Fingerprint authentication device and information processing device

Abstract

A fingerprint authentication device includes a sweep fingerprint sensor that acquires images of a fingerprint on a finger at at least two different sensitivity levels in a single scan, and a counterfeit-finger determining unit that determines whether the finger is counterfeit based on the images acquired by the sweep fingerprint sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic for explaining image acquisition by a sweep fingerprint sensor according to a first embodiment of the present invention;

FIGS. 2A to 2C are examples of a mid-sensitivity image, a low-sensitivity image, and a high-sensitivity image, respectively, of a living finger acquired by the sweep fingerprint sensor shown in FIG. 1;

FIGS. 3A to 3C are examples of a mid-sensitivity image, a low-sensitivity image, and a high-sensitivity image, respectively, of a counterfeit finger made from gummy material acquired by the sweep fingerprint sensor shown in FIG. 1;

FIGS. 4A and 4B are examples of a luminance distribution in a low-sensitivity image and a high-sensitivity image respectively;

FIG. 5 is a functional block diagram of a fingerprint authentication device according to the first embodiment;

FIG. 6 is a flowchart of a process performed by the fingerprint authentication device shown in FIG. 5;

FIGS. 7A to 7C are examples of sweat patterns;

FIG. 8 is a functional block diagram of a fingerprint authentication device according to a second embodiment of the present invention; and

FIG. 9 is a flowchart of a process performed by the fingerprint authentication device shown in FIG. 8.

Claims

1. A fingerprint authentication device comprising: a sweep fingerprint sensor that acquires images of a fingerprint on a finger at at least two different sensitivity levels in a single scan; anda counterfeit-finger determining unit that determines whether the finger is counterfeit based on the images acquired by the sweep fingerprint sensor.

2. The fingerprint authentication device according to claim 1, wherein the counterfeit-finger determining unit determines that the finger is counterfeit when a difference in a parameter relating to the images is less than a threshold.

3. The fingerprint authentication device according to claim 2, wherein the parameter includes luminance of the images.

4. The fingerprint authentication device according to claim 2, wherein the parameter includes unevenness in luminance of the images.

5. The fingerprint authentication device according to claim 2, wherein the parameter includes distribution in luminance of the images.

6. The fingerprint authentication device according to claim 2, wherein the parameter includes difference in the images.

7. The fingerprint authentication device according to claim 1, further comprising a sweat-pattern detecting unit that detects whether any of the images acquired by the sweep fingerprint sensor includes a sweat pattern, wherein the counterfeit-finger determining unit determines whether the finger is counterfeit based on the images acquired by the sweep fingerprint sensor and a result of detection obtained by the sweat-pattern detecting unit.

8. The fingerprint authentication device according to claim 7, wherein the counterfeit-finger determining unit determines that the finger is counterfeit when a difference in a parameter relating to the images is less than a threshold and when the sweat-pattern detecting unit detects a sweat pattern in any of the images.

9. The fingerprint authentication device according to claim 1, wherein the sweep fingerprint sensor acquires images of the fingerprint at three different sensitivity levels in a single scan, andthe fingerprint authentication device further comprises a fingerprint authentication unit that determines whether the fingerprint is authentic based on the image of the fingerprint at an intermediate sensitivity level among the images at the three different sensitivity levels.

10. The fingerprint authentication device according to claim 1, further comprising a warning unit that outputs a warning when the sweep fingerprint sensor can not acquire an image of the fingerprint on the finger.

11. The fingerprint authentication device according to claim 1, wherein the sweep fingerprint sensor is a capacitance fingerprint sensor.

12. The fingerprint authentication device according to claim 1, wherein the sweep fingerprint sensor is a weak-electric-field fingerprint sensor.

13. An information processing device comprising: a storage unit that stores therein images of a fingerprint on a finger acquired by a sweep fingerprint sensor at at least two different sensitivity levels in a single scan; anda counterfeit-finger determining unit that determines whether the finger is counterfeit based on the images in the storage unit.