Dual-imager biometric sensor
First Claim
Patent Images
1. A biometric system comprising:
- first illumination means for illuminating an object through an image region of a first facet of a multifaceted prism, wherein light from the first illumination means undergoes total internal reflectance at a second facet of the multifaceted prism prior to illuminating the object, and the image region is smaller than the first facet;
second illumination means for illuminating the object through the second facet of the multifaceted prism; and
first imaging means for imaging light scattered from the object and passing though the image region of the first facet at an angle less than the critical angle and undergoing total internal reflectance at the second facet, wherein the scattered light originates from both the first and second illumination means, and the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet.
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Accused Products
Abstract
Embodiments disclose a two imager biometric sensor. In some embodiments, the two imagers can include a direct imager and a TIR imager. In some embodiments, multispectral light sources can be used to illuminate target tissue imaged by two imagers. In some embodiments, composite images can be created from images detected using both imagers.
358 Citations
41 Claims
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1. A biometric system comprising:
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first illumination means for illuminating an object through an image region of a first facet of a multifaceted prism, wherein light from the first illumination means undergoes total internal reflectance at a second facet of the multifaceted prism prior to illuminating the object, and the image region is smaller than the first facet; second illumination means for illuminating the object through the second facet of the multifaceted prism; and first imaging means for imaging light scattered from the object and passing though the image region of the first facet at an angle less than the critical angle and undergoing total internal reflectance at the second facet, wherein the scattered light originates from both the first and second illumination means, and the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 40, 41)
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10. A method comprising:
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illuminating an object positioned at an image region of a first facet with light that undergoes total internal reflectance at a second facet, the image region is smaller than the first facet; illuminating the object positioned at the image region of the first facet with light that passes through the second facet; imaging light scattered by the object that passes through the image region of the first facet at an angle less than the critical angle and undergoes total internal reflectance at the second facet; and imaging light scattered by the object that passes through the image region of the first facet at an angle greater than the critical angle, wherein the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet. - View Dependent Claims (11, 12, 13, 14)
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15. A multifaceted prism comprising:
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a first facet having an image region that is smaller than the first facet; and a second facet, wherein the first facet and the second facet are oriented relative to each other such that; an object positioned at the image region of the first facet can be illuminated with light that undergoes total internal reflectance at the second facet and by light that passes through the second facet, a portion of light scattered by the object that passes through the image region of the first facet at an angle less than the critical angle can be imaged after undergoing total internal reflectance at the second facet, and a portion of light scattered by the object positioned at the image region of the first facet that passes through the image region of the first facet at an angle greater than the critical angle can be imaged without interacting with the second facet, wherein the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet. - View Dependent Claims (16, 17, 18, 19)
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20. A system comprising:
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first illumination means for illuminating an object located at an image region of a first facet of a multifaceted prism, the image region being smaller than the first facet, light from the first illumination means internally reflecting off of a second facet of the multifaceted prism prior to illuminating the object; second illumination means for illuminating the object through the second facet and through the image region of the first facet at an angle greater than the critical angle of the first facet; first imaging means for imaging light scattered by the object, passes through the image region of the first facet at an angle less than the critical angle, and undergoes total internal reflectance at the second facet; and second imaging means for imaging light totally internally reflected from the image region of the first facet, wherein the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet. - View Dependent Claims (21, 22, 23, 24)
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25. A system comprising:
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first illumination means for illuminating an object located at an image region of a first facet of a multifaceted prism, the image region being smaller than the first facet, light from the first illumination means internally reflecting off of a second facet of the multifaceted prism prior to illuminating the object; second illumination means for illuminating the object through the second facet and through the image region of the first facet at an angle greater than the critical angle of the first facet; first imaging means for imaging light scattered by the object, passes through the image region of the first facet at an angle less than the critical angle, and undergoes total internal reflectance at the second facet; and second imaging means for imaging light scattered from the object at points where the object is in contact with the platen, wherein the critical angle is defined by an interface of the image region of the first facet with an external environment and is measured relative to the normal of the first facet. - View Dependent Claims (26, 27, 28, 29)
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30. A method comprising:
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illuminating an object located at an image region of a first facet of a prism at an angle less than the critical angle with light that internally reflects off of a second facet of the prism prior to illuminating the object, the image region being smaller than the first facet; illuminating the object at the image region of the first facet at an angle greater than the critical angle, wherein the light enters the prism through the second facet of the prism; imaging light that is scattered by the object at an angle less than the critical angle relative to the first facet and totally internally reflected at the second facet using a first imaging system; and imaging light from the image region of the first facet using a second imaging system, wherein the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet. - View Dependent Claims (31, 32, 33, 34)
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35. A system comprising:
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a multifaceted prism having a first and second facet, the first facet having an image region that is smaller than the first facet; a first illumination source configured to illuminate the image region of the first facet at an angle less than the critical angle, light from the first illumination source internally reflecting off of the second facet of the multifaceted prism prior to illuminating the image region of the first facet; a second illumination source configured to illuminate the image region of the first facet at an angle greater than the critical angle, wherein light from the second illumination source enters the prism through the second facet; a first imager configured to image light from the image region of the first facet that is totally internally reflected by the second facet; and a second imager configured to image light from the first illumination source that is totally internally reflected from the image region of the first facet, wherein the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet.
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36. A system comprising:
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a multifaceted prism having a first and second facet, the first facet having an image region that is smaller than the first facet; a first illumination source configured to illuminate the image region of the first facet at an angle less than the critical angle with light that internally reflects off of the second facet prior to illuminating the image region of the first facet; a second illumination source configured to illuminate the image region of the first facet at an angle greater than the critical angle, wherein light from the second illumination source enters the prism through the second facet; a first imager configured to image light from the image region of the first facet that is totally internally reflected by the second facet; and a second imager configured to image light scattered from the interface of the object and the image region of the first facet, wherein the critical angle is defined by an interface of the first facet with an external environment and is measured relative to the normal of the first facet. - View Dependent Claims (37, 38, 39)
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Specification