Compact holographic illumination device
First Claim
Patent Images
1. An illumination device comprising in series:
- at least first and second light sources;
a lens;
a first grating layer;
a second grating layer;
a half wave plate;
a third grating layer; and
a fourth grating layer,wherein said third grating layer and said first grating layer have identical optical prescriptions and said fourth grating layer and said second grating layer have identical optical prescriptions,wherein each said grating layer is operative to diffract light from at least one source into an illumination direction,wherein said lens collimates and directs a first polarization of light from said first source into a direction at a first angle to said illumination direction and collimates and directs a first polarization of light from said second source into a direction at second angle to said illumination direction.
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Abstract
There is provided a color sequential illumination device comprising in series: first and second light sources; a condenser lens; and a grating device. The grating device comprises at least one Bragg grating. The condenser lens directs light from the first and second sources into the grating device at first and second incidence angles respectively. The grating device diffracts light from the first and second sources into a common direction. Desirably, the Bragg gratings are Electrically Switchable Bragg Gratings. In one embodiment of the invention the light sources are Light Emitting Diodes. Alternatively lasers may be used.
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Citations
20 Claims
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1. An illumination device comprising in series:
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at least first and second light sources; a lens; a first grating layer; a second grating layer; a half wave plate; a third grating layer; and a fourth grating layer, wherein said third grating layer and said first grating layer have identical optical prescriptions and said fourth grating layer and said second grating layer have identical optical prescriptions, wherein each said grating layer is operative to diffract light from at least one source into an illumination direction, wherein said lens collimates and directs a first polarization of light from said first source into a direction at a first angle to said illumination direction and collimates and directs a first polarization of light from said second source into a direction at second angle to said illumination direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification