Authentication of identifiers by light scattering
AssigneeArizona Board of Regents on behalf of Arizona State University
InventorMichael N. Kozicki
Life of this patent
Estimating the term…
Abstract
Identifying a test pattern includes positioning a test pattern that includes a first multiplicity of particles that reflect or emit light in the field of view of a first imaging device; illuminating the test pattern with light from a first light source; obtaining, with the first imaging device, a first test image of light reflected by the first multiplicity of particles; and comparing the first test image with a first reference image of a reference pattern obtained by a second imaging device.
Claims20
A method of identifying a test pattern, the method comprising:
- positioning a test pattern in the field of view of a first imaging device, wherein the test pattern is on a first substrate and comprises a first multiplicity of particles that reflect or emit light;
- illuminating the test pattern with light from a first light source, wherein the light from the first light source defines a first test angle of incidence with respect to the first substrate and a first test azimuthal angle with respect to an optical axis of the first imaging device;
- obtaining, with the first imaging device, a first test image of light reflected by the first multiplicity of particles, wherein the first test image comprises first indicia associated with the first test angle of incidence and the first test azimuthal angle;
- and
- comparing the first test image with a first reference image of a reference pattern obtained by a second imaging device, wherein the reference pattern is on a second substrate and comprises a second multiplicity of particles that reflect light, and the first reference image comprises second indicia associated with the second alignment feature and is obtained by illuminating the reference pattern with light from a reference light source that defines a first reference angle of incidence with respect to the second substrate and a first reference azimuthal angle with respect to an optical axis of the second imaging device.
A method of identifying a test pattern, the method comprising:
- positioning an apparatus comprising a light source and an imaging device in a first orientation with respect to a test pattern on a substrate, wherein the test pattern comprises a multiplicity of particles that reflect or emit light and the first orientation of the device comprises a first pitch, a first roll, and a first yaw of the device with respect to the substrate;
- illuminating the test pattern with light from the light source;
- imaging light reflected by the multiplicity of particles with the imaging device to yield a first test image comprising a first multiplicity of bright regions;
- positioning the apparatus comprising the light source and the imaging device in a second orientation with respect to the test pattern, wherein the second orientation comprises a second pitch, a second roll, and a second yaw of the device with respect to the substrate, wherein the first roll and the second roll are different;
- illuminating the test pattern with the light source;
- and
- imaging light reflected by the multiplicity of particles with the imaging device to yield a second test image comprising a second multiplicity of bright regions,
- wherein a location and intensity of the first multiplicity of bright regions in the first test image differs from a location and intensity of the second multiplicity of bright regions in the second test image.
Dependencies are inferred from the claim text.