Methods for capturing fingerprint images using a moving platen

• US 7,103,201 B2
• Filed: 09/03/2003
• Issued: 09/05/2006
• Est. Priority Date: 04/28/1998
• Status: Expired due to Term

• Current Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Original Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Inventors: Scott, Walter Guy, Fedele, Dean J.
• Primary Examiner(s): Couso, Yon J.
• Application Number:
  US10/653,141
• Publication Number:
  US 20050100196A1
• Time in Patent Office: 1,098 Days
• Field of Search: 382/124, 382/125, 382/126, 382/127, 382/115, 382/116, 356/71, 250/556, 376/15, 707/6, 707/9, 713/186.2
• US Class Current: 382/124
• CPC Class Codes: G06V 40/1335 Combining adjacent partial images (e.g. slices) to create a composite input or reference pattern; Tracking a sweeping finger movement

Abstract

A method and apparatus whereby a fingerprint verifier has a mechanism to slide a prism over an imaged area of a camera. The position of the prism being determined by a binary absolute linear code on a sliding mechanism imaged by the same camera at the side of the fingerprint wherein the images are knitted together to simulate a large CCD.

Claims

1. A method for acquiring fingerprint images, comprising the steps of:

(a) providing an optical platen having a transparent scanning area movable along a scanning direction;

(b) selecting one of at least two available operating modes, said available operating modes including a roll print capture mode and a four finger flat print capture mode;

(c) placing at least one fingertip on said optical platen and moving said optical platen in said scanning direction under said fingertip;

(d) imaging said fingertip through a prism to collect a plurality of fingertip image portions; and

(e) assembling said plurality of fingertip image portions using an electronic processor to form a composite fingerprint image.

2. The method of claim 1, wherein step (d) comprises imaging said fingertip from a presentation sequence of fingertip portions, and said fingertip image portions are recorded in a sequence different from the presentation sequence of fingertip portions.

3. The method of claim 1, comprising the further steps of:

performing steps (c) through (e) repeatedly to obtain roll print images for each of four fingers;

performing steps (c) through (e) to obtain a four finger flat print image; and

verifying the order of the fingers imaged in said roll print images by electronically matching said roll print images to fingerprint image data obtained from said four finger flat print image.

4. The method of claim 1, wherein in step (d) a charge coupled device (CCD) camera is used to image said fingertip.

5. The method of claim 1, wherein in step (d) a CMOS camera is used to image said fingertip.

6. The method of claim 1, wherein in step (e) said processor knits together an integrated image of said fingertip from a plurality of partial fingertip images collected as the fingertip moves past an imaging path on the optical platen.

7. The method of claim 1, wherein in said roll print capture mode, in step (c) said optical platen moves in response to a finger being rotated.

8. A method for acquiring roll print fingerprint images, comprising the steps of:

(a) providing an optical platen having a transparent scanning area movable in a linear motion along a scanning direction;

(b) placing at least one finger having a fingertip on said optical platen and rotating said finger about a rotational axis along the length of the finger with said optical platen moving in said scanning direction under said finger;

(c) imaging said fingertip to collect a plurality of fingertip image portions during rotation of said finger; and

(d) assembling said plurality of fingertip image portions using an electronic processor to form a composite roll print image.

9. The method of claim 8, wherein step (c) comprises imaging said fingertip from a presentation sequence of fingertip portions, and said fingertip image portions are recorded in a sequence different from the presentation sequence of fingertip portions.

10. The method of claim 8, wherein in step (c) a charge coupled device (CCD) camera is used to image said fingertip.

11. The method of claim 8, wherein in step (c) a CMOS camera is used to image said fingertip.

12. The method of claim 8, wherein in step (a) said optical platen is a surface of a prism, said prism moving linearly in said scanning direction.

13. The method of claim 8, wherein a prism is mounted under said optical platen to move linearly with said optical platen in said scanning direction, and in step (c), said fingertip is imaged through said prism.

14. The method of claim 8, wherein in step (b) said finger is placed against a finger guide adjacent to the optical platen to guide movement of the fingertip in a rotating motion.

15. A method for acquiring flat print fingerprint images, comprising the steps of:

(a) providing an optical platen having a transparent scanning area movable in a linear motion along a scanning direction;

(b) placing a plurality of fingers having fingertips on said optical platen and moving said fingers linearly with said optical platen moving in said scanning direction under said fingers;

(c) imaging said fingertips to collect a plurality of fingertip image portions during movement of said fingers; and

(d) assembling said plurality of fingertip image portions using an electronic processor to form composite flat print images of said plurality of fingers.

16. The method of claim 15, wherein step (c) comprises imaging said fingertips from a presentation sequence of fingertip portions, and said fingertip image portions are recorded in a sequence different from the presentation sequence of fingertip portions.

17. The method of claim 15, wherein in step (c) a charge coupled device (CCD) camera is used to image said fingertip.

18. The method of claim 15, wherein in step (c) a CMOS camera is used to image said fingertip.

19. The method of claim 15, wherein in step (a) said optical platen is a surface of a prism, said prism moving linearly in said scanning direction.

20. The method of claim 15, wherein a prism is mounted under said optical platen to move linearly with said optical platen in said scanning direction, and in step (c), said fingertips are imaged through said prism.

21. The method of claim 15, wherein in step (b) four fingers are placed on the optical platen to produce a four-finger flat print.