Optical apparatus for fingerprint identification system

• US 5,187,748 A
• Filed: 07/19/1991
• Issued: 02/16/1993
• Est. Priority Date: 07/21/1990
• Status: Expired due to Term

• Current Assignee: Goldstar Jewellery LLC
• Original Assignee: Goldstar Jewellery LLC
• Inventors: Lee, Ho-Gyu
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): COUSO, YON JUNG
• Application Number:
  US07/733,132
• Time in Patent Office: 578 Days
• Field of Search: 382/31, 382/4, 382/5, 382/32, 382/34, 356/71, 356/19, 350/112, 350/286, 250/557
• US Class Current: 382/127
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

An optical apparatus for a fingerprint identification system having a multi-LED for emitting a light, a prism having a slant surface to which a fingerprint being identified is contacted and in which the incident light is absorbed at each ridge but reflected at each valley of the fingerprint, a cover glass functioning as a partial reflecting glass adapted to partially relfect the beam representing a fingerprint image reflected from the prism, a target adapted for focusing a virtual image of the fingerprint thereon, a magnifying glass for magnifying the fingerprint image partially reflected by the cover glass, thereby allowing the user to easily see the fingerprint image, a producing lens for producing the fingerprint image transmitted through the cover glass, and a CCD camera module for converting the fingerprint image produced by the producing lens into an electric signal. The optical fingerprint identification system enables a user to easily adjust the identifying position of the fingerprint improving the accuracy of the fingerprint identification.

Claims

1. An optical apparatus for a fingerprint identification system comprising:

a multi-LED for emitting a light;

a prism having a slant surface to which a fingerprint being identified is contacted and in which the light from said multi-LED is absorbed at each ridge but reflected at each valley of the fingerprint creating a fingerprint image;

a cover glass functioning as a partial reflecting glass adapted to partially reflect the light representing the fingerprint image from said prism;

a target, positioned with respect to said cover glass for receiving the light from said prism and for focusing a virtual image of the fingerprint thereon facilitating proper positioning of the fingerprint on the prism by aligning the virtual image reflected by said cover glass with a reference image produced by said target, said target having,

a target case,

a blue filter covering said target case for producing a black background except for a transparent reference cross,

light means provided in said target case for illuminating the blue filter and reference cross, and

a switch adapted to selectively turn on said light means when positioning the fingerprint on the slant surface of the prism and off once the fingerprint is properly positioned;

a magnifying glass for magnifying the virtual image partially reflected by said cover glass, thereby allowing the user to easily see the virtual image;

a producing lens for producing the fingerprint image from said prism as transmitted through said cover glass; and

a CCD camera module for converting the fingerprint image produced by said producing lens into an electric signal.