U.S. patent application number 09/746609 was filed with the patent office on 2001-08-16 for system and method for producing and displaying a one-step, edge-lit hologram.
Invention is credited to Holzbach, Mark E., Klug, Michael Anthony.
Application Number | 20010013961 09/746609 |
Document ID | / |
Family ID | 22390249 |
Filed Date | 2001-08-16 |
United States Patent
Application |
20010013961 |
Kind Code |
A1 |
Klug, Michael Anthony ; et
al. |
August 16, 2001 |
System and method for producing and displaying a one-step, edge-lit
hologram
Abstract
A system and method are disclosed for producing and displaying a
one-step, edge-lit hologram. For production, an object beam and an
edge-lit reference beam are directed at holographic recording
material and to interfere with one another. The holographic
recording material and the object beam and edge-lit reference beam
are then translated with respect to one another. The translation
successively exposes multiple portions of the holographic recording
material to the interference of the object beam and the edge-lit
reference beam to record an edge-lit hologram on the holographic
recording material. In one embodiment, the holographic recording
material is moved while the object beam and the edge-lit reference
beam remain generally stationary. In another embodiment, the object
beam and the edge-lit reference beam move in unison with each other
while the holographic recording material remains generally
stationary. A base enclosure is preferably formed to removably
receive an edge of a plinth having an edge-lit hologram mounted
thereon. A light source may be positioned within the base enclosure
to provide an illumination beam to reconstruct the edge-lit
hologram when the plinth is received by the base enclosure.
Inventors: |
Klug, Michael Anthony;
(Austin, TX) ; Holzbach, Mark E.; (Austin,
TX) |
Correspondence
Address: |
Marc R. Ascolese
Skjerven Morrill MacPherson LLP
Suite 700
25 Metro Drive
San Jose
CA
95110
US
|
Family ID: |
22390249 |
Appl. No.: |
09/746609 |
Filed: |
December 20, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09746609 |
Dec 20, 2000 |
|
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09504730 |
Feb 16, 2000 |
|
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60120433 |
Feb 16, 1999 |
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Current U.S.
Class: |
359/32 ; 359/1;
359/15 |
Current CPC
Class: |
G03H 1/00 20130101; G03H
1/2249 20130101; G03H 2001/043 20130101; G03H 2210/22 20130101;
G03H 1/0408 20130101; G03H 1/268 20130101; G03H 2001/2685 20130101;
G03H 2001/2695 20130101; G03H 2210/30 20130101 |
Class at
Publication: |
359/32 ; 359/1;
359/15 |
International
Class: |
G03H 001/00; G02B
005/32; G03H 001/22 |
Claims
What is claimed is:
1. A system for producing an edge-lit hologram, comprising: an
object beam head operable to direct an object beam; a reference
beam head operable to direct an edge-lit reference beam to
interfere with the object beam; and a frame operable to position
and translate a holographic recording material such that multiple
portions of the holographic recording material are successively
exposed to interference of the object beam and the edge-lit
reference beam to record the edge-lit hologram on the holographic
recording material.
2. The system of claim 1, wherein the reference beam head
comprises: an assembly base; and a prism coupled to the assembly
base, the prism operable to receive a reference beam and condition
the reference beam into an edge-lit reference beam.
3. The system of claim 2, wherein the reference beam head further
comprises a lens coupled to the assembly base in a path of the
reference beam such that the reference beam travels through the
lens to the prism.
4. The system of claim 3, wherein the lens comprises an anamorphic
collimating lens for conditioning the reference beam sufficient to
create a horizontal parallax only edge-lit hologram.
5. The system of claim 3, wherein the lens comprises a collimating
lens for conditioning the reference beam sufficient to create a
full parallax edge-lit hologram.
6. The system of claim 2, wherein the reference beam head further
comprises an optical fiber coupled to the assembly base, the
optical fiber having a tip oriented to deliver the reference beam
to the prism.
7. The system of claim 2, wherein the reference beam comprises a
red beam, a green beam and a blue beam.
8. The system of claim 7, wherein the reference beam head further
comprises three lenses coupled to the assembly base, each
positioned in a path of one beam, such that each beam travels
through one of the three lenses to the prism.
9. The system of claim 8, wherein the three lenses comprise
anamorphic collimating lenses for conditioning the red, green and
blue beams sufficient to create a full-color horizontal parallax
only hologram.
10. The system of claim 8, wherein the three lenses comprise
spherical collimating lenses for conditioning the red, green and
blue beams sufficient to create a full-color full parallax
hologram.
11. The system of claim 7, wherein the reference beam head
comprises: a first optical fiber coupled to the assembly base, the
first optical fiber having a tip oriented to deliver the red beam
to the prism; a second optical fiber coupled to the assembly base,
the second optical fiber having a tip oriented to deliver the green
beam to the prism; and a third optical fiber coupled to the
assembly base, the third optical fiber having a tip oriented to
deliver the blue beam to the prism.
12. The system of claim 7, wherein the reference beam head further
comprises a dichroic combiner coupled to the assembly base, the
dichroic combiner positioned to receive two of the three beams from
the collimating lenses and operable to provide a combined beam to
the prism.
13. The system of claim 12, wherein the dichroic combiner is
positioned to receive the red beam and the blue beam.
14. The system of claim 2, wherein the prism comprises a dove
prism.
15. The system of claim 2, wherein the reference beam head further
comprises a reservoir coupled to the assembly base proximate the
prism, the reservoir operable to hold an index matching fluid and
allowing a layer of the index matching fluid to form between the
prism and a holographic recording material.
16. The system of claim 15, further comprising: a fluid pump; and a
fluid tube extending between the fluid pump and the reference beam
head; the fluid pump operable to provide index matching fluid to
the reservoir through the fluid tube.
17. The system of claim 2, wherein the reference beam head further
comprises a masking plate coupled to the prism in a path of the
edge-lit reference beam.
18. The system of claim 1, further comprising a transparent
plateholder coupled to the frame, the transparent plateholder
positioned between the object beam head and the reference beam
head.
19. The system of claim 18, wherein the plateholder is operable to
receive a holographic recording material on a side proximate the
object beam head.
20. The system of claim 18, wherein the plateholder is operable to
receive a holographic recording material on a side proximate the
reference beam head.
21. The system of claim 1, further comprising a computer operable
to control translation of the holographic recording material.
22. The system of claim 21, further comprising the computer
operable to control translation of the frame along a first axis and
a second axis, where the first axis is substantially perpendicular
to the second axis.
23. A system for producing an edge-lit hologram, comprising: a
frame operable to position a holographic recording material; an
object beam head coupled to a first support, the object beam head
operable to direct an object beam; a reference beam head coupled to
a second support, the reference beam head operable to direct an
edge-lit reference beam to interfere with the object beam; and the
first support and the second support operable to translate the
object beam head and the reference beam head generally in unison
with each other and relative to the holographic recording material
such that portions of the holographic recording material are
successively exposed to interference of the object beam and the
edge-lit reference beam to record the edge-lit hologram on the
holographic recording material.
24. The system of claim 23, wherein the reference beam head further
comprises at least one lens disposed in a path of a reference beam
such that the reference beam travels through the lens to a prism
which conditions the reference beam into an edge-lit reference
beam.
25. The system of claim 24, wherein the lens comprises an
anamorphic collimating lens for conditioning the reference beam
sufficient to create a horizontal parallax only edge-lit
hologram.
26. The system of claim 24, wherein the lens comprises a
collimating lens for conditioning the reference beam sufficient to
create a full parallax edge-lit hologram.
27. The system of claim 23, wherein the edge-lit reference beam
further comprises a red beam, a green beam and a blue beam.
28. The system of claim 27, wherein the reference beam head further
comprises at least three lenses, each positioned in a path of one
of the beams, such that each beam travels through one of the three
lenses to a prism.
29. The system of claim 23, wherein the reference beam head
comprises: a first optical fiber coupled to an assembly base, the
first optical fiber having a tip oriented to deliver a red beam to
a prism; a second optical fiber coupled to the assembly base, the
second optical fiber having a tip oriented to deliver a green beam
to the prism; a third optical fiber coupled to the assembly base,
the third optical fiber having a tip oriented to deliver a blue
beam to the prism; and the prism operable to condition the red
beam, green beam and blue beam into respective edge-lit reference
beams.
30. The system of claim 29, wherein the reference beam head further
comprises a dichroic combiner coupled to the assembly base, the
dichroic combiner positioned to receive two of the three beams from
respective collimating lenses and operable to provide a combined
beam to the prism.
31. The system of claim 29, wherein the prism comprises a dove
prism.
32. The system of claim 23, wherein the reference beam head further
comprises a masking plate coupled to a prism in a path of the
edge-lit reference beam.
33. The system of claim 23, further comprising a transparent
plateholder positioned between the object beam head and the
reference beam head.
34. The system of claim 33, wherein the plateholder is operable to
receive a holographic recording material on a side proximate the
object beam head.
35. The system of claim 33, wherein the plateholder is operable to
receive a holographic recording material on a side proximate the
reference beam head.
36. The system of claim 23, further comprising a computer operable
to control translation of the object beam head and the reference
beam head.
37. A reference beam head for use in producing edge-lit holograms,
comprising: an assembly base; a prism coupled to the assembly base
operable to receive a reference beam and condition the reference
beam into an edge-lit reference beam; a reservoir coupled to the
assembly base proximate the prism; and the reservoir operable to
hold an index matching fluid and to allow a layer of the index
matching fluid to form between the prism and a holographic
recording material.
38. The reference beam head of claim 37, further comprising a
masking plate coupled to the prism in a path of the edge-lit
reference beam.
39. The reference beam head of claim 37, further comprising a lens
coupled to the assembly base in a path of the reference beam such
that the reference beam travels through the lens to the prism.
40. The reference beam head of claim 39, wherein the lens comprises
an anamorphic collimating lens for conditioning the reference beam
sufficient to create a horizontal parallax only edge-lit
hologram.
41. The reference beam head of claim 39, wherein the lens comprises
a collimating lens for conditioning the reference beam sufficient
to create a full parallax edge-lit hologram.
42. The reference beam head of claim 38, wherein the reference beam
head further comprises an optical fiber coupled to the assembly
base, the optical fiber having a tip oriented to deliver the
reference beam to the prism.
43. The reference beam head of claim 38, wherein the reference beam
comprises a red beam, a green beam and a blue beam.
44. The reference beam head of claim 43, wherein the reference beam
head further comprises three lenses coupled to the assembly base,
one lens positioned in a path of each beam, such that each beam
travels through one of the three lenses to the prism.
45. The reference beam head of claim 44, wherein the three lenses
comprise anamorphic collimating lenses for conditioning the red,
green and blue beams sufficient to create a full-color horizontal
parallax only hologram.
46. The reference beam head of claim 44, wherein the three lenses
comprise collimating lenses for conditioning the red, green and
blue beams sufficient to create a full-color full parallax
hologram.
47. The reference beam head of claim 43, further comprising: a
first optical fiber coupled to the assembly base, the first optical
fiber having a tip for oriented to deliver the red beam to the
prism; a second optical fiber coupled to the assembly base, the
second optical fiber having a tip oriented to deliver the green
beam to the prism; and a third optical fiber coupled to the
assembly base, the third optical fiber having a tip oriented to
deliver the blue beam to the prism.
48. The reference beam head of claim 43, wherein the reference beam
head further comprises a dichroic combiner coupled to the assembly
base, the dichroic combiner positioned to receive two of the three
beams from the collimating lenses and operable to provide a
combined beam to the prism.
49. The reference beam head of claim 48, wherein the dichroic
combiner is positioned to receive the red beam and the blue
beam.
50. The reference beam head of claim 48, wherein the prism
comprises a dove prism.
51. A method for producing an edge-lit hologram, comprising:
directing an object beam at holographic recording material;
directing an edge-lit reference beam at the holographic recording
material to interfere with the object beam; and translating the
holographic recording material and the object beam and edge-lit
reference beam with respect to one another to successively expose
multiple portions of the holographic recording material to the
interference of the object beam and the edge-lit reference beam to
record the edge-lit hologram on the holographic recording
material.
52. The method of claim 51, wherein translating further comprises
changing a position of the holographic recording material while the
object beam and the edge-lit reference beam remain in generally
fixed positions.
53. The method of claim 51, wherein translating further comprises
changing positions of the object beam and the edge-lit reference
beam while the holographic recording material remains in a
generally fixed position.
54. The method of claim 51, wherein translating further comprises:
moving the holographic recording material relative to the object
beam and the edge-lit reference beam; and moving the object beam
and the edge-lit reference beam substantially in unison with each
other relative to the holographic recording material.
55. The method of claim 51, wherein directing an edge-lit reference
beam comprises using a prism to receive a reference beam and to
condition the reference beam into an edge-lit reference beam.
56. The method of claim 55, further comprising anamorphically
collimating the reference beam before the reference beam strikes
the prism to assist in creating a horizontal parallax only edge-lit
hologram.
57. The method of claim 55, further comprising collimating a
reference beam before the reference beam strikes the prism to
assist in creating a full parallax edge-lit hologram.
58. The method of claim 55, further comprising forming a layer of
index matching fluid between the prism and the holographic
recording material.
59. The method of claim 51, further comprising the edge-lit
hologram having a size substantially larger than the size of
associated production optics used to form the object beam and
edge-lit reference beam.
60. A reference beam head for use in producing an edge-lit
hologram, comprising a base; a prism coupled to the base for
receiving multiple reference beams and conditioning the reference
beams to form respective edge-lit reference beams; and the prism
having a first end for receiving a green reference beam and a
second end opposite from the first end for receiving a red
reference beam and a blue reference beam.
61. A system for producing an edge-lit hologram comprising; a
holographic recording material disposed on and attached to a
supporting substrate; a prism for receiving at least one reference
beam and conditioning the reference beam to provide an edge-lit
reference beam; the supporting substrate and the holographic
recording material having at least one common edge with the prism
disposed thereon; and a layer of index matching fluid formed
between the prism and the associated edge of the supporting
substrate and the holographic recording material.
62. A prism for use in producing an edge-lit hologram, comprising:
the prism having multiple surfaces defined in part by a top
surface, a bottom surface, a first side surface, a second side
surface, a first end surface and a second end surface which are
joined with each other; the top surface and the bottom surface
aligned generally parallel with each other; the first side surface
and the second side surface disposed generally parallel with each
other and extending between the top surface and the bottom surface;
the first side surface and the second side surface having
approximately the same size and the same configuration; the first
end surface extending at an angle from a first end of the bottom
surface to a first end of the top surface; and the second end
surface extending at an angle from a second end of the bottom
surface to a second end of the top surface.
63. A system for displaying an edge-lit hologram comprising: a
plinth formed from material which allows transmission of light
therethrough; the plinth having a first surface and a second
surface disposed generally parallel with each other; the plinth
having a first edge and a second edge disposed generally parallel
with each other and extending between the first surface and the
second surface; an image hologram mounted on the first surface; a
first holographic optical element attached to and extending along
the first edge; a first source of illuminating light disposed on
the second edge; and the holographic optical element formed to
collimate and reflect light from the illuminating source to strike
the image hologram disposed on the first surface at appropriate
angles to make the image hologram visible from the second surface
of the plinth.
64. The display system of claim 62 further comprising; a second
illuminating source of light disposed on the first edge of the
plinth; a second holographic optical element disposed on the second
edge of the plinth; the first holographic optical element formed
from material which will collimate and reflect light from the first
illuminating source and will be substantially transparent with
respect to light from the second illuminating source; and the
second holographic optical element formed from material which will
generally collimate and reflect light from the second illuminating
source and will be substantially transparent with respect to light
from the first illuminating source.
65. The display system of claim 62 further comprising: a second
illuminating source of light disposed on the first edge of the
plinth; a second holographic optical element disposed on the second
edge of the plinth; a third illuminating source of light disposed
on the first edge of the plinth adjacent to the second illuminating
source of light; the first holographic element formed from material
which will collimate and reflect light from the first illuminating
source and will be substantially transparent with respect to light
from the second illuminating source and the third illuminating
source; and the second holographic element formed from material
which will generally collimate and reflect light from the second
illuminating source and the third illuminating source and will be
substantially transparent with respect to light from the first
illuminating source.
66. The display system of claim 64 further comprising: the first
illumination source providing green light; the second illumination
source providing red light; and the third illumination source
providing blue light.
67. The display system of claim 62 further comprising at least two
holographic optical elements and two sources of illuminating light
for use in displaying a two color edge-lit reflection hologram.
68. The display system of claim 62 further comprising at least two
holographic optical elements and at least three sources of
illuminating light for use in displaying a full color edge-lit
reflection hologram.
Description
RELATED APPLICATION
[0001] This application claims the benefit of previously filed
provisional application Serial No. 60/120,433 filed Feb. 16, 1999
entitled System and Method for Producing and Displaying a One-Step,
Edge-Lit Hologram.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates in general to the field of
hologram production and display and, more particularly, to a system
and method for producing and displaying a one-step, edge-lit
hologram.
BACKGROUND OF THE INVENTION
[0003] Edge-illuminated or edge-lit holograms are considered to be
a subcategory of holographic displays, in general. Typically,
conventional edge-lit holograms are recorded onto a holographic
recording material mounted on a material supporting substrate. The
edge-lit hologram is then reconstructed by an illumination source
that introduces an illumination beam through the edge of the
substrate. The illumination beam preferably strikes the material
supporting substrate at a steep angle relative to a light ray
extending perpendicular to the surface of the substrate.
[0004] Edge-lit holograms contain interesting display properties.
The holographic image can only be reconstructed with an
illumination source introduced through the edge of the substrate.
The illumination source is preferably disposed within the display.
Thus, the display may be self contained which allows the
holographic image to be protected from detrimental effects of
ambient light sources. Some conventional systems place the
illumination source relatively close to the edge-lit hologram.
Additionally, some conventional systems integrate the illumination
source with the edge-lit hologram in a stand-alone self-contained
display. Such a system can eliminate the need for placement and
adjustment of external illumination sources.
[0005] However, the recording and production of edge-lit holograms
can be problematic. A typical hologram production system introduces
an object beam carrying a digitally rendered image to coincide with
a reference beam. The interference of the two beams forms a
hologram on associated holographic recording material. To
satisfactorily record the edge-lit hologram, the reference beam
should approximate the high angle of incidence of the intended
image reconstruction illumination source, taking into consideration
optical characteristics of the material supporting substrate
through which the eventual illumination source will travel. In
general, a reference beam that sufficiently approximates such
properties can be referred to as an "edge-lit reference beam."
[0006] One conventional system for producing edge-lit holograms is
disclosed in "A Printer for Edge-Lit Holographic Stereograms," by
Sean T. Nolan, which is a thesis submitted to the Department of
Electrical Engineering Computer Sciences of Massachusetts Institute
of Technology in February 1994. This reference documents a printer
geometry that incorporates a reference beam introduced to a series
of lenses that produce an anamorphically collimated reference beam
with dimensions of approximately 25 millimeters by 0.4 millimeters.
In order to condition the reference beam into an edge-lit reference
beam, the disclosed device uses a plateholder consisting of a thick
polymethylmethacrilate (PMMA) plinth and glass sandwich. The
anamorphic or edge-lit reference beam is then introduced to the
holographic recording material through the edge of the PMMA
plinth.
[0007] This conventional production process is disadvantageous
because the plinth is generally permanently laminated to the glass
plateholder. Thus, the plinth must be approximately the same size
as or larger than the hologram being recorded which typically
limits the size of the hologram that the system can produce.
[0008] Another disadvantage of many conventional systems is
introduction of the reference beam into an edge cut perpendicular
to the face of the plate. This arrangement links the thickness of
the PMMA plinth to the illumination angle of the hologram and
further limits the size of the eventual hologram that can be
produced.
[0009] A further disadvantage is that many conventional systems can
not record full parallax edge-lit holograms and can not record
full-color holograms.
[0010] One step hologram production technology has been used to
satisfactorily record a hologram without the traditional step of
creating a preliminary hologram. Both computer image holograms and
non-computer image holograms may be produced by such one step
technology. Also, not all computer image holograms are produced by
one step technology. In some one-step systems, computer processed
images of objects or computer models of objects allow the
respective system to build a hologram from a number of contiguous,
small, elemental pieces known as elemental holograms or hogels. To
record each hogel on holographic recording material, an object beam
is conditioned through the rendered image and interfered with by a
reference beam.
SUMMARY OF THE INVENTION
[0011] In accordance with teachings of the present invention, a
system and method are disclosed for producing and displaying a
one-step, edge-lit hologram that provide significant advantages
over prior edge-lit hologram production and display systems and
methods.
[0012] According to one aspect of the present invention, a system
for producing an edge-lit hologram comprises an object beam head, a
reference beam head and a frame. The object beam head directs an
object beam, and the reference beam head directs an edge-lit
reference beam to interfere with the object beam. The holographic
recording material and the object beam head and the reference beam
head may then be translated in accordance with teachings of the
present invention to record the hologram. The translation
successively exposes multiple portions of the holographic recording
material to interference of the object beam and the edge-lit
reference beam to record an edge-lit hologram on the holographic
recording material.
[0013] For one embodiment, the holographic recording material may
be moved relative to the object beam head and the reference beam
head which remain in a generally fixed position relative to each
other. For another embodiment, the object beam head and the
reference beam head may be moved in unison with respect to the
holographic recording material which remains in a generally fixed
position. For a further embodiment, the holographic recording
material may be moved relative to the object beam and the edge-lit
reference beam which are also moving substantially in unison with
each other relative to the holographic recording material. For some
embodiments, the reference beam head may comprise an assembly base
and a prism coupled to the assembly base, where the prism is
operable to receive the reference beam and condition the reference
beam into an edge-lit reference beam.
[0014] Another aspect of the present invention includes a system
for displaying an edge-lit hologram. The system preferably includes
a base enclosure and a light source. The base enclosure may be
formed to removably receive an edge of a plinth having an edge-lit
hologram mounted thereon. The light source is preferably positioned
within the base enclosure and provides an illumination beam to
reconstruct the edge-lit hologram when the plinth is received by
the base enclosure.
[0015] A technical advantage of the present invention is that the
size of an edge-lit hologram to be produced is not limited to the
size of the associated production optics. For example, a reference
beam head incorporating teachings of the present invention may be
used to record a hologram having dimensions substantially larger
than the reference beam head.
[0016] Another technical advantage of the present invention is that
an edge-lit reference beam does not have to be introduced into a
perpendicular edge. Thus, the size of the edge-lit hologram to be
recorded is not limited by the thickness of a plate or plinth
having such an edge.
[0017] An additional technical advantage of the present invention
is that either a horizontal parallax only or a full parallax
edge-lit hologram can be recorded.
[0018] A further technical advantage of the present invention is
that full-color edge-lit holograms may be recorded and displayed
with substantially reduced color "crosstalk."
[0019] Still another technical advantage of the present invention
is that multiple object beams and multiple edge-lit reference beams
may be used to substantially increase the speed of printing an
edge-lit hologram.
[0020] Another aspect of the present invention includes the use of
one or more holographic optical elements (HOE) which may be placed
along a respective edge of an edge-lit hologram opposite from an
associated illumination source. Each HOE is preferably selected to
function as a collimating mirror with respect to the associated
illumination source which may be disposed adjacent to an opposite
edge of the associated edge-lit hologram. Each HOE is selected to
fold or reflect a beam of light from the associated illumination
source at appropriate angles required for display of the associated
edge-lit hologram. Placing an illumination source on one edge of an
edge-lit hologram and an HOE on an opposite edge of the edge-lit
hologram in accordance with teachings of the present invention will
often allow a substantial reduction of the size or the length of
the plinth or substrate used to support the edge-lit hologram.
[0021] Depending upon the type of image hologram which will be
displayed, such as horizontal parallax only or full parallax, the
present invention allows placing illumination sources and
associated holographic optical elements at the desired location to
minimize color crosstalk and to substantially reduce the size of
the associated plinth and other components of the respective
display systems.
[0022] A still further aspect of the present invention includes
combining multiple color selective HOEs with corresponding colored
illumination sources to substantially reduce or eliminate color
crosstalk which is often associated with conventional techniques
for illuminating edge-lit holograms. For example, a red
illumination source may be disposed on a first edge of an edge-lit
hologram and an HOE which is color selective with respect to
collimating and reflecting a red light beam may be disposed on a
second edge of the edge-lit hologram opposite from the first edge.
In a similar manner a green illuminating source may be disposed on
the second edge of the edge-lit hologram and an HOE selected to
collimate and reflect green light may be disposed on the first edge
of the edge-lit hologram. Each HOE is preferably transparent to any
color other than the selected color which the HOE will collimate
and reflect. For the above example the red HOE will reflect and
collimate red light and will be effectively transparent to blue
light, green light or any other color of light. The green HOE will
reflect and collimate green light and will be effectively
transparent to blue light, red light or any other color of light.
The present invention allows placing colored light sources adjacent
to selected edges of an edge-lit hologram to effectively reduce or
eliminate color crosstalk.
[0023] The present invention teaches various techniques and
apparatus for combining edge-lit hologram production with one step
hologram production which makes possible the production of three
dimensional hologram images that can be illuminated with an
integrated light source to simplify and minimize the size of the
resulting self-contained holographic display.
[0024] Other technical advantages should be apparent to one of
ordinary skill in the art in view of the specification, drawings
and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] A more complete understanding of the present invention and
advantages thereof may be acquired by referring to the following
description taken in conjunction with the accompanying drawings, in
which like reference numbers indicate like features, and
wherein:
[0026] FIG. 1 is a schematic diagram of one embodiment of a system
for producing horizontal parallax only (HPO) edge-lit
holograms;
[0027] FIG. 2 is a schematic diagram of one embodiment of a system
for producing full parallax edge-lit holograms;
[0028] FIG. 3 is a schematic diagram of one embodiment of an object
beam head for use in a system for producing full color, full
parallax edge-lit holograms;
[0029] FIG. 4 is a schematic diagram of one embodiment of tail end
optics in an object beam head of a system for producing full
parallax edge-lit holograms;
[0030] FIG. 5 is a schematic diagram of one embodiment of tail end
optics for an object beam head in a system for producing HPO
edge-lit holograms;
[0031] FIG. 6 is a schematic diagram of one embodiment of a
reference beam head for use in a system for producing full color,
full parallax, edge-lit holograms;
[0032] FIG. 7 is a top view of the reference beam head of FIG.
6;
[0033] FIG. 8 is a schematic diagram of one embodiment of a
reference beam head for use in a system for producing full color,
HPO, edge-lit holograms;
[0034] FIG. 9 is a schematic diagram of one embodiment of a prism
for use in a system for producing full color edge-lit
holograms;
[0035] FIG. 10 is a schematic diagram of one embodiment of a prism
for use in a system for producing monochrome edge-lit
holograms;
[0036] FIG. 11 is a schematic diagram of one embodiment of a prism
for use in a system for producing edge-lit holograms;
[0037] FIG. 12 is a schematic diagram of another embodiment of a
prism for use in a system for producing edge-lit holograms;
[0038] FIG. 13A is a schematic diagram of another embodiment of a
system for producing edge-lit holograms;
[0039] FIG. 13B is a schematic diagram of one embodiment of
holographic recording material used for recording edge-lit
holograms;
[0040] FIG. 14 is a schematic diagram of a further embodiment of a
system for producing edge-lit holograms;
[0041] FIG. 15 is a schematic diagram of one embodiment of a system
for displaying an edge-lit hologram;
[0042] FIG. 16 is a schematic diagram of a one embodiment of a
system for displaying an interchangeable edge-lit hologram;
[0043] FIG. 17 is a schematic diagram of another embodiment of a
system for displaying an interchangeable, interactive edge-lit
hologram;
[0044] FIG. 18 is a schematic diagram of a further embodiment of a
system for displaying an edge-lit hologram;
[0045] FIG. 19 is a schematic drawing in section with portions
broken away of a system for displaying a monochrome edge-lit
reflective hologram incorporating a collimating and reflecting
holographic optical element in accordance with teachings of the
present invention;
[0046] FIG. 20 is a schematic drawing in section with portions
broken away of a system for displaying a two color edge-lit
reflective hologram having two holographic optical elements and two
illumination sources incorporating teachings of the present
invention; and
[0047] FIG. 21 is a schematic drawing in section with portions
broken away showing a system for displaying a full color edge-lit
reflective hologram having three holographic optical elements and
three illumination sources incorporating teachings of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0048] Preferred embodiments of the present invention and its
advantages are best understood by reference to FIGS. 1-21 of the
drawings, light numerals being used for like and corresponding
parts of the various drawings.
[0049] FIG. 1 is a diagram of one embodiment of a system, indicated
generally at 10, for producing horizontal parallax only (HPO)
edge-lit holograms. As shown, system 10 includes multiple object
beam heads 14 and multiple reference beam heads 18. However, it
should be understood that fewer or more object beam heads 14 and
reference beam heads 18 could be used. System 10 further includes a
frame 22 and a transparent plateholder 24 with a holographic
recording material 23. Frame 22 positions plateholder with the
holographic recording material 23 disposed thereon such that the
interference of an object beam from object beam heads 14 and an
edge-lit reference beam from reference beam heads 18 will record an
edge-lit hologram onto the holographic recording material.
Production optics such as object beam heads 14 and reference beam
heads 18 are preferably provided as part of system 10.
[0050] The present invention may be satisfactorily used to produce
full parallax and full color edge-lit holograms. The present
invention may also be satisfactorily used to produce edge-lit
holograms on a wide variety of holographic recording material
including but not limited to roll-to-roll film. The present
invention may be satisfactorily used with a wide variety of
equipment and techniques for positioning holographic recording
material, object beam heads and reference beam heads relative to
each other. The present invention is not limited to the specific
equipment and techniques which are described in more detail in this
written description.
[0051] In the embodiment of FIG. 1, a transparent plateholder 23 is
coupled to frame 22 and is positioned between object beam heads 14
and reference beam heads 18. Plateholder 23 may include, for
example, a glass plate. A holographic recording material, such as
silver halide or photopolymer film, may be coupled to plateholder
23. For example, the holographic recording material may be coupled
to the side of plateholder 23 proximate object beam heads 14 or the
opposite side of plateholder 23 proximate reference beam heads
18.
[0052] System 10 further includes light source 26 which may be
coupled to object beam heads 14 through respective optical fiber
cables 30. Light source 26 may also be coupled to reference beam
heads 18 through respective optical fiber cables 32. For some
applications, light source 26 may be satisfactorily coupled with
object beam heads 14 and reference beam heads 18 using a system of
mirrors and/or lenses (not expressly shown).
[0053] Light source 26 preferably provides a coherent light beam to
object beam heads 14 and reference beam heads 18. Light source 26
may be, for example, a monochrome laser or a red-blue-green laser.
A wide variety of lasers may be satisfactorily used as light source
26. Object beam heads 14 are preferably coupled to a computer 34
through respective video lines 36. Computer 34 uses serial
communications line 37 to provide control signals to a motor
controller 38. Motor controller 38 is, in turn, coupled through
communications lines 40 to a first axis motor 44 and a second axis
motor 48. Additionally, an index matching fluid pump 52 is
preferably coupled to reference beam heads 18 through respective
fluid tubes 56 and provides index matching fluid to reference beam
heads 18. As discussed below, reference beam heads 18 use the index
matching fluid to condition the edge-lit reference beams.
[0054] In operation, light source 26 provides a coherent light beam
to object beam heads 14 and reference beam heads 18. In the
illustrated embodiment, this coherent light beam is carried to
object beam heads 14 and reference beam heads 18 through optical
fibers 30 and 32. However, it should be understood that other
components, such as a system of mirrors, could carry the coherent
light beam to object beam heads 14 and reference beam heads 18.
[0055] After receiving a coherent light beam from light source 26,
object beam heads 14 direct an object beam toward the holographic
recording material. After receiving a coherent light beam from
light source 26, reference beam heads 18 condition or transform the
coherent light beam into a edge-lit reference beam. The edge-lit
reference beam simulates the angle and conditions of an
illumination source for displaying the edge-lit hologram. Reference
beam heads 18 then direct the edge-lit reference beam to interfere
with the object beam and to record an edge-lit hologram on the
holographic recording material.
[0056] System 10 of FIG. 1 is generally controlled through the
operation of computer 34. For example, computer 34 provides video
image signals for one or more spatial light modulators (SLMs) in
object beam heads 14. In general, an SLM is a device that can
display a two-dimensional image. Object beam heads 14 then pass the
object beam through the associated SLMs such that the interference
of an object beam and a respective reference beam will record a
holographic image on the holographic recording material.
[0057] Computer 34 may also provide control signals to the SLMs in
order to properly record each elemental hologram in the associated
one-step production process. Computer 34, through motor controller
38, also controls first axis motor 44 and second axis motor 48. As
such, computer 34 can effect the translation of frame 22. This
translation allows multiple portions of the holographic recording
material to be successively exposed to the interference of object
beams from object beam heads 14 and respective edge-lit reference
beams from reference beam heads 18. Thus, computer 34 coordinates
the images of the SLMs in object beam heads 14 with the movement of
frame 22 such that individual hogels can be successively recorded
on the holographic recording material to create a large edge-lit
hologram.
[0058] In system 10 of FIG. 1, object beam heads 14 can direct
respective anamorphically collimated object beams of the SLM image
to be projected upon the holographic recording material. Similarly,
reference beam heads 18 can direct respective anamorphically
collimated edge-lit reference beams to interfere with a selected
object beam. Each object beam/reference beam interference creates a
horizontal parallax only (HPO) holographic image. In this
embodiment, object beam heads 14 and reference beam heads 18 are
generally stationary. Frame 22 preferably translates the
holographic recording material along a first axis and a second axis
substantially perpendicular to the first axis. As mentioned above,
this translation allows multiple portions of the holographic
recording material to be successively exposed to the interference
of the object beams and respective edge-lit reference beams.
[0059] It should be understood that alternate arrangements can be
used to provide for a similar result. For example, in one alternate
arrangement, object beam heads 14 and reference beam heads 18 can
be coupled to the frame. The holographic recording material may
remain generally stationary, while the frame is operable to
translate the object beam heads and respective reference beam heads
in unison with each other such that multiple portions of the
holographic recording material are exposed to the interference of
the object beams and respective edge-lit reference beams. For other
applications object beam head 14 and reference beam head 18 may be
translated generally in unison with each other while frame 22
translates the holographic recording material at substantially the
same time. Teachings of the present invention may be satisfactorily
used to record an edge-lit hologram on roll-to-roll film or any
other type of holographic recording material.
[0060] FIG. 2 is a diagram of one embodiment of a system, indicated
generally at 12, for producing full parallax edge-lit holograms. As
shown, system 12 comprises many of the same components as system 10
of FIG. 1. However, in system 12, object beam heads 59 and
reference beam heads 60 differ from the analogous components in
system 10 of FIG. 1. In FIG. 2, object beam heads 59 and reference
beam heads 60 are operable to provide respective object beams and
collimated edge-lit reference beams. Interference between the
object beams and respective edge-lit reference beams may be used to
produce a full parallax edge-lit hologram on the holographic
recording material. The beam output of object beam heads 59 and
reference beam heads 60 can approximate in size, for example, an
elemental hologram or hogel. Therefore, object beam heads 59 and
reference beam heads 60 of system 12 may be smaller than required
for analogous counterpart components of an HPO recording system
such as system 10 to record the same size hologram.
[0061] FIG. 3 is a schematic diagram of one embodiment of an object
beam head 59 for use in a system for producing full color, full
parallax edge-lit holograms in accordance with the teachings of the
present invention. For the embodiment of FIG. 3, object beams 75
are carried by fiber optic cable 30 into object beam head 59.
Inside object beam head 59, fiber optic cables 64, 68 and 72 carry
the blue, green and red object beams, respectively, into lenses 76.
It should be understood, however, that other components, such as a
system of mirrors and/or lenses, may replace fiber optic cables 30,
64, 68 and 72 to carry desired object beams 75. In the embodiment
of FIG. 3, object beams 75 are transmitted by fiber optic cables
64, 68 and 72 to fiber optic tips 65, 69 and 73 which are located
in the focal planes of respective lenses 76. Object beams 75 then
pass through respective lenses 76, reflect off mirrors 77 (if
necessary) and pass through respective SLMs 80. Object beams 75
also pass through band-limited diffusers 84, which may be color
specific.
[0062] Lenses 76 operate to expand and collimate object beams 75
such that object beams 75 more evenly illuminate SLMs 80. In
general, SLMs 80 allow the production of full-color holographic
stereograms. In one embodiment, SLMs 80 comprise LCD panels of high
resolution, such as 1,280.times.1,024 pixels, where the total size
of each LCD panel is approximately 10 cm.times.10 cm. However,
smaller LCD panels may be used with the same or a different number
of pixels.
[0063] After passing through diffusers 84, object beams 75 are
directed through an optical combiner unit 88 that uses, for
example, two dichroic combiners in an "x" configuration (or other
suitable optical combiners) to combine the three object beams 75
into a single object beam 83. In the embodiment of FIG. 3, single
object beam 83 then passes through tail end optics 90.
[0064] As shown, tail end optics 90 comprises a first projection
lens 92 and a Fourier transform filter 94 that may remove undesired
effects such as, but not limited to, high frequency image
components like pixel or grid artifacts that result from an SLM
display with pixels separated by an opaque matrix.
[0065] The object beam 83 then passes through a second projection
lens 96 and a converging lens 100. The first projection lens 92 is
located such that images of SLMs 80 lie in the focal plane of first
projection lens 92. Fourier transform filter 94 is located in the
focal planes of both first projection lens 92 and second projection
lens 96. However, in alternate embodiments, tail end optics 90 may
not use first and second projection lenses 92 and 96 or the Fourier
transform filter 94. Lastly, converging lens 100 is located such
that its focal plane intersects an exposure plane 102 of the
associated holographic recording material.
[0066] FIG. 4 is a diagram of one embodiment of tail end optics 90
in object beam head 59 of system 12. As discussed above, tail end
optics 90 comprises first projection lens 92, Fourier transform
filter 94, second projection lens 96 and converging lens 100. As
shown, these components may be coupled to base platform 105. In the
embodiment of FIG. 4, lenses 92, 96 and 100 are preferably achromat
lenses for producing full color holograms. Alternatively, lenses
92, 96 and 100 may be monochrome lenses for recording monochrome
holograms. Tail end optics 90 of FIG. 4 may also include exposure
mask plate 103 with exposure aperture 104 disposed proximate
exposure plane 102. Exposure mask plate 103 may be used to limit
the object beam from over-exposing holographic recording material
placed in the adjacent exposure plane 102. For example, exposure
aperture 104 may be sized to approximately match a hogel. For some
alternative embodiments, tail end optics 90 may not include first
and second projection lenses 92 and 96 and/or Fourier transform
filter 94.
[0067] FIG. 5 is a diagram of one embodiment of tail end optics for
an object beam head in a system for producing HPO edge-lit
holograms. Tail end optics 91 of FIG. 5 can operate, for example,
in place of tail end optics 90 of FIGS. 3 and 4. Tail end optics 91
preferably includes a base platform 106 to which is coupled a first
projection lens 92, Fourier transform filter 94 and cylindrical
achromat lenses 110, 112, 114, 116 and 118. All of the components
are positioned in the path of an object beam. For some
applications, tail end optics 91 may be provided without projection
lenses 92, Fourier transform filter 94 and/or acromatic lenses 110
and 112.
[0068] In operation, tail end optics 91 produces an anamorphic
image of the image rendered by associated SLMs in the object beam
head. Thus, the effect of tail end optics 91 is to produce an
anamorphic object beam. For one application the resulting
anamorphic object beam may have a generally extended oval shaped
cross section. Interference between a proper edge-lit reference
beam in exposure plate 102 with the output beam from tail end
optics 91 will then produce an HPO edge-lit hologram on holographic
recording material positioned at exposure plate 102.
[0069] FIG. 6 is a diagram of one embodiment of a reference beam
head, indicated generally at 60, for use in a system for producing
full color, full parallax, edge-lit holograms. FIG. 7 is a top view
of reference beam head 60 of FIG. 6. Reference beam head 60 may be
used, for example, in system 12 of FIG. 2. As shown in FIGS. 6 and
7, optical fiber 32 carries a reference beam to reference beam head
60. Then, inside reference beam head 60, separate optical fibers
130, 132 and 134 carry green, blue and red beams, respectively, to
tips 137, 133 and 135. Alternately, a system of mirrors and/or
lenses may be used rather than optical fibers 130, 132 and 134 to
carry the desired reference beams.
[0070] A plurality of collimating lenses 138, 140 and 142 are
preferably coupled to an assembly base 131 and positioned proximate
respective tips 137, 133 and 135. For example, collimating lenses
138, 140, and 142 may be spherical collimating lenses. A dichroic
combiner 146 is also coupled to assembly base 131 and positioned to
receive beams from optical fibers 132 and 134. As shown, reference
beam head 60 further includes a prism 150 and a reservoir 154
coupled to assembly base 131.
[0071] In operation, tips 137, 133 and 135 are oriented to deliver
green, blue and red beams, respectively, to prism 150. As shown,
dichroic combiner 146 is positioned to receive two of the three
beams (e.g., the blue and red beams) to provide a combined beam of
the two beams to prism 150. Collimating lenses 138, 140 and 142 are
preferably positioned in a path of the respective beams and operate
to receive and condition the beams so that they can create a full
parallax edge-lit hologram when the beams eventually interfere with
an object beam.
[0072] For some applications in which a full parallax hologram is
produced, tips 137, 133 and 135 may be oriented relative to each
other at angles other than as shown in FIGS. 6 and 7. For example,
the respective red, blue and green reference beams may intersect
with each other at an angle of approximately ninety degrees
(90.degree.). Full parallax holograms may be satisfactorily
prepared in accordance with teachings of the present invention
without combining the red and blue reference beams as shown in
FIGS. 6 and 7.
[0073] Edge-lit full-color holograms are typically dispersive,
suffering from classic signal crosstalk problems when illuminated
with red, green, and blue light sources. Crosstalk between the
green and red illumination sources, and between the green and blue
illumination sources, is generally much worse than crosstalk
between the red and blue illumination sources since proximity of
respective light wavelengths is generally inversely proportional to
crosstalk problem. The present invention allows separating
respective illumination source angles, particularly where color
crosstalk may be most apparent.
[0074] A rectangular shaped edge-lit hologram with a red
illumination source on a first edge, a green illumination source on
a second edge extending approximately ninety degrees (90.degree.)
relative to the first edge, and a blue illumination source on a
third edge extending approximately one hundred and eighty degrees
(180.degree.) relative to the first edge in accordance with
teachings of the present invention would often exhibit
substantially no detectable color crosstalk. Placing the red and
blue illumination sources together on the first edge, and green
illumination source on the second edge extending approximately
ninety degrees (90.degree.) relative to the first edge, or the
third edge extending approximately one hundred and eighty degrees
(180.degree.) relative to the first edge in accordance with
teachings of the present invention, would also be acceptable
because red and blue wavelengths are far enough apart to be on the
same edge. As previously noted the present invention is not limited
to rectangular shaped edge-lit holograms.
[0075] In FIGS. 6 and 7, reservoir 154 preferably contains an index
matching fluid selected to have an index of refraction value
approximately equal to the index of refraction value associated
with optically transmissive materials in contact with prism 150.
Reservoir 154 is preferably formed to allow a layer of the selected
index matching fluid to be disposed between prism 150 and the
holographic recording material. Fluid tube 56 replenishes the
supply of index matching fluid to reservoir 154.
[0076] After striking prism 150, the reference beams travel through
prism 150. Prism 150 and the index matching fluid then operate
together to condition or transform the reference beam into an
edge-lit reference beam by changing the incidence angle of the
reference beam. After this conditioning, the intersection of the
edge-lit reference beam and the object beam can create an
interference pattern sufficient to form a full-parallax edge-lit
hologram.
[0077] FIG. 8 is a diagram of one embodiment of a reference beam
head, indicated generally at 18, for use in a system for producing
full color, HPO, edge-lit holograms. Reference beam head 18 may be
used, for example, in conjunction with system 10 of FIG. 1. As can
be seen, the embodiment of FIG. 8 is similar to the embodiment of
FIG. 6. However, collimating lenses 138, 140 and 142 are replaced
with anamorphic collimating lenses 160, 170 and 180, respectively.
Anamorphic collimating lenses 160, 170 and 180 condition the
respective reference beams sufficiently to create an HPO hologram
when interfered with by an appropriate object beam.
[0078] FIG. 9 is a diagram of one embodiment of a prism for use in
a system for producing full color edge-lit holograms. In the
embodiment of FIG. 9, prism 150 and reservoir 154 are coupled to
assembly base 131. In this embodiment, reservoir 154 is coupled to
assembly base 131 on one side of prism 150, and prism 150 is
preferably coupled flush to assembly base 131. Assembly base 131
is, in turn, coupled via index matching fluid to a transparent
plateholder 24 (e.g., FIGS. 1 and 2) which in turn receives
holographic recording material 23.
[0079] In operation, green reference beam 190 may enter prism 150
from one direction, and respective red and blue reference beams 192
may enter prism 150 from the opposite direction, as shown. Prism
150 then directs beams 190 and 192 towards plateholder 24 and
holographic recording material 23. Reservoir 154 preferably holds a
selected index matching fluid to allow a layer of index matching
fluid to be formed between and in contact with prism 150 and
transparent plateholder 24. This layer may be formed, for example,
using "capillary action."
[0080] Prism 150 and the layer of index matching fluid operate to
transform reference beams 190 and 192 into respective edge-lit
reference beams. As shown, an object beam 200 is directed from an
object beam head positioned on an opposite side of plateholder 24
and holographic recording material 23. Reference beams 190 and 192
and object beam 200 then intersect at holographic recording
material 23. Interference of the reference beams and respective
object beams will record an edge-lit hologram on holographic
recording material 23.
[0081] It should be understood that, in the embodiment of FIG. 9,
prism 150 and index matching fluid reservoir 154 can operate to
produce full color edge-lit holograms in both full parallax and
HPO. For full parallax, a reference beam head would collimate
reference beams 190 and 192. For an HPO edge-lit hologram, the
reference beam head would anamorphically collimate reference beams
190 and 192. As previously noted, full parallax holograms may be
satisfactorily formed without aligning the red and blue reference
beams coincident with each other.
[0082] FIG. 10 is a diagram of one embodiment of a prism for use in
a system for producing monochrome edge-lit holograms. Similar to
FIG. 9, prism 210 is coupled to assembly base 131. Reservoir 154 is
coupled to one side of prism 210. Transparent plateholder 24 is
then positioned proximate assembly base 131, and holographic
recording material 23 coupled to plateholder 24.
[0083] In operation, prism 210 and reservoir 154 perform
substantially the same function as prism 150 and reservoir 154 of
FIG. 9. However, in the monochrome embodiment of FIG. 10, only one
reference beam 214 is directed to prism 210. Thus, reference beam
214 passes through prism 210 and through a layer of index matching
fluid. Reference beam 214 then passes through transparent
plateholder 24 and interferes with a respective object beam 218 to
produce a monochrome edge-lit hologram on holographic recording
material 23. As was the case with respect to FIG. 9, prism 210 of
FIG. 10 can be used to produce full parallax or HPO holograms,
depending on the conditioning of the associated reference beam
214.
[0084] FIG. 11 is a diagram of one embodiment of a prism for use in
a system for producing edge-lit holograms. In particular, FIG. 11
illustrates one embodiment of the layer of index matching fluid
through which the reference beam passes. As shown, a prism 150 and
a reservoir 154, for holding index matching fluid, are coupled to
assembly base 131. A transparent plateholder 24 is positioned
proximate assembly base 131, and holographic recording material 23
is coupled to transparent plateholder on a side distant from prism
150. As shown, reservoir 154 is coupled to assembly base 131 on one
side of prism 150, and a layer 194 of index matching fluid extends
from reservoir 154 between prism 150 and a plateholder 24. In one
embodiment, reservoir 154 allows layer 194 to form between prism
150 and transparent plateholder 24 due to "capillary action." This
capillary action is the result both of the spacing between assembly
base 131, prism 150 and transparent plateholder 24 and of the
surface tension created by the proximity of those surfaces.
[0085] Thus, in operation, a reference beam can travel through
prism 150 and through layer 194 which will transform or condition
the reference beam into an edge-lit reference beam. In particular,
prism 150 and layer 194 direct the reference beam at a sufficiently
steep angle of incidence such that the edge-lit reference beam
approximates an eventual illumination source of the edge-lit
hologram to be produced. After passing through layer 194, the
edge-lit reference beam travels through transparent plateholder 24
and interferes with an object beam at holographic recording
material 23.
[0086] FIG. 12 is a diagram of another embodiment of a prism for
use in a system for producing edge-lit holograms. As with FIG. 11,
FIG. 12 particularly illustrates an embodiment of the layer of
index matching fluid through which the reference beam passes. As
shown, there are several differences between the embodiments of
FIG. 12 and FIG. 11. First, the embodiment of FIG. 12 includes a
mask layer 196 coupled to the bottom surface of prism 150.
Secondly, holographic recording material 23 is coupled to the
opposite side of transparent plateholder 24 and is proximate prism
150. In this embodiment, mask layer 196 allows precise control,
through sizing of an aperture, of the exposure area of holographic
recording material 23 by filtering out portions of the reference
beam. The size of the aperture in mask layer 196, for example,
could be the size of an elemental hologram.
[0087] FIG. 13A is a diagram of another embodiment of a system for
producing edge-lit holograms. In particular, FIG. 13A illustrates
the movement of holographic recorded material 256 within the
system. As shown, in this embodiment, holographic recorded material
256 moves from left to right. Four pinch rollers 250 are positioned
in contact with holographic recording material 256, and a fluid
spray applicator 254 is positioned proximate holographic recording
material 256. Prism 150 is positioned proximate holographic
recording material 256, and a pressure spring 257 is positioned to
be in contact with holographic recording material 256 below prism
150.
[0088] In operation, holographic recording material 256 travels
from left to right, and pinch rollers 250 operate to maintain
tension on holographic recording material 256. Pressure spring 257
then operates to maintain tension in holographic recording material
256 with respect to prism 150. In this embodiment, fluid spray
applicator 254 applies the index matching fluid (e.g., xylene) to a
top surface of holographic recording material 256. As described
above, prism 150 receives a reference beam and conditions the
reference beam to produce an edge-lit reference beam to strike
holographic recording material 256 and interfere with an object
beam (not shown). One advantage of the embodiment of FIG. 13A is
that an edge-lit hologram may be recorded without the need for a
plateholder in the production system.
[0089] FIG. 13B is a diagram of one embodiment of holographic
recording material 256 used for recording edge-lit holograms. In
this embodiment, holographic recording material 256 comprises
recording material 257. A top cover sheet 258 is coupled to a top
surface of recording material 257, and a bottom cover sheet 259 is
coupled to a bottom surface of recording material 257. Recording
material 257 can comprise, for example, silver halide film or a
photopolymer. Top cover sheet 258 and bottom cover sheet 259 may
comprise, for example, transparent polymers such as transparent
polyester (PEP) (preferably non-birefringent).
[0090] FIG. 14 is a diagram of a further embodiment of a system for
producing edge-lit holograms. As with FIG. 13A, FIG. 14
particularly illustrates the movement of holographic recorded
material 256 within the system. In this embodiment, holographic
recording material 256 comprises recording material 257, top cover
sheet 258 and bottom cover sheet 259 as shown in FIG. 13B. A first
roller 272 is positioned in contact with top cover sheet 258, and a
cylindrical prism coupler 274 is positioned proximate to and in
contact with recording material 256. A plateholder 270 is also
positioned proximate holographic recording material 256 as
shown.
[0091] In operation, holographic recording material 256 is moved
from left to right. During this movement, first roller 272 removes
top cover sheet 258 from holographic recording material 256.
Cylindrical prism coupler 274 then rotates in contact with
holographic recording material 257 as shown. In this embodiment,
cylindrical prism 274 will preferably index match to holographic
recording material 256 due to natural tackiness associated with
photopolymers and may be used to condition the associated reference
beam. Thus, it is a technical advantage of the system of FIG. 14
that an edge-lit hologram can be recorded without using index
matching fluid.
[0092] FIG. 15 is a schematic diagram representative of previously
available systems, indicated generally at 300, for displaying an
interchangeable edge-lit hologram. System 300 comprises a base 310
fixedly coupled to a plinth 314. Plinth 314 includes edge-lit
hologram 318 produced, for example, by one of the systems described
above. Further, an edge 320 of plinth 314 is fixedly attached to
base 310. A power source 330 is coupled to base 310 and may
include, for example, a battery. A light source 324 is positioned
within base 310 and provides light to a concave cylindrical lens
328. Light source 324 may include, for example, one or more light
emitting diodes (LED).
[0093] In operation, power source 330 provides power to light
source 324. Light from light source 324 enters concave cylindrical
lens 328 and then enters edge 320 of plinth 314. The light entering
edge 320 then acts as a proper illumination source and illuminates
hologram 318 such that the recorded image is reconstructed. In the
case of conventional edge-lit holograms, such illumination systems
must permanently fix edge 320 to base 310 to obtain effective
reconstructing light.
[0094] The present invention is not limited to producing or
displaying a hologram mounted on a plinth having a generally
rectangular configuration. The present invention may be
satisfactorily used to produce and/or display a hologram mounted on
a plinth having various configurations and multi-faceted shapes
such as a pentagon, hexagon, octagon, or a smooth curve such as
circular or oval shapes.
[0095] FIG. 16 is a diagram of a one embodiment of a system,
indicated generally at 340, for displaying an interchangeable
edge-lit hologram. In this embodiment, system 340 comprises a base
enclosure 342 formed to removably receive an edge 350 of a plinth
344. An edge-lit hologram 348 is mounted to plinth 344. A light
source 354 is positioned within base enclosure 342 and produces an
illumination beam to reconstruct edge-lit hologram 348. As shown,
system 340 further comprises power source 352 and concave
cylindrical lens 356. Power source 352 may include, for example, a
battery or A/C transformer. Light source 354 may include, for
example, one or more light emitting diodes (LEDs).
[0096] In operation, edge 350 of plinth 344 may be removably
coupled to base enclosure 342. When plinth 344 is in place, light
source 354 provides light to concave cylindrical lens 356 which in
turn illuminates edge-lit hologram 348. Because edge 350 is
preferably removably coupled to base enclosure 342, plinth 344 may
be removed, and a second plinth 360 with a second edge-lit hologram
362 may be coupled to base enclosure 342. Further, system 340 may
include a switch (not expressly shown) to activate and de-activate
light source 356. The switch may be positioned such that light
source 356 is activated whenever plinth 344 or 360 is coupled to
base enclosure 342 and is deactivated when no plinth is
installed.
[0097] FIG. 17 is a diagram of another embodiment of a system,
indicated generally at 370, for displaying an interchangeable
edge-lit hologram. As shown, system 370 comprises a base enclosure
374, and a plinth 378 is removably coupled to base enclosure 374.
An edge-lit hologram 376 is mounted to plinth 378. Multiple light
sources (not expressly shown) may be positioned within base
enclosure 374 and are preferably separately operable to illuminate
edge-lit hologram 376. Further, a plurality of switches 382 may be
coupled to base enclosure 374 to activate respective light sources.
In addition, plinth 378 may be removed from base 374 and
replaced.
[0098] In operation, multiple reference beams may be introduced to
plinth 378. This allows for multiple edge-lit holograms 376 to be
mounted onto plinth 378 and reconstructed with the multiple light
sources. Alternatively, if the multiple images are viewed
simultaneously, the reference beam intensities created by the light
sources may be independently varied. In addition, a sound system
may be installed into base enclosure 374 and be operable to
interact with the images displayed as well as buttons 382.
Alternatively, multiple plinths 378 may be stacked on top of each
other, each illuminated by a separate light source. Further, base
enclosure 374 may be operable to rotate plinth 378.
[0099] FIG. 18 is a diagram of a further embodiment of a system for
displaying an edge-lit hologram. As can be seen, the system of FIG.
18 includes an automated vending machine 380 which includes a base
enclosure 384. Plinth 386 may be releasably coupled or permanently
fixed to base enclosure 384 by one edge of plinth 386.
Alternatively, base enclosure 384 may be coupled to a plurality of
edges of plinth 386. In the embodiment of FIG. 18, base enclosure
384 and plinth 386 may be attached, for example, to a front door
382 of automated vending machine 380. Further, an edge-lit hologram
388 can be mounted to plinth 386. Base enclosure 384 preferably
includes a light source (not expressly shown) to illuminate and
reconstruct hologram 388. Plinth 386 may be removably coupled to
base enclosure 384 such that hologram 388 may be changed
periodically by changing plinth 386.
[0100] Portions of system 400 for displaying monochrome edge-lit
reflection hologram 402 are shown in FIG. 19. Display system 400
includes plinth 404 having a generally rectangular box type
configuration. Plinth 404 preferably includes first surface 410 and
second surface 412 which are disposed generally parallel with each
other on opposite sides thereof. For the embodiment of the present
invention represented by display system 400, first surface 410 and
second surface 412 each have a generally rectangular configuration
with approximately the same length and width. Plinth 404 also
preferably includes first edge 408 and second edge 414 which are
disposed on opposite ends from each other and extending between
first surface 410 and second surface 412. For the embodiment of the
present invention represented by display system 400, first edge 408
and second 414 have generally rectangular configurations with
approximately the same length and width.
[0101] Image hologram or reflection hologram 402 is preferably
mounted on first surface or side 410 of plinth 404. Holographic
optical element (HOE) 406 is preferably disposed along first edge
408 of plinth 404. HOE 406 may sometimes be referred to as a
hologram lens or mirror.
[0102] Monochrome light source or illumination source 416 may be
disposed adjacent to second edge 414 opposite from HOE 406. HOE 406
is preferably formed to reflect and collimate monochrome light from
illumination source 416. For some applications HOE 406 may be
described as an off-axis collimating HOE for use with a monochrome
light source. The dimensions of plinth 404 and HOE 406 and the
location of illumination source 416 are preferably selected so that
monochrome light from illumination source 416 striking HOE 406 will
be collimated and reflected at the required angles to strike and
illuminate image hologram 402. As a result, image hologram 402 will
be visible to a viewer looking at second surface 412 of plinth
404.
[0103] HOE 406 and other HOE's, which will be described later in
this written description, may be satisfactorily used to condition
light beams which converge or diverge according to requirements of
the specific image hologram that will be illuminated in accordance
with teachings of the present invention. Collimated light beams are
generally preferred for use as a reference beam when recording a
hologram and when illuminating the resulting hologram.
[0104] Portions of system 400a for displaying two color edge-lit
reflection hologram 402a are shown in FIG. 20. Display system 400a
preferably includes plinth 404a having a generally rectangular
box-type configuration similar to previously described plinth 404.
Image hologram 402a is preferably mounted on first surface or side
410 of plinth 404a. Plinth 404a also includes second surface 412
which is disposed generally parallel with first surface 410 on
opposite sides of plinth 404a.
[0105] First holographic optical element (HOE) 406a is preferably
disposed along first edge 408 of plinth 404a. Second holographic
optical element (HOE) 407a is preferably disposed along second edge
414 of plinth 404a. First light source or illumination source 416a
is preferably disposed adjacent to second HOE 407a opposite from
second edge 414 of plinth 404a. In a similar manner second
illumination source or light source 417a is preferably disposed
adjacent to first HOE 406a opposite from first edge 408 of plinth
404a.
[0106] For those applications in which image hologram 402 is a
horizontal parallax only (HPO) hologram first light source 416a and
second light source 417a are preferably disposed approximately 180
degrees opposite from each other. For those applications in which
image hologram 402b is a full parallax hologram, first light source
416a and second light source 417a may be disposed at an angle of
approximately 90 degrees relative to each other (not expressly
shown).
[0107] For purposes of describing various features of the present
invention, first illumination source 416a will be referred to as a
"green light source" and second illumination source 417a will be
referred to as a "red light source." However, the present invention
is not limited to use with only green and red illumination sources.
Other colored illumination sources may be satisfactory use with the
present invention depending upon characteristics of the associated
reflection hologram which will be displayed.
[0108] First HOE 406a is preferably formed to reflect and collimate
green light from first illumination force 416a. First HOE 406a may
be generally described as an off-axis collimating HOE for use with
a green light source. First HOE 406b is also preferably formed to
be substantially transparent with respect to red light from second
illumination source 417a. In a similar manner second HOE 407a is
preferably formed to reflect and collimate red light from second
illumination source 417a and to be substantially transparent with
respect to green light from first illumination source 416a. Second
HOE 406a may be generally described as an off-axis collimating HOE
for use with a red light source.
[0109] The dimensions of plinth 404a, first HOE 406a and second HOE
407a and the location of respective illumination sources 416a and
417a are preferably selected in accordance with teachings of the
present invention such that HOE 406a and 407a will collimate and
reflect green light and red light from respective illumination
sources 416a and 417a to strike reflection hologram 402a at the
required angles to illuminate the associated two color hologram
402b.
[0110] Portions of system 400b for displaying full color edge-lit
reflection hologram 402b are shown in FIG. 21. Display system 400b
preferably includes plinth 404b having a generally rectangular
box-type configuration. Plinth 404b may have substantially the same
dimensions and configuration as previously described plinths 404
and 404a. Image hologram or reflection hologram 402b is preferably
mounted on first surface or side 410 of plinth 404b.
[0111] First holographic optical element (HOE) 406b is preferably
disposed along first edge 408 of plinth 404b. Second holographic
optical element (HOE) 407b is preferably disposed along second edge
414 of plinth 404b. HOE 406b and HOE 407a may each be generally
described as an off-axis collimating HOE. First light source or
illumination source 416a is preferably disposed adjacent to second
HOE 407b opposite from second edge 414 of plinth 404b. In a similar
manner, second illumination source or light source 417a and third
illumination source or light source 418 are preferably disposed
adjacent to first HOE 406b opposite from first edge 408 of plinth
404b.
[0112] For purposes of describing various features of the present
invention, first illumination source 416a will be referred to as a
"green light source". Second illumination source 417a will be
referred to as a "red light source". Third illumination source 418
will be referred to as a "blue light source". However, the present
invention is not limited to use with only green, red and blue
illumination sources. Other colored illumination sources may be
satisfactorily used with the present invention depending upon
characteristics of the associated reflection hologram which will be
displayed.
[0113] First HOE 406b is preferably formed to reflect and collimate
green light from first illumination source 416a. First HOE 406b is
also preferably formed to be substantially transparent with respect
to red light from second illumination source 417a and blue light
from third illumination source 418. In a similar manner, second HOE
407b is preferably formed to reflect and collimate red light from
second illumination source 417a and blue light from third
illumination source 418. Second HOE 407b is also preferably formed
to be substantially transparent with respect to green light from
first illumination source 416a. The dimensions of plinth 404b,
first HOE 406b, and second HOE 407b, along with the location of
respective illumination sources 416a, 417a and 418 are preferably
selected in accordance with teachings of the present invention such
that HOEs 406b and 407b will collimate and reflect green, red and
blue light from respective illumination sources 416a, 417a and 418
to strike reflection hologram 402b at the required angle to
illuminate the associated full color hologram.
[0114] For those applications in which image hologram 402b is a
horizontal parallax only hologram, first light source 416a is
preferably disposed approximately one hundred eighty degrees
(180.degree.) opposite from second light source 417a and third
light source 418. For those applications in which image hologram
402b is a full parallax hologram, first light source 416a, second
light source 417a and third light source 418 may be disposed at
various angles relative to each other.
[0115] Holographic optical elements 406, 406a, 406b, 407, 407a and
407b are preferably formed from relatively thin, flat strips of
material having the previously described optical characteristics.
By combining holographic optical elements with illumination sources
such as shown in FIGS. 19, 20 and 21, each holographic optical
element will effectively fold or bend light from an associated
illumination source to substantially reduce the required distance
between the illumination source and the associated edge-lit
hologram. Previously available systems for displaying edge-lit
holograms often required a plinth which was much larger than the
associated image hologram. The increased size of such-plinths was
generally necessary to place the associated illumination source at
an appropriate distance to allow light from the illumination source
to strike the image hologram at required angles for illumination
thereof.
[0116] For illustrating various features of the present invention,
second light source 417a and third light source 418 are shown
disposed adjacent to each other along first edge 408 of plinth
404b. Depending upon the characteristics and configuration of the
associated plinth and the type of image hologram (full parallax or
horizontal parallax only), a first illumination source and its
associated HOE may be placed on a first pair of opposite edges.
Second illumination source and its associated HOE may be placed on
a second pair of opposite edges. Third illumination source and its
associated HOE may be placed on a third pair of opposite edges.
[0117] Although the present invention has been described in detail,
it should be understood that various changes, substitutions and
alterations can be made thereto without departing from the spirit
and scope of the invention as defined by the appended claims.
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