exist.
`An article entitled “The Amateur Scientist; Mirrors Make a
`Maze So Bewildering That the Explorer Must Rely on a
`Map” by Jearl Walker on pages 120-126 of Scientific
`American, volume 254 (June 1986) discloses a number of
`mirror labyrinths and method for designing and analyzing
`mirror labyrinths. The mirror labyrinths are constructed
`using mirrors aligned along the edges of equilateral
`tri-
`angles. Thus, the mirrors meet each other at angles that are
`multiples of 60°. The mirrors produce regularly repeated
`images around the borders of a “hallway” when viewed from
`the proper location and direction. The image that appears at
`the distant end of a “hallway” can be controlled. However,
`traditional mirror labyrinths do not provide for images
`having some degree of transparency to be interposed
`between the viewer and the distant end of a “hallway” such
`that objects at the distant end of the hallway can still be seen
`through the interposed images. Furthermore, traditional mir-
`ror labyrinths do not allow images to pass through mirrors
`and do not provide images originating behind exterior
`mirrors to be seen within the labyrinth.
`Other approaches have been used to simulate stereo
`vision, where each eye sees a difl’erent image so as to
`provide a three dimensional eifect. One prior art method of
`providing stereo vision involved a viewer with spectrally
`filtered eyeglasses viewing an image having spectrally
`encoded stereo information. For this approach, the viewer
`wears eyeglasses that typically have a red lens over one eye
`and a green or blue lens over the opposite eye. The viewer
`views an image that includes a left component and a right
`component. The left component is of the color of the lens
`covering the left eye, while the right component is of the
`color of the lens covering the right eye. The left component
`provides the left eye with a view representative of what the
`left eye would see if the image were three dimensional. The
`right component provides the right eye with a view repre-
`sentative of what the right eye would see if the image were
`three dimensional. The views seen by the right and left eyes
`are mentally combined to form a three dimensional percep-
`tion of the image. However, since colors are used to encode
`stereo vision information, the colors of the image must be
`carefully controlled, and the image cannot be naturally
`
`5,585,967
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`2
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`colored. Thus, while the images may appear three dimen-
`sional, they are unnaturally colored. Furthermore, the three
`dimensional effect is lost unless the viewer wears the filter»
`ing eyeglasses.
`Another approach involves the viewer wearing orthogo-
`nally oriented polarizing filters over each eye. An image
`having stereo vision information encoded with orthogonal
`polarization is viewed by the viewer. Stereo vision infor-
`mation relevant to the left eye is encoded with a polarization
`matching the polarization of the lens over the left eye, while
`stereo vision information relevant to the right eye is encoded
`with a polarization matching the polarization of the lens over
`the right eye. Thus, the left and right eyes receive their
`respective stereo vision information, which is mentally
`combined to form a three dimensional perception. However,
`the three dimensional effect is lost unless the viewer wears
`cross polarized eyeglasses.
`Another approach involves a viewer wearing (liquid crys-
`tal display) LCD shuttered eyeglasses and viewing an image
`that alternates between a left component and a fight com-
`ponent while the LCD shutters alternate between blocking
`vision of the right eye and left eye, respectively. The
`eyeglasses contain individually controllable LCD shutters
`over the left eye and over the right eye. The eyeglasses are
`used to view a display device, such as a cathode ray tube
`(CRT) that can rapidly change the image it is displaying.
`When the display device displays a left component of stereo
`vision information, the LCD shutter over the left eye is
`opened and the LCD shutter over the right eye is closed.
`When the display device displays a right component of
`stereo vision information, the LCD shutter over the right eye
`is opened and the LCD shutter over the left eye is closed.
`Thus, the left and right eyes receive their respective left and
`right components of stereo vision information. The left and
`right components of stereo vision information are combined
`mentally to form a three dimensional perception. However,
`the three dimensional effect is lost unless the viewer wears
`the LCD shutter eyeglasses.
`One method of the prior art for causing a semi-transparent
`image to appear in front of a background is known as
`“Pepper’s Ghost” and involves reflecting an image from a
`beam splitter placed in front of a scene. “Pepper’s Ghost”
`provides only a single reflection. It does not allow multiple
`planes of transparent images. Furthermore, it cannot produce
`images that pass through each other in a direction parallel to
`the optical path to the viewer. Also, to produce expansive
`three dimensional images, the “Pepper’s Ghost” technique
`requires a large three dimensional volume.
`Another prior art method has been used for displaying the
`image of an object located behind a beam splitter. This
`method involves placing an object in an opaque enclosure
`having one side constructed of a beam splitter. A lamp that
`, may be dimmed is placed inside the enclosure to illuminate
`the surface of the object facing the beam splitter. When the
`lamp is 011",
`the object is not visible from outside the
`enclosure, and the beam splitter appears to be a mirror when
`viewed from the outside. When the lamp is on, the object can
`be seen through the beam splitter. This method does not
`allow multiple images to be superimposed on one another.
`This method cannot provide multiple planes of transparent
`images. Also, this method does not allow the image to be
`made to disappear without reverting to a mirror condition.
`Additionally, this method cannot produce images that pass
`through each other in a direction parallel to the optical path
`to the viewer. Furthermore, to provide large expansive three
`dimensional images, this technique requires a large three
`dimensional volume.
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`5,585,967
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`3
`SUMMARY OF THE INVENTION
`
`The present invention provides a method and apparatus
`for displaying three-dimensional virtual images. The present
`invention provides perspective and parallax automatically
`without adjusting the actual size of images to be displayed.
`The present invention provides stereo vision perceptual cues
`without the need for special eyeglasses or lenses over the
`eyes. The present invention allows multiple planes or vol—
`umes of semitransparent two or three dimensional images to
`overlap and/or pass through each other, even in directions
`towards and away from the viewer. The present invention
`also allows images beyond the walls of a labyrinth to seem
`to appear and disappear within the labyrinth. Furthermore,
`the present invention may be used to produce the perception
`of a deep volume while occupying only a compact space.
`In the present invention, a series of beam splitters is
`configured as
`an optical
`labyrinth whereby multiple
`extended optical paths are constructed by positioning the
`beam splitters in planes that include the sides of equilateral
`triangles. The equilateral triangles are positioned adjacent to
`one another so as to create a network of equilateral triangles
`having common sides. By positioning objects, images or
`animated sequences of images behind the beam splitters and
`selectively lighting each of them, optical paths that appear to
`contain partially transparent images in three dimensions can
`be created. Several images can be simultaneously displayed
`in different regions of three dimensional space. An optical
`labyrinth provides a carefully planned path for light rays, but
`it need not have the form of a physical labyrinth.
`In the preferred embodiment of the present invention, a
`series of beam splitters is used to construct an optical
`labyrinth. The beam splitters are two-way mirrors that differ
`from regular mirrors in that they have a coating, such as a
`partially silvered coating,
`that reflects a portion of the
`incident light striking the front surface, but also allows a
`portion of the incident light striking the rear surface to be
`transmitted through the two-way mirror. This property of
`beam splitters also allows them to be used as beam com-
`biners. A first light beam can be reflected by the beam
`splitter, and a second light beam can be transmitted through
`the beam splitter. If the angles of reflection and transmission
`are properly aligned, light from the first and second light
`beams can be combined to form a third light beam. By
`controlling the amount of incident light on each side of the
`beam splitter,
`the images seen from each side can be
`controlled. In the preferred embodiment of the present
`invention, both sides of the beam splitters are maintained
`relatively unilluminated, while the images to be presented
`are illuminated. The beam splitters are positioned in planes
`that contain the common sides of a grid of adjacent equi-
`lateral triangles. Objects for producing images are posi-
`tioned exterior to the labyrinth at locations relative to the
`beam splitters that result in the appearance of the objects at
`the desired location along an optical path.
`Light from the object intended to have the most distant
`appearance radiates from that object and is reflected by a
`beam splitter placed in front of the object intended to have
`the second most distant appearance. In addition to reflecting
`the light from the object intended to have the most distant
`appearance, the beam splitter placed in front of the object
`intended to havethe second most distant appearance also
`transmits light from the object intended to have the second
`most distant appearance through the beam splitter and into
`the optical path toward the viewer. The light from both the
`object intended to have the most distant appearance and the
`object intended to have the second most distant appearance
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`is then reflected by a beam splitter positioned in front of an
`object intended to have the third most distant appearance. In
`addition to reflecting the light from the more distant appear-
`ing objects, the beam splitter in front of the object intended
`to have the third most distant appearance transmits the light
`from the object intended to have the third most distant
`appearance through the beam splitter and into the optical
`path toward the viewer. This process continues with subse-
`quent beam splitters with the light from additional objects or
`images being added to the optical path directed toward the
`viewer. Ultimately, light from all of the objects or images
`reaches the viewer, and the viewer sees a composite image
`that includes the light from all of the objects or images. The
`light from the various objects or images is additively com-
`bined, causing the images to appear to be superimposed
`upon one another. Since light from the various objects and
`images travels diflerent distances before reaching the
`viewer, the various images appear in perspective and with
`parallax at their respective apparent distances. The images
`can also be made to move and to pass through each other by
`moving their positions relative to their respective beam
`splitters. Thus, the disadvantages of the prior art have been
`overcome.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1A is a cross section of the preferred embodiment of
`the present invention.
`_ FIG. 1B is a cross section illustrating the apparent
`arrangement of the embodiment of FIG. 1A as viewed by
`viewer 101.
`FIG. 2A is a cross section of an alternate embodiment of
`the present invention.
`FIG. 2B is a cross section illustrating the apparent
`arrangement of the embodiment of FIG. 2A as viewed by
`viewer 201.
`FIG. 3A illustrates a cross section of an alternate embodi-
`ment of the present invention.
`FIG. 3B is a cross section illustrating the apparent
`arrangement of the embodiment of FIG. 3A as viewed by
`viewer 301.
`
`FIG. 4 is a cross section of an embodiment of the present
`invention with a large angle of incidence.
`FIG. 5 is a cross section of an embodiment of the present
`invention with a large angle of incidence.
`FIG. 6 is a cross section of an embodiment of the present
`invention with small angles of incidence.
`FIG. 7 is a cross section of an embodiment of the present
`invention with small angles of incidence.
`FIG. 8 is a cross section of a beam splitter of the present
`invention showing angles of incidence, reflection, and trans-
`mission.
`
`FIG. 9 is a cross section of an embodiment of the present
`invention that allows incandescent and ultraviolet (UV)
`lighting effects to be combined.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`A method and apparatus for displaying a three dimen-
`sional virtual image are described, In the following descrip-
`tion, numerous specific details are set forth in order to
`provide a more thorough understanding of the present inven-
`tion, It will be apparent, however, to one skilled in the art,
`that the present invention may be practiced without these
`
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`5,585,967
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`5
`specific details, In other instances, well-known features have
`not been described in detail in order not to unnecessarily
`obscure the present invention,
`In the past, it has not been possible to display a three
`dimensional virtual image that can include visual compo-
`nents derived from different sources, each of which can be
`individually controlled, such that the components appear
`superimposed on each other with the proper perspective and
`parallax. Such a display system would be useful for enter—
`tainment, production of animated sequences and three
`dimensional imaging applications, such as architecture and
`engineering. Therefore, there is a need for such a system.
`The present invention avoids these problems by using
`beam splitters oriented to allow multiple images to be
`introduced into an optical path to a viewer with the appear»
`ance that the images are at different distances from the
`viewer. The beam splitters allow transmission of light from
`a light source through the beam splitter and reflection of
`light from an incident optical path to a reflected optical path.
`If the light source producing the light transmitted through
`the beam splitter is aligned properly, the transmitted light
`can be made to join the reflected optical path. Thus, a viewer
`of the reflected optical path Will see the transmitted light
`from the light source superimposed on the incident light
`from the incident optical path. By combining the light from
`all light sources, the viewer will see a composite image with
`light from each of the light sources superimposed. on the
`light from the other light sources. The composite image
`provides the correct perspective and parallax to show the
`three dimensional relationship between the light sources.
`Each eye sees the correct component of stereo vision infor-
`mation. Thus, stereo vision is provided.
`FIG. 1A illustrates the preferred embodiment of the
`present invention. Viewer 101 is positioned in front of an
`optical labyrinth. The optical labyrinth is comprised of an
`assembly of beam splitters that includes beam splitters 111,
`112, 113, 114, 115, 116, 117 and 118. The beam splitters are
`oriented at angles that are multiples of 60° to each other.
`Objects 102, 103, 104, 105, 106, 107, 108, 109 and 110 are
`positioned at locations around the beam splitter assembly. A
`first optical path is comprised of light rays 119, 120, 121,
`122, 123. A second optical path is comprised of light rays
`124, 125, 126, 127 and 128. Light rays 129, 130, 131 and
`132 from objects 103, 104, 105 and 106, respectively, are
`added to the first optical path before the first optical path is
`viewed by viewer 101. Light rays 133, 134, 135 and 136
`from objects 103, 108, 109 and 110 are added to the second
`optical path before the second optical path is viewed by
`viewer 101.
`
`Viewer 101 may be one or more humans, animals, video
`cameras, movie cameras, still cameras, any other cameras or
`photosensitive devices, such as one or more photodiodes,
`phototransistors, photoresistive elements, photovoltaic cells
`or charge coupled devices (CCDs), or a combination of any
`of the above. The vision or photosensitivity of viewer 101
`may be directed toward beam splitter 114 or toward beam
`splitter 118.
`The ambient illumination level of the elements in FIG. 1A
`is maintained substantially in darkness, although the present
`invention may also be practiced with other ambient illumi-
`nation levels. Objects 102, 103, 104, 105, 106, 107, 108, 109
`and 110 may be physical objects or may be real or virtual
`(i.e. apparent) images. One or more of the objects may be
`replaced by another virtual image display system according
`to the present invention that is located so as to put the
`position where a viewer of the second display system would
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`be at the position where the object to be replaced would be.
`Alignment of the angles of the light rays should be main—
`tained if such a replacement is to be made. The light rays that
`would have entered the viewer of the second display system
`should be collinear with the light rays that would have left
`the object to be replaced.
`Beam splitters 111,112, 113, 114, 115, 116, 117 and 118
`may be partially silvered mirrors or other optical elements
`providing partial transmission and partial reflection. Beam
`splitters may be constructed on transparent substrates of
`glass, plastic, such as acrylic, polycarbonate or mylar, or any
`other suitable optical material. Beam splitters have a first
`surface and a second surface. The first and second surfaces
`may be substantially coplanar. For example, a partial coating
`of a metallic substance, such as silver, aluminum, nickel or
`some alloy, may be deposited on one side of a transparent
`glass substrate using an electroplating process, vapor depo-
`sition process, electron beam deposition process, ion depo-
`sition process, sputtering process, or some other suitable
`process. An anti-reflective coating may be applied to the
`opposite side of the glass substrate. A beam splitter thus
`constructed includes the metallic layer and has one surface
`adjacent to the glass substrate and another surface opposite
`the glass substrate. It is desirable to keep the metallic layer
`thin so as to make the two surfaces substantially coplanar. It
`is also desirable to reduce reflections from the opposite side
`of the substrate, such as by applying an anti-reflective
`coating. These measures help assure good image quality.
`Beam splitters are available with different levels of trans—
`mittance and reflectance. For example, a 50% transmittance/
`50% reflectance beam splitter transmits 50% of the incident
`light and reflects 50% of the incident light. The present
`invention may be practiced with 40% transmittance/60%
`reflectance beam splitters, although by controlling the light-
`ing, beam splitters having a wide range of transmittance and
`reflectance characteristics may be used. Difierent beam
`splitters within a single embodiment may also have diiferent
`transmittance and reflectance characteristics.
`
`Light rays 119 from object 102 are reflected by beam
`splitter 111. Light rays 129 from object 103 are transmitted
`through beam splitter 111 and join the reflection of light rays
`119 to form light rays 120. Light rays 120 are reflected by
`beam splitter 112. Light rays 130 from object 104 are
`transmitted through beam splitter 112 and join the reflection
`of light rays 120 to form light rays 121. Light rays 121 are
`reflected by beam splitter 113. Light rays 131 from object
`105 are transmitted through beam splitter 113 and join the
`reflection of light rays 121 to form light rays 122. Light rays
`122 are reflected by beam splitter 114. Light rays 132 from
`object 106 are transmitted through beam splitter 114 and join
`the reflection of light rays 122 to form light rays 123. Light
`rays 123 are visible to viewer 101.
`Light rays 124 from object 107 are reflected by beam
`splitter 115. Light rays 133 from object 103 are transmitted
`through beam splitter 115 and join the reflection of light rays
`124 to form light rays 125. Light rays 125 are reflected by
`beam splitter 116. Light rays 134 from object 108 are
`transmitted through beam splitter 116 and join the reflection
`of light rays 125 to form light rays 126. Light rays 126 are
`reflected by beam splitter 117. Light rays 135 from object
`109 are transmitted through beam splitter 117 and join the
`reflection of light rays 126 to form light rays 127. Light rays
`127 are reflected by beam splitter 118. Light rays 136 from
`object 110 are transmitted through beam splitter 118 and join
`the reflection of light rays 127 to form light rays 128. Light
`rays 128 are visible to viewer 101.
`Since light rays originating beyond objects 102, 103, 104,
`105, 106, 107, 108, 109 and 110 may join the optical path
`
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`toward viewer 101, any extraneous light sources should be
`controlled to avoid interference. It is preferable to surround
`the sides of objects 102, 103, 104, 105, 106, 107, 108, 109
`and 110 away from the optical labyrinth with a light shield—
`ing material, such as an opaque black curtain. Other means
`of controlling ambient and extraneous light may be used.
`FIG. 1B is a cross section of the apparent arrangement of
`the embodiment of HG. 1A as viewed by viewer 101. If
`viewer 101 looks in a first direction, viewer 101 secs objects
`102, 103, 104, 105 and 106. Object 106 appears in the
`foreground, with object 105 behind object 106, object 104
`behind object 105, object 103 behind object 104, and object
`102 behind object 103. If viewer 101 looks in a second
`direction, viewer 101 sees objects 107, 103, 108, 109 and
`110. Object 110 appears in the foreground, with object 109
`behind object 110, object 108 behind object 109, object 103
`behind object 108, and object 107 behind object 103. Since
`object 103 is viewed from diflerent angles when viewer 101
`is looking in the first direction than when viewer 101 is
`looking in the second direction, the image of object 103 that
`appears behind object 104 may be different than the image
`of object 103 that appears behind object 108.
`By changing the positions of the objects relative to the
`beam splitters, the apparent positions of the objects can be
`altered. The apparent distance of the objects from the viewer
`can be changed in this manner. Objects can be made to
`appear to move closer to the viewer or farther from the
`viewer. Objects can even be made to appear as if they are
`moving through other objects. Thus, the apparent order of
`the objects can be changed. For example, by moving object
`104 away from beam splitter 112 along an extension of the
`line of light rays 130, object 104 can be made to appear as
`if it is moving farther from viewer 101. As object 104 is
`being moved away, at some point object 104 will appear to
`move through object 103. If object 104 is moved farther
`away, object 104 will appear to be positioned between
`objects 102 and 103. Other objects can be moved in other
`directions for other similar effects.
`
`When viewer 101 is looking in the first direction, an
`image of object 102 is reflected by beam splitter 111. and an
`image of object 103 is transmitted through beam splitter 111.
`The combined image of objects 102 and 103 is reflected by
`beam splitter 112, and an image of object 104 is transmitted
`through beam splitter 112. The combined image of objects
`102, 103 and 104 is reflected by beam splitter 113, and an
`image of object 105 is transmitted through beam splitter 113.
`The combined image of objects 102, 103, 104 and 105 is
`reflected by beam splitter 114, and an image of object 106
`is transmitted through beam splitter 114. The combined
`image of objects 102, 103, 104, 105 and 106 travels along
`optical path 123 to viewer 101 and appears to viewer 101 as
`a composite three dimensional image.
`The optical path does not pass through beam splitters 111,
`112, 113 and 114 at a perpendicular angle. Rather, beam
`splitters 111, 112, 113 and 114 are slanted 30° relative to
`perpendicular. Beam splitter 111 is slanted at 30° angle 15].
`Beam splitter 112 is slanted at 30° angle 152. Beam splitter
`113 is slanted at 30° angle 153. Beam splitter 114 is slanted
`at 30° angle 154.
`The center of object 102 is located distance 137 away
`from the center of beam splitter 111. The center of object 103
`is located distance 138 away from the center of beam splitter
`111. The center of beam splitter 111 is located distance 139
`away from the center of beam splitter 112. The center of
`object 104 is located distance 140 away from the center of
`beam splitter 112. The center of beam splitter 112 is located
`
`10
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`15
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`20
`
`25
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`30
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`35
`
`4O
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`45
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`50
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`55
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`60
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`65
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`8
`distance 141 away from the center of beam splitter 113. The
`center of object 105 is located distance 142 away from the
`center of beam splitter 113. The center of beam splitter 113
`is located distance 143 away from the center of beam splitter
`114. The center of object 106 is located distance 144 away
`from the center of beam splitter 114. The center of beam
`splitter 114 is located distance 145 away from viewer 101.
`When viewer 101 is looking in the second direction, an
`image of object 107 is reflected by beam splitter 115, and an
`image of object 103 transmitted through beam splitter 115.
`The combined image of objects 107 and 103 is reflected by
`beam splitter 116, and an image of object 108 is transmitted
`through beam splitter 116. The combined image of objects
`107, 103 and 108 is reflected by beam splitter 117, and an
`image of object 109 is transmitted through beam splitter 117.
`The combined image of objects 107, 103, 108 and 109 is
`reflected by beam splitter 118, and an image of object 110 is
`transmitted through beam splitter 118. The combined image
`of objects 107, 103, 108, 109 and 110 travels along optical
`path 128 to viewer 101 and appears to viewer 101 as a
`composite three dimensional image.
`Object 107 appears to be located distance 146 away from
`viewer 101. Object 103 appears to be located distance 147
`away from viewer 101. Object 108 appears to be located
`distance 148 away from viewer 101. Object 109 appears to
`be located distance 149 away from viewer 101. Object 110
`appears to be located distance 150 away from viewer 101.
`Although the present invention may be practiced over a
`wide range of dimensions, the dimensions of the preferred
`embodiment are given as an example. Distance 150 is 4.5
`feet (approximately 1.37 meters). Distance 145 is 4 feet
`(approximately 1.22 meters). Distance 144 is 0.5 feet
`(approximately 0.15 meters). Distance 149 is 6.5 feet
`(approximately 1.98 meters). Distance 143 is 2 feet
`(approximately 0.61 meters). Distance 142 is 0.5 feet
`(approximately 0.15 meters). Distance 148 is 8.5 feet
`(approximately 2.59 meters). Distance 141 is
`1
`foot
`(approximately 0.30 meters). Distance 140 is 1.5 feet
`(approximately 0.46 meters). Distance 147 is 10.5 feet
`(approximately 3.20 meters). Distance 139 is
`3
`feet
`(approximately 0.91 meters). Distance 138 is 0.5 feet
`(approximately 0.15 meters). Distance 146 is 12.5 feet
`(approximately 3.81 meters). Distance 137 is 2.5 feet
`(approximately 0.76 meters).
`FIG. 2A is a cross section of an alternate embodiment of
`the present invention. Viewer 201 views an optical path
`comprising light rays 211, 212, 213, 214 and 215. Objects
`202, 203, 204, 205 and 206 may be any objects or real or
`virtual images.
`Light rays 211 from object 202 are reflected by beam
`splitter 207. Light rays 216 from object 203 are transmitted
`through beam splitter 207