U.S. patent application number 09/942150 was filed with the patent office on 2002-03-14 for tiled fiber optic display apparatus.
Invention is credited to Lowry, Brian C..
Application Number | 20020031316 09/942150 |
Document ID | / |
Family ID | 23915483 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020031316 |
Kind Code |
A1 |
Lowry, Brian C. |
March 14, 2002 |
Tiled fiber optic display apparatus
Abstract
A fiber optic display apparatus consists of a plurality of
optical fibers which convey a projected image from an input, or
first surface, to a display, or second surface, whose area is
greater than or equal to that of the first surface, such that any
image projected on to the first surface appears enlarged on the
second surface. The second surface is comprised of tiles which
attach to adjoining tiles by means of flexible tabs and pliable
locator rods in such a fashion as to allow the second surface to
follow general contours (e g concave or convex), while the optical
fiber bundles from each tile are collected into a fixture to form
the first planar surface Because of the modular design of the
display it can be assembled or disassembled rapidly A
light-diffusing thin sheet or film is applied to the front of each
tile of the second surface to effectively increase the numerical
aperture of each fiber, thus producing a uniform wide-angle
distribution of light from each fiber end and enabling viewing from
any angle in front of the display.
Inventors: |
Lowry, Brian C.; (Emlenton,
PA) |
Correspondence
Address: |
PEPPER HAMILTON LLP
Attn: James M. Singer
50th Floor
500 Grant Street
Pittsburgh
PA
15219
US
|
Family ID: |
23915483 |
Appl. No.: |
09/942150 |
Filed: |
August 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09942150 |
Aug 29, 2001 |
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09482290 |
Jan 13, 2000 |
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6304703 |
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Current U.S.
Class: |
385/120 ;
362/559; 385/115; 385/901 |
Current CPC
Class: |
G02B 6/06 20130101; Y10S
385/901 20130101; G02B 6/4298 20130101; G02B 6/32 20130101; G09F
9/305 20130101 |
Class at
Publication: |
385/120 ;
385/115; 385/901; 362/559 |
International
Class: |
G02B 006/08; G02B
006/04 |
Claims
We claim:
1. A multiply-contoured optical display (1) consisting of a
plurality of tiles (2), a dual input matrix assembly (9), a display
surface (3) and a connecting means between assembly (9) and surface
(3) for the purpose of conveying and, in general, enlarging images:
a structural frame (14) and matrix of flexible horizontal and
vertical locator rods (16) which attach to the tiles (2) to provide
stability to the display (1); a means of projecting spatially
modulated light images onto the input assembly (9) of said display
(1); a means of connection between tiles (2) which allows a
multiply-contoured or display of virtually any size and/or
shape.
2. The display (1) of claim 1 in which the display surface (3) is
partially or fully covered by a holographic diffusion film to act
as a light-shaping diffuser for the purpose of increasing the
effective numerical aperture of the fibers and thus creating a
uniform distribution of light irrespective of viewer position
(viewing angle).
3. The display (1) of claim 1 in which the connecting means between
input assembly (9) and the display surface (3) is comprised of
fiber optics (5) or other type of optical light guide, which
terminate on display surface (3) and are collected into a pigtail
(6)
4. The display (1) of claim 3 in which a mechanism is provided for
quickly connecting and disconnecting the fiber pigtails (6) from
the rear of the display tiles (2) for the purpose of rapid setup
and take-down of the display (1) which involves an optical coupler
(20) attached to both tile (2) and pigtail (6)
5. The display (1) of claim 3 in which the distal fiber optic ends
(5) are recessed in orifices (4) in the display surface (3) such
that the point of light emitted from each distal fiber end (5) is
enlarged by the holographic diffusion film on the display surface
(3).
6. The display (1) of claim 1 in which the means of projection
consist of any type of spatial light modulator (19), whether
transmissive or reflective, for the purposes of conveying moving or
static images to the input assembly (9).
7. The display (1) of claim 1 in which the dual input assembly (9)
consists of two distinct components, a primary (11) for forming a
projection surface (10) by organizing the pigtails (6) in a matrix
in horizontal and vertical directions, and a secondary (12) for
fixing the pigtails (6) in such a fashion so as to limit their
movement in a direction perpendicular to the plane formed by the
projection surface (10) by fixing a collar (13) to said fiber
pigtail (6).
8. The display (1) of claim 1 in which the dual input assembly (9)
receives a plurality of pigtails (6) from said display tiles (2),
distributed in a regular array corresponding one-to-one to the
arrangement of the display surface tiles (2), such that the
pigtails (6) and their associated display tiles (2) can be readily
removed and replaced
9. The display (1) of claim 1 in which the structural frame (14)
consists of tubular or extruded metal or plastic elements to which
are attached pliable horizontal and vertical locator rods (16)
which give structural stability to the surface created by joining
the display tiles (2)
10. The display (1) of claim 1 in which the display tiles (2) are
square, rectangular, or, in general, polygonal in shape with
flexible tabs (7) on each of four or three sides
11. The display (1) of claim 1 in which the means of connection
between tiles (2) are flexible tabs (7) on the side of tile (2)
attached to clips (8) which allows for a multiply -contoured or
planar display (1) of virtually any size and/or shape.
12. The display (1) of claim 1 in which the display tile (2) is
molded or machined in such a fashion as to allow for a range of
pixel densities so that the same tile assembly may be used for a
wide variety of display applications.
13. The display (1) of claim 1 in which the means of connection
between multiple display tiles (2) can be an interstitial webbing
(18) of plastic, canvas, or other fabric or material, which aids in
the rapid set-up, take-down and ease of storage and transportation
of said display (1)
14. A multiply-contoured optical display (1) consisting of a
plurality of tiles (2) attached to each other by tabs (7) with a
display surface (3) containing a holographic diffusion film, a dual
input assembly (9) connected to said tiles (2) by fiber optics (5)
grouped into pigtails (6) for purpose of conveying and enlarging
images and recessed in orifice (4) in display surface (3) such that
a point of light from optics (5) is enlarged by diffusion film on
display surface (3), said dual input assembly (9) containing a
primary assembly (11) for forming a projection surface (10) by
organizing the fiber pigtail (6) in a matrix in horizontal and
vertical directions, and a secondary assembly (12) for fixing the
fiber pigtail (6) to limit movement in direction perpendicular to
plane formed by said projection surface (10) by fixing a collar
(13) to said fiber pigtail (6); a structural frame (14) with
locator rods (16) attaching to tiles (2) to provide stability to
display (1); a spatial light modulator (19) for conveying moving or
static images to dual input assembly (9).
15. A display (1) of claim 14 in which said fiber optics (5)
connected to said tiles (2) may be quickly connected or
disconnected by way of an optical coupler (20).
16. A multiply-contoured optical display (1) consisting of a
plurality of tiles (2) attached to each other by an interstitial
webbing with a display surface (3) containing a holographic
diffusion film, a dual input assembly (9) connected to said tiles
(2) by fiber optics (5) grouped into pigtails (6) for purpose of
conveying and enlarging images and recessed in orifice (4) in
display surface (3) such that a point of light from optics (5) is
enlarged by diffusion film on display surface (3); said dual input
assembly (9) containing a primary assembly (11) for forming a
projection surface (10) by organizing the fiber pigtail (6) in a
matrix in horizontal and vertical directions, and a secondary
assembly (12) for fixing the fiber pigtail (6) to limit movement in
direction perpendicular to plane formed by said projection surface
(10) by fixing a collar (13) to said fiber pigtail (6); a
structural frame (14) with locator rods (16) attaching to tiles (2)
to provide stability to display (1); a spatial light modulator (19)
for conveying moving or static images to dual input assembly
(9).
17. A display (1) of claim 16 in which said fiber optics (5)
connected to said tiles (2) may be quickly connected or
disconnected by way of an optical coupler (20).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] According to Stanford Resources, the Large Screen Display
(LSD) market will generate revenues of nearly $4 billion annually
by 2002.sup.1. LSD's are typically used in sports stadia and
arenas, airports, casinos, and areas of high pedestrian and
vehicular traffic. High initial cost, high maintenance costs,
installation requirements, and lack of robustness have prevented
current LSD technologies from more quickly penetrating the
marketplace. Moreover, current LSD technology is limited to two
dimensions (i.e. planar displays), and thus is not as appealing for
new LSD uses such as interactive gaming and immersive environments
such as simulators, and integration with architectural structures.
.sup.1"Large Screen Formation Displays--Market Trends,
Technologies--Applications," Third Edition 1995-96, Stanford
Resources, Inc.
[0003] Fiber optic LSD's offer substantial improvements over
current CRT- and LED-based displays, due to their smaller depth,
lighter weight, and elimination of sensitive and expensive
electronic components on the surface of the display. Because the
displayed image is generated by a data/video projector, LCD panel,
or other equivalent spatial light modulator, fiber optic displays
are not "resolution bound" as are LED and CRT displays, which are
comprised of a fixed number of RGB pixels on the display surface
Furthermore, fiber optic LSD's generate neither heat nor EMI at the
display surface.
[0004] Fiber optic displays, however, are not without shortcomings.
One of the most difficult technical problems of LSD's is the tiling
or "shingling" effect due to slight misalignment of the many tiles
of which the display is comprised. This problem is made worse in
fiber optic displays, where it is imperative that the fibers
terminate on the display at precisely right angles. Without such
precise termination, the displays appear to lack uniformity in
brightness. Since the human visual system is very adept at pattern
recognition, means must be taken to mitigate the effects of the
inter-tile mullions as well as the alignment and termination of the
fiber terminals.
[0005] 2. Description of Related Art
[0006] Several LSD's have been successfully constructed using
optical fiber, and modular displays have been patented. However,
because of the method by which the modules are joined, as well as
the lack of a suitable light-shaping diffusion element at the
display surface, current displays cannot be contoured.
[0007] The use of smaller tiles is based upon the concept of a
"throw-away" display In other words, if one or more of the tiles
are damaged (e.g., by the impact of a rock or other hard object),
they can be discarded and replaced in the field at minimal cost,
without dismantling the entire display
[0008] U.S. Pat. No. 5,832,168 discloses a fiber optic display
comprised of modules which can be adjusted both horizontally and
vertically to eliminate the shingling effect. Because of the
two-dimensional alignment mechanism, contoured display surfaces are
not feasible with this invention No lensing process is discussed in
this patent, a feature that is essential for contoured
displays.
[0009] U.S. Pat. No. 5,818,998 discloses a portable fiber optic
LSD. The specific embodiment disclosed is not modular, however, and
may only be contoured by wrapping it around a contoured object.
[0010] U.S. Pat. No. 5,381,502 discloses a thin or curved display
comprised of fixed waveguides. Because of its reliance on a
scanning device, such as a laser, for producing the image, the
physical dimensions and contours of the display are limited. As
with the preceding patent, the display is not modular.
BRIEF SUMMARY OF THE INVENTION
[0011] A novel solution to many of these limitations is the intent
of the present invention. A contourable fiber optic display
apparatus comprised of modular tiles is disclosed. Despite the
possible contours introduced by the tiles, the display can be
viewed from any angle because the luminance from each tile is
essentially constant The application of the light diffusing film
obscures each distal fiber end to the point that the human eye
cannot detect small tile misalignments or mullions Moreover, the
small, lightweight tiles are comprised entirely of rugged materials
and plastic optic fiber, making the display ideal for "harsh"
environments A method of construction is described which allows the
display tiles to be semi-permanently joined by flexible members
such that the entire LSD can be quickly set up and taken down and
can be easily stored in a small place for transport. Such a display
is ideal for military field use, for outdoor sporting events, and
for trade shows Permanent displays can be fabricated as well
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 depicts an example of a contoured large screen
display.
[0013] FIG. 2 shows three views--front (FIG. 2A); side (cut-away)
(FIG. 2B); and rear perspective view (FIG. 2C) of a specific
embodiment of the present invention.
[0014] FIG. 3 shows a rear perspective view of a modular display,
showing the relationship between display tiles and their
corresponding inputs.
[0015] FIG. 4 shows five views, a front/back (FIG. 4A); side (FIG.
4B); top (FIG. 4C); and perspective (FIG. 4D) of the design of the
fiber bundle collars used in the secondary input matrix. FIG. 4E
shows how the fiber bundle collars are attached to each other and
to the secondary input matrix
[0016] FIG. 5 shows a block diagram of a complete LSD system,
including projector, primary and secondary input matrices, and
display surface
[0017] FIG. 6 shows how a piece of material can be cut out to form
an interstitial webbing that can be used to hold display tiles in
proximity in a secondary embodiment of the present invention
[0018] FIG. 7 shows two views; a top (FIG. 7A); and front
perspective (FIG. 7B) of a simple mechanism for quickly connecting
optical fiber bundles to display tiles.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention is an LSD comprised of a matrix or
array of tiles. An exemplary multiply-contoured optical display (1)
is illustrated in FIG. 1 Each display consists of a plurality of
equally sized tiles (2) adjoined to each other and/or a structural
frame (14), in rows and columns, and supported by flexible support
rods (16), as may be viewed in FIG 3 FIGS. 2A-C are referred to in
the following description of the display tiles. Each display tile
(2) is assembled from parts made of injection-molded plastic, ABS,
polycarbonate, or other material appropriate to the environmental
conditions in which the display will be deployed. The size of each
tile (2) is sufficiently small as to allow the radius of curvature
required to contour the display in the desired fashion, with
smaller tiles (2) allowing a smaller radius (greater curvature) In
the specific embodiment disclosed, the tile size is a 152 mm (6 in)
square, and is comprised of three distinct parts a front piece, a
lower cowl, and an upper cowl, which are snapped and cemented
together after the fibers are inserted into front the piece, as is
standard in the art The lower and upper cowls, in addition to
protecting the fibers, serve as a strain relief for the fiber
bundle (6) The display surface (3) of each tile is perforated by a
matrix of concave orifices (4) into which the distal fiber optic
ends (5) terminate as may be viewed in FIGS. 2A and 2B. The
half-angle of the concave orifices (4) must correspond to the
numerical aperture (NA) of the fiber used, such that the cone of
light emitted from the distal fiber (5) end is not occluded or
limited. The fiber optic strands are collected into a pigtail (6)
and are run out of the rear of the enclosed tile (2) as shown in
FIGS. 2B and 2C. The tile assembly (2) is then filled with
expanding foam that serves to both insulate and protect the fiber
optic strands enveloped therein. On the surface of the display (3),
the fiber terminals (5) are located so that they are slightly
recessed with respect to the tile surface as is illustrated in FIG.
2B, and are affixed with optical epoxy (e.g., EpoTek 301). A
light-shaping diffusion film, preferably a holographic diffusion
film with very high optical transmission and low back-scattering,
is then applied to the display surface (3) of each tile (2). The
diffusion film is stamped out in such a manner as to leave
approximately 30% of the tile surface exposed, as illustrated in
FIG. 2A. Exposing greater or lesser percentages of the tile with
the holographic diffusion film relates to the application of the
display. For example, indoor displays requiring higher pixel
densities may have up to 100% of the tile surface covered by the
holographic film. The base material chosen for the tile (2) must be
black, with a matte or stippled surface in order to enhance the
contrast of the display by absorbing ambient light. Alternatively,
a translucent or light-diffusing material may be used for the base
material. In this case, black, light-absorbing material may be
adhered, or silk-screened onto the tile surface to achieve the same
effect as illustrated in FIG. 2A. The pitch or spacing between
adjacent distal fiber ends (5) is determined by the application, so
that displays to be used for proximal viewing will have a higher
pixel density than displays used for viewing at a distance In the
specific embodiment disclosed, the display surface (3) is designed
with a matrix of orifices spaced 4 mm on center, so that pixel
pitches in multiples of 4 mm may be used (e.g., 4 mm, 8 mm, 16 mm,
etc) The present invention uses a uniform 8 mm on center pitch in
both the vertical and horizontal axes The distal fiber ends (5) on
the perimeter of the tile are situated half of the pixel pitch, or
4 mm, from the tile edge, so that when several tiles are joined,
the 8 mm pitch is preserved Each tile (2) is designed with tabs (7)
along each of its four sides (edge tiles may have only three tabs
and corner tiles only two tabs) as shown in FIG. 2. The tabs (7)
although part of each tile (2), are flexible. Each tile (2) is
joined to its four (or three) neighboring tiles by means of a clip
(8) which are inserted around and slid over adjacent tabs.
Alternatively, several different clip widths can be made which
"force" the adjoining tiles to be disposed at specific angles.
[0020] Optionally, in a secondary embodiment of the invention, an
interstitial fabric webbing (18) can be used to semi-permanently
locate each tile in proximity to its neighbors as is illustrated in
FIG. 6. In FIG. 6, the white areas (17) correspond to the portion
of the material that is cut out, while the shaded areas (18)
correspond to the material itself During assembly of the tiles, the
front piece of each tile is placed in front of the material (18),
the tabs (17) and locator pins inserted through the material, and
then the two rear cowl pieces are snapped and cemented onto the
front piece as is standard in the art Such a webbing (18)
facilitates a more rapid set-up and tear-down of the display if it
is to be used for a temporary application To further aid in rapid
set-up and take-down of the display, an optical coupler (20) may be
used where the fiber bundle emerges from the rear of the tile as
illustrated in FIGS. 7A and 7B. The optical coupler (20) is
attached to each fiber bundle (6) by means of a collar which has a
mating attachment fixed to the rear of the display tile assembly
(2), as may be viewed in FIGS. 3 and 4E. By separating the fiber
bundle from the display tile, a matrix of display tiles, joined by
interstitial webbing (18) may be folded in the same fashion as a
map Efficient optical coupling between fiber bundles is achieved by
the use of spherical refractive, or diffractive microlens arrays
such as are known by those skilled in the state of the art The
fiber bundles may be color coded according to length, and each
bundle may be marked so as to make clear its orientation
[0021] The fiber pigtail (6) emerging from the rear of each tile
(2) is jacketed so as to protect the fibers from damage. The fiber
pigtails are then collected into a dual input matrix assembly (9)
which collectively forms the projection surface (10) as shown in
FIGS. 3 and 5. The primary input matrix assembly (11) is designed
in such a way as to allow for two degrees of freedom such that a
wide range of display sizes and formats (e.g., 3:4 or letterbox)
can be accommodated. A secondary input matrix (12) interposed
between the display tiles and the primary input matrix (11), limits
the motion of the fiber pigtails (6) in the direction longitudinal
to the path of light through the system. This is achieved by
affixing a collar (13) at a fixed distance from the polished end of
each fiber pigtail as show in FIGS. 4A-E. The collars (13) consist
of male and female tabs that lock together so that all of the
collars (13) are coplanar. This aspect of the dual input matrix
assembly (9) is essential in that if the fiber pigtail input ends
are not coplanar, an image projected onto the projection surface
(10) will have segments that are out of focus The input matrix
assembly (9) may be disposed at any angle or position relative to
the display (1) as constrained by the location of the display
installation
[0022] A structural frame (14) may be used in non-permanent
applications as may be viewed in FIG. 3 Such a frame (14) may be
constructed of extruded or tubular aluminum plastic, or other
suitable material Each display tile (2) has a series of vertical
and horizontal locator passages (15) through which flexible locator
rods (16) pass Alternatively, the locator passages can be formed
into the clips (7) that are used to attach adjoining tiles as shown
in FIGS. 2B, 2C, and 3. The locator rods (16) can then be attached
to the top, bottom, and two sides of the structural frame as
illustrated in FIG. 3 The projection device (19) and other
electronics are disposed in a separate enclosure from the display.
After the display is assembled, the projector assembly is mounted
to the input matrix assembly (9), as may be viewed in FIG. 5
SUMMARY AND CLAIMS
[0023] The fiber optic display screen of the present invention
provides a novel method for forming modular contoured or planar
displays from small, inexpensive tiles, while still maintaining
uniform viewing from any position or angle Moreover, the display is
rugged and portable. Although specific embodiments are disclosed
herein, such embodiments are not intended to limit the scope of the
following claims
* * * * *