U.S. patent application number 12/184043 was filed with the patent office on 2010-02-04 for wide angle immersive display system.
Invention is credited to Michel Doucet.
Application Number | 20100027093 12/184043 |
Document ID | / |
Family ID | 41608058 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100027093 |
Kind Code |
A1 |
Doucet; Michel |
February 4, 2010 |
WIDE ANGLE IMMERSIVE DISPLAY SYSTEM
Abstract
A wide angle display system, comprising a scanner having at
least one reflective surface and an axis of rotation, a dome having
a reflective inner surface, the inner surface having an axis of
revolution which is coincident with the axis of rotation of the
scanner, at least one linear arrangement of light sources producing
beams of light. The reflective surface of the scanner reflects the
beams of light towards the reflective inner surface of the dome
which in turn collimates the beams of light and reflects them
towards an observer positioned within the wide angle display
system.
Inventors: |
Doucet; Michel; (Sainte-Foy,
CA) |
Correspondence
Address: |
UNGARETTI & HARRIS LLP;INTELLECTUAL PROPERTY GROUP - PATENTS
70 WEST MADISON STREET, SUITE 3500
CHICAGO
IL
60602-4224
US
|
Family ID: |
41608058 |
Appl. No.: |
12/184043 |
Filed: |
July 31, 2008 |
Current U.S.
Class: |
359/225.1 |
Current CPC
Class: |
G02B 30/40 20200101;
G02B 17/08 20130101; G09B 9/32 20130101; G02B 26/10 20130101 |
Class at
Publication: |
359/225.1 |
International
Class: |
G02B 26/10 20060101
G02B026/10 |
Claims
1. A wide angle display system, comprising: a scanner having at
least one reflective surface and an axis of rotation; a dome having
a reflective inner surface, the inner surface having an axis of
revolution which is coincident with the axis of rotation of the
scanner; at least one linear arrangement of light sources producing
beams of light; and wherein the reflective surface of the scanner
reflects the beams of light towards the reflective inner surface of
the dome which in turn collimates the beams of light and reflects
them towards an observer positioned within the wide angle display
system.
2. A wide angle display system according to claim 1, whereby in use
the synchronous addressing of the linear arrangement of light
sources with the rotation of the scanner allows the generation of
images appearing to come from an infinite radius screen.
3. A wide angle display system according to claim 1, further
comprising a shaping module associated with each of the at least
one linear arrangement of light sources for aiming the beams of
light at the reflective surface of the scanner.
4. A wide angle display system according to claim 3, wherein the
shaping modules are shifted along and angularly around the axis of
revolution of the dome.
5. A wide angle display system according to claim 3, wherein the
shaping module includes: a collecting group for transforming
characteristics of the beams of light; and a converter for
adjusting the divergence of the beams of light and redirecting the
beams of light from the linear arrangement of light sources towards
the collecting group.
6. A wide angle display system according to claim 4, wherein the
characteristics include direction, divergence and wavefront.
7. A wide angle display system according to claim 4, wherein the
converter includes at least one element selected from a group
consisting of a refractive component, a reflective component, a
diffusing element, a diffractive element, optic fibers, fiber
optics faceplate and an array of micro components.
8. A wide angle display system according to claim 3, wherein each
shaping module is located inside the dome.
9. A wide angle display system according to claim 3, wherein each
shaping module is located outside the dome.
10. A wide angle display system according to claim 9, wherein the
dome includes input ports associated with each shaping module for
introducing the beams of light inside the dome.
11. A wide angle display system according to claim 10, wherein an
outside surface of the input ports is shaped so as to deviate the
beams of light.
12. A wide angle display system according to claim 10, wherein an
outside surface of the input ports is shaped so as to correct
aberrations in the beams of light.
13. A wide angle display system according to claim 1, wherein the
reflective inner surface is symmetrical about the axis of
revolution of the dome.
14. A wide angle display system according to claim 1, wherein the
reflective inner surface has an ellipsoidal profile having a first
and second focal points and wherein the scanner is positioned at a
first focal point and the observer is positioned at the second
focal point.
15. A wide angle display system according to claim 1, wherein the
at least one reflective surface of the scanner is encapsulated
within a profiled transparent body.
16. A wide angle display system according to claim 15, wherein the
profiled transparent body is generally cylindrical in shape about
the axis of revolution of the dome.
17. A wide angle display system according to claim 15, wherein the
profiled transparent body includes a plurality of layers having
different refraction indexes.
18. A wide angle display system according to claim 17, wherein at
least one of an inner or outer surface of one of the layers is
profiled so as to provide a desired optical correction.
19. A wide angle display system according to claim 1, wherein the
at least one linear arrangement of light sources includes a line of
elements selected from a group consisting of LEDs and illuminated
micro-mirrors.
20. A wide angle display system according to claim 1, wherein the
axis of revolution of the dome is tilted with respect to the
nominal sight direction of the observer.
21. A wide angle display system according to claim 1, further
comprising a second dome, the two domes having coincident axes of
revolution.
Description
TECHNICAL FIELD
[0001] The present invention relates to display systems. More
specifically, the present invention relates to a wide angle
immersive display system for simulators, for example flight
simulators.
BACKGROUND
[0002] A simulator is a system that attempts to replicate, or
simulate, a given experience by performing operations as
realistically and as close as possible to the real experience for
training, investigation or development purposes. A well known type
of simulator is the flight simulator, which is used to train
pilots. The majority of simulators require high performance display
systems in order to emulate the visual environment in as realistic
a manner as possible.
[0003] For some types of simulation, for example flight simulation,
the visual environment generally consists in a set of objects
located at great distances away from the observer. For such types
of simulation, conventional display systems that produce a dynamic
structured pattern of light, such as a matrix of pixel, on a
surface, for example a screen, do not allow a realistic simulation
of the visual environment. Such display systems allow the emulation
of the visual context but the objects, i.e. the sources of light,
still appear to come from short distances away. The visual context
thus suggests large distances but the physiological responses of
the eye reveal another reality. This is an important disadvantage
since this contradictory information may alter the observer's
perception or even cause illness. This problem is not present in
the case of a display system using a collimated screen. Such a
display system produces a collimated beam for each individual
picture element, i.e. pixel, which emulates the real set of beams
corresponding to a real scene consisting of distant objects.
[0004] For a realistic experience, images should extend over a wide
angle of view. Thus, the observer has the impression of being
immersed in the action when he or she is surrounded by the images
over an important part of his viewing space.
[0005] The Head-Up Display (HUD) that equips most modern fighter
aircrafts is a well known example of a collimated display. A HUD is
used to project information in the nominal line of sight of the
observer by means of a partially reflective or dichroic (color
selective reflection) window. The HUD is a see through device since
it allows the pilot to see both the outside scene and the projected
information. The image projected by a HUD is a virtual image and
appears to be located at far away in front of the pilot. This is
accomplished with a large projection lens. The display is located
close to the back focal surface of the optical system which results
in the production of a virtual image located at a great distance
away from the observer. The window may be either flat or curved.
Conversely to the flat window, the curved window possesses an
optical power and contributes to the optical power of the global
optical system. The field of view of a HUD is generally small,
15-20 degrees and 30-40 degrees respectively for flat and curved
window, respectively.
[0006] Collimated displays have been designed specifically for
simulator purposes. There exist many types of such displays. The
most simple type consists of a video display (CRT, LCD etc.)
located at the focal plane of a large lens. A collimated beam with
the specific propagation direction is produced for each pixel of
the display. The observer is located on the other side of the lens
and he or she sees the image as if it was located at an infinite
distance in front of the device. Because of weight, size and cost,
a conventional glass lens is generally not useable for this type of
collimated display configuration. Referring to FIG. 1, such
collimated display 10 generally use Fresnel lenses 12 placed
between a display device 14 and the observer 1 in his or her line
of sight 16. In practice, the collimating lens 12 may consist of a
plurality of Fresnel lenses in order to allow an acceptable
correction of the optical aberrations. The Fresnel lens virtual
display approach has been used, for example, by McDonnell Douglas
in the design of the Vital IV system and by Boeing.
[0007] Concave mirrors may also be used to make collimated
displays. There exist at least two main optical configurations of
such collimated displays, which are the on axis and the off axis
configurations. Referring to FIG. 2, the on axis configuration 20
consists of a display device 22, a beam splitter 24 and a concave
mirror 26. The beams of light 23 from the display device 22 is
reflected on the beam splitter 24 and reflected towards the concave
mirror 26. The concave mirror 26 then reflects and collimates the
beams of light 27 back through the beam splitter 24 towards the
observer 1. In general, the beam splitter 24 is simply a partial
reflectivity flat window and has no optical power. The beam
splitter 24 acts as a folding mirror for the object space part of
the optical path and as a window for the rest of the path. For the
object space part of the optical path, the display system is
equivalent to having the display device 22 located directly in
front of the concave mirror 26 at the position corresponding to the
virtual image 25 formed by the beam splitter 24. On the other hand,
the off axis mirror configuration 30, shown in FIG. 3, uses an off
axis portion 31 of a concave mirror 32 to reflect beams of light 35
from a display device 34 towards the observer 1 and achieve the
same goal of producing a distant virtual image without requiring
the use of a beam splitter. The off axis configuration 30 is much
more energy efficient in comparison to its on axis counterpart
20.
[0008] There exists a variant of the concave mirror configurations
20, 30 commercialized under the name Pancake Window.TM. by Farrand
Optical Company. The Pancake Window.TM. optical system 40,
illustrated in FIG. 4, uses a partially reflective concave mirror
42 together with a flat beam splitter 44 and different types of
polarizing components 46 (quarter-wave plates 46a and linear
polarizers 46b). The polarizing components 46 are used to eliminate
undesirable ghost images and reflections. The polarizing components
46 have the shape of thin flat sheets having their normal axis
coincident with the optical axis 41 of the optical system 40. The
beam splitter 44 also has its normal coincident with the optical
axis 41 of the optical system 40. The display device 48 is located
behind the concave mirror 42. In the object space path 49, the
beams of light 47 from the display device 48 pass through the
concave mirror 42 and are reflected back toward the concave mirror
42 by the beam splitter 44. The beams of light 47 are then
reflected by the concave mirror 42 and pass through the beam
splitter 44. Most of the beams of light 47 with optical paths
different than the nominal path 45 are eliminated by the polarizing
components 46. In an alternative version, the concave mirror 42 may
be replaced by a holographic element with similar optical
properties. The optical system 40 is relatively compact and
provides a relatively large field of view (60 degrees by 90
degrees) but it is not energy efficient. It has a transmission of
only about 1%. This is an important drawback since this imposes a
limitation on the image brightness.
[0009] Collimated displays have also been made using only
holographic elements, as shown in FIG. 5. Such collimated display
50 consists of a holographic diffusing screen 52 with a holographic
lens 54. The image to be displayed is projected by a projector 56
on the holographic diffusing screen 52. The holographic diffusing
screen 52 is used to control the light divergence to ensure that
each image pixel produces a cone of light which illuminates the
entire surface of the holographic lens 54. The intermediary image
53 on the holographic diffusing screen 52 is located on the front
focal plane of the holographic lens 54. The holographic lens 54
produces a virtual copy of the image at an infinite distance.
Hence, a large collimated beam is produced for each pixel of the
input image.
[0010] The above-presented collimated displays do not have large
enough field of view to provide an immersive sensation. Larger
field of view may be achieved by producing a mosaic of several
Pancake Windows.TM., Fresnel lens virtual displays, holographic
collimated displays or others single channel collimated displays.
Very large field of view may be achieved with the mosaic approach
at the expense of the complexity related to the calibration
required to obtain uniform properties and the necessity to drive
all of those displays simultaneously. In addition to the
complexity, another drawback of the mosaic approach is the fact
that it does not provide a truly continuous image since there are
dead zones in between adjacent displays.
[0011] Continuous displays with a medium field of view may be made
using an off axis mirror with a plurality of display devices. In
comparison with the single channel off axis mirror display, the
field of view increase is generally achieved for only the
horizontal direction. For some of those systems, the images are
produced with video projector and projected on a curved (with
aspheric shape) screen which acts as a secondary image. The light
diffused from the screen is then reflected and collimated by the
off axis mirror. Such devices are generally used for commercial
airplane flight simulators and vehicle simulators.
[0012] The realization of a wide angle display is challenging as
such a device must produce a large number of collimated beams
coming from a very large range of directions and, using
conventional approaches as described above, involves large optical
components.
[0013] In the present specification, there are described
embodiments of a wide angle display system designed to overcome the
above-described limitations of the conventional display
systems.
SUMMARY
[0014] The present invention relates to a wide angle display
system, comprising: [0015] a scanner having at least one reflective
surface and an axis of rotation; [0016] a dome having a reflective
inner surface, the inner surface having an axis of revolution which
is coincident with the axis of rotation of the scanner; [0017] at
least one linear arrangement of light sources producing beams of
light; and [0018] wherein the reflective surface of the scanner
reflects the beams of light towards the reflective inner surface of
the dome which in turn collimates the beams of light and reflects
them towards an observer positioned within the wide angle display
system.
BRIEF DESCRIPTION OF THE FIGURES
[0019] A non-limitative illustrative embodiment of the invention
will now be described by way of example only with reference to the
accompanying drawings, in which:
[0020] FIG. 1 is schematic view of a prior art collimated display
using Fresnel lenses;
[0021] FIG. 2 is schematic view of a prior art collimated display
using a concave mirror in an on axis configuration;
[0022] FIG. 3 is schematic view of a prior art collimated display
using a concave mirror in an off axis configuration;
[0023] FIG. 4 is schematic view of a prior art collimated display
using a concave mirror in an Pancake Window.TM. configuration;
[0024] FIG. 5 is schematic view of a prior art collimated display
using holographic elements;
[0025] FIG. 6 is a schematic perspective view of the wide angle
immersive display system according to the illustrative embodiment
of the present invention;
[0026] FIG. 7 is a schematic view of an example of a shaping module
for use with the wide angle immersive display system of FIG. 6;
[0027] FIG. 8 is a schematic perspective view of the wide angle
immersive display system of FIG. 6 on which is superimposed a
system of coordinates;
[0028] FIG. 9 is a perspective view of a scanner with a profiled
transparent body;
[0029] FIGS. 10A and 10B are illustrative examples of
cross-sectional views of the scanner along axis X-X in FIG. 9;
[0030] FIG. 11 is a schematic view of a first alternative
embodiment of the wide angle immersive display system including two
domes;
[0031] FIG. 12 is a first schematic view of a second alternative
embodiment of the wide angle immersive display system including two
shaping modules, which are shown shifted along the revolution axis
of the dome;
[0032] FIG. 13 is a second schematic view of the second alternative
embodiment of the wide angle immersive display system of FIG. 13
where the two shaping modules are shown shifted angularly around
the revolution axis of the dome; and
[0033] FIG. 14 is a schematic perspective view of the second
alternative embodiment of the wide angle immersive display system
shown in FIGS. 12 and 13.
DETAILED DESCRIPTION
[0034] Generally stated, the non-limitative illustrative embodiment
of the present invention provides a wide angle immersive display
system for applications requiring both a wide field of view and
collimated display capabilities. Flight simulators and other types
of training simulator (ship, motor bike, car, etc,) are examples of
such applications but many other display applications may take
advantage of the present invention, such as, for example, the
display of information in vehicles or the cockpit of an airplane or
even video games.
[0035] As mentioned previously, the realization of a wide angle
display is challenging as such a device must produce a large number
of collimated beams coming from a very large range of directions
and, using conventional approaches, involves large optical
components. The present invention discloses a scanning process
which allows the realization of a compact wide angle display,
having collimated display capabilities, with relatively small
optical components.
[0036] Referring to FIG. 6, the main components of the wide angle
immersive display system 100 are a dome 102 having a reflective
inner surface 101 forming an optical mirror surrounding an observer
1, a scanner 104 and at least one linear array of pixels (LAP) 106.
A LAP 106 generates dynamic images consisting of a line of luminous
pixels from a linear arrangement of light sources 106a such as, for
example, a line of LEDs or an illuminated line of deformable or
reclining micro-mirrors. The beams of light 107 produced by each
LAP 106 are transformed by a shaping module 130 and directed toward
the scanner 104, which produces scanned beams of light 103 that are
then reflected toward the observer 1 by the inner surface 101 of
the dome 102. The final result of the transformation chain of the
beams of light is a collimated beams of light 105 pointing toward
the eyes 2 of the observer 1 for each image pixel generated by each
LAP 106.
[0037] The shaping module 130 that makes the link between each LAP
106 and the scanner 104 consist of a set of optical components that
take the beams of light 107 from the LAP 106 and aim them toward
the scanner 104. Each individual beam associated with each pixel
106a of the LAP 106 is transformed by the shaping module 130 in
order to give it appropriate divergence (or convergence) and main
direction properties before reaching the scanner 104.
[0038] Referring to FIG. 7, there is shown an example of a generic
configuration for the shaping module 130. The shaping module 130
consists of a converter 132 and a collecting group 134. The
collecting group 134 transforms the individual beams of light 107
to feed the scanner 104 with beams having appropriate direction,
divergence and wavefront characteristics. The purpose of the
converter 132 is to match the numerical aperture (a measure of the
divergence of a beam of light) characteristics of the beams of
light produced by individual pixels of the LAP 106 with those
required for the rest of the optical train. Moreover, the converter
132 redirects the individual beams of light 107 toward the
collecting group. The converter 132 may include refractive and
reflective components, diffusing and diffractive elements, optic
fibers, fiber optics faceplate or an array of micro components (one
for each pixel 106a for example). It will be apparent to a person
skilled in the art that other configurations may be considered for
the shaping module 130.
[0039] Referring now to FIG. 8, at each rotational position of the
scanner 104, only a 1-D series of pixels is displayed by each LAP
106 and appears to the observer 1 as if coming from a portion of a
meridian 114 located on a virtual spherical screen 112 with
infinite radius and centered on the observer 1. Selecting another
rotational position of the scanner 104 changes the direction of the
scanned beams of light 103 and the system 100 generates the
collimated beams of light 105 appearing to come from a 1-D series
of pixels located on another meridian on the virtual spherical
screen 112. The synchronous addressing of the LAP 106 with the
rotation of the scanner 104 allows the generation of 2D images
appearing to come from an infinite radius virtual spherical screen
112.
[0040] To ensure the invariance of the optical properties with
respect to the rotational position of the scanner 104, the
reflective inner surface 101 of the dome 102 is advantageously a
symmetrical surface having an axis of revolution 121 which is
coincident with the axis of rotation of the scanner 104. Moreover,
the nominal position of the eyes 2 of the observer 1 is also
advantageously located on the axis of revolution 121 of the dome
102. In that configuration, the 1-D series of pixels 117 associated
with each LAP 106, and a specific rotational position of the
scanner 104, appears to the observer 1 as if located on a portion
of a meridian 114 on an infinite size virtual spherical screen 112.
The collimated beams of light 105 for a specific rotational
position are all parallel to the meridian plane 116 containing the
axis of revolution 121 of the dome 102 and the associated meridian
114. The meridian plane 116 and the collimated beams of light 105
rotate around the axis of revolution 121 two time faster than the
scanner 104.
[0041] The combination of the rotating scanner 104 with reflection
of the scanned beams of light 103 on the reflective inner surface
101 of the dome 102 allows for the generation of a large number of
collimated beams of light 105 projected toward the eyes 2 of the
observer 1 from a wide range of directions, thus realizing a wide
angle immersive display. The wide angle immersive display system
100 has the potential to be compact due to the scanning approach.
The generation of the collimated beams of light 105 over a wide
range of directions all around the observer 1 without scanning
would requires optical components all around the observer 1. The
part of the optical train preceding the scanner 104 deals only with
1-D images. This liberates space and thus permits the folding of
the optical train and makes thus the system 100 more compact.
[0042] The profile of the reflective inner surface 101 of the dome
102, e.g. the curve corresponding to the intersection of the inner
surface 101 of the dome 102 with a plane containing the axis of
revolution 121 of the dome 102, should be chosen such as to perform
both the deviation of the collimated beams of light 105 towards the
eyes 2 of the observer I and, in collaboration with the other
optical components, the collimation of the scanned beams of light
103 for each pixel 106a. An elliptical or an elliptical like
profile is advantageous since all scanned beams of light 103
passing through one focal point of an ellipsoidal (ellipse of
revolution) mirror are reflected toward the other focal point. For
an ellipsoidal reflective inner surface 101, the foci are both
located on the axis of revolution 121 and the scanner 104 would be
centered around one of the foci while the eyes 2 of the observer 1
would be located around the other focal point. Other shapes for the
reflective inner surface 101 may be considered, for example
parabola, free form, etc.
[0043] The curvature of the reflective inner surface 101 of the
dome 102 differ according to direction. This geometrical anisotropy
translates into anisotropic optical properties such as the optical
power. A set of rays from the collimated beams of light 105
contained in a given meridian plane will be focalized by the inner
reflective surface 101 at a distance different from its counterpart
for rays contained in a plane perpendicular to this meridian
plane.
[0044] Referring to FIG. 9, a possible way to address this issue is
to encapsulate the reflective inner surface 142 of the scanner 104
within a profiled transparent body 144, for example a profiled
solid cylinder, having a symmetry of revolution about the scanner's
104 rotation axis 146. In this case, the reflective inner surface
142 may be a thin layer of reflective material such as, for
example, a thin metal coating, embedded within the transparent body
144 produced by, for example, gluing two separate pieces together.
This profiled transparent body 144 acts as a cylindrical lens and
allows a partial compensation for the directional optical power
anisotropy of the reflective inner surface 142 of the dome 102 (see
FIG. 8). For a scanner 104 such as illustrated in FIG. 9, the
scanning is done by rotating the transparent body 144 itself about
its cylindrical (or symmetry) axis 146.
[0045] Toric layers made of, for example, different type of glasses
or plastics, may be added to the transparent body 144 in a
concentric configuration to improve the control of aberrations.
Transparent bodies 144 with radial (or other) distribution of the
index of refraction may also be considered. For example, referring
to FIGS. 10A and 10B, there are shown cross sections of alternative
embodiments of scanners 104', 104'' having a series of layers each
having an associated thickness and/or refraction index, namely core
shells 1441 a, 1441b within which is embedded the reflective inner
surface 142, internal shells 1443a, 1443b and external shells
1445a, 1445b, the various shells being separated by respective air
gaps 1442a, 1444a and 1442b, 1444b. It is to be understood that the
number of layers as well as the thickness and refraction index of
each layer may vary according to the desired correction.
Furthermore, the exterior and/or interior surfaces of the various
layers composing the scanners 104', 104'' may be sculpted or
profiled so as to provide specific corrections. It is further to be
understood that the various layers may form imbricate tubes whose
thickness varies longitudinally.
[0046] Referring back to FIG. 8, for a small longitudinal angular
field of view (defined by angle .quadrature.), the shaping
module(s) 130 can be placed inside of the dome 102. However, the
shaping module(s) 130 may occlude rays in the case of larger fields
of view. In that case, all the optics, except the scanner 104, may
be placed outside of the dome 102. The beams of light 107 produced
by the LAP(s) 106, which are transformed by the shaping module(s)
130, may be introduced in the system 100 by passing through the
dome 102. The inner surface 101 of the dome 102 can be made
partially reflective (and thus partially transmissive) to allow the
transmission of the light through its shell.
[0047] The dome 102 can be made, for example, of a transparent
material with an outside surface 111 covered with absorbing
material except at the input ports (places on the dome 102 where
the beams of light 107 are introduced). It can also be made of a
plurality of sections made of different types of material. The
outside surface of the input ports may be shaped to deviate the
beams or for aberration correction purposes. The approach of
placing the optics outside the dome 102 allows displaying over a
360.degree. longitudinal angular field of view about the axis of
revolution 121 of the dome 102 since the shaping module(s) 130 are
positioned all around the scanner 104 in such a way as to not cause
any obscuration.
[0048] The difficulties encountered in the correction of the
aberrations increase with the angular field of view. A multi-dome
approach may be envisioned to improve the optical performances
according to the latitudinal angular field of view (defined by
angle .quadrature. in FIG. 8) by distributing the large field of
view over a plurality of smaller fields.
[0049] Referring to FIG. 11, There is shown an example of a system
100' having a configuration that includes two domes 102a and 102b.
In this example, the front dome 102a covers the latitudinal angular
field of view from 10.degree. to 50.degree. while the back dome
102b covers the 50.degree. to 100.degree. part of the latitudinal
angular field of view. As it may be observed, the axis of
revolution 121b of the second dome 102b is coincident with the axis
of revolution 121a of the first dome 102a. Moreover, in this
example, the common axes of revolution 121a and 121b are tilted by
an angle .quadrature. with respect to the nominal sight direction 3
of the observer 1 so as to increase forward visibility, i.e. to
lessen the forward obscuration caused by the scanner 104a. It is to
be understood that this feature can also be used in the case of the
single dome configuration.
[0050] Difficulties encountered in the correction of aberrations
can also be reduced by splitting the latitudinal angular field of
view over a plurality of LAPs 106 and associated shaping modules
130.
[0051] Referring back to FIG. 8, in the particular case of a system
100 with a single shaping module 130, adjacent beams of light 107
generally overlap on the various optical surfaces. To avoid this, a
configuration using multiple shaping modules 130 sharing the
latitudinal angular field of view may be used, each shaping module
130 being shifted both along and angularly around the axis of
revolution 121 of the dome 102 with respect to its predecessor.
[0052] FIGS. 12 and 13 show an example of a system 100'' having a
configuration that includes two shaping modules 130a and 130b which
are both shifted along (FIG. 12) and angularly around (FIG. 13) the
axis of revolution 121 of the dome 102. The shaping modules 130a
and 130b provide respective plurality of beams of light such as
beams of light 107a and 107b to scanner 104, which produces scanned
beams of light 103a and 103b that are then reflected toward the
observer 1 as collimated beams of light 105a and 105b by the inner
surface 101 of the dome 102.
[0053] Referring now to FIG. 14, the resulting image from the
collimated beams of light 105a and 105b is displayed as a 1-D
series of pixels 117a and 117b appearing on respective angularly
shifted meridians 114a and 114b on the infinite size virtual
spherical screen 112. The entire set of shaping modules 130a and
130b, with their associated LAP (not shown) may be replicated
around the axis of revolution 121 of the dome 102 to increase the
longitudinal angular field of view.
[0054] Although the present invention has been described by way of
particular embodiments and examples thereof, it should be noted
that it will be apparent to persons skilled in the art that
modifications may be applied to the present particular embodiment
without departing from the scope of the present invention.
* * * * *