Optical fingerprint acquisition apparatus
First Claim
1. An optical fingerprint acquisition apparatus for acquiring a fingerprint image by light scattered from a fingerprint, the apparatus comprising:
- a prism including a fingerprint contacting surface to be touched by a fingerprint of a person, a totally reflecting surface facing the fingerprint contacting surface with an angle θ
for totally and inwardly reflecting the light scattered from the fingerprint in contact with the fingerprint contacting surface, a primarily projecting/re-incident surface linking the fingerprint contacting surface with an angle φ
to the totally reflecting surface for primarily projecting the light totally reflected from the totally reflecting surface so as to be re-incident from outside the prism, and an ultimately projecting surface facing the primarily projecting/re-incident surface for ultimately projecting the light re-incident to the primarily projecting/re-incident surface toward the outside of the prism; and
a reflecting mirror installed outside the prism, adjacent to the primarily projecting/re-incident surface of the prism and at an angle δ
thereto, the reflecting mirror for reflecting the light projected from the primarily projecting/re-incident surface so as to be re-incident to the prism through the primarily projecting/re-incident surface.
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Accused Products
Abstract
Disclosed is an optical fingerprint acquisition apparatus capable of reducing an image distortion and a size of an optical system by deforming the shape of a prism. The prism according to the invention includes a fingerprint contacting surface to be touched by a fingerprint of a person, a totally reflecting surface facing the fingerprint contacting surface with an angle θ for totally and inwardly reflecting the light scattered from the fingerprint in contact with the fingerprint contacting surface, a primarily projecting/re-incident surface linking the fingerprint contacting surface to the totally reflecting surface with an angle φ for primarily projecting the light totally reflected from the totally reflecting surface so as to be re-incident from outside, and an ultimately projecting surface facing the primarily projecting/re-incident surface for ultimately projecting the light re-incident to the primarily projecting/re-incident surface toward outside.
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Citations
6 Claims
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1. An optical fingerprint acquisition apparatus for acquiring a fingerprint image by light scattered from a fingerprint, the apparatus comprising:
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a prism including a fingerprint contacting surface to be touched by a fingerprint of a person, a totally reflecting surface facing the fingerprint contacting surface with an angle θ
for totally and inwardly reflecting the light scattered from the fingerprint in contact with the fingerprint contacting surface, a primarily projecting/re-incident surface linking the fingerprint contacting surface with an angle φ
to the totally reflecting surface for primarily projecting the light totally reflected from the totally reflecting surface so as to be re-incident from outside the prism, and an ultimately projecting surface facing the primarily projecting/re-incident surface for ultimately projecting the light re-incident to the primarily projecting/re-incident surface toward the outside of the prism; and
a reflecting mirror installed outside the prism, adjacent to the primarily projecting/re-incident surface of the prism and at an angle δ
thereto, the reflecting mirror for reflecting the light projected from the primarily projecting/re-incident surface so as to be re-incident to the prism through the primarily projecting/re-incident surface. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification