JP2007159762A - Distance measuring equipment for biometric authentication system and biometric authentication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out a biometric authentication work by precisely and quickly detecting a distance to a subject even if there are fluctuations in reflected waves due to a subject surface such as the subject's skin and hair moving continuously in the biometric authentication. <P>SOLUTION: This biometric authentication system is provided with a distance surveying section 40 calculating distance information to the subject, a distance calculation section 33 calculating the distance information to the subject based on the image of a light source 12a and a light source 12b included in an eye image obtained by capturing with an imaging section 20, a proofreading section 34 proofreading the distance information calculation calculated by the distance surveying section 40 based on the calculated distance information; guides the subject to an optimal imaging position using the proofread distance information of the distance surveying section 40; and captures the image of the guided subject's eyes by the imaging section 20. An iris information processing section 70 authenticates the subject based on the authentication information obtained by the imaging. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a biometric authentication, in particular, a biometric authentication device distance measuring device used in a device for authenticating a biometric based on image information obtained by imaging the biometric, and a biometric authentication equipped with the biometric authentication device distance measuring device. The present invention relates to a device, a portable information device with a biometric authentication device, a calibration method for a biometric authentication device distance measurement device, a biometric authentication method, and a biometric authentication distance measurement method.

  In recent years, as a method of personal authentication at the time of access in devices requiring high security such as entry / exit management devices and information devices storing important information such as personal information, human fingerprints, irises, fundus blood vessels, facial Various authentication methods using so-called biometric information unique to the subject, such as features and blood vessel patterns of arms and hands, have been put into practical use.

  As one of them, an authentication method (hereinafter referred to as “iris authentication method”) using a difference in the eyelid pattern of the iris portion of the eye has been proposed and put into practical use.

  In this iris authentication method, the eye of the subject and its surroundings are illuminated with near-infrared illumination or the like, and a region including the subject's eye is photographed using a camera. Authentication is encoded so that the iris area is extracted from the image including the eyes obtained by photographing with the camera (hereinafter referred to as “eye image”), and the difference in the eyelid pattern of the iris part is expressed as numerical information. Information is created, and this authentication information is compared and verified with previously registered authentication information (hereinafter referred to as “registered authentication information”). As a result of the comparison and collation, if it is determined that they match each other, it is authenticated that the subject is registered in advance.

  On the other hand, in an authentication device that performs identity authentication by the iris authentication method as described above, an eye image that can be authenticated by the authentication device, that is, an iris portion of an eye of a subject is photographed with an appropriate size and position, and a clear image obtained by photographing is obtained. The eye image must be taken into the authentication device. Usually, since the subject is constantly moving away from the camera, the authentication apparatus has to guide the subject to an appropriate shooting position. For this purpose, the authentication device needs to guide the subject to the shooting position while quickly and accurately measuring the distance between the camera and the subject.

  As a device for measuring the distance to the object, the object is irradiated with an irradiation wave consisting of electromagnetic waves, ultrasonic waves or a light source, and the reflected wave of the irradiation wave reflected on the surface of the object is received, thereby the distance to the object A so-called distance measuring sensor for measuring the distance is generally known. And the technique regarding the imaging device using this ranging sensor is proposed (for example, refer to patent documents 1).

On the other hand, as a device for accurately measuring the distance to an object, the eye area of the subject illuminated by the illumination unit is photographed, and the image of the illumination area is detected from the eye images obtained by photographing, and the detection is performed. A method for calculating the distance to the subject's eye based on the result is disclosed (for example, see Patent Document 2).
JP 2004-287621 A JP 2005-140667 A

  However, in the distance measuring method using the conventional distance measuring sensor, the distance to the object measured by the distance measuring sensor is greater than the actual distance if the surface of the subject's skin relatively reflects the irradiation wave strongly. However, if the surface of the subject's skin reflects the irradiation wave relatively weakly, the distance to the subject measured by the distance measuring sensor tends to be longer than the actual result.

  As described above, the distance measurement method using the distance measuring sensor can measure the distance at a high speed, but the measurement result changes for each subject, so that the authentication device for authenticating different subjects cannot obtain the accuracy. There was a problem.

  On the other hand, the distance measurement method using the eye image obtained by photographing the eye area illuminated by the illumination unit can measure the distance to the subject with higher accuracy than the distance measurement sensor. However, since the distance is calculated by performing various image processing such as image quality correction, iris region extraction, and feature extraction on the eye image obtained by photographing, there is a problem that the distance cannot be measured quickly. For this reason, the authentication device cannot always guide a moving subject to an appropriate photographing position.

  As described above, none of the conventionally disclosed methods has a distance measuring device that can accurately and quickly measure the distance between the subject and the authentication device. For this reason, the authentication device cannot perform the authentication operation while obtaining an optimal eye image for a subject that is constantly moving.

  The present invention has been made in view of such problems, and relates to biometric authentication, even when there is a variation in reflected waves due to differences in the surface of the subject such as skin or hair of a subject that moves constantly, accurately and quickly. It is an object of the present invention to provide a biometric authentication device distance measurement device and a biometric authentication device that can detect a distance to a subject and perform authentication work.

  To achieve this object, a distance measuring device for a biometric authentication device according to the present invention includes an illuminating unit having at least two light sources that illuminate a region including the subject's eyes from different positions, and at least the eyes of the subject. An imaging unit that captures an area, a distance measuring unit that irradiates the subject with an irradiation wave and receives a reflected wave of the irradiation wave from the subject, and calculates distance information to the subject. A distance calculation unit that calculates distance information to the subject based on an interval between images of the light source included in the eye image of the subject obtained in the above, and based on the distance information to the subject calculated by the distance calculation unit. And a calibration unit that calibrates the calculation of distance information calculated by the distance measuring unit.

  According to this configuration, the distance information to the eye of the subject is accurately calculated based on the interval between the images of the light source included in the eye image obtained by photographing each subject, and the measurement is performed based on the calculated distance information. Calibration of distance information calculation at the distance portion can be performed. Therefore, it is possible to photograph the eye of the subject by guiding the subject to an appropriate position using the calibrated distance information. Therefore, even if there is a variation in the reflected wave due to the surface of the subject such as skin or hair for each subject, the distance to the subject can be measured quickly and accurately.

  A contrast information storage unit that stores in advance contrast information indicating a relationship between an interval between the light source images included in the eye image and a distance to the subject; and the distance calculation unit captures images in the imaging unit. The distance information to the subject may be calculated from the interval between the images of the light sources included in the eye image of the subject obtained in this way and the comparison information.

  According to this configuration, for each subject to be authenticated, distance information to the subject's eye is accurately calculated based on an eye image in which light sources from two directions are reflected, and the distance in the distance measuring unit Calibration of information calculation can be performed.

  In addition, the distance measurement unit includes a distance measurement comparison information storage unit that stores in advance distance measurement comparison information representing a relationship between an output obtained by the received reflected wave and a distance to the subject, and the distance measurement comparison information. A distance measuring distance calculating unit that calculates a distance to the subject based on the distance information calculated by the distance calculating unit and the distance information calculated by the distance measuring distance calculating unit; The distance measurement contrast information may be calibrated so as to correct the distance information calculated by the distance measurement distance calculation unit to the distance information calculated by the distance calculation unit based on the difference.

  According to this configuration, the distance measurement distance calculation unit can further calculate the distance using the corrected distance measurement contrast information, and the distance information calculation accuracy can be improved.

  The biometric authentication device of the present invention includes the biometric authentication device distance measurement device, a guide unit that guides the subject to a predetermined position based on the distance information calculated by the distance measurement unit, And an authentication processing unit that authenticates the subject based on authentication information obtained by photographing the subject with the photographing unit.

  According to this configuration, it is possible to guide the subject with the distance information calibrated for each subject and photograph the eye. Therefore, the authentication processing unit can perform authentication work quickly and accurately even when there is a variation in reflected waves due to differences in the surface of the subject such as skin and hair.

  The biometric authentication device of the present invention includes the biometric authentication device distance measurement device and a focus adjustment unit that performs focus adjustment of the photographing unit on the subject based on distance information calculated by the distance measurement unit. And an authentication processing unit that authenticates the subject based on authentication information obtained by photographing with the focus-adjusted photographing unit.

  According to this configuration, it is possible to focus on the calibrated distance information and photograph the eye of the subject. Therefore, the authentication processing unit can perform authentication work quickly and accurately even if there is a variation in reflected waves due to differences in the surface of the subject such as skin or hair.

  The calibration unit may calibrate distance information calculated by the distance measurement unit for each subject.

  According to this, distance information can be calibrated for each subject, and even if there is a variation in reflected waves due to differences in the surface of the subject such as skin or hair, authentication work can be performed quickly and accurately. Is possible.

  The guidance unit includes a distance determination unit that compares the distance information calculated by the distance measurement unit with the predetermined position information and determines whether or not the distance to the subject is appropriate. A configuration may be adopted in which the subject is guided to the predetermined position based on the determination result of the determination unit.

  According to this configuration, the subject can be quickly guided to a position suitable for photographing.

  The photographing unit may include a fixed focus lens, and the predetermined position information may be focal depth region information of the fixed focus lens.

  Accordingly, it is possible to guide the subject into the area of the focal depth of the fixed focus lens by the biometric authentication device including the photographing unit having the fixed focus lens.

  The photographing unit may include a fixed focus lens, and the guide unit may guide the subject forward or backward so that the subject passes a focal position of the fixed focus lens.

  According to this, the guiding unit can further guide the subject to the focal position of the fixed focus lens, and can obtain a clear photographed image in focus.

  According to another aspect of the present invention, there is provided a portable information device with a biometric authentication device including the biometric authentication device and a data transmission / reception unit for transmitting / receiving voice or information.

  According to this configuration, the biometric authentication apparatus can perform guidance of the subject or focus adjustment of the imaging unit based on the distance information. Thus, even in a portable device that authenticates a subject that moves constantly from a distant position, such as a portable information device, the authentication operation can be performed quickly and reliably.

  According to the calibration method of the distance measuring device for a biometric authentication device of the present invention, at least two light sources are used to illuminate a region including at least an eye of a subject from different directions, and illumination is performed by the at least two light sources. A step of photographing a region including at least an eye of the subject, a step of detecting an image of each of the light sources included in the eye image of the subject obtained by photographing, and an interval between the images of the light sources detected from the eye image A step of calculating distance information to the subject based on an interval between images of the light source, an output obtained by irradiating the subject with an irradiation wave and receiving a reflected wave of the irradiation wave at the subject The distance information to the subject is calculated based on distance measurement contrast information that represents the relationship between the distance to the subject and the distance to the subject. And distance information calculated using the distance measurement contrast information based on the difference between the distance information calculated based on the distance between the light source images and the distance information calculated based on the distance measurement contrast information. Calibrating the distance measurement contrast information so as to correct the distance information calculated based on the interval between images of the light source.

  According to this method, even if there is a variation in reflected light due to differences in the surface of the subject such as the skin and hair of each subject, the distance of the distance measuring device for biometric authentication device is calculated so as to accurately calculate the distance information to the subject. The information calculation can be calibrated.

  Further, the biometric authentication method of the present invention is based on distance measurement contrast information representing a relationship between an output obtained by irradiating the object with an irradiation wave and receiving a reflected wave of the irradiation wave on the object and a distance to the object. A first distance measuring step for calculating distance information to the subject; illuminating an area including at least the eye of the subject from at least two light sources from different directions; and at least the subject illuminated by the light source The area including the eye is imaged, the image of each of the light sources included in the eye image of the subject obtained by imaging is detected, and the distance to the subject is determined based on the interval between the light source images detected from the eye image A second distance measuring step for calculating information, and distance information obtained in the first distance measuring step for each subject obtained in the second distance measuring step. A calibration step for calibrating the distance information calculation in the first distance measurement step so as to correct the separation information, a guidance step for guiding the subject to a predetermined position based on the calibrated distance information, and the guided guidance An authentication step for authenticating the subject based on authentication information obtained by photographing the subject.

  According to this method, although the response speed is fast, the first distance measurement step in which the distance information fluctuates due to variations in reflected light due to differences in the surface of the subject such as skin and hair of each subject. By calibrating and using the distance information obtained in the accurate second distance measurement step, distance measurement with high responsiveness and high distance measurement accuracy is enabled. The eye of the subject can be photographed while guiding the subject to a predetermined position using the calibrated distance information, and the authentication work can be performed using the authentication information obtained by photographing. Therefore, even if the shooting distance to the subject constantly changes, the authentication operation can be performed while detecting a quick and accurate distance.

  Further, the biometric authentication method of the present invention is based on distance measurement contrast information representing a relationship between an output obtained by irradiating a subject with an irradiation wave and a reflected wave of the irradiation wave at the subject and a distance to the subject. A first distance measuring step for calculating distance information to the subject; and at least an eye of the subject illuminated by the light source by illuminating an area including at least the eye of the subject from at least two light sources using at least two light sources. The distance information to the subject is detected based on the interval of the image of the light source detected from the eye image by detecting an image of each of the light sources included in the eye image of the subject obtained by photographing the region including And the distance information obtained in the second distance measuring step for the distance information obtained in the first distance measuring step for each subject. A calibration step for calibrating distance information calculation in the first distance measuring step so as to correct the information, a focus adjustment step for performing focus adjustment of the imaging unit based on the calibrated distance information, and the imaging unit after focus adjustment And an authentication step for authenticating the subject based on the authentication information of the subject obtained by shooting in (1).

  According to this method, although the response speed is fast, the first distance measurement step in which the distance information fluctuates due to variations in reflected light due to differences in the surface of the subject such as skin and hair of each subject. By calibrating and using the distance information obtained in the accurate second distance measurement step, distance measurement with good responsiveness and high distance measurement accuracy is possible. The subject can be photographed for authentication while the focus of the photographing unit is adjusted using the calibrated distance information. Therefore, even if the shooting distance to the subject constantly changes, the authentication operation can be performed while detecting a quick and accurate distance.

  In addition, the biometric distance measurement method of the present invention includes a first distance measuring step for calculating distance information to the subject with the first response and the first accuracy, and a second that is slower than the first response. A second distance measuring step for calculating distance information to the subject with responsiveness and a second accuracy higher than the first accuracy; and distance information obtained in the first distance measuring step for each subject. A calibration step for calibrating the distance information calculation in the first distance measurement step so as to correct the distance information obtained in the second distance measurement step.

  According to this method, the first distance measurement step in which the distance information fluctuates due to the difference in reflected light due to the difference in reflected light between the subject surfaces such as the skin and hair of each subject is high. By calibrating and using the distance information obtained in the good second distance measurement step, distance measurement with high distance measurement accuracy is possible.

  According to the present invention, with respect to biometric authentication, even if there is a variation in reflected waves due to differences in the surface of the subject such as skin or hair of a subject that moves constantly, the distance to the subject is detected accurately and quickly. A distance measuring device for a biometric authentication device and a biometric authentication device that can be performed can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The biometric authentication device according to the embodiment of the present invention captures a subject, compares the subject authentication information obtained by photographing with registered authentication information registered in advance, and the subject is registered in advance. Whether or not. The authentication information is, for example, information coded so that the iris area is extracted from the eye image and the difference in the eyelid pattern of the iris portion is expressed as numerical information. Note that face information obtained by extracting feature amounts such as grayscale information and spatial frequency information from a face image obtained by photographing the face of the subject may be used.

  In order to obtain a clear authentication image (for example, an eye image) from a constantly moving subject, it is necessary to quickly and accurately detect the distance to the subject and perform an authentication operation. However, there has been no distance measuring device that can accurately and quickly detect the distance to the subject even if there is a variation in reflected light due to differences in the subject surface such as the skin or hair of the subject.

  For this purpose, the biometric authentication device of the present invention includes a first distance measuring method for calculating distance information to a subject with a first response and a first accuracy, and a second response that is slower than the first response. And using the second distance measuring method for calculating the distance information to the subject with the second accuracy higher than the first accuracy, the distance information obtained by the first distance measuring method for each subject is calculated using the second distance measuring method. The distance information calculation in the first distance measuring method is calibrated to correct the distance information obtained by the distance measuring method. The subject is guided based on the calibrated distance information, and the iris part of the eye image obtained by photographing the guided subject is used to authenticate whether the subject is registered in advance. .

  In the embodiment of the present invention, as the first distance measuring method, contrast information representing a relationship between an output obtained by irradiating a subject with an irradiation wave and receiving a reflected wave of the irradiation wave and a distance to the subject is used. A method of calculating distance information to the subject based on the above will be described as an example. The irradiation wave is an electromagnetic wave, an ultrasonic wave or a light beam. Hereinafter, a light beam will be described as an example.

  In addition, as the second distance measuring method, an image of an eye in which illumination light illuminated from different positions is captured using two light sources, and an image of a spot (hereinafter referred to as “eye spot image”) reflected in the captured eye image is obtained. A method for calculating distance information to the subject based on the interval of “light source image” will be described as an example.

  Moreover, iris information is demonstrated as an Example as authentication information.

  A biometric authentication apparatus according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a front view showing an appearance of biometric authentication device 1 according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the biometric authentication device 1 includes a distance measuring sensor 41 having a light beam irradiation unit 41 a that irradiates a subject with an irradiation wave and a reflected light receiving unit 41 b that receives a reflected wave of the irradiation wave on the subject. A distance measuring unit 40 that calculates distance information to the subject based on information indicating the relationship between the output of the light receiving unit 41b and the distance to the subject (hereinafter referred to as “distance comparison information”), and an area including at least the eye of the subject The illumination unit 10 that illuminates from two different directions using the two light sources 12a and 12b, and at least an area including the eye of the subject illuminated by the light sources 12a and 12b, and an image of the light source included in the eye image of the subject And an imaging unit 20 for obtaining

  The biometric authentication device 1 is information (hereinafter referred to as “contrast information”) that represents the relationship between the distance between the image of the light source obtained by photographing including the spot of the two light sources reflected in the subject's eye and the distance to the subject. ) To calculate the distance information to the subject. Then, the distance measurement contrast information is calibrated so as to approximate the distance information calculated based on the interval between the images of the light source. The distance measuring unit 40 calculates calibrated distance information using the distance measurement contrast information corrected from the output of the distance measuring sensor 41. Details of the distance measurement contrast information and the contrast information will be described later.

  This calibration is performed for each subject. Thereby, even if there is a variation in reflected light due to the surface of the subject such as skin or hair of each subject, the distance to the subject can be measured accurately and quickly.

  Next, the subject is guided based on the calibrated distance information, and it is authenticated whether or not the subject is registered in advance using the iris portion of the eye image obtained by photographing the guided subject. Is.

  The illumination LED 12 is a light emitting element that emits near-infrared light, and is a pair of LEDs (light emitting diodes) arranged symmetrically with respect to the optical axis of the imaging unit 20.

  Further, although two illumination LEDs 12 are used, any number may be used as long as the interval between images of at least one set of light sources can be measured. Further, the number of illumination LEDs 12 may be three or four. Thus, for example, an eye image obtained by photographing an eye illuminated using three LEDs for illumination 12 includes images of three light sources, and two sets of intervals can be measured therefrom. Similarly, when four illumination LEDs 12 are provided, four sets of intervals can be measured. Thereby, in order to eliminate the error due to the curvature of the eye, it is possible to improve the accuracy of the distance, such as obtaining the average of a plurality of intervals.

  The biometric authentication device 1 has two functions: a registration function for registering authentication information of a person who requires authentication, and an authentication function for performing authentication of the person based on the registration authentication information. That is, at the time of registration, the biometric authentication device 1 causes the illumination LED 12 to emit light in an area including the subject's eye, and registers the information related to the iris portion of the eye image obtained as a registration authentication information. To do. The biometric authentication device 1 performs iris authentication using the iris portion of the eye image obtained by photographing at the time of authentication, determines whether or not the subject is registered in advance, and outputs the result as an electrical signal.

  In addition, you may provide the guidance mirror 13 so that a to-be-photographed object can confirm the position of eyes. If the subject is guided using only the calibrated distance measuring unit 40, the guide mirror 13 may be omitted.

  Next, the basic configuration of the biometric authentication device 1 and the function of each unit in Embodiment 1 of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the biometric authentication device 1.

  As shown in FIG. 2, the biometric authentication device 1 irradiates a subject with an irradiation wave and receives the reflected wave from the subject of the irradiation wave and the distance measurement contrast information indicating the relationship between the distance to the subject. A distance measuring unit 40 that calculates distance information to the subject, an illumination unit 10 that irradiates at least two illumination lights to a region including at least eyes of the subject from different directions, and a subject illuminated by at least two illumination lights A distance measurement unit 40 that calculates distance information to the subject based on an interval between at least two light source images captured in the eye image of the subject obtained by photographing, and an imaging region 20 that captures at least the region including the eye. The image signal processing unit 30 that calibrates the distance information calculated in step S4, the guidance unit 14 that guides the subject based on the distance information calculated after calibration by the distance measurement unit 40, and the guidance Subject using iris portion of the eye image obtained by photographing a and an iris information processing unit 70 to authenticate the subject. A guide mirror 13 may be provided to confirm the position of the eye of the subject.

  The illumination unit 10 includes an illumination LED 12 that illuminates the subject's eye, and an illumination control unit 11 that controls the brightness of the illumination LED 12.

  The illumination LED 12 includes a pair of LEDs 12a and 12b arranged symmetrically with respect to the optical axis of the lens 21 and at a certain distance from the center of the lens 21, respectively. Illumination light can be irradiated to a region including The illumination control unit 11 has a function of controlling the brightness of light emission so that the illumination light from the illumination LED 12 has a light amount suitable for eye image acquisition.

  The distance measuring unit 40 includes a distance measuring sensor 41 having a light beam irradiation unit 41 a that irradiates a subject with a light beam for distance measurement, a reflected light receiving unit 41 b that receives reflected light from the subject, and a light received by the distance measuring sensor 41. A distance measurement contrast information storage unit 43 for storing distance measurement contrast information for converting the output of the detected signal into distance information, and the eye of the subject based on the distance measurement comparison information from the distance measurement contrast information storage unit 43 A distance measuring distance calculating unit 42 that calculates distance information (hereinafter, this distance is referred to as “imaging distance”) between the imaging area including the image capturing area (hereinafter, this area is referred to as “imaging area”) and the imaging element is provided.

  The guidance unit 14 compares the shooting distance calculated by the distance measuring unit 40 with a predetermined distance held in advance and determines whether or not the shooting distance is suitable for shooting. An instruction unit 16 that gives a guidance instruction to move the subject to an optimal position for photographing according to the result, and a speaker 17 that transmits the instruction of the instruction unit 16 to the subject are provided.

  The guide mirror 13 installed on the front surface of the lens 21 is used for the subject to confirm the position of his / her eyes by viewing the reflected image. The guide mirror 13 is formed of a generally known semi-transparent material, and reflects and transmits light at the same time, and part of the transmitted light is input to the photographing unit 20.

  The distance determination unit 15 informs the instruction unit 16 as one of the determination result information whether the photographing distance to the subject is too close or too far. The instruction unit 16 obtains an instruction for guiding the subject to approach or move away from the subject based on the information determination result from the distance determination unit 15, an operation method of the apparatus, precautions, and an appropriate eye image. The subject is informed to the subject sequentially by voice from the speaker 17. Further, the distance determination unit 15 determines whether or not the eye photographed by the photographing unit 20 is in an appropriate position from the distance information acquired from the distance calculation unit 33 of the image signal processing unit 30 described later, and sends it to the calibration unit 34. When the shooting position is appropriate, calibration is performed. Further, the distance determination unit 15 does not cause the calibration unit 34 to perform calibration work when the photographing position is not appropriate.

  The photographing unit 20 includes a lens 21 configured by a generally used fixed focus lens, an imaging device 22 configured by an element such as a CCD, and a preprocessing unit 23. Near-infrared light emitted from the illumination LED 12 is reflected by the subject's eye and its surroundings, and the reflected light is input to the image sensor 22 through the lens 21. The input incident light is photoelectrically converted by the image sensor 22 and input to the preprocessing unit 23 as an electrical signal.

  The preprocessing unit 23 extracts an image signal component from the electric signal input from the image sensor 22 and performs image quality determination regarding contrast, focus, and the like. Further, the preprocessing unit 23 performs processing necessary as an image signal such as gain adjustment, and then outputs an optimal image signal to the image signal processing unit 30. Note that the lens 21 or the image sensor 22 preferably includes a filter having characteristics that transmit near infrared light and cut visible light.

  The photographing unit 20 receives the calibrated distance information from the distance measuring unit 40, moves the lens 21 by the focus adjustment unit 24 based on the calibrated distance information, and performs focus adjustment on the subject. Also good. As a result, a clear eye image that can be authenticated can be obtained without guiding the subject.

  The image signal processing unit 30 stores reflected light detection unit 31 that detects an eye image from the photographing unit 20 and contrast information that is a relationship between the distance between the images of the light source reflected in the detected eye image and the imaging distance. Comparison information storage unit 32, distance calculation unit 33 that calculates an imaging distance based on information in reflected light detection unit 31 and comparison information storage unit 32, and calibration of distance information calculation of distance measurement unit 40 based on the calculated distance A calibrating unit 34 for performing the above, a pupil detecting unit 35 for detecting the pupil position from the eye image output from the photographing unit 20, and whether or not the position of the pupil detected by the pupil detecting unit 35 is at the center position of the eye image. The eye position determination unit 36 that receives the determination result and the determination result from the eye position determination unit 36 receives the eye image from the photographing unit 20 and outputs the eye image to the iris information processing unit 70 as an eye image for authentication or registration. Authentication image acquisition unit 37 It is equipped with a.

  More specifically, the reflected light detection unit 31 detects the reflected light of the illumination LED 12 from the eye image captured by the imaging unit 20. The comparison information storage unit 32 stores comparison information representing the relationship between the imaging distance and the interval between the images of the light sources included in the eye image in which the illumination from the illumination LED 12 is reflected. The distance calculation unit 33 calculates the imaging distance from the reflected light detection unit 31 and the comparison information stored in the comparison information storage unit 32, and transmits the distance information to the calibration unit 34 and the distance determination unit 15. The calibration unit 34 calibrates information related to distance information calculation in the distance measuring unit 40 based on the calculated imaging distance. Here, the calibration unit 34 calibrates the distance information calculation by correcting the distance measurement contrast information. In addition, the calibration unit 34 corrects the distance measurement contrast information based on the eye image obtained by the photographing unit 20 after receiving the information that the photographing position with the subject is appropriate from the distance determining unit 15. The calibration of distance information calculation is performed. Although the distance measurement contrast information is calibrated, it may be corrected by adding an offset to the output of the distance measurement sensor 41. Either method can be calibrated to be the same as the distance information obtained from the image interval of the light source.

  The pupil detection unit 35 detects the pupil position from the eye image signal output from the preprocessing unit 23. As a method for detecting the pupil position from the signal of the eye image, a generally known technique such as a method using template matching or a method using circular integration (Japanese Patent Laid-Open No. 8-504979) can be used. .

  The eye position determination unit 36 determines whether or not the position of the pupil detected by the pupil detection unit 35 is at the center position of the eye image, and keeps the pupil at the center position of the eye image for a certain time (for example, 0.5 seconds). To the extent that stable detection is possible, a signal to the effect that the eye has been placed at an appropriate position is output to the authentication image acquisition unit 37.

  The authentication image acquisition unit 37 receives the signal from the eye position determination unit 36, takes in the signal of the eye image output from the preprocessing unit 23, and uses it as an authentication or registration eye image to the iris information processing unit 70. Output.

  The iris information processing unit 70 registers an iris authentication processing unit 71 that performs iris authentication processing using the eye image captured by the eye image capturing device 50 and iris information of the eye image captured by the eye image capturing device 50. An iris information registration unit 72 for performing the above and a storage unit 73 for storing the iris information.

  The iris authentication processing unit 71 cuts out the image of the iris region from the authentication eye image output from the image signal processing unit 30, creates authentication information based on the iris pattern of the iris part, and then registers the authentication information registered in advance. It is compared with the iris information for use, and it is determined whether or not the subject is registered by determining whether or not they match each other.

  The iris information registration unit 72 cuts out the image of the iris region from the authentication eye image output from the image signal processing unit 30, creates authentication information based on the iris pattern of the iris, and then registers the authentication information. It registers in the storage unit 73 as authentication information.

  The storage unit 73 includes a recording device that records information using magnetism or light, a recording device that uses a semiconductor memory, and the like, and stores registration authentication information and other necessary information.

  Note that in the iris information processing unit 70, an iris region image is cut out from an authentication eye image output from the image signal processing unit 30, for example, a process common to the iris authentication processing unit 71 and the iris information registration unit 72. A process of creating authentication information based on the pattern of the wrinkles of the portions may be performed in common. For the function of the iris information processing unit 70, for example, the conventional method described in Patent Document 1 described above can be used.

  Note that the functions of the image signal processing unit 30, the preprocessing unit 23, the illumination control unit 11, the calibration unit 34, the distance determination unit 15, and the iris information processing unit 70 may each be realized by hardware or realized by software. The configuration may be described and executed by an arithmetic device or the like. When software is used, it is possible to configure the eye image capturing device 50 and the iris information processing unit 70 using a computer in which a program related to each functional block is loaded into the arithmetic device.

  Next, the operation of the biometric authentication device 1 in Embodiment 1 of the present invention will be described.

  FIG. 3 is a flowchart illustrating an example of the operation of the biometric authentication device 1. First, an authentication operation or registration operation is started by an operation such as pressing a start button (not shown) arranged on the biometric authentication device 1 according to a guide (not shown) displayed on the biometric authentication device 1 by the subject. To do.

  Next, the subject performs eye alignment while looking at the guide mirror 13 of the biometric authentication device 1 in accordance with an instruction from the speaker 17. The image signal processing unit 30 instructs the illumination control unit 11 to prepare for eye image shooting in order to calibrate the distance information calculation in the distance measuring unit 40. When the preparation for photographing is completed, the illumination control unit 11 instructs the photographing unit 20 to perform photographing. The imaging unit 20 uses the two LEDs 12a and 12b to illuminate the subject's eye area from different directions, and images the subject's eyes (S100). The biometric authentication device 1 may perform the calibration work once every time the subject to be authenticated changes, or may perform the same subject a plurality of times during authentication. Since the distance measuring sensor 41 outputs different for each subject, at least one calibration operation may be performed when the subject changes.

  Then, the distance determination unit 15 determines whether or not the eye image obtained by photographing with the photographing unit 20 is photographed at an appropriate photographing distance from the distance information acquired from the distance calculating unit 33, and determines an appropriate value. When the photographing at the photographing position is successful, the photographing of the calibration eye image of the distance measuring unit 40 is finished (S101). If the biometric authentication device 1 is photographed at an improper photographing position, the biometric authentication device 1 returns to S100 and captures the calibration eye image again.

  When the photographing of the calibration eye image by the distance measuring unit 40 is completed, the biometric authentication device 1 transmits information about the eye image from the pre-processing unit 23 to the image signal processing unit 30, and the image signal processing unit 30 relates to the eye image. Calibration of distance information calculation of the distance measuring unit 40 is performed using the information (S102).

  The distance measuring unit 40 calculates distance information using distance measurement contrast information that represents the relationship between the output of the distance measuring sensor 41 and the distance to the subject. Specifically, the distance measurement distance calculation unit 42 uses the distance measurement comparison information stored in the distance measurement comparison information storage unit 43 to calculate information on the shooting distance from the output of the distance measurement sensor 41 to the subject. Here, the distance measurement calculation unit 42 uses a distance measurement contrast information stored in advance in the distance comparison information storage unit 43 (hereinafter, this distance comparison information is referred to as “basic contrast information”). Based on the output of 41, distance information to the subject is calculated. Details of the calibration method of the distance measuring unit 40 will be described later.

  Based on the information from the preprocessing unit 23, the image signal processing unit 30 calculates the imaging distance from the subject by the reflected light detection unit 31 and the comparison information stored in the comparison information storage unit 32 and the distance calculation unit 33. The calibration unit 34 detects the difference between the distance information calculated by the distance calculation unit 33 and the distance information calculated by the distance measurement distance calculation unit 42, and the basic comparison information stored in the distance measurement comparison information storage unit 43. Correct. Accordingly, the calibration unit 34 calibrates the distance information calculated by the distance measurement distance calculation unit 42 so that the distance information calculated by the distance calculation unit 33 is substantially the same. Here, the reflected light detection unit 31 detects an image of the light source of the spot of the illumination LED 12 included in the eye image obtained by photographing with the photographing unit 20, and the distance calculation unit 33 detects the images of the two detected light sources. The interval is detected, and the shooting distance is calculated using the contrast information stored in the contrast information storage unit 32.

  Next, the distance measurement distance calculation unit 42 acquires the output of the distance measurement sensor 41, and performs conversion to distance information using the corrected basic comparison information stored in the distance measurement comparison information storage unit 43. Calculate the calibrated distance information.

  The guiding unit 14 determines the distance information calculated using the distance measuring unit 40, and gives a guidance instruction regarding the movement of the position to the subject based on the determination result (S103). The guiding unit 14 guides the subject to a region within the focal depth including the focal length of the fixed focus lens included in the photographing unit, so that the photographing distance to the position for guiding the subject in advance (hereinafter, this photographing distance is referred to as “reference distance”). Hold). The guide unit 14 guides the subject based on the distance information calculated by the distance measuring unit 40 using the reference distance as a reference for determination. Further, the guide unit 14 moves in the forward or backward direction so that the subject passes through the focal position within the focal depth region so that the photographing unit 20 can photograph the subject at the focal position of the lens 21. Give instructions to the subject. Here, the direction in which the subject approaches the photographing unit 20 is defined as the forward direction, and the direction in which the subject moves away is defined as the backward direction. Accordingly, the guiding unit 14 can guide the subject to pass through the focal position of the lens 21 without fail.

  Thereby, the guide unit 14 can guide the subject to the focal position of the fixed focus lens. In addition, the photographing unit 20 can obtain a clear eye image in focus.

  The distance determination unit 15 determines whether or not the imaging distance is within the allowable range including the reference distance based on the distance information from the distance measuring unit 40 (S104), and instructs the imaging unit 20 when it is within the allowable range. Then, the subject's eyes are photographed (S105).

  The pre-processing unit 23 determines whether the image quality such as focus, brightness, and contrast of the eye image obtained by photographing is appropriate. If not, the pre-processing unit 23 performs necessary processing including a guidance instruction for the subject. Then, the eye is photographed again (S106).

  When the preprocessing unit 23 determines that the image quality is appropriate, the pupil detection unit 35 detects the pupil position from the eye image signal output from the preprocessing unit 23. The eye position determination unit 36 determines whether or not the position of the pupil is at the center position of the eye image. The authentication image acquisition unit 37 outputs, to the iris information processing unit 70, an eye image for which the image quality and the position of the pupil are determined to be appropriate by the preprocessing unit 23 and the eye position determination unit 36 as an eye image for authentication or registration. (S107).

  If the determined eye image is inappropriate, the biometric authentication device 1 returns to S103 and captures the eye image again. In addition, when the imaging of the eye image is completed, the distance determination unit 15 notifies the subject 17 that an appropriate eye image has been obtained by the speaker 17 via the instruction unit 16.

  The iris information processing unit 70 cuts out an iris image from the eye image data based on the center coordinates of the pupil (S108), and converts the iris image into unique authentication information indicating the iris pattern as a numerical value (S109).

  Further, the biometric authentication device 1 determines whether the request for the subject is registration of authentication information or authentication based on the registration authentication information (S110). If the request for the subject is authentication, the biometric authentication device 1 compares the authentication information obtained by photographing with the registered authentication information that has been registered, and executes an authentication operation (S111). When the subject request is registration, the biometric authentication device 1 registers the unique authentication information obtained from the iris image included in the eye image in the storage unit 73 as registration authentication information (S112). Thereby, the biometric authentication device 1 completes the process.

  Next, the calculation method of the imaging distance information by the distance measurement unit 40 and the distance information calculation of the distance measurement unit 40 in S102 will be described in detail with reference to FIGS.

  The calibration method of the distance measuring unit 40 performs the first distance measurement by the distance measuring sensor 41 with respect to the imaging distance and the second distance measurement with respect to the distance (imaging distance) from the subject eye to the distance measuring sensor 41. The measurement result obtained by the distance measurement is calibrated so as to become the measurement result obtained by the second distance measurement.

  First, in the second distance measurement, the biometric authentication device 1 illuminates the subject using the two LEDs 12a and 12b for the purpose of calibrating the distance measuring unit 40 prior to calculating the imaging distance to the subject. Take a picture of the eye of the illuminated subject. Next, the biometric authentication device 1 measures a distance related to a distance (imaging distance) from the subject's eye to the distance measuring sensor 41. As shown in FIG. 4, the biometric authentication device 1 illuminates the imaging regions of the subject 61 with illumination lights 62 and 63 using the LEDs 12 a and 12 b, and uses the imaging unit 20 to display the eye image shown in FIG. Get it by shooting. As a result, the biometric authentication device 1 can obtain an eye image 80a in which spots of two light sources by the LEDs 12a and 12b are reflected. In the eye image 80a, the interval between the reflected images 56a of the light source is L1. When the distance between the subject 61 and the distance measuring sensor 41 changes, as shown in FIGS. 5B and 5C, in the eye images 80b and 80c obtained by photographing, the reflected image 56b of the light source is used. , 56c change to L2, L3.

  Information indicating the relationship between the distance L between the images of the light source and the imaging distance (hereinafter, this information is referred to as “calibration contrast information”) is obtained in advance through experiments or the like and stored in the biometric authentication device 1. For example, the biometric authentication device 1 can calculate the imaging distance by detecting the interval L between the images of the light sources.

  FIG. 6 shows an example of calibration contrast information obtained by experiments. In FIG. 6, when the intervals of the light source images included in the eye image detected by the reflected light detection unit 31 are SD1, SD2, SD3, the distances from the distance measuring sensor 41 to the subject's eyes are SC1, SC2, This indicates that it was SC3. Similarly, by measuring a number of distances SC from the distance measuring sensor 41 corresponding to the light source image interval SD to the subject's eye, an approximate curve D indicating the correspondence between the distance SD and the distance SC is obtained. The approximate curve D is stored in the comparison information storage unit 32 as calibration comparison information.

  This second distance measuring method can accurately measure the imaging distance without being affected by the surface state of the subject 61. However, in the biometric authentication device 1, the subject's eyes are photographed, the reflection of the light source included in the eye image obtained by photographing is detected, the distance between the light source images is compared with the contrast information, and the distance information is calculated. Perform the process. Therefore, it takes a long time to calculate the imaging distance.

  Next, in the first distance measurement, the distance measurement unit 40 performs distance measurement regarding the imaging distance. FIG. 7 shows an experimental example of distance measurement contrast information between the distance from the distance measuring sensor 41 to the object and the detection voltage of the distance measuring sensor 41 that receives the reflected light from the object.

  FIG. 7 shows the contrast characteristics of the distance measuring sensor 41 with respect to the subject A, the subject B, and the subject C, and the range of output variations thereof. That is, the detection voltage of the distance measuring sensor 41 varies depending on the surface state of the object (for example, skin color, presence / absence of makeup, etc.), and when the distance measuring light beam is strongly reflected, an error is generated in a direction shorter than the actual direction. When it occurs and reflects weakly, it indicates that an error occurs in a long direction. From this experimental result, as shown in FIG. 7, it can be seen that, with respect to a distance of 30 cm to the object corresponding to the detection voltage V1, a variation of about ± 8 cm as the measurement error X occurs depending on the subject. Usually, when a fixed focus lens having a focal length of 30 cm is used for the biometric authentication device 1, an allowable range of the imaging distance is required to be about 30 cm ± 3 cm, and the subject is allowed using the distance information of the distance measuring unit 40 as it is. Even if it is guided inward, it is difficult to photograph the subject's eyes in focus. However, the distance measuring sensor 41 has a feature that the detection speed is fast, and sets information (hereinafter, this information is referred to as “basic contrast information”) as a base indicating the relationship between the imaging distance and the detection voltage. By measuring the distance to the subject at short time intervals using the distance measuring sensor 41, the biometric authentication device 1 can promptly give a guidance instruction to the subject. Here, the allowable range of the imaging distance is set within the focal depth of the fixed focus lens. Therefore, it is preferable to set the reference distance of the guide portion 14 to the center of the allowable range, for example, 30 cm.

  In the first embodiment of the present invention, based on the first and second distance measurement results, the calibration unit 34 uses the calibration contrast information obtained by the second distance measurement. The basic contrast information is corrected, and the distance information calculation in the distance measuring unit 40 is calibrated. Although the correction of the distance information calculation in the distance measuring unit 40 is performed by correcting the basic contrast information, the correction may be performed by adding an offset value to the output of the distance measuring sensor 41. Either method can calibrate the distance information calculation in the distance measuring unit 40.

  First, the distance calculation unit 33 calculates the imaging distance SC from the interval (detection value) SD of the image of the light source included in the eye image from the calibration contrast information Ic shown in FIG.

  Next, as shown in FIG. 8B, the calibration unit 34 calculates the imaging distance SC calculated from the basic contrast information Ia with respect to the detected voltage V2 detected by the distance measuring sensor 41. Make a comparison. When the error C has occurred between SE and SC, the calibration unit 34 sets the calibration value of the contrast information to the basic contrast information Ia representing the relationship between the output of the distance measuring sensor 41 and the distance to the subject. "C", the basic contrast information is corrected, and corrected contrast information Ib is created. Next, the calibration unit 34 stores the contrast information Ib after calibration in the distance measurement contrast information storage unit 43.

  Thereafter, the distance measurement distance calculation unit 42 calculates the imaging distance based on the corrected comparison information Ib stored in the distance measurement comparison information storage unit 43 with respect to the detection voltage V of the distance measurement sensor 41.

  As described above, according to the first embodiment of the present invention, the biometric authentication device 1 uses the two LEDs 12a and 12b and the photographing unit 20 to capture the light source prior to obtaining the eye image for authentication. An eye image can be acquired, and the imaging distance can be accurately calculated from the interval between the images of the light sources. Then, the distance information calculated by the distance measuring unit 40 is calibrated using the distance information calculated based on the image interval of the light source. Accordingly, the biometric authentication device 1 can correct an error in the measurement result of the distance that varies for each subject in the distance measuring unit 40. Therefore, the biometric authentication device 1 detects an accurate imaging distance by utilizing the high-speed response performance of the distance measuring unit 40 for an authentication target person having different surface conditions such as skin and hair, and positions the subject at an appropriate position. Authentication information can be acquired promptly by guiding to.

  Further, since the biometric authentication device 1 can quickly guide the subject to an appropriate shooting position using the calibrated distance information of the distance measuring unit 40, high-precision authentication can be performed even when a fixed-focus lens is used for the shooting unit 20. Information can be obtained promptly.

(Embodiment 2)
As a second embodiment of the present invention, an example in which the biometric authentication device 1 of the first embodiment is mounted on a portable information device will be described. Parts similar to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The biometric authentication device 1 is equipped with a high-accuracy distance measuring device with a high-speed response, and can perform authentication work by detecting the shooting distance between the subject and the device. This is suitable for a device that performs authentication by photographing a subject that moves constantly from a certain position.

  For example, as an embodiment applied to a mobile phone, as shown in the front view of FIG. 9A, a display unit 95 using a liquid crystal display panel or the like is mounted on one housing unit 101 connected by a rotating connection unit. On the connecting part side, there are a photographing unit 20, an illumination unit 10 (not shown) having two light sources 12a and 12b that illuminate the subject, and a distance measuring unit 40 that measures the distance to the subject. The biometric authentication device 1 provided in the width direction is mounted. Note that the biometric authentication device 1 may be provided side by side in the longitudinal direction of the housing for the convenience of arrangement of the other display unit 95. The biometric authentication device 1 mounted on a mobile phone uses the two light sources 12a and 12b of the illumination unit 10 to illuminate the subject's eyes, and the imaging unit 20 captures an area including the illuminated subject's eyes. The interval between the light source images included in the obtained eye image is detected, the distance to the subject is calculated from the interval between the light source images, and the calculation of the distance information measured by the distance measuring unit 40 is calibrated. Then, the calibrated distance information from the distance measuring unit 40 is used to guide the subject to a photographing position suitable for photographing, and the subject's eyes are photographed. Whether or not the user is an identity person is generated by cutting out the iris portion from the eye image of the subject obtained by photographing and generating authentication information and comparing it with registered authentication information stored in advance in the storage unit of the mobile phone. Authenticate.

  The housing portion 101 of the display portion 95 is equipped with an antenna 98 and a speaker 96, and the other housing portion 102 rotatably connected thereto has a microphone 97 and a key having a numeric keypad and other operation buttons. The input unit 90 and components for information processing and control are mounted.

  As shown in FIG. 9B as an example of the configuration, this cellular phone is connected to an antenna 98, and these signals are used to enable wireless communication of audio signals, video signals, and other various signals. A control unit 92 that performs various controls based on information from the wireless transmission / reception unit 91 for modulation or demodulation, information from the biometric authentication device 1 and the key input unit 90, and information exchanged with the wireless transmission / reception unit 91, and information exchanged , A storage unit 93 for storing authentication information and the like, and a ROM and RAM (not shown) that store information necessary for various controls, message information, and the like. The audio signal input / output unit 94 transmits audio information from the control unit 92 to the speaker 96 as an audio signal. The audio signal input / output unit 94 also has a function of supplying audio information obtained from the microphone 97 to the control unit 92. In addition, the control unit 92 includes various line devices (not shown) necessary as a radio telephone such as a dial pulse generator and as an information processing device.

  When the biometric authentication device 1 determines that the subject is not the person who registered the subject, the control unit 92 refuses to accept the key at the key input unit 90 and prevents the mobile phone from being used.

  The speaker 17 of the biometric authentication device 1 may be shared with the speaker 96. The biometric authentication device 1 can instruct the subject from the speaker 96 via the audio signal input / output unit 94 by transmitting the guidance information to the control unit 92.

  Further, the focus information of the photographing unit 20 may be adjusted using the calibrated distance information from the distance measuring unit 40, and then the eye of the subject may be photographed.

  When a mobile phone user intends to transmit, first, the biometric authentication device 1 is used to perform the personal authentication operation described in the first embodiment. Based on the comparison result, the control unit 92 performs a call permission / inhibition operation, and enables a call only when it is determined that the user is the user, and performs a control operation according to an input signal from the key input unit 90. Do. As a result, transmission and reception are performed in response to voice and other key operations.

  Further, based on the authentication result by the biometric authentication device 1 mounted on the mobile phone, various databases, for example, whether or not access to personal information is possible, personal authentication at the time of settlement when used in vending machines, stores, etc., It can be used for identity verification in business transactions, and authentication work can be easily, quickly and reliably performed.

  As described above, according to the second embodiment, the biometric authentication device 1 is equipped with the distance measuring device that enables high-speed and high-accuracy distance measurement described in the first embodiment. The authentication distance can be detected by detecting the shooting distance between the camera and the device. Thereby, even a device that authenticates a subject that constantly moves from a distant position, such as a portable information device, an information processing device, and a game device, can perform authentication work quickly and reliably.

  In the first embodiment, the calibration unit 34 may be configured as follows.

  The calibration unit 34 may prepare a plurality of candidates for contrast information (approximate curve) for each subject, and may select the approximate curve closest to the correction point h. For example, as shown in FIG. 7, the biometric authentication device 1 previously obtains contrast information corresponding to the subjects A, B, and C as an approximate curve A, an approximate curve B, and an approximate curve C, and uses each as basic contrast information. It is stored in the distance measurement contrast information storage unit 43. Then, the calibration unit 34 may select the closest approximate curve that passes through the correction point h from the approximate curve group stored in the distance measurement contrast information storage unit 43 and use it as the corrected contrast information Ib. . Further, the calibration unit 34 may translate the approximate curve of the basic contrast information so as to pass over the correction point h to obtain the contrast information Ib after calibration. In any method, the calibration unit 34 can approximate the distance information calculated by using the distance measuring unit 40 to the distance information calculated from the interval between the reflected light source images reflected in the eye image.

  Further, the calibration unit 34 may calibrate the distance measuring unit 40 based on the average value of the distance information calculated by detecting the eye images of both eyes for updating the approximate curve. Thereby, even if there is an error in the distance calculated from the interval between the images of the light sources included in the eye image, it can be suppressed.

  Further, the calibration unit 34 may set a maximum value for correcting the basic contrast information in advance. As a result, calibration can be performed within an appropriate range, and abnormal correction due to errors can be eliminated.

  Further, the calibration unit 34 may perform calibration in a stepwise manner over a plurality of times. As a result, if the calibration value for correcting the basic contrast information is divided and gradually calibrated, even if a large error occurs in the distance calculated from the interval of the image of the light source reflected in the eye image, it immediately spreads. Therefore, the influence of the error can be suppressed.

  Note that the reliability of the distance information may be improved as follows.

  That is, in the eye image in which the images of the two light sources are reflected, the position of the image may be detected, and the distance information may be calculated from the eye image in which the image of the light source is reflected almost in the middle of the eyeball. In addition, the distance information is calculated from the interval between the images of the light source reflected in the eye images obtained by illuminating both eyes with the same method and photographing each, and the average value of the calculated distance information is used as the distance information. It may be output. Thereby, the calculation error due to the curvature of the eyeball can be suppressed, and the accuracy of the calculated distance information can be increased.

  Moreover, you may further provide the spectacles detection part which detects the presence or absence of the spectacles of a to-be-photographed object. When the spectacle detection unit detects that there is spectacles, the distance information calculated from the interval between the images of the light sources included in the eye image is corrected. Thereby, the calculation error can be suppressed in consideration of the effect of the reduction ratio of the size of the eye image by the glasses, and the accuracy of the calculated distance information can be increased.

  The photographing unit 20 photographs the subject's face and detects an irradiation position detection unit that detects which position of the face is irradiated with the irradiation light from the light beam irradiation unit 41a of the distance measuring sensor 41, and the detected irradiation. And an abnormality detection unit that determines whether the irradiation position is more appropriate than the position. Further, when the abnormality detection unit detects an abnormality, the biometric authentication device 1 invalidates the distance information obtained by the distance measurement unit 40 and based on the distance information calculated from the interval between the light source images included in the eye image. You may switch so that distance information may be acquired. Thereby, when abnormality is recognized in the distance information calculated by the distance measuring unit 40, it can be invalidated. Moreover, the influence on authentication work can be suppressed by switching to another distance information.

  The photographing unit 20 may further include a focus level detection unit that detects the focus level of the image of the light source of the illumination LED 12 reflected in the eye image. The calibration unit 34 changes the weights of the distance information calculated from the interval between the light source images included in the eye image and the distance information measured by the distance measuring unit 40 according to the detected focus level, and either You may make it calibrate so that the weight of may be increased. For example, when the focus level is low, the basic contrast information is corrected so as to increase the weight of the distance information measured by the distance measuring unit 40, and the distance information calculation is calibrated. Thereby, a measurement result with higher reliability can be used.

  The illumination LED 12 may be configured as follows.

  That is, in Embodiment 1 of the present invention, the illumination LED 12 is configured by a pair of LEDs, but is not limited to this configuration. For example, each of the pair of LEDs may be composed of a plurality. In this case, an LED having a relatively low light emission luminance can be used, and the amount of light when irradiating the eye of the subject can be controlled by changing the number of LEDs to emit light. Furthermore, you may comprise a pair of LED12 for illumination in multiple pairs. Thereby, it becomes possible to increase the combination of the illumination angle of the illumination light with respect to the eyes of the subject.

  Moreover, although LED12 for illumination illuminates eyes with a pair of LED arrange | positioned at the both sides of an imaging | photography part, you may illuminate eyes with a pair of LED arrange | positioned at one side of an imaging | photography part.

  Moreover, although it was made to illuminate one eye, as shown in FIG. 10, LED12c and LED12d were increased so that illumination light 62, 63, 66, 67 could be illuminated with respect to each eye of both eyes. Also good. Further, two imaging units 20 that capture both eyes may be provided, and a distance may be calculated from an interval between light source images included in the eye images captured by the two imaging units 20, and the calculated distances may be averaged. . Thereby, a measurement error can be suppressed.

  Further, the illumination LED 12 may be moved relative to the subject. By moving the illumination LED 12 between the position close to the lens 21 and the position far from the lens 21 by the movable portion, it is possible to photograph the eyes of the subject with different illumination angles of the illumination light.

  Also, a method of changing the illumination angle of the illumination light with respect to the subject's eye by changing the optical path of the illumination light by using reflection, refraction, spectroscopy, etc. of a lens, a prism, a mirror, or the like is possible.

  In the embodiment of the present invention, the illumination light from the illumination LED 12 may be near infrared light. Since the iris has a characteristic of easily reflecting infrared light, the use of this near infrared light increases the contrast of an eye image obtained by photographing and improves the accuracy of discrimination. The same effect can also be achieved by a method of covering the illumination LED 12 with a filter that blocks visible light and transmits near-infrared light.

  In the first embodiment of the present invention, the illumination LEDs 12 are arranged on the left and right sides of the guide mirror 13. For example, the illumination LEDs 12 are arranged above and below the guide mirror 13. Also good. It is preferable that the illumination LED 12 can illuminate the subject at an appropriate illumination angle so that reflection of glasses or contacts can be suppressed.

  The guidance of the subject and the confirmation of the subject may be performed as follows.

  That is, the biometric authentication device 1 according to the embodiment of the present invention may include a display unit using a liquid crystal or an EL that displays the acquired eye image. When the display unit is used for confirmation by an administrator of the authentication device, it is desirable to install the display unit away from the biometric authentication device.

  In the first embodiment of the present invention, the guide mirror 13 is arranged on the front surface of the lens. However, the lens 21 and the guide mirror 13 are integrated, or the guide mirror 13 is arranged in the vicinity of the lens 21. Even if it is a structure etc., the same effect can be exhibited.

  Further, in the embodiment of the present invention, if the subject is guided by video or audio and the eyes of the subject are guided to an appropriate position, the guide mirror 13 need not be used.

  In the first embodiment of the present invention, the eye image capturing device 50 and the iris authentication processing unit 71 are integrated. However, each component such as the eye image capturing device 50 and the iris authentication processing unit 71 is used. May be configured as separate devices. The eye image capturing device 50 can be used only for capturing an eye image.

  According to the biometric authentication device of the present invention and the distance measurement device for a biometric authentication device mounted on the biometric authentication device, even if there is a variation in reflected waves due to the surface of the subject such as skin or hair of a subject that moves constantly, the subject can be accurately and quickly Information processing apparatus such as a biometric authentication device, a mobile phone device equipped with a biometric authentication device, a portable information device such as a PDA, a game device equipped with a biometric authentication device, and a computer It is useful as such.

The front view which shows the external appearance of the biometrics authentication apparatus in Embodiment 1 of this invention. Block diagram showing the configuration of the biometric authentication device Flow chart showing operation of the biometric authentication device Explanatory drawing explaining operation | movement of the ranging part of the biometrics authentication apparatus (A) An explanatory diagram of a reflected image of a light source in an eye image (b) An explanatory diagram of an reflected image of a light source in an eye image (c) An explanatory diagram of an reflected image of a light source in an eye image Explanatory drawing of contrast information for calibration of the biometric authentication device Explanatory drawing explaining ranging comparison information of the biometric authentication device (A) Explanatory diagram explaining calculation of distance from calibration contrast information (b) Explanatory diagram explaining calibration of distance measurement contrast information (A) Front view of mobile phone in embodiment 2 of the present invention (b) Block diagram showing functions of the mobile phone Explanatory drawing explaining the state which another biometrics apparatus in embodiment of this invention illuminated the light source to both eyes

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biometric apparatus 10 Illumination part 11 Illumination control part 12 LED for illumination
12a, 12b, 12c, 12d Light source (LED)
DESCRIPTION OF SYMBOLS 13 Guide mirror 14 Guide part 15 Distance discrimination | determination part 16 Instruction part 17 Speaker 20 Image pick-up part 21 Lens 22 Image pick-up element 23 Pre-processing part 24 Focus adjustment part 30 Image signal process part 31 Reflected light detection part 32 Contrast information memory | storage part 33 Distance calculation part 34 Calibration section 35 Pupil detection section 36 Eye position determination section 37 Authentication image acquisition section 40 Distance measurement section 41 Distance measurement sensor 41a Light beam irradiation section 41b Reflected light reception section 42 Distance measurement distance calculation section 43 Distance comparison information storage section 50 Eye image Photographing device 56a, 56b, 56c Reflected image of light source 61 Subject 62, 63, 66, 67 Illumination light 70 Iris information processing unit 71 Iris authentication processing unit 72 Iris information registration unit 73, 93 Storage unit 80a, 80b, 80c Eye image 90 Key input unit 91 Wireless transmission / reception unit 92 Control unit 94 Audio signal input / output unit 95 Display unit 96 Speaker 9 Microphone 98 antenna 101 and 102 housing unit

Claims (14)

An illumination unit having at least two light sources that illuminate an area including the subject's eyes from different positions;
An imaging unit for imaging an area including at least eyes of the subject;
A distance measuring unit that irradiates the object with an irradiation wave and receives a reflected wave of the irradiation wave from the object; and calculates distance information to the object;
A distance calculation unit that calculates distance information to the subject based on an interval between images of the light source included in an eye image of the subject obtained by photographing in the photographing unit;
A calibration unit that calibrates the calculation of the distance information calculated by the distance measuring unit based on the distance information to the subject calculated by the distance calculating unit;
A distance measuring device for a biometric authentication device, comprising: A contrast information storage unit that stores in advance contrast information representing the relationship between the distance between the images of the light sources included in the eye image and the distance to the subject;
The distance calculation unit calculates distance information to the subject from an interval of the image of the light source included in the eye image of the subject obtained by photographing in the photographing unit and the contrast information. The distance measuring device for a biometric authentication device according to claim 1. The distance measurement unit is based on a distance measurement contrast information storage unit that stores in advance distance measurement comparison information representing a relationship between an output obtained by the received reflected wave and a distance to the subject, and the distance measurement comparison information. A distance measuring distance calculating unit for calculating a distance to the subject;
The calibration unit calculates distance information calculated by the distance measurement distance calculation unit based on a difference between distance information calculated by the distance calculation unit and distance information calculated by the distance measurement distance calculation unit. The distance measuring device for a biometric authentication device according to claim 1, wherein the distance measurement contrast information is calibrated so as to be corrected to the distance information calculated in (1). The distance measuring device for a biometric authentication device according to any one of claims 1 to 3,
A guiding unit that guides the subject to a predetermined position based on the distance information calculated by the ranging unit;
An authentication processing unit that authenticates the subject based on authentication information obtained by photographing the guided subject by the photographing unit;
A biometric authentication device comprising: The distance measuring device for a biometric authentication device according to any one of claims 1 to 3,
A focus adjustment unit that performs focus adjustment of the photographing unit on the subject based on distance information calculated by the distance measurement unit;
An authentication processing unit that performs authentication of the subject based on authentication information obtained by photographing with the focus-adjusted photographing unit;
A biometric authentication device comprising: The biometric authentication device according to claim 4, wherein the calibration unit calibrates distance information calculated by the distance measurement unit for each subject. The guidance unit includes a distance determination unit that compares the distance information calculated by the distance measurement unit with the predetermined position information and determines whether or not the distance to the subject is appropriate.
The biometric authentication device according to claim 4, wherein the subject is guided to the predetermined position based on a determination result of the distance determination unit. The photographing unit has a fixed focus lens,
The biometric authentication apparatus according to claim 7, wherein the predetermined position information is focal depth area information of the fixed focus lens. The photographing unit has a fixed focus lens,
The biometric authentication device according to claim 7, wherein the guide unit guides the subject forward or backward so that the subject passes through a focal position of the fixed focus lens. The biometric authentication device according to claim 4 or 5,
A data transmitter / receiver for transmitting / receiving voice or information;
A portable information device with a biometric authentication device. Illuminating an area including at least eyes of a subject from at least two light sources from different directions;
Photographing a region including at least eyes of a subject illuminated by the at least two light sources;
Detecting an image of each of the light sources included in an eye image of the subject obtained by photographing;
Calculating an interval between images of the light source detected from the eye image;
Calculating distance information to the subject based on an interval between images of the light source;
Distance information to the subject is calculated on the basis of distance measurement contrast information representing a relationship between an output obtained by irradiating the subject with the reflected wave of the irradiation wave on the subject and a distance to the subject. Steps,
The distance information calculated using the distance measurement contrast information based on the difference between the distance information calculated based on the interval of the light source image and the distance information calculated based on the distance measurement contrast information is the image of the light source. Calibrating the distance measurement contrast information so as to correct the distance information calculated based on the interval;
A method for calibrating a distance measuring device for a biometric authentication device, comprising: First, distance information to the subject is calculated based on distance measurement comparison information representing a relationship between an output obtained by receiving the reflected wave of the irradiation wave on the subject and the distance to the subject. 1 ranging step,
The area of the subject including at least the eyes is illuminated from different directions using at least two light sources, the area of the subject including at least the eyes illuminated by the light source is photographed, and the subject's eyes obtained by photographing A second distance measuring step of detecting an image of each of the light sources included in the image and calculating distance information to the subject based on an interval of the image of the light source detected from the eye image;
The distance information calculation in the first distance measurement step is calibrated so that the distance information obtained in the first distance measurement step is corrected for each subject to the distance information obtained in the second distance measurement step. A calibration step;
A guiding step for guiding the subject to a predetermined position based on the calibrated distance information;
An authentication step of authenticating the subject based on authentication information obtained by photographing the guided subject;
A biometric authentication method comprising: First, distance information to the subject is calculated based on distance measurement comparison information representing a relationship between an output obtained by receiving the reflected wave of the irradiation wave on the subject and the distance to the subject. 1 ranging step,
The area of the subject including at least the eyes is illuminated from different directions using at least two light sources, the area of the subject including at least the eyes illuminated by the light source is photographed, and the subject's eyes obtained by photographing A second distance measuring step of detecting an image of each of the light sources included in the image and calculating distance information to the subject based on an interval between the images of the light sources detected from the eye image;
The distance information calculation in the first distance measurement step is calibrated so that the distance information obtained in the first distance measurement step is corrected for each subject to the distance information obtained in the second distance measurement step. A calibration step;
A focus adjustment step for adjusting the focus of the photographing unit based on the calibrated distance information;
An authentication step of performing authentication of the subject based on authentication information of the subject obtained by photographing with the photographing unit after focus adjustment;
A biometric authentication method comprising: A first ranging step of calculating distance information to the subject with first responsiveness and first accuracy;
A second ranging step of calculating distance information to the subject with a second responsiveness slower than the first responsiveness and a second accuracy higher than the first accuracy;
The distance information calculation in the first distance measurement step is calibrated so that the distance information obtained in the first distance measurement step is corrected for each subject to the distance information obtained in the second distance measurement step. A calibration step;
A distance measuring method for biometric authentication, comprising:

Images