Biometric detection using spatial, temporal, and/or spectral techniques
First Claim
1. A biometric feature detection system comprising:
- a target including a target surface configured to receive a biometric feature at the target surface;
an illumination source configured to illuminate at least a portion of a target surface from below the target surface with monochromatic blue light at a large angle of incidence measured from the normal of the target surface;
a color filter array comprising a plurality of color mosaics arrayed across the color filter array;
a light detector configured to receive light from the target through the color-filter array and provide an image of the target surface, wherein each pixel of the light detector corresponds to one of the plurality of color mosaics such that each pixel detects light associated with corresponding color filter; and
a computational unit interfaced with the light detector, wherein the computation unit includes instructions to monitor the levels of blue light and compute a mathematical function on the levels of blue light in proportion with levels of other light.
2 Assignments
0 Petitions
Accused Products
Abstract
A biometric feature detection system is provided according to one embodiment. The system may include a target, an illumination source, a color filter array, a light detector, and a computational unit. The illumination source illuminates a portion of the target with monochromatic light at a large angle of incidence measured from the normal of the target surface. The light detector may be configured to receive light from the target through the color-filter array and provide an image of the target surface. Each pixel of the light detector may correspond to one of a plurality of color filter mosaics such that each pixel detects light associated with a corresponding color filter. The computational unit may be interfaced with at least the light detector. The computational unit may include instructions to monitor the levels of monochromatic light and make proximity, presence and segmentation determinations based on the detected levels of monochromatic light.
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Citations
32 Claims
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1. A biometric feature detection system comprising:
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a target including a target surface configured to receive a biometric feature at the target surface; an illumination source configured to illuminate at least a portion of a target surface from below the target surface with monochromatic blue light at a large angle of incidence measured from the normal of the target surface; a color filter array comprising a plurality of color mosaics arrayed across the color filter array; a light detector configured to receive light from the target through the color-filter array and provide an image of the target surface, wherein each pixel of the light detector corresponds to one of the plurality of color mosaics such that each pixel detects light associated with corresponding color filter; and a computational unit interfaced with the light detector, wherein the computation unit includes instructions to monitor the levels of blue light and compute a mathematical function on the levels of blue light in proportion with levels of other light. - View Dependent Claims (2, 3, 4, 5)
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6. A method for detecting the proximity of a potential biometric feature to a target, the method comprising:
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illuminating at least a portion of the target surface and a portion of the area above the target surface from below the target surface with monochromatic light at a large angle of incidence measured from normal of the target surface; receiving light at a light detector, wherein the light received at the light detector includes ambient light from above the target surface; and determining whether a potential biometric feature is near the surface target based on the intensity of the monochromatic light received at the light detector relative to the intensity of light other than the monochromatic light received at the light detector. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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15. A biometric proximity detector, comprising:
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a target including a target surface adapted to receive a potential biometric feature; at least one monochromatic light source configured to illuminate at least a portion of the target surface and a portion of the area above the target surface from below the target surface with monochromatic light at a large angle of incidence measured from normal of the target surface; a light detector configured to receive light from the target surface and a portion of the area above the target surface, wherein the light received at the light detector includes ambient light from above the target; and means for determining whether a potential biometric feature is near the surface target based on the intensity of the monochromatic light received at the light detector relative to the intensity of light other than the monochromatic light received at the light detector. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. A method for identifying when a purported biometric feature is placed on a target surface, the method comprising:
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illuminating at least a portion of the target surface and a portion of the area above the target surface from below the target surface with monochromatic light, wherein the monochromatic light is absorbed by blood; receiving light at a light detector, wherein the light received at the light detector includes monochromatic light reflected from the purported biometric feature at or near the target surface; monitoring the intensity of the monochromatic light received at the light detector; and identifying when the purported biometric feature is placed on the target surface by determining when the intensity of monochromatic light received at the light detector increases due to blood loss in portions of the purported biometric feature. - View Dependent Claims (24, 25)
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26. A biometric feature presence detector comprising:
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a target including a target surface adapted to receive a potential biometric feature; a monochromatic light source disposed below the target surface, wherein the monochromatic light source illuminates at least a portion of the target surface and a portion of the area above the target surface with monochromatic light; a light detector disposed below the target surface and configured to receive light from the target surface and a portion of the area above the target surface; and a computational unit interfaced with the light detector and having; instructions to monitor the intensity of monochromatic light received at the light detector; and instructions to identify when the purported biometric feature is placed on the target surface by determining when the intensity of monochromatic light received at the light detector increases due to blood loss in portions of the purported biometric feature. - View Dependent Claims (27)
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28. A biometric feature presence detector comprising:
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a target including a target surface adapted to receive a potential biometric feature; means for illuminating at least a portion of the target surface and a portion of the area above the target surface with monochromatic light originating from below the target surface; a light detector configured to receive light from the target surface and a portion of the area above the target surface; and means for identifying when the purported biometric feature is placed on the target surface by determining when the intensity of monochromatic light received at the light detector increases due to blood loss in portions of the purported biometric feature. - View Dependent Claims (29)
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30. A method for segmenting a biometric feature from the background, the method comprising:
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illuminating the biometric feature with monochromatic light; filtering light reflected from the biometric feature and ambient light with a color filter array into a plurality of wavelength bands, wherein one of said plurality of wavelength bands corresponds with the wavelength of the monochromatic light illuminating the biometric feature; detecting light reflected from the biometric feature and ambient light filtered by the color filter array, wherein each pixel of the detector receives light corresponding to a wavelength band and providing an image of the target; comparing pixels corresponding with the wavelength of the monochromatic light; segmenting portions of the image corresponding to a purported biometric feature from portions of the image corresponding to the background by comparing the levels of a wavelength band corresponding to the monochromatic light with the levels of another wavelength band. - View Dependent Claims (31)
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32. A biometric feature presence detector comprising:
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a target including a target surface adapted to receive a potential biometric feature; a monochromatic light source disposed below the target surface, wherein the monochromatic light source illuminates at least a portion of the target surface and a portion of the area above the target surface with monochromatic light; a color filter array; a light detector disposed below the color filter array and the target surface, and configured to receive light from the target surface and ambient light from an area above the target surface through the color filter array; and a computational unit interfaced with the light detector and having; instructions to segment portions of the image corresponding to a purported biometric feature from portions of the image corresponding to the background by comparing the levels of a wavelength band corresponding to monochromatic light with the levels of another wavelength band.
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Specification