Apparatus and method for adjusting focus position in iris recognition system

• US 7,095,901 B2
• Filed: 03/14/2002
• Issued: 08/22/2006
• Est. Priority Date: 03/15/2001
• Status: Active Grant

• Current Assignee: Iris Id
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Won Hee, Chae, Jang Jin, Yang, Ae Kyung
• Primary Examiner(s): CHAWAN, SHEELA C
• Application Number:
  US10/096,848
• Publication Number:
  US 20020131622A1
• Time in Patent Office: 1,622 Days
• Field of Search: 382/115, 382/117, 382/218, 382/291, 382/255, 357/206, 357/207, 357/208, 357/210, 357/221, 359/210, 359/225, 359/226, 348/77, 348/78, 348/143, 340/156, 340/5.52, 340/5.53, 340/5.82, 340/5.83, 351/208
• US Class Current: 382/255
• CPC Class Codes: G06V 40/19 Sensors therefor

Abstract

The present invention relates to a method for adjusting a focus position in an iris recognition system, the method including the steps of: projecting a designated light for measuring a distance between the user and a camera; acquiring user images including the image projected by the light; and measuring a distance between the user and the camera by extracting the projected image by the light out of the user images and analyzing characteristics of the image. In addition, the present invention relates to an apparatus for adjusting a focus position in an iris recognition system, which enables to adjust the focal angle of an iris, the apparatus includes an illumination device; an iris recognition camera for acquiring user images having an iris image when the illumination device irradiates a light; an illuminator for helping the user with the focal angle according to sharpness of the visible ray that depends on the focal angle by transmitting a visible ray from the illuminator and by reflecting the user images.

Claims

1. A method for adjusting a focus position in an iris recognition system, the method comprising:

projecting a designated light which forms an image on a user;

acquiring at least one user image including the image of the designated light; and

measuring the distance between the user and the camera by extracting out the image formed by the designated light from the acquired user image and analyzing characteristics of the image of the designated light.

2. The method of claim 1, wherein the designated light has a wavelength that is invisible to the eyes of the user.

3. The method of claim 1, wherein the characteristics of the image include at least one of size, location, brightness or sharpness of the image.

4. The method of claim 1, further comprising displaying an extent of the distance to the user after measuring the distance between the user and the camera.

5. The method of claim 4, wherein the light is infrared light, the extent is indicated by color, and the designated light is projected onto the face of the user.

6. A method for adjusting a focus position in an iris recognition system, the method comprising:

irradiating at least one designated spot image on a user using a light beam, of which an irradiation axis intersects with respect to an iris recognition camera;

acquiring user images including the irradiated at least one designated spot image by using the iris recognition camera; and

calculating the distance between the user and the iris recognition camera based on characteristics of the at least one designated spot image that is extracted from the acquired user images.

7. The method of claim 6, wherein the at least one designated spot image for measuring the distance is formed of a light having an invisible wavelength to the naked eyes of the user.

8. The method of claim 6, wherein the characteristics of the at least one spot image include at least one of size, location, brightness, or sharpness of the at least one spot image.

9. An apparatus for adjusting a focus position in an iris recognition system, the apparatus comprising:

an iris recognition camera, which photographs user images;

a plurality of distance detection pointers in symmetric positions with respect to the iris recognition camera, which projects light to form spot images on a user; and

a distance calculator, which calculates the distance between the user and the iris recognition camera by performing an image process analysis on the user images, which have been photographed by the iris recognition camera and which have been projected by the distance detection spot light, wherein the distance calculation is based on the spot images on the user images.

10. The apparatus of claim 9, wherein the plurality of distance detection pointers is an infrared light emitting diode.

11. The apparatus of claim 9, wherein the spot images, which are formed by the light irradiated from the distance detection pointer, are projected to the user after irradiation axes of the distance detection pointer are crossed to each other.

12. The apparatus of claim 9, wherein the distance calculator further comprises:

a first detector for detecting locations of the spot images;

a second detector for detecting sizes of the spot images; and

a third detector for detecting sharpness of the spot images.

13. The apparatus of claim 9, further comprising a designated indicator for notifying a result from the distance calculator to the user.

14. A method for an iris recognition system, the method comprising:

forming a light image on a user using a light beam;

taking a picture of the light image using a camera;

extracting the light image from the picture; and

determining the distance between the user and the camera based on at least one characteristic of the extracted light image adjusting the focus position in the iris recognition system using the determined distance.

15. The method of claim 14, wherein the at least one characteristic of the light image includes at least one of size, location, brightness, or sharpness, and the light image is formed from infrared light.