Method of identifying iris

Abstract

A method of identifying iris is provided. The method includes providing a plurality of incident lights entering an eye located at a reference position; setting a first, second and third reference points; forming a first, second and third measuring glint by the incident lights after the eye moves to a measuring position; capturing an eye image of the eye including a first, second and third measuring glint images and an iris image; analyzing a gray scale value of the eye image to obtain the positions of the first, second and third measuring glints; and calculating a variation of the distance between the first measuring glint and the second measuring glint, a variation of the distance between the second measuring glint and the third measuring glint to obtain an resolution variation of the iris image when the eye is located at the measuring position.

What is claimed is: 
     
         1 . A method of identifying iris comprising:
 providing a plurality of incident lights entering an eye, the eye locating at a reference position;   setting a first reference point, a second reference point and a third reference point as a mark for locating the eye at the reference position, wherein the positions of the first reference point, the second reference point and the third reference point are corresponding to the emission position of the incident lights;   forming a first measuring glint, a second measuring glint, and a third measuring glint near a pupil of the eye by the incident lights after the eye moves from the reference position to a measuring position, and a plurality of positions of the first measuring glint, the second measuring glint, and the third measuring glint are corresponding to those positions of the first reference point, the second reference point and the third reference point;   capturing an eye image of the eye including a first measuring glint image, a second measuring glint image, a third measuring glint image, and an iris image;   analyzing a gray scale value of the eye image to obtain the positions of the first measuring glint, the second measuring glint, and the third measuring glint; and   calculating a variation of the distance between the first measuring glint and the second measuring glint with respect to the distance between the first reference point and the second reference point, and calculating a variation of the distance between the second measuring glint and the third measuring glint with respect to the distance between the second reference point and the third reference point, so as to obtain an resolution variation of the iris image when the eye is located at the measuring position.   
     
     
         2 . The method of identifying iris according to  claim 1 , wherein a first reference axis is formed between the first reference point and the second reference point, and a second reference axis is formed between the second reference point and the third reference point. 
     
     
         3 . The method of identifying iris according to  claim 2  wherein a first axis is formed between the first glint and the second glint, and a second axis is formed between the second glint and the third glint. 
     
     
         4 . The method of identifying iris according to  claim 3 , wherein the step of obtaining the resolution variation of the iris image comprising:
 calculating a first variation, wherein the first variation is a length variation of the first axis relatives to the first reference axis;   calculating a second variation, wherein the second variation is a length variation of the second axis relatives to the second reference axis; and   calculating the resolution variation of the iris image according to the first variation, and the second variation.   
     
     
         5 . The method of identifying iris according to  claim 4 , wherein a reference angle is formed between the first reference axis and the second reference axis and an angle is formed between the first axis and the second axis, the step of obtaining the resolution variation of the iris image further comprising:
 calculating a third variation, wherein the third variation is an angular variation of the angle relatives to the reference angle is calculated.   
     
     
         6 . The method of identifying iris according to  claim 1 , wherein the reference position is corresponding to a position where the eye gazes straight ahead. 
     
     
         7 . The method of identifying iris according to  claim 1 , wherein the incident lights are infrared lights. 
     
     
         8 . The method of identifying iris according to  claim 1 , wherein the incident lights are provided by an optical assembly. 
     
     
         9 . The method of identifying iris according to  claim 1 , wherein the eye image is captured by an image sensor. 
     
     
         10 . The method of identifying iris according to  claim 1 , wherein the incident lights are provided by at least one light source and at least one dispersing component, the light source providing lights, lights passing through the dispersing component for forming the incident lights.