Patent ID: 12198393

EXAMPLE EMBODIMENT

An example embodiment according to this disclosure will be described hereinafter with reference to the drawings. For clarifying the explanation, the following descriptions and the drawings are partially omitted and simplified as appropriate. Further, the same symbols are assigned to the same components/structures throughout the drawings, and redundant explanations thereof are omitted as appropriate.

First Example Embodiment

A first example embodiment will be described hereinafter.

FIG.1is a block diagram showing a configuration of an imaging system10according to a first example embodiment. As shown inFIG.1, the imaging system10includes an iris imaging device (iris imaging means)1, first irradiation means (a first illuminator)2a, and second irradiation means (a second illuminator)2b.

The iris imaging device1is used to photograph an iris(es) of a subject. The first illuminator2ais used to apply light to the subject. The second illuminator2bis configured for applying light to the subject so that an angle between the optical axis of light emitted from the second illuminator2band the optical axis of the iris imaging means is larger than an angle between the optical axis of light emitted from the first illuminator2aand the optical axis of the iris imaging device1.

By using the above-described configuration, it is possible to obtain an image in which the iris(es) of the subject is properly photographed (i.e., is properly shown) irrespective of whether or not the subject is wearing glasses or the like.

Second Example Embodiment

A second example embodiment will be described hereinafter.

Firstly, an example of a configuration of an imaging system according to the second example embodiment will be described.FIG.2is a block diagram showing a configuration of an imaging system510according to the second example embodiment. As shown inFIG.2, the imaging system510includes an iris imaging device1, a first illuminator2a, a second illuminator2b, and a controller (control means)5. That is, the imaging system510is different from the above-described imaging system10according to the first example embodiment (seeFIG.1) in that the imaging system510further includes the controller5.

The controller5determines whether or not the subject is wearing glasses or the like, and controls the operations performed by the first and second illuminators2aand2bbased on the result of the determination. Specifically, when the controller5determines that the subject is not wearing glasses or the like, the controller5operates the first illuminator2aso that light is emitted from the first illuminator2a. On the other hand, when the controller5determines that the subject is wearing glasses or the like, the controller5operates the second illuminator2bso that light is emitted from the second illuminator2b.

FIG.3is a flowchart for explaining a flow of an imaging process performed in the imaging system510. As shown inFIG.3, firstly, the controller determines whether or not the subject is wearing glasses or the like (Step S1).

In the step S1, when the controller5determines that the subject is not wearing glasses or the like (No), the controller5operates the first illuminator2aso that light is emitted from the first illuminator2a(Step S2). In the step S1, when the controller5determines that the subject is wearing glasses or the like (Yes), the controller5operates the second illuminator2bso that light is emitted from the second illuminator2b(Step S3). Subsequent to the step S2or S3, the controller5acquires a captured image of an iris(es) by controlling the iris imaging device1(Step S4). The captured image of the iris(es) acquired in the step S4is used for iris authentication or registration.

As described above, the imaging system510includes the first illuminator2a, and the second illuminator2bwhich is configured so that the angle between the optical axis of light emitted from the second illuminator2band the optical axis of the iris imaging means is larger than the angle between the optical axis of light emitted from the first illuminator2aand the optical axis of the iris imaging device1. By emitting light from the second illuminator2bwhen the subject is wearing glasses or the like, it is possible to prevent (or reduce) the reflected light from the glasses or the like from entering the iris imaging means1. As a result, a possibility that a captured image acquired by the imaging system510is appropriate for iris authentication even when the subject is wearing glasses or the like is increased, thus making it possible, by performing iris authentication by using the above-described captured image, to improve the success rate of the iris authentication. As a result, the subject wearing the glasses or the like does not have to take off the glasses or the like, so that the convenience is improved.

On the other hand, when the subject is not wearing glasses or the like, light is emitted from the first illuminator2a. The overlapping range between the irradiation range of the first illuminator2aand the imaging range of the iris imaging device1is larger than the overlapping range between the irradiation range of the second illuminator2band the imaging range of the iris imaging device1. The larger the overlapping range is, the higher the possibility that the acquired captured image of the iris(es) of the subject is appropriate for iris authentication becomes. When the subject is not wearing glasses or the like, there is no need to take the prevention (or the reduction) of the reflected light from the glasses or the like into consideration. Therefore, by emitting light from the first illuminator2aof which the overlapping range with the imaging range of the iris imaging device1is large, the risk that the photographing needs to performed again is reduced, so that the convenience is improved.

Third Example Embodiment

A third example embodiment will be described hereinafter.

Firstly, an example of a configuration of an imaging system according to the third example embodiment will be described.FIG.4is a block diagram showing a configuration of an imaging system110according to the third example embodiment. As shown inFIG.4, the imaging system110includes an iris imaging device (iris imaging means)101, a first illuminator (first illumination means)102a, a second illuminator (second illumination means)102b, a guiding device (guiding means)103, and a controller (controlling means)105.

The iris imaging device101is a camera for photographing an iris(es) of a subject P. The iris imaging device101is disposed so as to be able to properly photographing a focusing area including an eye(s) of the subject P who is present (e.g., standing) at a predetermined position. The iris imaging device101is composed of, for example, a general-purpose camera having a resolution of 12 M pixels (4,000 pixels in the horizontal direction and 3,000 pixels in the vertical direction) and a frame rate of 60 fps, which is becoming popular as an industrial camera or the like.

Each of the first illuminator102aand the second illuminator102bincludes an LED(s) (Light Emitting Diode) as a light source and a synchronization signal generator. The amount of light emitted from each of the first and second illuminators102aand102bto the subject P is determined by the value (i.e., the amount) of the current supplied to the LED(s), the lighting time (i.e., the lighting duration) of the LED(s), and the lighting cycle thereof, and illumination control information includes these numerical values. Note that the arrangement of the first and second illuminators102aand102bwill be described later.

The guiding device103is used to guide the subject P. The guiding device103includes a speaker. The guiding device103presents (i.e., outputs) a voice for guiding the subject P from the speaker. From the speaker, for example, a voice guidance for guiding the subject P such as “Take a couple of steps forward”, “Step backward”, or “Stop” is output.

The controller105determines whether or not the subject P is wearing glasses or the like, and controls the operations performed by the first illuminator102a, the second illuminator102b, and the guiding device103based on the result of the determination. Further, the controller105also controls the operation performed by the iris imaging device101. As a method for determining whether or not the subject P is wearing glasses or the like, a publicly-known method, for example, a method for checking whether or not diffused reflection occurs due to lenses such as glasses or the like disclosed in Patent Literature 1, may be used.

Next, the arrangement of the first and second illuminators102aand102bwill be described.

FIG.5is a schematic diagram for explaining the position of the first illuminator102a. The first illuminator102aapplies light to the subject P when the controller105has determined that the subject is not wearing glasses or the like (naked eyes). As shown inFIG.5, an angle between the optical axis of light emitted from the first illuminator102aand the optical axis of the iris imaging device101is represented by an angle θ1. The angle θ1is determined empirically and experimentally so that the overlapping range between the imaging range A1of the iris imaging means1and the irradiation range A2of the first irradiation means2abecomes as large as possible.

FIG.6is a schematic diagram for explaining the position of the second illuminator102b. The second illuminator102bapplies light to the subject P when the controller105has determined that the subject is wearing glasses or the like. As shown inFIG.6, an angle between the optical axis of light emitted from the second illuminator102band the optical axis of the iris imaging device101is represented by an angle θ2. The angle θ2is larger than the angle θ1(θ2>θ1). The angle θ2is set so that, assuming the curvature of lenses of ordinary glasses or the like, light reflected on the glasses or the like does not overlap (i.e., does not enter) the iris area.

Next, a flow of an imaging process performed in the imaging system110will be described. Note that the following description will be given while also referring toFIG.4as appropriate.

FIG.7is a flowchart for explaining a flow of an imaging process performed in the imaging system110. As shown inFIG.7, firstly, the controller105determines whether or not the subject is wearing glasses or the like (Step S101).

In the step S101, when the controller105determines that the subject is not wearing glasses or the like (No), the controller105operates the first illuminator102aso that light is emitted from the first illuminator102a(Step S102). Next, the controller105operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the first illuminator102aand the imaging range of the iris imaging device101(Step S103).

In the step S101, when the controller105determines that the subject is wearing glasses or the like (Yes), the controller105operates the second illuminator102bso that light is emitted from the second illuminator102b(Step S104). Next, the controller105operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the second illuminator102band the imaging range of the iris imaging device101(Step S105).

Subsequent to the step S103or S105, the controller105acquires a captured image of an iris(es) by controlling the iris imaging device101(Step S106). The captured image of the iris(es) acquired in the step S106is used for iris authentication or registration.

As described above, in the imaging system110according to the third example embodiment, the controller105determines whether or not the subject is wearing glasses or the like. Then, when the controller105determines that the subject is not wearing glasses or the like, the controller105operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the first illuminator102aand the imaging range of the iris imaging device101, and operates the first illuminator2aso that light is emitted from the first illuminator102a.

On the other hand, when the controller105determines that the subject is wearing glasses or the like, the controller105operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the second illuminator102band the imaging range of the iris imaging device101, and operates the second illuminator102bso that light is emitted from the second illuminator102b.

By emitting light from the second illuminator102bwhen the subject is wearing glasses or the like, it is possible to prevent (or reduce) the reflected light from the glasses or the like from entering the iris imaging means1. The overlapping range between the irradiation range of the first illuminator102aand the imaging range of the iris imaging device101is larger than the overlapping range between the irradiation range of the second illuminator102band the imaging range of the iris imaging device101. When the subject is not wearing glasses or the like, there is no need to take the prevention (or the reduction) of the reflected light from the glasses or the like into consideration. Therefore, light is emitted from the first illuminator2aof which the overlapping range with the imaging range of the iris imaging device1is large. As a result, when the subject is not wearing glasses or the like, the guiding of the subject becomes easier, so that the convenience is improved.

Fourth Example Embodiment

A fourth example embodiment will be described hereinafter.

FIG.8is a block diagram showing a configuration of an imaging system210according to a fourth example embodiment. As shown inFIG.8, the imaging system210includes an iris imaging device101, a first illuminator102a, a second illuminator202b, a guiding device103, and a controller105. That is, in the imaging system210, the configuration of the second illuminator202bis different from that of the imaging system110according to the above-described third example embodiment (seeFIG.4). The second illuminator202bhas a left-eye illuminator (left-eye irradiation means)202bA and a right-eye illuminator (right-eye irradiation means)202bB.

FIG.9is a schematic diagram for explaining the position of the second illuminator102b. As shown inFIG.9, the left-eye illuminator202bA is disposed at a position appropriate for photographing the iris of the left eye of the subject P. Further, the right-eye illuminator202bB is disposed at a position appropriate for photographing the iris of the right eye of the subject P.

The flow of the imaging process performed in the imaging system210is basically the same as that performed in the imaging system110according to the third example embodiment described above with reference toFIG.3or7. In the step S3inFIG.3or the step S104inFIG.7, when a captured image of the iris of the left eye of the subject P is acquired, light is applied from the left-eye illuminator202bA to the subject P. Further, when a captured image of the iris of the left eye of the subject P is acquired, light is applied from the right-eye illuminator202bB to the subject P. In this way, it is possible to acquire captured images of the irises of both eyes of the subject P with high accuracy.

Note that when it is desired to acquire captured images of the irises of both eyes of the subject P in one imaging operation, light is applied from both the left-eye and right-eye illuminators202bA and202bB to the subject P in the step S3inFIG.3or the step S104inFIG.7. However, the accuracy of captured images of the irises can be improved by separately acquiring a captured image of the iris of the left eye of the subject P by applying light from the left-eye illuminator202bA to the subject P and acquiring a captured image of the iris of the right eye of the subject P by applying light from the right-eye illuminator202bB to the subject P. This is because the effect of preventing (or reducing) reflection is high when a captured image of the iris of only one of the eyes is acquired by turning on only a respective one of the left-eye and right-eye illuminators202bA and202bB.

Fifth Example Embodiment

A fifth example embodiment will be described hereinafter.

FIG.10is a block diagram showing a configuration of an imaging system310according to the fifth example embodiment. As shown inFIG.10, the imaging system310includes an iris imaging device101, a first illuminator102a, a second illuminator102b, a guiding device103, a controller305, and a range sensor306. That is, the imaging system210is different from the imaging system110according to third example embodiment described above (seeFIG.4) in that the imaging system210further includes a range sensor (distance measuring means)306. The range sensor306measures a distance between the face of the subject P and the iris imaging device101. Further, the controller305includes the functions of the controller105of the imaging system110according to the third example embodiment.

The flow of the imaging process performed in the imaging system310is basically the same as that performed in the imaging system110according to the third example embodiment described above with reference toFIG.7, but the process in the step S105inFIG.7is different in the imaging system310. In the imaging system310, in the step S105inFIG.7, the controller305determines whether or not the subject is present at a distance d from the imaging device based on the result of the distance measurement by the range sensor306. When the subject is not present at the distance d from the imaging device, the controller305operates the guiding device103so that the subject P is guided so as to move to the overlapping range between the irradiation range of the second illuminator102band the imaging range of the iris imaging device101. Further, in the step S105inFIG.7, the controller305operates the guiding device103so that the subject P is guided to a position where the distance measured by the range sensor306becomes equal to a predetermined length d which is determined according to the angle between the optical axis of light emitted from the second illuminator102band the optical axis of the iris imaging means. By determining whether or not the subject is present at the distance d from the imaging device based on the result of the distance measurement, and guiding the subject only when the subject is not present at the distance d from the imaging device as described above, it is possible to skip the unnecessary guiding operation.

When the subject is guided to the above-described position as described above, the controller305operates the iris imaging device101so that the iris imaging device101photographs the iris(es) of the subject in the step S106.

FIG.11is a graph showing an example of a relationship between the predetermined length d and the angle θ2between the optical axis of light emitted from the second illuminator102band the optical axis of the iris imaging device101. As shown inFIG.11, the predetermined length d is determined according to the angle θ2between the optical axis of light emitted from the second illuminator102band the optical axis of the iris imaging device101. For example, when the angle θ2between the optical axis of light emitted from the second illuminator102band the optical axis of the iris imaging device101is 20 [deg], the predetermined length d is 45 [cm].

As described above, the angle θ2is set so that light reflected on the glasses or the like does not overlap (i.e., does not enter) the iris area. The angle at which light reflected on the glasses or the like does not overlap the iris area can be calculated by assuming (i.e., using) the curvature of lenses of ordinary glasses or the like. When the angle θ2is determined, the predetermined length can be determined from the graph shown inFIG.11.

As described above, in the imaging system310, when it is determined that the subject is wearing glasses or the like, the subject is guided to a position which is located in the overlapping range between the irradiation range of the second illuminator102band the imaging range of the iris imaging device101, and where the distance between the range sensor306and the face of the subject is equal to the predetermined length d. In this way, it is possible to improve the accuracy of the acquired captured image even further. Further, it is possible, by performing iris authentication by using the above-described captured image, to improve the success rate of the iris authentication.

Sixth Example Embodiment

A sixth example embodiment will be described hereinafter.

FIG.12is a block diagram showing a configuration of an imaging system410according to the sixth example embodiment. As shown inFIG.12, the imaging system410includes an iris imaging device101, a first illuminator102a, a second illuminator102b, a guiding device103, a controller305, a range sensor306, and a position adjustment device407. That is, the imaging system410is different from the imaging system310according to the fifth example embodiment described above (seeFIG.10) in that the imaging system410further includes a position adjustment device (position adjustment means)407. The position adjustment device407is used to adjust the position of the second illuminator102b.

FIG.13is a flowchart for explaining a flow of an imaging process performed in the imaging system410. As shown inFIG.13, firstly, a subject is guided so as to move to a predetermined range (Step S201). Note that the predetermined range is, for example, the overlapping range between the irradiation range of the first illuminator102aand the imaging range of the iris imaging device101. Next, the controller405determines whether or not the subject is wearing glasses or the like (Step S202).

In the step S202, when the controller405determines that the subject is not wearing glasses or the like (No), the controller405operates the first illuminator102aso that light is emitted from the first illuminator102a(Step S203).

In the step S202, when the controller405determines that the subject is wearing glasses or the like (Yes), a distance to the face of the subject is measured by the range sensor306(Step S204). Next, the controller405operates the position adjustment device407so that the angle between the optical axis of light emitted from the second illuminator102band the optical axis of the iris imaging means becomes equal to a predetermined angle that is determined according to the distance measured by the range sensor306(Step S205). Next, the controller405operates the second illuminator102bso that light is emitted from the second illuminator102b(Step S206).

Subsequent to the step S203or S206, the controller405acquires a captured image of an iris(es) by controlling the iris imaging device101to (Step S207). The captured image of the iris(es) acquired in the step S207is used for iris authentication or registration.

Seventh Example Embodiment

A seventh example embodiment will be described hereinafter.

FIG.14is a block diagram showing a configuration of an imaging system510according to the seventh example embodiment. As shown inFIG.14, the configuration of the imaging system510according to the seventh example embodiment is basically the same as that of the imaging system110according to the third example embodiment described above with reference toFIG.4. In the imaging system510according to the seventh example embodiment, the configuration of a guiding device503is different from the configuration of the guiding device103of the imaging system110according to the third example embodiment. The guiding device503includes a display503a. The guiding device503presents (i.e., shows) a video image for guiding the subject P on the display503a.

FIG.15is a schematic diagram showing an example of the image displayed on the display503a. As shown inFIG.15, the irradiation range of the illuminator (the irradiation range A2of the second illuminator102binFIG.15) and the imaging range A1of the iris imaging device101are displayed on the display503a. Note that when light is emitted from the first illuminator102a, the irradiation range of the first illuminator102ais displayed as the irradiation range of the illuminator on the display503a. On the display503a, as the video image for guiding the subject P, an overlapping range A4between the irradiation range of the illuminator and the imaging range of the iris imaging device101is highlighted by hatching. Note that, instead of highlighting the overlapping range A4by hatching, the overlapping range A4may be highlighted by a different method such as simply adding a circular mark inside the overlapping range A4. It is possible to properly guide the subject by configuring the guiding device503as described above.

Eighth Example Embodiment

An eighth example embodiment will be described hereinafter.

FIG.16is a block diagram showing a configuration of an imaging system610according to the eighth example embodiment. As shown inFIG.16, the configuration of the imaging system610according to the eighth example embodiment is basically the same as that of the imaging system310according to the fifth example embodiment described above with reference toFIG.10. In the imaging system610according to the eighth example embodiment, a guiding device603is different from the guiding device103of the imaging system310according to the fifth example embodiment. The guiding device603includes a display603a. The guiding device603presents (i.e., shows) a video image for guiding the subject P on the display603a.

FIG.17is a schematic diagram showing an example of the image displayed on the display603a. As shown inFIG.15, the irradiation range of the illuminator (the irradiation range A2of the second illuminator102binFIG.15) and the imaging range A1of the iris imaging device101are displayed on the display603a. Note that when light is emitted from the first illuminator102a, the irradiation range of the first illuminator102ais displayed as the irradiation range of the illuminator on the display603a. Further, the position of the subject P is displayed on the display603a. Note that the position of the subject P is specified by the range sensor306. Further, on the display603a, as the video image for guiding the subject P, an overlapping range A4between the irradiation range of the illuminator and the imaging range of the iris imaging device101is highlighted by hatching, and the direction in which the subject P should move is indicated by an arrow. Further, an instruction “Move to the hatched range” is displayed. It is possible to guide the subject P in a more appropriate manner by configuring the guiding device603as described above.

Ninth Example Embodiment

A ninth example embodiment will be described hereinafter.

FIG.18is a block diagram showing a configuration of an imaging system710according to the ninth example embodiment. As shown inFIG.18, the imaging system710includes an iris imaging device101, a first illuminator102a, a second illuminator202b, a guiding device103, and a controller705. In the imaging system710, the process performed in the controller705is different from that performed in the controller105of the imaging system210according to the fourth example embodiment.

FIGS.19and20are flowcharts for explaining a flow of an imaging process performed in the imaging system710according to the ninth example embodiment. As shown inFIG.19, firstly, the controller705determines whether or not the subject is wearing glasses or the like (Step S301).

In the step S301, when the controller705determines that the subject is not wearing glasses or the like (No), the controller705operates the first illuminator102aso that light is emitted from the first illuminator102a(Step S302). Next, the controller705operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the first illuminator102aand the imaging range of the iris imaging device101(Step S303). Next, the controller705acquires a captured image of an iris(es) by controlling the iris imaging device101(Step S304).

In the step S301, when the controller705determines that the subject is wearing glasses or the like (Yes), it determines whether or not the glasses or the like worn by the subject are a monocle (Step S305).

In the step S305, when it is determined that the glasses or the like worn by the subject are not a monocle (No), the controller705operates the second illuminator202b(the left-eye and right-eye illuminators202bA and202bB) so that light is emitted from the second illuminator202b(Step S306). Next, the controller705operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the second illuminator202band the imaging range of the iris imaging device101(Step S307). Next, the controller705acquires a captured image of an iris(es) by controlling the iris imaging device101to (Step S308).

In the step S305, when it is determined that the glasses or the like worn by the subject are a monocle (Yes), the controller705operates the second illuminator202bso that light is emitted from one of the left-eye and right-eye illuminators202bA and202bB of the second illuminator202bthat corresponds to the eye on which the monocle is worn as shown inFIG.20(Step S309). Next, the controller705operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the second illuminator202band the imaging range of the iris imaging device101(Step S310). Note that the irradiation range of the left-eye illuminator202bA becomes the irradiation range of the second illuminator202bwhen light is emitted from the left-eye illuminator202bA, and the irradiation range of the right-eye illuminator202bB becomes the irradiation range of the second illuminator202bwhen light is emitted from the right-eye illuminator202bB. Next, the controller705acquires a captured image of an iris(es) by controlling the iris imaging device101to (Step S311). Next, the controller705operates the first illuminator102aso that light is emitted from the first illuminator102a(Step S312). In this process, the second illuminator202bremains in the turned-off state. Next, the controller705operates the guiding device103so that the subject is guided so as to move to the overlapping range between the irradiation range of the first illuminator102aand the imaging range of the iris imaging device101(Step S313). Next, the controller705acquires a captured image of an iris(es) by controlling the iris imaging device101to (Step S314).

The captured images of the iris(es) acquired in the steps S304and S308inFIG.19, and those acquired in the steps S311and S314inFIG.20are used for iris authentication or registration. In this way, in the case where iris authentication is performed for each of the left and right eyes of the subject, it is possible to acquire a captured image of the iris of each of the left and right eyes of the subject, who is wearing the monocle, with high accuracy.

Although the above-described example embodiments have been described on the assumption that this disclosure is implemented as a hardware configuration, this disclosure is not limited to the hardware configuration. In this disclosure, the imaging process performed in any of the imaging systems shown inFIGS.3,7,13and18can also be carried out by having a CPU (Central Processing Unit) execute a program. Further, each process in the imaging operation performed in any of the imaging systems shown inFIGS.3,7,13and18may be carried out by a GPU (Graphics Processing Unit), an FPGA (field-programmable gate array), a DSP (Demand-Side Platform), or an ASIC (Application Specific Integrated Circuit).

The program for implementing the above-described imaging method can be stored in various types of non-transitory computer readable media and thereby supplied to computers. The non-transitory computer readable media includes various types of tangible storage media. Examples of the non-transitory computer readable media include a magnetic recording medium (such as a flexible disk, a magnetic tape, and a hard disk drive), a magneto-optic recording medium (such as a magneto-optic disk), a Compact Disc Read Only Memory (CD-ROM), a CD-R, and a CD-R/W, and a semiconductor memory (such as a mask ROM, a Programmable ROM (PROM), an Erasable PROM (EPROM), a flash ROM, and a Random Access Memory (RAM)). Further, the program can be supplied to computers by using various types of transitory computer readable media. Examples of the transitory computer readable media include an electrical signal, an optical signal, and an electromagnetic wave. The transitory computer readable media can be used to supply programs to computer through a wire communication path such as an electrical wire and an optical fiber, or wireless communication path.

Although the present invention is described above with reference to example embodiments, the present invention is not limited to the above-described example embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention. For example, although the first and second irradiation means are two-dimensionally arranged, i.e., are arranged so that they are disposed on the same horizontal plane in the above-described example embodiments, their arrangement is not limited to the two-dimensional arrangement. The first and second irradiation means may be three-dimensionally arranged.

In the above-described sixth example embodiment, the angle between the optical axis of light emitted from the second illuminator and the optical axis of the iris imaging means is adjusted by using the position adjustment device. Instead of using such a method, a plurality of second illuminators of which angles between the optical axes of the emitted light and the optical axis of the iris imaging means differ from each other may be provided. In such a case, one of the plurality of second illuminators of which the angle between the optical axis of the emitted light and the optical axis of the iris imaging means is closest to a predetermined angle that is determined according to a distance measured by a range sensor applies light to the subject.

The whole or part of the example embodiments disclosed above can be described as, but not limited to, the following supplementary notes.

(Supplementary note 1)

An imaging system comprising:iris imaging means for photographing an iris of a subject;first irradiation means for applying light to the subject; andsecond irradiation means for applying light to the subject in such a manner that an angle between an optical axis of the light emitted from the second irradiation means and an optical axis of the iris imaging means is larger than an angle between an optical axis of the light emitted from the first irradiation means and the optical axis of the iris imaging means.
(Supplementary note 2)

The imaging system described in Supplementary note 1, further comprising control means for determining whether or not the subject is wearing glasses or the like, and controlling an operation performed by the first and second irradiation means based on a result of the determination, whereinthe control means operates the first irradiation means so that light is emitted from the first irradiation means when it is determined that the subject is not wearing glasses or the like, andthe control means operates the second irradiation means so that light is emitted from the second irradiation means when it is determined that the subject is wearing glasses or the like.
(Supplementary note 3)

The imaging system described in Supplementary note 2, further comprising guiding means for guiding the subject, whereinthe control means operates the guiding means so that the subject is guided so as to move to an overlapping range between an irradiation range of the first irradiation means and an imaging range of the iris imaging means when it is determined that the subject is not wearing glasses or the like, andthe control means operates the guiding means so that the subject is guided so as to move to an overlapping range between an irradiation range of the second irradiation means and the imaging range of the iris imaging means when it is determined that the subject is wearing glasses or the like.
(Supplementary note 4)

The imaging system described in Supplementary note 1, wherein the second irradiation means comprises left-eye irradiation means disposed at a position appropriate for photographing an iris of a left eye of the subject and right-eye irradiation means disposed at a position appropriate for photographing an iris of a right eye of the subject.

(Supplementary note 5)

The imaging system described in Supplementary note 3, further comprising distance measurement means for measuring a distance between a face of the subject and the iris imaging means, whereinthe control means operates the guiding means, when it is determined that the subject is wearing glasses or the like, so that the subject is guided to a position where the distance measured by the distance measurement means becomes equal to a predetermined length determined according to an angle between the optical axis of the light emitted from the second irradiation means and the optical axis of the iris imaging means.
(Supplementary note 6)

The imaging system described in Supplementary note 2, further comprising:

distance measurement means for measuring a distance between a face of the subject and the iris imaging means; and

position adjustment means for adjusting a position of the second irradiation means, whereinthe control means operates the position adjustment means so that an angle between the optical axis of the light emitted from the second irradiation means and the optical axis of the iris imaging means becomes equal to a predetermined angle determined according to the distance measured by the distance measurement means.
(Supplementary note 7)

An imaging method comprising:a step of determining whether or not a subject is wearing a glass or the like;a step of, when it is determined that the subject is not wearing the glass or the like, applying light to the subject from first irradiation means; anda step of, when it is determined that the subject is wearing the glass or the like, applying light to the subject from second irradiation means, the second irradiation means being configured so that an angle between an optical axis of the light emitted from the second irradiation means and an optical axis of iris imaging means is larger than an angle between an optical axis of the light emitted from the first irradiation means and the optical axis of the iris imaging means, the iris imaging means being means for photographing an iris of the subject.
(Supplementary note 8)

A non-transitory computer readable medium storing a program for causing a computer to perform:a step of determining whether or not a subject is wearing a glass or the like;a step of, when it is determined that the subject is not wearing the glass or the like, applying light to the subject from first irradiation means; anda step of, when it is determined that the subject is wearing the glass or the like, applying light to the subject from second irradiation means, the second irradiation means being configured so that an angle between an optical axis of the light emitted from the second irradiation means and an optical axis of iris imaging means is larger than an angle between an optical axis of the light emitted from the first irradiation means and the optical axis of the iris imaging means, the iris imaging means being means for photographing an iris of the subject.

REFERENCE SIGNS LIST

1,101IRIS IMAGING DEVICE2a,102aFIRST ILLUMINATOR2b,102b,202bSECOND ILLUMINATOR5,105,305,705CONTROLLER10,110,210,310,410,510,610,710IMAGING SYSTEM103,503,603GUIDING DEVICE202bA LEFT EYE ILLUMINATOR202bB RIGHT EYE ILLUMINATOR503a603aDISPLAY