Fingerprint photographing system

• US 5,175,593 A
• Filed: 07/26/1991
• Issued: 12/29/1992
• Est. Priority Date: 07/27/1990
• Status: Expired due to Fees

• Current Assignee: Sharp Corporation (Hon Hai Precision Industry Co., Ltd.), YOZAN, Inc.
• Original Assignee: Ezel, Inc., Sharp Corporation (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Maruta, Kazuo, Kumagai, Ryohei
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US07/735,608
• Time in Patent Office: 522 Days
• Field of Search: 356/71, 356/237
• US Class Current: 356/71
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G07C 9/257 electronically G07C9/26 takes precedence

Abstract

A fingerprint photographing system comprising: a prism having a detection surface where a finger is pressed thereon; a luminous source for irradiating light to the detection surface; a camera for detecting the light reflected upon the detection surface; and means for comparing the image before and after the finger is pressed upon the detection surface and for storing the image of fingerprint to a memory when the number of pixels of the image with a predetermined density difference is in the range of predetermined number.

Claims

1. A fingerprint photographing system comprising:

a prism having a detection surface, said detection surface detecting a finger pressed thereon;

a luminous source irradiating light to said detection surface;

a camera detecting light from said luminous source which is reflected off of said detection surface; and

means for comparing an image of said finger pressed upon said detection surface to other fingerprints and for storing said image of said finger when a number of pixels of said image having a predetermined density difference before and after said finger is pressed upon said detection surface is within a predetermined range of numbers.

2. The fingerprint photographing system claimed in claim 1, further comprising a card reader for receiving data which identifies a master data file of said other fingerprints to be compared with said image of said finger in said comparing means.

3. The fingerprint photographing system claimed in claim 1, further comprising an actuator for opening a door.

4. The fingerprint photographing system claimed in claim 1, further comprising a keyboard for manually inputting identification numbers to identify said other fingerprints to be compared with said image of said finger in said comparing means.

5. The fingerprint photographing system claimed in claim 1, wherein said predetermined density difference is 16 levels and said predetermined range of pixel numbers is between 30000 and 35000.