High contrast, low distortion optical acquisition system for image capturing
AssigneeSecuGen Corporation
InventorsHarry H. Teng, Sung-Chan Jo
Life of this patent
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Abstract
Disclosed is an apparatus for forming a high contrast image of a patterned object, such as a fingerprint, including a first lens having a light receiving surface and a viewing surface and a second lens adjacent to the viewing surface of the first lens. A light source projects incident light into the first lens between the viewing surface and imaging surface such that at least a portion of the incident light undergoes total internal reflection. In this way, an image of the patterned object is generated by substantially all scattered light from the imaging surface.
Claims16
An apparatus for forming a high contrast image of a patterned object comprising:
- a first lens including;
- an imaging surface against which a patterned object to be imaged is to be placed;
- at least one light receiving surface adjacent to the imaging surface and through which light enters the first lens;
- and
- a viewing surface opposite to the light entrance surface and through which an image of the patterned object to be imaged is projected;
- a second lens adjacent to the viewing surface and for receiving and focusing an image of the patterned object projected through the viewing surface;
- and
- at least one light source for projecting incident light into the first lens and located adjacent to the light entrance surface to project incident light between the viewing surface and the imaging surface wherein at least a portion of the incident light undergoes total internal reflection between and off of both the imaging surface and the viewing surface without passing through the viewing surface such that the image of the patterned object is generated by substantially all scattered light from the imaging surface.
An apparatus for forming a high contrast image of a patterned object comprising:
- a first lens including;
- an imaging surface against which a patterned object to be imaged is to be placed;
- at least one light receiving surface adjacent to the imaging surface and through which light enters the first lens;
- and
- a viewing surface opposite to the light entrance surface and through which an image of the patterned object to be imaged is projected;
- a second lens adjacent to the viewing surface and for receiving and focusing an image of the patterned object projected through the viewing surface;
- and
- at least one light source for projecting incident light into the first lens and located adjacent to the light entrance surface to project incident light between the viewing surface and the imaging surface wherein at least a portion of the incident light undergoes total internal reflection off of the imaging surface at portions of the imaging surface in which the patterned object does not touch the imaging surface, the portion of the incident light also totally internally reflecting off the viewing surface without passing through the viewing surface such that the image of the patterned object is generated by substantially all scattered light from the imaging surface.
An method of forming a high contrast image of a patterned object including:
- locating at least one light source adjacent to a first lens, the first lens including;
- an imaging surface against which a patterned object to be imaged is to be placed;
- at least one light receiving surface adjacent to the imaging surface and through which the incident light enters the first lens;
- and
- a viewing surface opposite to the light entrance surface and through which an image of the patterned object to be imaged is projected;
- projecting incident light from the at least one light source into the first lens between the viewing surface and the imaging surface;
- and
- totally internally reflecting at least a portion of the incident light between and off of both the imaging surface and the viewing surface without passing the portion of incident light through the viewing surface such that the image of the patterned object is generated by substantially all scattered light from the imaging surface.
Dependencies are inferred from the claim text.