Note: Descriptions are shown in the official language in which they were submitted.
CA 02289999 2004-08-03
Description
Title
Holographic Statue Projection Device
Technical Field
This invention relates to holographic projection devices fo~_
displaying a 3-dimensional image, more particularly to a
holographic projection device for displaying a 3-dimensional image
of a statue.
Background Art
There are many instances where it would be desirable to be
able to have a compact holographic projection device for
displaying a 3-dimensional image such as a statue.
A large number of patents disclose holographic projection
devices with different configurations for displaying holographic
images.
These prior art arrangements have a hologram placed
vertically to project an upright virtual or real holographic
image. When placed horizontally, a conventional hologram projector
a 3-dimensional virtual or real holographic image horizontally,
parallel to the hologram.
Canadian Application 2 277 653 discloses a "Cylindrical
Holographic Display Device" for displaying an upright holographic'
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image perpendicularly to the hologram. However, this prior art
suffers from a limited viewing angle, and a small height of the
upright holographic image.
Canadian Application 2 278 110 discloses a "Holographic
Display Device with a Paraboloidal Hologram" for displaying an
upright holographic image perpendicularly to the hologram having a
wider viewing angle. However, this prior art applies only to
transmission-type holograms, and is too complex and difficult to
manufacture.
Description of the Invention
It is a primary object of the invention to provide a
holographic projection device with a circular or elliptical
hologram for displaying an upright holographic image having both
horizontal and vertical parallaxes.
It is another object of the invention to provide means for
rotatably oscillating the circular or elliptical hologram.
A holographic projection device for displaying a
3-dimensional image has a cylindrical casing, diagonally-cut
cylindrical mount, and a circular or elliptical reflection-type
hologram in order to project an upright orthoscopic real image or-
a combination of real and virtual images having both horizontal
and vertical parallaxes, perpendicularly to the horizon. The
diagonally-placed hologram is illuminated by a point source of
white light, preferably a high-efficiency light emitting diode,
securely attached to means integrated into the holographic
projection device. The holographic projection device may comprise
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an electric motor for rotatably oscillating the hologram in order
to display the front and sides of the 3-dimensional image of a
statue. The holographic projection device may comprise a motion
sensor or an audio sensor for switching on for a pre-set length of
time. The holographic projection device may comprise a sound chap
for producing a voice or music effect.
Brief Description of the Figures in the Drawings
In drawings which illustrate embodiments of the invention:
Figure 1 marked "Prior Art" is a perspective view of a
conventional holographic projection device with a reflection-typE~
hologram;
Figure 2 is a perspective view of one embodiment of a
holographic projection device with a circular or elliptical
reflection-type hologram according to the invention;
Figure 3 is a sectional view of the invention along
line I-I of Figure 2; and
Figure 4 is a sectional view of the invention along
line I I - I I of Figure 2 .
Modes for Carrying Out the Invention
In one prior art holographic projection device shown in
Figure 1 marked "Prior Art", a circular reflection-type hologram
1- 1 is illuminated by a point source of white light 1 - 4 from abcwe
in order to project an orthoscopic real image 1- 6. Means for
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mounting the point source of white light 1-5 is securely attached
to a cylindrical casing 1 -3. A circular mount for supporting the
hologram 1- 2 is attached to the top end of the cylindrical casing
1- 3. A motor inside the cylindrical casing 1 - 3 rotates the
circular reflection-type hologram 1- 1.
In this prior art holographic projection device, the
flatly-placed circular reflection-type hologram 1- 1 projects a
holographic image 1- 6 into a conical field of view around a
vertical axis at the centre of the circular reflection-type
hologram 1-1, as indicated in the figure.
In one embodiment of the invention shown in Figure 2, a
circular or elliptical reflection-type hologram 2 -1 is detachably
placed on a diagonally-cut cylindrical mount 2 -2, which is
rotatably attached to a cylindrical casing 2 -3. A point source ~of
white light 2 - 4 for illuminating the hologram is securely attached
to means for mounting the point source of white light 2 - 5. The
means for mounting the point source of white light 2 - 5 is securely
attached to the diagonally-cut cylindrical mount 2 -2, or to the
cylindrical casing 2 -3. A motor inside the cylindrical casing 2 - 3
rotatably oscillates the circular or elliptical reflection-type
hologram 2 -1.
The circular or elliptical reflection-type hologram 2 - 1
projects an upright orthoscopic real image or a combination of
real and virtual images 2 - 6 having both horizontal and vertical
parallaxes, perpendicularly to the level floor. The upper portion
of the upright holographic image may be an orthoscopic real image
in front of the hologram, while the lower portion of the upright
holographic image may be an orthoscopic virtual image behind the
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hologram.
The holographic image is projected perpendicularly to the level
floor when the rotational axis of the reflection-type hologram 2 - 1
at pi/2 radian (90 degrees) from the level floor is positioned in
alignment with the rotational axis of the cylindrical mount 2 - 2 at
pi/2 radian (90 degrees) from the level floor.
According to the present invention, the diagonally-placed
circular or elliptical reflection-type hologram 2 - 1 projects a
holographic image 2 - 6 into a conical field of view around a
diagonal axis at the centre of the circular or elliptical
reflection-type hologram 2 - 1, as indicated in the figure.
Although the angle of view is the same as that of the prior art
holographic projection device, the conical field of view enables
side-viewing of the holographic image, while disabling
back-viewing of the holographic image.
The size of a holographic image is proportional to the area of the
hologram visible to a viewer. Since the visible area of a
diagonally-placed hologram is greater than the visible area of a
flatly-placed hologram, the diagonally-placed hologram enables the
height of the holographic image to be increased relative to the
diameter of the circular or elliptical hologram, compared with the
flatly-placed hologram of the prior art.
Figure 3 shows a sectional view of the holographic
projection device along line I-I of Figure 2. Figure 4 shows a
sectional view of the holographic projection device along line
II-II of Figure 2. A unit comprising a power supply and a
control circuit 3 - 1 is securely attached to the interior of the
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cylindrical casing 2 -3, and is operably connected to the point
source of white Light 2 - 4 in order to illuminate the circular or
elliptical reflection-type hologram 2 -1. Holding means may be
provided at the top and the bottom of the diagonally-cut
cylindrical mount 2 -2 in order to detachably hold the circular or
elliptical reflection-type hologram 2 - 1 in place. Bearing means
such as a magnetic bearing or a ball bearing may be provided in
order to reduce friction between the diagonally-cut cylindrical
mount 2 -2 and the cylindrical casing 2 -3. Switching means may be
provided in order to control the unit comprising a power supply
and a control circuit 3 - 1.
An electric motor 3 -2, securely attached to the interior of
the cylindrical casing 2 - 3 and operably connected to the unit
comprising a power supply and a control circuit 3 - l, may be
provided for rotatably oscillating the diagonally-cut cylindrical
mount 2 -2 in order to progressively display the front and sides of
the holographic image by up to pi radian (180 degrees).
An extra unit 3 - 3, securely attached to the interior of the
cylindrical casing 2 -3 and operably connected to the unit
comprising a power supply and a control circuit 3 - 1, may house a
motion sensor or an audio sensor for switching on the power supp7_y
for a pre-set length of time. The extra unit 3 -3 may also house a
sound chip for producing a voice or music effect.
Preferably, the circular or elliptical reflection-type
hologram 2 - 1 is computer-generated and has full colour. The
holographic image may be superimposed with a real object having
the same shape and size as the holographic image in order to
demonstrate a phantom effect. The circular or elliptical
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reflection-type hologram 2 - 1 may be double-sided in order to
include 2 different holographic images.
Preferably, the point source of white light 2 - 4 is a
high-efficiency light emitting diode. The means for mounting the
point source of white light 2 - 5 may be telescopically or flexibly
extensible so that the angle of incidence may be adjusted.
