EP-4141820-B1 - CONTROLLING A TWO-DIMENSIONAL MIRROR GIMBAL FOR PURPOSES OF IRIS SCANNING

EP4141820B1EP 4141820 B1EP4141820 B1EP 4141820B1EP-4141820-B1

Inventors

Herbig, Sandro
Haertsfelder, Daniel
Pugnet, Auguste
Blania, Alex
Bodensteiner, Fabian
Brendel, Christian
WEIDNER, TOBIAS
Tabrizi, Cyrus
Pugnet, Saturin
Thäter, Johannes

Dates

Publication Date: 20260506
Application Date: 20210825

Claims (15)

An iris scanning device (102), comprising: a first camera (106) that is configured to: capture an image of a face of a user (104) of the iris scanning device; a second camera (108) that is configured to: capture an image of an eye of the user subsequent to the image of the face of the user being captured; a gimbal (110) having a mirror (112) mounted thereon; a facial feature detector (114) that is configured to: identify facial features of the user based upon the image of the face of the user, the facial features of the user comprise a predicted location of the eye of the user; and compute a desired angle between the eye of the user and the mirror mounted on the gimbal based on the facial features of the user; and control circuitry (116) that is configured to: subsequent to capture of the image of the face of the user, adjust an orientation of the gimbal based upon the facial features of the user such that an angle between the eye of the user and the mirror mounted on the gimbal is the desired angle, wherein the image of the eye of the user is captured upon the orientation of the gimbal being adjusted, wherein the mirror mounted on the gimbal is oriented to cause the image of the eye of the user to be captured; wherein the facial feature detector is further configured to: identify features of the eye of the user based upon the image of the eye of the user; and determine whether the image of the eye of the user satisfies criteria based upon the features of the eye, wherein a code is generated based upon the image of the eye of the user when the image of the eye satisfies the criteria; and wherein the control circuitry is further configured to: adjust the orientation of the gimbal having the mirror mounted thereon based upon the features of the eye when the image of the eye of the user does not satisfy the criteria, wherein the mirror mounted on the gimbal is oriented to cause a second image of the eye of the user to be captured by the second camera upon the orientation being adjusted based upon the features of the eye.
The iris scanning device of claim 1, wherein the first camera comprises at least one of a red green blue (RGB) camera, a three-dimensional (3D) camera, or a monochrome infrared (IR) camera.
The iris scanning device of claim 1 and/or 2, wherein the first camera has a first field of view, wherein the second camera has a second field of view.
The iris scanning device of claim 1, 2, and/or 3, further comprising: a processor (124); and memory (126), wherein the facial feature detector is implemented in software stored in the memory, wherein the processor executes the software to identify the facial features of the user based upon the image of the face of the user.
The iris scanning device of claim 1, 2, 3, and/or 4, wherein the gimbal comprises a first gimbal (110A) and a second gimbal (110B), wherein the mirror comprises a first mirror (112A) and a second mirror (112B), wherein the first mirror is mounted on the first gimbal and the second mirror is mounted on the second gimbal, wherein the first mirror is oriented to cause the image of the eye of the user to be captured, wherein the second mirror is oriented to cause an image of a second eye of the user to be captured.
The iris scanning device of claim 1, 2, 3, 4, and/or 5, wherein the iris scanning device comprises a casing that defines a volume within the iris scanning device, wherein the second camera and the gimbal having the mirror mounted thereon are located in the volume within the iris scanning device, wherein light enters the iris scanning device through a transparent or semi-transparent aperture on the casing, wherein the light reflects off of the mirror.
The iris scanning device of claim 1, 2, 3, 4, 5, and/or 6, wherein the image of the face of the user includes the eye of the user and an additional facial feature of the user, wherein the image of the eye of the user does not include the additional facial feature, wherein a resolution of the image of the eye of the user is greater than a resolution of the image of the face of the user.
The iris scanning device of claim 1, 2, 3, 4, 6, and/or 7 further comprising: a second mirror, wherein the second mirror is stationary, wherein light is reflected off of the mirror onto the second mirror, thereby causing the image of the eye of the user to be captured.
A method performed by an iris scanning device (102) for capturing images of irises of users, the method comprising: capturing an image of a face of a user (104) of the iris scanning device by way of a first camera (106) comprised by the iris scanning device; identifying facial features of the user based upon the image of the face of the user, the facial features of the user comprise a prediction location of the eye of the user; computing a desired angle between the eye of the user and a mirror (112) mounted on a gimbal (110) based on the facial features of the user, wherein the gimbal and the mirror are comprised by the iris scanning device; adjusting an orientation of the gimbal having the mirror mounted thereon based upon the facial features of the user such that an angle between the eye of the user and the mirror mounted on the gimbal is the desired angle; upon adjusting the orientation of the gimbal based upon the facial features of the user, capturing an image of the eye of the user by way of a second camera (108) comprised by the iris scanning device, wherein the mirror mounted on the gimbal is oriented to cause the image of the eye of the user to be captured; identifying features of the eye of the user based upon the image of the eye of the user; determining whether the image of the eye of the user satisfies criteria based upon the features of the eye; generating a code based upon the image of the eye of the user when the image of the eye satisfies the criteria; and when the image of the eye does not satisfy the criteria: adjusting the orientation of the gimbal having the mirror mounted thereon based upon the features of the eye; and upon adjusting the orientation of the gimbal based upon the features of the eye, capturing a second image of the eye of the user by way of the second camera.
The method of claim 9, wherein capturing the image of the face of the user, identifying the facial features of the user, computing the desired angle, adjusting the orientation of the gimbal, capturing the image of the eye of the user, identifying the features of the eye of the user, determining whether the image of the eye of the user satisfies the criteria, and generating the code occur as the iris scanning device is held in one or more hands of the user.
The method of claim 9 and/or 10, wherein adjusting the orientation of the gimbal based upon the facial features of the user comprises: rotating the gimbal such that the angle between the mirror and the eye of the user is the desired angle, wherein the mirror having the desired angle facilitates capture of the image of the eye of the user.
The method of claim 9, 10, and/or 11, wherein: the image of the eye is determined to not satisfy the criteria upon determining that a portion of the eye of the user is not included in the image of the eye of the user or that an iris of the eye of the user is not located in a central region of the image based upon the features of the eye of the user; and an entirety of the iris of the eye of the user is located in the second image of the eye of the user.
The method of claim 9, 10, 11, and/or 12, wherein a lens of the second camera has a focal length that ranges from 30 mm to 150 mm.
The method of claim 9, 10, 11, and/or 13, further comprising: readjusting the orientation of the gimbal having the mirror mounted thereon based upon the facial features of the user; upon readjusting the orientation of the gimbal based upon the facial features of the user, capturing an image of a second eye of the user by way of the second camera; determining whether an iris of the eye of the user is located in a central region of the image of the eye of the user; determining whether a second iris of the second eye of the user is located in a central region of the second image of the second eye of the user; and when the iris of the eye of the user is located in the central region of the image of the eye of the user and when the second iris of the second eye of the user is located in the central region of the image of the second eye of the user, outputting an audible or visible indication to the user.
The method of claim 9, 10, 11, and/or 13, further comprising: determining that the eye of the user is opened based upon the image of the eye of the user; identifying an iris of the eye of the user based upon the image of the eye of the user; determining an area occupied by the iris of the eye in the image of the eye of the user; comparing the area to a threshold area; determining a sharpness of the image of the eye of the user; comparing the sharpness to a threshold sharpness; and when the area exceeds the threshold area and when the sharpness exceeds the threshold sharpness, outputting an audible or visible indication to the user.

Description

BACKGROUND Iris scanning is a method of biometric identification that uses pattern-recognition techniques on images of one or both irises of eyes of an individual. Conventional iris scanning devices tend to be mounted in a fixed location so as to facilitate iris tracking. Conventional iris scanning devices also tend to include two separate imaging sensors that respectively scan a left iris of the individual and a right iris of the individual. Conventional iris scanning devices additionally tend to require the individual to orient his/her eyes within a relatively short distance of an imaging sensor (e.g., several centimeters), which may be uncomfortable for the individual. Furthermore, conventional iris scanning devices have difficulty tracking an iris of the user. The following documents are relevant prior art: WO 98/08439, US 2015/0085096 A1, and, KR 20070117027 A discloses a device for detecting information for both eyes. SUMMARY The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims. Various technologies pertaining to controlling a two-dimensional mirror gimbal for purposes of iris scanning are described herein. With more particularity, an iris scanning device is described herein that is configured to adjust an orientation of a gimbal having a mirror mounted thereon such that an image of an eye of a user of the iris scanning device is captured. The image of the eye of the user may have an iris of the eye of the user located in a central region of the image of the eye and is well-suited for biometric identification purposes. Furthermore, the iris scanning device is portable and can perform iris scans at arm's length distances (e.g., 15 cm to 50 cm). In operation, an iris scanning device captures an image of a face of a user by way of a first camera. The iris scanning device identifies facial features of the user based upon the image of the face of the user. The facial features of the user comprise a predicted location of the eye of the user. The iris scanning device computes a desired angle between the eye of the user and a mirror mounted on a gimbal based on the facial features of the user, where the gimbal and the mirror are comprised by the iris scanning device. The iris scanning device adjusts an orientation of the gimbal having the mirror mounted thereon based upon the facial features. The iris scanning device captures an image of the eye of the user (e.g., a left eye) by way of a second camera comprised by the iris scanning device, where the mirror is oriented to cause the image of the eye of the user to be captured. The iris scanning device identifies features of the eye of the user based upon the image of the eye of the user. The iris scanning device determines whether the image of the eye of the user satisfies criteria based upon the features of the eye. The iris scanning device generates a code based upon the image of the eye of the user when the image of the eye satisfies the criteria. When the image of the eye does not satisfy the criteria, the iris scanning device adjusts the orientation of the gimbal having the mirror mounted thereon based upon the features of the eye, and upon adjusting the orientation of the gimbal based upon the features of the eye, captures a second image of the eye of the user by way of the second camera. The first camera and the second camera have different field of views. According to an embodiment, the first camera is a red green blue (RGB) camera and the second camera is an infrared (IR) camera. When the image of the eye of the user satisfies criteria, the iris scanning device may output an indication to the user that a scan of an iris of the user has been successful. The criteria may include one of the iris of the eye being located in a central region of the image of the eye, an entirety of the eye being located in the image of the eye, and/or an area occupied by the iris in the image of the eye being greater than a threshold area. The criteria may also include a sharpness of the image of the eye being greater than a threshold sharpness. When the image of the eye of the user does not satisfy the criteria, the iris scanning device identifies features of the eye (via the second camera) based upon the image of the eye, (re)adjusts the orientation of the gimbal based upon the features of the eye, and captures a second image of the eye of the user by way of the second camera. According to embodiments, the second camera captures a continuous video stream (e.g., 30 or 60 frames per second (FPS)) of the eye of the user. This process may be repeated multiple times in order to capture an image that satisfies the criteria. Furthermore, the iris scanning device may scan a second eye of the user (e.g., a right eye) in a similar manner. The above-described technologies present various advantages over conventional iris scanning devices. First, unlike conventional iris