Encoded hologram for producing a machine readable image and a human readable image
AssigneeHughes Aircraft Company
InventorsJohn E. Wreede, John E. Gunther, Michael J. Virgadamo, Kevin Yu, Lillian Yin, Jerry L. Mulder, Richard B. Upper, James E. Scott
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Abstract
An encoded hologram that produces a first image and a second image pursuant to playback illumination, wherein the first image is resolvable by human vision while the second image is not resolvable by human vision when the playback illumination comprises non-coherent broad band illumination, and wherein the second image is machine readable when the hologram is illuminated with playback illumination that is based on the original reference beam.
Claims33
A hologram recorded pursuant to an original reference beam and an original object beam, the hologram comprising hologram fringes recorded pursuant to a single exposure for producing (a) a first image pursuant to playback illumination, said first image being resolvable by human vision when produced pursuant to first playback illumination comprised of non-coherent broadband illumination, and (b) a second image pursuant to playback illumination, said second image being displaced from the hologram and unresolvable by human vision when produced pursuant to playback illumination that does not emulate the original reference beam as defined by a grating equation but being machine readable when produced pursuant to playback illumination that emulates the original reference beam as defined by the grating equation.
A hologram recorded pursuant to an original converging reference beam and an original object beam, the hologram comprising hologram fringes recorded pursuant to a single exposure for producing (a) a first image that is produced pursuant to playback illumination, said first image being resolvable by human vision when produced pursuant to non-coherent broad band playback illumination, and (b) a second image that is produced pursuant to playback illumination, said second image being displaced from the hologram and unresolvable by human vision when produced pursuant to playback illumination that does not emulate the original converging reference beam as defined by a grating equation but being machine readable when produced pursuant to playback illumination that emulates the original converging reference beam as defined by the grating equation.
A hologram recorded pursuant to an original reference beam at a reference beam angle and an original object beam at an object beam angle, the hologram comprising hologram fringes recorded pursuant to a single exposure for producing (a) a first image that is produced pursuant to playback illumination, said first image being resolvable by human vision when produced pursuant to playback illumination that comprises ambient light, and (b) a second image that is produced pursuant to playback illumination, said second image being displaced from the hologram and unresolvable by human vision when produced pursuant to playback illumination that does not emulate the original reference beam as defined by a grating equation but being machine readable when produced pursuant to playback illumination that emulates a conjugate of the original reference beam as defined by the grating equation.
A hologram recorded pursuant to an original converging reference beam and an original object beam, the hologram comprising hologram fringes recorded pursuant to a single exposure for producing (a) a first image that is produced pursuant to playback illumination, said first image being resolvable by human vision when produced pursuant to non-coherent broad band playback illumination, and (b) a second image that is produced pursuant to playback illumination, said second image being displaced from the hologram and unresolvable by human vision when produced pursuant to playback illumination that does not emulate the original converging reference beam as defined by a grating equation but being machine readable when produced pursuant to playback illumination that emulates a conjugate of the original converging reference beam as defined by the grating equation.
An exposure system for exposing a holographic recording layer having a first side and a second side that is opposite the first side, comprising:
- object beam means for illuminating the first side of the holographic recording layer with an object beam that produces an optical image of a first object at a first optical image location and an optical image of a second object at a second optical image location displaced from the holographic recording layer, said object beam means including:
- (a) diffuser means for providing a diffuse light output;
- (b) first and second imaging lenses responsive to said diffuse light output for directing imaging illumination to the first side of said holographic recording layer, said imaging illumination producing an optical image of said diffuser means at a diffuser means optical image position located at the holographic recording layer;
- (c) masking means interposed between said first and second imaging lenses;
- (d) said second imaging lens configured such that said imaging illumination further produces an optical image of said masking means at a masking means optical image position displaced from the holographic recording layer;
- and
- means for illuminating the second side of the holographic recording layer with a reference beam.
An exposure system for exposing a holographic recording layer having a first side and a second side that is opposite the first side, comprising:
- an imaging lens for directing imaging illumination to the first side of said holographic recording layer, said imaging illumination comprising a first object beam and producing an optical image of a first object at a first optical image position;
- means for providing a second object beam to the second side of the holographic recording layer;
- and
- means for illuminating the second side of the holographic recording layer with reference beam.
Dependencies are inferred from the claim text.