U.S. patent application number 13/547923 was filed with the patent office on 2012-11-01 for 3d volumetric display.
Invention is credited to Martina Dreyer, Gerald K. Newman, Erik Petrich, Hakki H. Refai, James J. Sluss, JR., Monte P. Tull, Pramode Verma.
Application Number | 20120274907 13/547923 |
Document ID | / |
Family ID | 38656143 |
Filed Date | 2012-11-01 |
United States Patent
Application |
20120274907 |
Kind Code |
A1 |
Refai; Hakki H. ; et
al. |
November 1, 2012 |
3D Volumetric Display
Abstract
A light surface display for providing a three-dimensional image
having a volumetric display, a first projection system, and a
second projection system. The first projection system projects
electromagnetic energy into the volumetric display sequentially
along the length and width of the volumetric display in a series of
2D image slices. The second projection system projects
electromagnetic energy in a series of slices along the depth of the
volumetric display. Particles intersected by the first and second
wavelengths form illuminated two-dimensional cross sections at
specific locations in the volumetric display.
Inventors: |
Refai; Hakki H.; (Tulsa,
OK) ; Petrich; Erik; (Norman, OK) ; Sluss,
JR.; James J.; (Broken Arrow, OK) ; Tull; Monte
P.; (Oklahoma City, OK) ; Verma; Pramode;
(Tulsa, OK) ; Newman; Gerald K.; (Norman, OK)
; Dreyer; Martina; (Norman, OK) |
Family ID: |
38656143 |
Appl. No.: |
13/547923 |
Filed: |
July 12, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13289487 |
Nov 4, 2011 |
8247755 |
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13547923 |
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12950716 |
Nov 19, 2010 |
8075139 |
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13289487 |
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11789767 |
Apr 25, 2007 |
7858913 |
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12950716 |
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60794901 |
Apr 25, 2006 |
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60796249 |
Apr 28, 2006 |
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60854557 |
Oct 26, 2006 |
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Current U.S.
Class: |
353/10 ; 353/121;
977/774; 977/952 |
Current CPC
Class: |
G02B 30/50 20200101;
G03B 21/26 20130101; H04N 13/39 20180501; G03B 35/20 20130101 |
Class at
Publication: |
353/10 ; 353/121;
977/774; 977/952 |
International
Class: |
G03B 21/14 20060101
G03B021/14 |
Claims
1. A method of producing at least one three-dimensional image,
comprising the steps of: a. projecting electromagnetic energy of
one or more first wavelengths into a volumetric display
sequentially along the length and width of the volumetric display
in a series of 2D image slices; b. projecting electromagnetic
energy of one or more second wavelengths in a series of slices
along the depth of the volumetric display whereby particles
intersected by the first and second wavelengths form illuminated
two-dimensional cross sections at specific locations in the
volumetric display; c. synchronizing the projection of
electromagnetic energy along the length and width of the volumetric
display with the projection of electromagnetic energy along the
depth of the volumetric display for a pre-determined length of time
to form an illuminated three-dimensional image.
2. The method of claim 1, wherein the volumetric display remains
static while forming the illuminated three-dimensional image.
3. The method of claim 1, wherein projection of electromagnetic
energy of one or more wavelengths is performed by a first
projection system including a single digital light processor.
4. The method of claim 3, wherein power of a first projection
system is modulated to provide variable brightness of the
image.
5. The method of claim 3, wherein the projection of electromagnetic
energy of one or more wavelengths along the depth of the volumetric
display is performed by a second projection system including a
single digital light processor having a digital micromirror device
with an array of micromechanical mirrors.
6. The method of claim 5, further comprising the step of dithering
the micromechanical mirrors to provide variable brightness of the
image
7. The method of claim 1, further comprising the step of providing
a pre-determined time-delay before intersecting the energized
particles through projection of electromagnetic energy of one or
more wavelengths along the depth of the volumetric display.
8. The method of claim 1, wherein the particles are supported by an
aerogel matrix.
9. The method of claim 1, wherein the particles are substantially
uniformly suspended.
10. The method of claim 1, wherein the optical illusion of movement
is selected from the group consisting of full rotating screen, half
rotating screen, two Archimedes spirals rotating around a common
center, and single spiral rotating screen.
11. A light surface display for providing a three-dimensional
image, comprising: a plurality of particles dispersed within a
volumetric display; a first projection system projecting
electromagnetic energy of one or more first wavelengths into the
volumetric display sequentially along the length and width of the
volumetric display in a series of 2D image slices; a second
projection system projecting electromagnetic energy of one or more
second wavelengths in a series of slices along the depth of the
volumetric display whereby particles intersected by the first and
second wavelengths form illuminated two-dimensional cross sections
at specific locations in the volumetric display; a control system
synchronizing the projection of electromagnetic energy along the
length and width of the volumetric display with the projection of
electromagnetic energy along the depth of the volumetric display
for a pre-determined length of time to form an illuminated
three-dimensional image.
12. The display of claim 11, further comprising a medium
substantially transparent and dispersed within the volumetric
display wherein the particles are dispersed within the medium.
13. The display of claim 12, wherein the medium is an aerogel
matrix.
14. The display of claim 12, wherein at least a portion of the
aerogel medium is composed of an inorganic substance.
15. The display of claim 12, wherein at least a portion of the
aerogel medium is composed of an organic substance.
16. The display of claim 12, wherein the medium is an xerogel
matrix.
17. The display of claim 16, wherein at least a portion of the
xerogel matrix is composed of an inorganic substance.
18. The display of claim 16, wherein at least a portion of the
xerogel matrix is composed of an organic substance.
19. The display of claim 12, wherein the medium is a transparent
glass ceramic matrix composed of an organic substance.
20. The display of claim 11, wherein the particles are quantum
dots.
21. The display of claim 11, wherein the particles are upconversion
materials.
22. The display of claim 21, wherein the upconversion materials
includes a host material doped with a sensitizer and rare-earth
ions.
23. The display of claim 22, wherein the sensitizer is
Ytterbium.
24. The display of claim 22, wherein the rare-earth ions are
lanthanides.
25. The display of claim 11, wherein the particles are upconversion
materials dispersed within an aerogel matrix.
26. The display of claim 25, wherein the display produces a
polychromatic three-dimensional image.
27. The display of claim 11, wherein the first projection system
includes at least one digital light processing projector.
28. The display of claim 11, wherein the second projection system
includes at least one digital light processing projector having a
digital micro-mirror device containing an array of micromechanical
mirrors.
29. The display of claim 28, wherein the micro-mirror device is
used in dithering the translational slices of electromagnetic
energy.
30. The display of claim 11, wherein the first projection system
projects wavelengths for a pre-determined amount of time prior to
the second projection system projecting wavelengths intersecting
the energized particles.
31. The display of claim 11, wherein power of the first projection
system is modulated to vary the intensity of electromagnetic energy
of the wavelengths along the length and width of the volumetric
display.
32. The display of claim 11, wherein the first projection system
includes a beam steering system for directing the wavelengths of
the first projection system.
33. The display of claim 11, wherein the control system is in
communication with an external source to download images.
34. The display of claim 11, further comprising a housing
supporting the volumetric display.
35. The display of claim 34, wherein the housing includes an
electromagnetic radiation filter.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No.
13/289,487 Filed Nov. 4, 2011 which is a continuation of U.S. Ser.
No. 12/950,716 Filed Nov. 19, 2010, now U.S. Pat. No. 8,075,139,
which is a continuation of U.S. Ser. No. 11/789,767 Filed Apr. 25,
2007, now U.S. Pat. No. 7,858,913, which claims priority under 37
C.F.R. 119(e) to U.S. Provisional application Ser. No. 60/794,901,
entitled COLORFUL TRANSLATIONAL LIGHT SURFACE 3-D DISPLAY, filed
Apr. 25, 2006, U.S. Ser. No. 60/796,249, entitled COLOR
TRANSLATIONAL 3-D VOLUMETRIC DISPLAY, filed Apr. 28, 2006, and U.S.
Ser. No. 60/854,557, entitled 3-D LIGHT SURFACE DISPLAY, filed Oct.
26, 2006, each of which is hereby incorporated by reference in its
entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
REFERENCE TO A "SEQUENCE LISTING", A TABLE, OR A COMPUTER PROGRAM
LISTING APPENDIX SUBMITTED ON A COMPACT DISC AND AN INCORPORATION
BY REFERENCE OF THE MATERIAL ON THE COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] Technological advances of the last decade have made
scientists and engineers increasingly aware of three dimensional
imaging as both viable and realistic. There is now widely
acknowledged incentive, both commercially and industrially, for
developing a color 3-D display system that can be viewed from
unencumbered perspectives. Recent developments using
micro-materials and nanostructure materials offer possibilities for
creating novel optically-writable displays that are efficient and
robust.
[0006] The three-dimensional displays currently available in the
market, including static-volume displays and swept-volume displays,
purport to construct three-dimensional images which are uniform in
a 3-D image space and viewable from practically any orientation. In
practice, these technologies have not fully achieved their
objectives and possess several drawbacks including low resolution
and translucent image representations.
[0007] Accordingly, a three dimensional imaging system and method
of using the imaging system to provide better-quality images, as
compared with the currently available technologies, will provide a
commercially and industrially marketable product.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention is related to a light surface display
for providing a three-dimensional image. In general, the light
surface display includes a plurality of particles suspended within
a volumetric display, that when energized by electromagnetic energy
of two or more wavelengths, illuminate to form a three dimensional
image.
[0009] In one embodiment, the light surface display includes a
first projection system projecting wavelengths forming sequential
slices of a two-dimensional image along the length and width of the
volumetric display, and a second projection system projecting
wavelengths forming translational slices across the depth of the
volumetric display. A control system synchronizes the projections
of the first projection system and the second projection system so
that the wavelengths forming the two-dimensional image and the
translational slices energize the particles in the volumetric
display for a pre-determined length of time. The energized
particles illuminate to form a three-dimensional image. The light
surface display may produce a monochromatic or polychromatic image
depending on the particular wavelength of electromagnetic energy
and/or the types of particles utilized.
[0010] The particles within the volumetric display preferably
include selectively-activated light sources activated by the
incidence of one or more directional light sources such as lasers,
coherent LED's, or the like. For example, particles may include
micro and/or nano particles such as quantum dots, upconversion
materials, or similar particles as long as the particles are
selectively-activated by the incidence of a directional light
source.
[0011] In one version, the first projection system projects
wavelengths for a pre-determined amount of time prior to the second
projection system in order to vary the color and/or intensity of
each particle. The power of the first projection system may also be
modulated to vary the intensity of the electromagnetic energy in
order to vary the relative brightness of each particle.
Additionally, the projection systems may include digital light
processing projectors having digital micro-mirror devices
containing an array of micromechanical mirrors. The micromechanical
mirrors may be used in a plurality of array groups for dithering
the translational slice to alter the relative brightness or color
depth of each particle that represents a voxel.
[0012] The control system may optionally interface with an external
source in order to provide images to the light surface display. The
external source may include a computer, a processor, a game
console, the Internet or the like.
[0013] In another embodiment, the light surface display further
comprises a housing containing the volumetric display and/or
projection systems. In addition to providing support for the
volumetric display and/or projection systems, the housing provides
an element of safety in securing the particles against outside
contact with the user or spectator if needed. Additionally, the
light surface display can include a filter, such as an
electromagnetic radiation filter, preventing exposure of
non-visible radiation to the user or spectator.
[0014] In another embodiment, the light surface display further
comprises a medium that is substantially transparent and dispersed
within the volumetric display. Preferably, the suspension of the
particles is substantially uniform throughout the medium. The
medium may be formed of high temperature transparent polymers,
transparent aerogel materials, xenogel materials, or any other
material that is substantially transparent and provides suspension
of the particles within the volumetric display. The medium may be
formed of inorganic substances, organic substances or combinations
thereof.
[0015] In another aspect, the present invention is directed toward
a method of using a light surface display to produce a
three-dimensional image. The light surface display includes a
plurality of particles suspended within a volumetric display. The
particles are energized sequentially along the length and width of
the volumetric display forming a two-dimensional image. The
particles are further energized by intersection of electromagnetic
energy along the depth of the volumetric display. The energizing of
the particles is synchronized so as to form an illuminated
three-dimensional image.
BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS
[0016] So that the above recited features and advantages of the
present invention can be understood in detail, a more particular
description of the invention, briefly summarized above, may be had
by reference to the embodiments thereof that are illustrated in the
appended drawings. It is to be noted however that the appended
drawings illustrate only typical embodiments of the invention and
are therefore not to be considered limiting of its scope, for the
invention may admit to other equally effective embodiments.
[0017] FIG. 1 is a schematic block diagram of a light surface
display providing a three-dimensional image within a volumetric
display in accordance with the present invention.
[0018] FIG. 2 illustrates exemplary wavelengths of visible light
generated by energizing a particle with two wavelengths.
[0019] FIG. 3 is a schematic diagram of one example of a projection
system in accordance with the embodiment of FIG. 1.
[0020] FIG. 4A is a perspective view of an embodiment of a light
surface display providing a three-dimensional image within a
volumetric display in accordance with the present invention. FIG.
4B is a schematic view of the light surface display in FIG. 4A.
[0021] FIG. 5A is a schematic view of another embodiment of a light
surface display providing a three-dimensional image in accordance
with the present invention. FIG. 5B and FIG. 5C are exemplary
versions of the light surface display of FIG. 5A.
[0022] FIG. 6 is a schematic view of another embodiment of a light
surface display providing a three-dimensional image in accordance
with the present invention.
[0023] FIG. 7 is a perspective view of one version of a light
surface display housing in accordance with the present
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] Present embodiments of the invention are shown in the
above-identified figures and described in detail below. In
describing the embodiments, like or identical reference numerals
are used to identify common or similar elements. The Figures are
not necessarily to scale and certain features in certain views of
the Figures may be shown exaggerated in scale or in schematic in
the interest of clarity and conciseness.
[0025] Referring now to the drawings, and in particular to FIG. 1,
shown therein and designated by reference numeral 10 is a light
surface display, constructed in accordance with the present
invention, for providing a three-dimensional image 12 within a
volumetric display 14. In general, the light surface display 10
includes a plurality of particles, suspended within the volumetric
display 14, that when energized by electromagnetic energy,
illuminate forming a three-dimensional image 12.
[0026] The light surface display 10 is provided with a first
projection system 16 projecting electromagnetic energy of one or
more wavelengths forming sequential slices of a two-dimensional
image along the length and width of the volumetric display 14, and
a second projection system 18 projecting electromagnetic energy of
one or more wavelengths forming translational slices across the
depth of the volumetric display 14. Although FIG. 1 demonstrates
the use of two projection systems 16 and 18, it is contemplated
that additional projection systems may be used to provide
assistance in projecting electromagnetic energy of one or more
wavelengths along the length, width, and/or depth of the volumetric
display 14. Additional projection systems may provide better
resolution, color selectivity, and/or brightness.
[0027] A control system 20 synchronizes the projections of the
first projection system 16 and the second projection system 18 so
that electromagnetic energy of the wavelengths forming the
two-dimensional image and the translational slices intersect on
individual particles to energize the particles for a pre-determined
length of time. The energized particles illuminate to form the
three-dimensional image 12. Depending on the amount of projection
systems and/or type of particles in use, the light surface display
10 is able to produce monochromatic images and/or polychromatic
images.
[0028] The particles within the volumetric display 10 preferably
include selectively-activated light sources capable of activation
by the incidence of one or more directional light sources such as
lasers, coherent LED's, or the like. Activation of the particles
adjusts the physical properties and/or characteristics displayed by
the particles. In the preferred embodiment, activation provides
visible light generation of varying wavelengths.
[0029] Particles may include micro and/or nano
selectively-activated light sources or combinations of micro and/or
nano selectively-activated light sources such as quantum dots,
upconversion materials, or the like. For example, by varying the
size and shape of quantum dots, and the depth of potential, the
energy level of the quantum dots can be controlled. The
discretional nature of the quantum dot bands means that the energy
separation between the valence and conduction bands can be altered
with the addition or subtraction of at least one atom.
Predetermination of the quantum dot size fixes the emitted photon
wavelength at about a specific color allowing quantum dots to be
suitable selectively-activated particles for use in the light
surface display 10.
[0030] Upconversion materials provide another example of suitable
selectively-activated particles. Upconversion materials, in
essence, convert lower energy beams into higher energy visible
beams and can function as light emitting phosphors. Brightness
obtained through the use of an upconversion material may be varied
by altering the intensity of the electromagnetic energy impinging
the surface of the upconversion material.
[0031] Upconversion materials may include a host material doped
with a sensitizer and then further doped with rare-earth ions. For
example, the particles may include fluoride crystal as a host
material, doped with ytterbium (Yb.sup.3+) as a sensitizer and
further doped with rare-earth ions. The rare-earth ions may include
erbium (Er.sup.3+), holmium (Ho.sup.3+), and thulium (Tm.sup.3+),
or other similar particles and/or lanthanides that are excited by
and emit fluorescence at different wavelengths. Doping a fluoride
crystal with Er.sup.3+, Ho.sup.3+, and Tm.sup.3+ enables the
fluoride crystal to emit red, green, and blue upconversion
emitters, respectively. Other host materials, such as oxysulfide,
and other rare-earth doping ions can also be used to construct the
particles. It is contemplated that other selectively-activated
particles may be used with the light surface display 10 as long as
the particles are capable of activation by the incidence of one or
more directional light sources.
[0032] In general, exciting a particle with electromagnetic energy
of different wavelengths produces visible light from the particle
of a specified color depending on the utilized excitation
wavelengths and the doping of the particle. For example, as shown
in FIG. 2, if the first projection system 16 uses the common
infrared wavelength 30 to all particles, then color selectivity is
chosen according to a second wavelength 30 to 32a, 30 to 32b, or 30
to 32c, provided by the second projection system 18. Alternatively,
each visible color can be emitted from the particle through the use
of at least two different wavelengths without the need for a common
wavelength. For example, six separate projection systems may
provide six separate wavelengths (W.sub.1, W.sub.2, W.sub.3,
W.sub.4, W.sub.5, W.sub.6), the combinations of which
(W.sub.1.times.W.sub.2, W.sub.3.times.W.sub.4,
W.sub.5.times.W.sub.6) provide for RGB color selectivity
respectively. Alternatively, each projection system may provide for
multiple wavelengths as discussed in more detail below.
[0033] Particles are suspended within the volumetric display 14.
Substantial uniformity in the suspension of the particles through
the volumetric display 14 is preferred. Particles may be suspended
through magnetic suspension, convection currents, and/or dispersed
within a medium.
[0034] Substantial uniformity in the dispersion of the particles
within the medium is preferred. A suitable medium should include
characteristics such as high transparency, durability, and/or low
phonon energy. A phonon is a discrete amount of energy that a
medium can absorb. If the medium absorbs the incoming energy, this
energy will not be available for light emission, and therefore
reduce the brightness of the light surface display 10.
[0035] The medium may be formed of high temperature transparent
polymers, transparent aerogel materials, xerogel materials, or any
other material permitting substantial uniformity of particle
dispersion. The medium may be composed of an inorganic substance,
an organic substance, or combinations thereof. For example, the
medium can be an aerogel matrix in which the particles are
synthesized with the aerogel matrix to create transparent
optically-active monoliths. Aerogel matrices offer unique
properties because they can be up to 99% air thus eliminating up to
99% of material interference with emitted light. This factor
diminishes the light absorption within the aerogel matrix and
allows for brighter light to be emitted. The aerogel matrix surface
also does not touch the particles completely thus reducing surface
contact and quenching effects on the emitted visible light of the
particles.
[0036] The particles are dispersed much like a cloud within the
aerogel matrix allowing for high illumination. An example of such
an aerogel matrix includes, but is not limited to, silicon oxide
aerogel. Silicon oxide aerogel matrices can be formed with surface
areas of up to about 2000 m.sup.2/g and densities of about 0.002
g/cm.sup.3 providing a high magnitude of surface area that is light
accessible. However, it should be noted, that other types of
mediums, including other aerogel matrices or polymers may be used,
provided the medium allows for dispersal of the particles in at
least a portion of the medium used to form the volumetric display
14.
[0037] Referring now to FIGS. 1 & 3, using image projection
technology such as digital light processing (DLP), grating light
valve (GLV), and/or the like, the projection systems 16 and 18
provide electromagnetic energy of different wavelengths to energize
the particles in the volumetric display 14.
[0038] In one embodiment, at least one of the projection systems 16
and/or 18 of the light surface display 10 uses DLP technology.
Examples of DLPs include, but are not limited to, the Discovery
1100 model which uses 0.7 XGA DDR DMD which operates at 60 MHz DDR
clock and provide 7.7 GbS data transfer rate and the Discovery 3000
which uses the 0.7 XGA LVDS DMD which operates at 200 MHz DDR clock
and provides a 12.8 GbS data transfer rate.
[0039] In general, DLP includes a digital micromirror device (DMD)
containing an array of micromechanical mirrors producing
resolutions of super video graphics array (SVGA) 800.times.600
pixels; extended graphics array (XGA), 1024.times.768 pixels; 720p
1280.times.72; and 1080p, 1920.times.1080 pixels, pico-size DMD,
and/or other like matrices.
[0040] FIG. 3 illustrates the projection system 18 using three-chip
DLP technology with three different light sources, 50, 52, and 54.
The light sources 50, 52, and 54 may include lasers, coherent LEDs,
or the like. Other light sources may be used as long as the
spectral line width of the light source is narrow and the output
beam is directional. Each of the light sources 50, 52, and 54
provides a separate wavelength passing through a special four-sided
prism 56. The prism 56 guides the wavelengths from each of the
light sources 50, 52, and 54 to the corresponding DMD 58, 60, and
62 respectively. The wavelengths from each of the light sources,
50, 52, and 54 is reflected from the DMD surfaces, 58, 60, and 62
and combined. The combination is passed through an open fourth side
64 of the prism 56 to the projection lens 66. The projection lens
66 directs the combination towards the particles in the volumetric
display 14.
[0041] Alternatively, the projection systems 16 and 18 may include
grating light valve technology (GLV). GLV is a diffractive
micro-opto-electro-mechanical system (MOEMS) spatial light
modulator capable of very high-speed modulation of light combined
with fine gray-scale attenuation. GLV is capable of projecting a
one-dimensional array through a second dimension, creating a full
high-definition image.
[0042] In another embodiment, in accordance with the present
invention, the light surface display 10 utilizes both DLP and GLV
technology in rendering a three-dimensional image 12. For example,
in FIG. 1, the first projector system 16 may use DLP to create a
series of 2D image slices, while the second projector system 18
uses GLV to create a series of transitional slices.
[0043] As illustrated in FIG. 4, at least two projection systems 16
and 18 are utilized to construct the three-dimensional image 12
within the volumetric display 14. The intersection of the projected
electromagnetic energy of the first projection system 16 and the
second projection system 18 activates the particles creating voxels
40 forming the three-dimensional image 12.
[0044] The first projection system 16 may include a single DLP or a
single GLV. The projection system 16 is used to project
electromagnetic energy of one or more wavelengths to form
sequential two-dimensional slices 42 projecting across the length
and width of the volumetric display 14. The projected
electromagnetic energy may include non-visible wavelengths, such as
an infrared wavelength or an ultra-violet wavelength, or a
combination of two or more infrared and/or ultra-violet wavelengths
depending on the projection system and/or the particles
utilized.
[0045] The second projection system 18 contains a single DLP or a
single GLV. The second projection system 18 projects
electromagnetic energy of one or more wavelengths to form planar
translational slices 44 translating across the depth of the
volumetric display 14. The projected electromagnetic energy can
include non-visible wavelengths, such as an infrared wavelength or
ultra violet wavelength, or a combination of two or more infrared
and/or ultraviolet wavelengths depending on the projection system
and/or the particles utilized.
[0046] In one embodiment, the projected electromagnetic energy from
the first projection system 16 is the common infrared wavelength
IRL0 forming the sequential two-dimensional slices 42, and the
projected electromagnetic energy from the second projection system
18 consists of three different infrared wavelengths IRL1, IRL2, and
IRL3 projected in sequence for each planar translational slice 44.
To produce the planar translational slice 44, all of the
micromirrors of the second projection system 18 are set to the
off-state except the first column and/or row, depending on the
physical positioning of the projection system 18 and/or volumetric
display 14. The projection of the planar translational slice 44 is
synchronized to the projection of the two-dimensional slices 42
from the first projection system 16. The approximately 90 degree
intersection of the planar translational slice 44 with the
two-dimensional slice 42 for a specified length of time energizes
the particles at the intersection and creates an illuminated
two-dimensional cross section at a specified location within the
volumetric display 14. Changing the wavelengths of the planar
translational slices 44 projected by the second projection system
18 provides the means to generate red, green, and/or blue, along
with a multitude of colors based on the combinations of red, green,
and/or blue.
[0047] To further create the three-dimensional image, all of the
micromirrors in the second projection system 18 are again switched
to the off-state except for a second column and/or row depending on
the orientation of the second projection system 18 and/or
volumetric display 14. A second intersection occurs between a
second two-dimensional slice 42 and a second planar translational
slice 44 illuminating a second two-dimensional cross section at a
specific location in the volumetric display 14. It is possible for
the second projection system 18 to project two or more columns
and/or rows simultaneously for each planar translational slice
44.
[0048] Synchronizing the operations of both projection systems 16
and 18 allows the series of illuminated cross sections of the
two-dimensional slice 42 and the planar translational slice 44 to
appear at a depth within the volumetric display 14. Repeating the
projections from the first projection system 16 and the second
projection system 18 throughout the entire volumetric display 14
creates the three-dimensional image 12.
[0049] The resolution, color, and/or brightness of the image may be
manipulated by altering the projection of electromagnetic energy
from the projection system 16 and 18. For example, allowing for a
pre-determined amount of time between projection by the first
projection system 16 and projection by the second projection system
18 can vary the color and/or intensity of each particle. Activation
by the first projection system 16 allows the particles to energize.
A time-delay after projection by the first projection system 16
allows the energy to dissipate before activation by the second
projection system 18. The dissipation of energy allows for
variations in particle color and/or intensity. Additionally,
altering the amplitude of wavelength of electromagnetic energy
projected by either the first projection system 16 and/or the
second projection system 18 can vary the intensity and vary the
relative brightness of each particle.
[0050] As previously discussed, the projection systems 16 and 18
may include DLPs having digital micro-mirror devices containing an
array of micromechanical mirrors. The micromechanical mirrors may
be used in a plurality of array groups for dithering the
translational slice to alter the relative brightness of each
particle that comprises a voxel. In this technique, each particle
receives electromagnetic energy that has been reflected from a
plurality of micromechanical mirrors; the brightness is then
controlled by selecting the number of micromechanical mirrors in
this plurality. For example, using a 2.times.2 array of DLP
micro-mirrors provides a relative color depth per voxel from zero
to four depending on how many mirrors in the array group are
activated at any given time. Larger micro-mirror array groups can
provide corresponding greater color depth. It is noted that this
dithering method decreases the overall resolution of the display
and that multiplexing the micro-mirrors in time or controlling the
laser power and/or laser activation timing to provide color depth
are the preferred embodiments.
[0051] As illustrated in FIGS. 5A, 5B, and 5C, the physical
placement of the projection system 16 and 18 and/or directing of
the electromagnetic energy provided by the projection systems 16
and 18 can provide for multiple viewing angles of the
three-dimensional image 12. For example, as shown in FIGS. 5A and
5B a 270-degree viewing of the three-dimensional image 12 is
produced when the first projection system 16, projecting the
two-dimensional cross section, occupies one side of the volumetric
display 14 and the projected planar transitional slices are
projected by the second projection system 18 on the perpendicular
side of the volumetric display 14. In another version, as
illustrated in FIG. 5C, the first projection system 16 utilizes a
beam expander to provide the array of electromagnetic energy in a
collimated beam to the volumetric image space 14.
[0052] The planar transitional slices are projected to the
volumetric display 14 through the use of a steering system 80. The
steering system may include one or more mirrors, including
deformable mirrors, that can be mechanically or electrically
altered to guide the electromagnetic energy from the projection
system 18 to the volumetric display 14.
[0053] Alternatively, as shown in FIG. 6, the steering system 80
can provide 360 degree viewing by angling the projections from the
first projection system 16 and the second projection system 18 so
that they are tilted from a base 82. Preferably, electromagnetic
energy from the first projection system 16 and the second
projection system 18 will ideally intersect the particle at
relative angles of approximately 90 degrees although other angles
of intersection are contemplated. Having the intersection at an
angle of approximately 90 degrees may eliminate any distortional
dead zones resulting from voxel elongation, wherein the
distortional dead zone is the region in which the size and/or shape
of the individual voxels deviates substantially from the ideal.
Control of the steering system may be provided by the projection
systems 16 and 18, the control system 20, and/or mechanical
manipulation by the user.
[0054] The control system 20 refreshes the images at a frequency
sufficient to ensure that the user and/or spectator perceive the
visual data as continually present. In one example, the volumetric
display 14 is in the form of a rectangle with sides of lengths
l.times.k comprising n by m pixels. Any combination of these
n.times.m pixels can be activated during each refresh period. For
example, if n=1024 rows, and m=768 pixels, the resultant number of
pixels is 786,432 pixels generated using the first projection
system 16. Flicker considerations give rise to a minimum image
refresh frequency. Therefore, if the second projection system 18
provides 333 slices across the depth of the volumetric display 14,
the first projection system 16 and the second projection system 18,
then the control system 20 refreshing the projection systems 16 and
18 at the same frequency, would provide 8000 images/sec from the
first projection system 16 and 8000 images/sec from the second
projection system 18. In this example, the generated volumetric
display 14 would provide 225 million-voxels for a single color
image and 85 million-voxels for a three-color image and 111 slices
across the depth. The obtained three-dimensional image 12 is
comprised of 24 three-dimensional images 12 per second (refresh
rate).
[0055] In another example, the first projection system 16 utilizes
a DLP projector with three different light sources simultaneously
projecting the two-dimensional image and the second projection
system 18 slices the two-dimensional images with a single light
source such as a common infra-red laser. In this example, when the
first projection system emits 1024.times.768 images, and the second
projection system slices 666 columns, synchronization by the
control system 20 generates the volumetric display 14 with 500
million-voxels for multi-color images.
[0056] In another example, the projection systems 16 and 18
described herein operate at a rate of 16,000 frames/sec. The
illuminated cross sections within the volumetric image space 14
take the form of rectangle comprised of n by m pixels. Any
combination of these n.times.m pixels are activated during each
refresh period. If n=1920 rows and m=1080 columns, the resultant
number of pixels generated for each 2D cross section is 2.0736
million pixels. If the equivalent volumetric image space 14
provides an additional spatial dimension (depth) d equal to 666
slices generated then flicker considerations give rise to a minimum
image refresh frequency equal to twenty-four---three-dimensional
images/sec. The first projection system 16 will project a
continuous combination of three mixed wavelengths to provide three
color images at 16,000 images/sec.
[0057] To provide moving images, the three-dimensional image 12 is
projected at least 24 times/sec, leading to a three-dimensional
projection speed equal to 666 images/sec. The second projection
system 18 switches 666 columns or rows to create 666 slices/sec,
over the depth of the volumetric image space 14. The resultant
projection system speed is 15984 frames/sec with a switching speed
for the three different wavelengths at 7992 switches/sec. Thus, the
volumetric image space 14, having more than 666 slices for the
depth direction and 1,381 million voxels for multi-color image,
gives a resulting three-dimensional image 12 comprised of
twenty-four three-dimensional images/sec (refresh rate).
[0058] As illustrated in FIG. 6, the control system 20 may
optionally communicate with an external source 62, such as a
computer, processor, or the Internet, to provide external control,
external programming, permitting measurement and reporting of
information regarding the light surface display 10, and/or
downloading of images to the control system 20. The external source
62 can be either proximally located to the light surface display 10
or located at a distance so long as there is communication between
the control system 20 and the external source 62. Communication
between the control system 20 and the external source 62 can be
wired or wireless.
[0059] As illustrated in FIG. 7, the light surface display 10 may
optionally include a housing 70 containing the three-dimensional
image 12. In addition to providing support for the particles, the
housing 70 provides an element of safety in securing the particles
against outside contact with the user or spectator. The housing 70
is constructed of a transparent material forming a transparent area
so that a user or spectator located outside the housing 70 can view
the image within the housing 70. It should be understood that the
amount and/or shape of the transparent material forming the housing
70 can be varied depending upon a number of factors, such as the
desired optical effect, or the end use of the light surface display
10. The housing 70 may additionally enclose the projection systems
16 and 18 and/or control system 20. The housing 70 is provided with
an opaque area 72 so as to hide various parts of the light surface
display 10 from the view of a user or spectator outside of the
housing 70. For example, the projection systems 16 and 18 and/or
control system 20 can be located adjacent to the opaque area 72 so
as to hide the projection systems 16 and 18 and/or control system
20 from the user or spectator.
[0060] Additionally, the light surface display 10 can include a
filter, such as an electromagnetic radiation filter, preventing
exposure of non-visible radiation to the user or spectator. The
filter may be integral to the housing 70 or separate from the
housing 70.
[0061] As discussed above, the light surface display 10 is used to
produce three-dimensional images 12. In using the light surface
display 10, a volumetric space 14 is provided, wherein a plurality
of particles are suspended within the volumetric space 14 via the
medium, magnetic suspension or the like. Substantially-uniform
dispersion of the particles within the volumetric space 14 is
preferred. The particles are energized sequentially along the
length and width of the volumetric display 14 through projection of
electromagnetic energy of one or more wavelengths. The
electromagnetic energy may be provided by one or more projection
systems 16 and/or 18. The energized particles form a
two-dimensional image along the length and width of the volumetric
space 14. The particles are intersected with a projection of
electromagnetic energy of one or more wavelengths along the depth
of the volumetric display 14. The projection of electromagnetic
energy along the length and width of the volumetric display 14 and
the projection of electromagnetic energy along the depth of the
volumetric display 14 are synchronized for a pre-determined length
of time. Synchronization of the projections forms the illuminated
three-dimensional image 12.
[0062] The foregoing disclosure includes the best mode for
practicing the invention. It is apparent, however, that those
skilled in the relevant art will recognize variations of the
invention that are not described herein. While the invention is
defined by the appended claims, the invention is not limited to the
literal meaning of the claims, but also includes these
variations.
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