Method and apparatus for reducing fingerprint image distortion
First Claim
1. A fingerprint sensing apparatus, comprising:
- a light source configured to produce an emitted light to illuminate a fingerprint of a user;
a light modifier configured to illuminate the fingerprint with a substantially uniform light intensity using the emitted light from the light source, wherein the light modifier includes a curved surface configured to produce a diffused and reflected light based on the emitted light from the light source;
a prism configured to direct a reflected light of the fingerprint illuminated by the diffused and reflected light from the light modifier;
an image sensor configured to capture a fingerprint image from the reflected light of the fingerprint;
a mirror and a lens in the light path between the prism and the image sensor, wherein the mirror and the lens are configured to direct the reflected light of the fingerprint image from the prism to the image sensor, whereinthe image sensor is configured to provide an image plane;
the prism and the mirror are configured to provide a subject plane, wherein the subject plane is adjusted based on the light path from the prism to the image sensor, and wherein the image plane and the subject plane are extended and are configured to form an intersection, andthe lens is adjusted to provide a lens plane that meets the intersection of the image plane and the subject plane; and
a housing configured to hold the light source, the light modifier, the prism, and the image sensor within the housing.
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Accused Products
Abstract
Methods and apparatuses are provided for reducing fingerprint image distortion. In one embodiment, a fingerprint sensing apparatus comprises an image sensor configured to capture a fingerprint image from a reflected light of the fingerprint, and a mirror and a lens in the light path between the prism and the image sensor to direct the reflected light of the fingerprint image from the prism to the image sensor. The image sensor is configured to provide an image plane, the prism and the mirror are configured to provide a subject plane, where the subject plane is adjusted based on a light path from a prism to the image sensor, and the image plane and the subject plane are extended and are configured to form an intersection, and the lens is adjusted to provide a lens plane that meets the intersection of the image plane and the subject plane.
23 Citations
21 Claims
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1. A fingerprint sensing apparatus, comprising:
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a light source configured to produce an emitted light to illuminate a fingerprint of a user; a light modifier configured to illuminate the fingerprint with a substantially uniform light intensity using the emitted light from the light source, wherein the light modifier includes a curved surface configured to produce a diffused and reflected light based on the emitted light from the light source; a prism configured to direct a reflected light of the fingerprint illuminated by the diffused and reflected light from the light modifier; an image sensor configured to capture a fingerprint image from the reflected light of the fingerprint; a mirror and a lens in the light path between the prism and the image sensor, wherein the mirror and the lens are configured to direct the reflected light of the fingerprint image from the prism to the image sensor, wherein the image sensor is configured to provide an image plane; the prism and the mirror are configured to provide a subject plane, wherein the subject plane is adjusted based on the light path from the prism to the image sensor, and wherein the image plane and the subject plane are extended and are configured to form an intersection, and the lens is adjusted to provide a lens plane that meets the intersection of the image plane and the subject plane; and a housing configured to hold the light source, the light modifier, the prism, and the image sensor within the housing. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A fingerprint sensing apparatus, comprising:
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a light source configured produce an emitted light to illuminate a fingerprint of a user; a light modifier prism configured to illuminate the fingerprint with a substantially uniform light intensity using the emitted light from the light source, wherein the light modifier prism includes a curved surface configured to produce a diffused and reflected light based on the emitted light from the light source; the light modifier prism is further configured to direct a reflected light of the fingerprint illuminated by the diffused and reflected light; an image sensor configured to capture a fingerprint image from the reflected light of the fingerprint; a mirror and a lens in the light path between the light modifier prism and the image sensor, wherein the mirror and the lens are configured to direct the reflected light of the fingerprint image from the light modifier prism to the image sensor, and wherein the image sensor is configured to provide an image plane; the light modifier prism and the mirror are configured to provide a subject plane, wherein the subject plane is adjusted based on the light path from the light modifier prism to the image sensor, and wherein the image plane and the subject plane are extended and are configured to form an intersection; and the lens is adjusted to provide a lens plane that meets the intersection of the image plane and the subject plane; and a housing configured to hold the light source, the light modifier prism, and the image sensor within the housing. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A method for reducing fingerprint image distortion, comprising:
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producing, by a light source, an emitted light to illuminate a fingerprint of a user; illuminating, by a light modifier, the fingerprint with a substantially uniform light intensity using the emitted light from the light source, wherein the light modifier includes a curved surface configured to produce a diffused and reflected light based on the emitted light from the light source; directing, by a prism, a reflected light of the fingerprint illuminated by the diffused and reflected light from the light modifier; directing, by a mirror and a lens in the light path between the prism and an image sensor, the reflected light of the fingerprint image from the prism to the image sensor, wherein the image sensor is configured to provide an image plane; the prism and the mirror are configured to provide a subject plane, wherein the subject plane is adjusted based on the light path from the prism to the image sensor, and wherein the image plane and the subject plane are extended and are configured to form an intersection; and the lens is adjusted to provide a lens plane that meets the intersection of the image plane and the subject plane; and capturing, by the image sensor, a fingerprint image from the reflected light of the fingerprint. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification