Biometric imaging device and biometric imaging system

Abstract

To provide a living body photographing device and a living body photographing system that quickly and accurately photograph a living body image with desired brightness, even when the ratio between the quantities of light radiated from a plurality of different light sources is different and the quantity of light radiated from some of the light sources reaches a settable upper limit.SOLUTION: A living body photographing device controls the quantity of light radiated from first radiation units 101-1, 101-2 and the quantity of light radiated from second radiation units 101-4, 101-5, in any one control state of a first control state where the quantity of light radiated from the first radiation units is larger than the quantity of light radiated from the second radiation units, the quantity of light radiated from the first radiation units has not reached an upper limit, and the ratio between the quantity of light radiated from the first radiation units and the quantity of light radiated from the second radiation units is made constant, and a second control state where the quantity of light radiated from the first radiation units is larger than the quantity of light radiated from the second radiation units, and the quantity of light radiated from the first radiation units has reached the upper limit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a biometric image capturing device and a biometric image capturing system, and more particularly to a biometric image capturing device and a biometric image capturing system that capture clear biometric images by irradiating a living body with light. [Background technology]

[0002] Biometric authentication technology using biometric images of living bodies has been attracting attention. For example, one biometric authentication technology uses blood vessel images of finger blood vessels, taking advantage of the difference in near-infrared light absorption characteristics between hemoglobin in blood vessels and other biological tissues.

[0003] Patent Document 1 discloses a biometric authentication device that simultaneously irradiates a living body with multiple lights of different wavelength bands, such as infrared light and visible light, and performs biometric authentication using a biometric image captured using the light from the living body. In this biometric authentication device, light sources are arranged at multiple locations on the fingertip and base sides to irradiate the entire area of ​​the living body to be photographed with light. Furthermore, the light source on the fingertip side, where the amount of light irradiation is insufficient, is made greater than the light source on the base side, so that the entire finger is irradiated with light uniformly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-89577 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors of the present application have been studying a biometric image capture device that determines the ratio of the light intensity of each light source so that the light intensity of the light source on the fingertip side is greater than the light intensity of the light source on the base side of the finger, and then controls the light intensity of the light sources while maintaining the determined ratio of the light intensity of each light source, thereby enabling the biometric image capture device to quickly capture clear biometric images.

[0006] However, when capturing a biological image by controlling the light sources to vary the light intensity while maintaining a constant ratio of the light intensity of each light source while the light intensity of the light source on the fingertip side and the light source on the base side is different, there is a possibility that the light intensity of only one light source (the fingertip-side light source) will reach the upper limit of the light intensity that can be set. Thus, when the light intensity of the fingertip-side light source reaches its upper limit, if you try to further increase the overall light intensity, you can increase the light intensity of the base-side light source, but you cannot increase the light intensity of the fingertip-side light source beyond the upper limit.

[0007] Even if the light intensity of some light sources reaches its upper limit, and light source control is attempted while maintaining the light intensity ratio of each light source, there are problems such as not being able to obtain a clear biometric image, or even if a clear biometric image can be obtained, it takes a long time to obtain it.

[0008] The present disclosure has been made to solve the above-mentioned problems. That is, one of the objects of the present disclosure is to provide a biometric image capture device and a biometric image capture system that can quickly and accurately capture a biometric image with a desired brightness even when the ratio of the light intensities emitted by multiple different light sources is different and the irradiated light intensity of some of the light sources reaches the settable upper limit. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the biometric image capturing device of the present disclosure includes a first irradiating unit and a second irradiating unit which are light sources that irradiate a biometric organism with light of at least a single wavelength, the first irradiating unit and the second irradiating unit being arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the biometric organism; an image processing unit that acquires a biometric image which is an image including the biometric organism that is captured by irradiating light onto the biometric organism presented in a presentation area included in the irradiation range of light of the first irradiating unit and the second irradiating unit, and detects a biometric region in the image by performing predetermined processing on the biometric image; and an image capturing unit that detects a biometric region by detecting the brightness of the detected biometric region using the first irradiating unit and the second irradiating unit based on the brightness of the detected biometric region. and a control unit that controls the amount of irradiation light, which is the amount of light irradiated by each of the first irradiation unit and the second irradiation unit, wherein the control unit is configured to control the amount of irradiation light of the first irradiation unit and the amount of irradiation light of the second irradiation unit in either of a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and has not reached an upper limit value, and the ratio between the amount of irradiation light of the first irradiation unit and the amount of irradiation light of the second irradiation unit is constant, and a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and has reached an upper limit value.

[0010] The biometric imaging system of the present disclosure includes a first irradiating unit and a second irradiating unit, which are light sources that irradiate a biometric organism with light of at least a single wavelength, and which are arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the biometric organism; an image processing unit that acquires a biometric image, which is an image including the biometric organism that is captured by irradiating light onto the biometric organism presented in a presentation area included in an irradiation range of light from the first irradiating unit and the second irradiating unit, and detects a biometric region in the image by performing predetermined processing on the biometric image; and an imaging unit that detects a biometric region in the image by detecting the brightness of the first irradiating unit and the second irradiating unit based on the brightness of the detected biometric region. and a control unit that controls the amount of irradiation light, which is the amount of light irradiated by each of the irradiation units, wherein the control unit is configured to control the amount of irradiation light of the first irradiation unit and the amount of irradiation light of the second irradiation unit in either of a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and has not reached an upper limit value, and the ratio between the amount of irradiation light of the first irradiation unit and the amount of irradiation light of the second irradiation unit is constant, and a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and has reached an upper limit value. [Effects of the Invention]

[0011] According to the present disclosure, even if the ratio of the amount of light emitted by multiple different light sources is different and the amount of light emitted by some light sources reaches the upper limit that can be set, it is possible to quickly and accurately capture biological images of the desired brightness. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is an explanatory diagram illustrating a first example of the configuration of an imaging device according to a first embodiment. [Figure 2] FIG. 2 is an explanatory diagram illustrating a first example of a block configuration of the imaging device according to the first embodiment. [Figure 3] FIG. 3 is an explanatory diagram illustrating a second example of a block configuration of the imaging device according to the first embodiment. [Figure 4]FIG. 4 is a flowchart illustrating a procedure for controlling a light source according to the first embodiment. [Figure 5A] FIG. 5A is a graph showing an example of the relationship between the amount of light emitted from a light source and the brightness of a finger area. [Figure 5B] FIG. 5B is a graph showing an example of the relationship between the amount of light emitted by the light source and the brightness of the finger area. [Figure 6A] FIG. 6A is an explanatory diagram showing an example of a procedure for controlling a light source. [Figure 6B] FIG. 6B is an explanatory diagram showing an example of a procedure for controlling a light source. [Figure 7] FIG. 7 is a flowchart illustrating a procedure of light source control according to the second embodiment. [Figure 8A] FIG. 8A is a graph showing an example of the relationship between the amount of light emitted from a light source and the brightness of a finger area. [Figure 8B] FIG. 8B is a graph showing an example of the relationship between the amount of light emitted from the light source and the brightness of the finger area. [Figure 9] FIG. 9 is an explanatory diagram showing changes in the position of the hand relative to the image capturing device. [Figure 10A] FIG. 10A is an explanatory diagram illustrating a first example of light intensity adjustment according to a change in hand position according to the third embodiment. [Figure 10B] FIG. 10B is an explanatory diagram illustrating a first example of light intensity adjustment according to a change in hand position according to the third embodiment. [Figure 11] FIG. 11 is a flowchart showing the detailed processing procedure of the light intensity value calculation (steps S407 and S708) shown in FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. In all drawings of the embodiments, the same or corresponding parts may be denoted by the same reference numerals.

[0014] <<Example 1>> <Example of imaging system configuration> FIG. 1 is an explanatory diagram illustrating a biometric image capturing device 108 (hereinafter referred to as "image capturing device 108") according to a first embodiment of the present disclosure. FIG. 1 includes a side cross-sectional view VW1 of the image capturing device 108 and a plan view VW2 of the image capturing device 108. The image capturing device 108 illustrated in FIG. 1 includes a main body 100 that captures an image of a living body and acquires biometric image data, and a controller 107 that is a control unit that controls the main body 100. The main body 100 also includes a housing 100A, a light source 101, an imaging unit 102, and a data memory 106. In this embodiment, the image capturing device 108 captures an image of the fingers of a hand 110 that is presented (specifically, held over) above a top panel 100B of the housing 100A as a subject (living body).

[0015] Here, the fingers to be photographed are the index finger 111, the middle finger 112, and the ring finger 113, but this is not a limitation, and the number and type of fingers to be photographed are not particularly limited. For example, the fingers to be photographed may include one or more of the ten fingers on both hands. In the following, the index finger 111, the middle finger 112, and the ring finger 113 may also be simply referred to as fingers 111 to 113.

[0016] The housing 100A is installed (for example, attached or placed) on an installation surface 120. The installation surface 120 may be a horizontal surface such as the ground, a ceiling, or a desk surface, a vertical surface such as a wall, or an obliquely inclined surface. In this embodiment, an axis perpendicular to the installation surface 120 is defined as the Z-axis, a direction along the Z-axis away from the installation surface 120 is defined as the +Z direction, and a direction along the Z-axis approaching the installation surface 120 is defined as the -Z direction. The installation surface 120 is parallel to an XY plane defined by the X-axis and the Y-axis. As shown in FIG. 1, the main body 100 is installed so that the fingers 111 to 113 of the hand 110 are presented above the upper panel 100B. The X-axis is the longitudinal direction of the fingers 111 to 113 when presented, and the Y-axis is the arrangement direction of the fingers 111 to 113.

[0017] The housing 100A includes a plurality of light sources 101 (light sources 101-1, 101-2, 101-4, and 101-5 in FIG. 1). When the light sources 101-1, 101-2, 101-4, and 101-5 do not need to be distinguished from one another, they are simply referred to as light sources 101. The light source 101 is an irradiation unit that irradiates light of a plurality of wavelengths having different wavelength bands as irradiation light toward the upper side (+Z direction) of the top panel 100B of the housing 100A. For convenience, the light source 101-1 and the light source 101-2 may also be referred to as a "first irradiation unit." The light source 101-4 and the light source 101-5 may also be referred to as a "second irradiation unit." The number of light sources constituting each of the first irradiation unit and the second irradiation unit is not limited to the above.

[0018] The light sources 101-1 and 101-4 corresponding to the index finger 111 are arranged in the X direction. For example, the light source 101-1 is provided at a position corresponding to the tip of the index finger 111, and the light source 101-4 is provided at a position corresponding to the base of the index finger 111.

[0019] The light sources 101-2 and 101-5 corresponding to the ring finger 113 are arranged in the X direction. For example, the light source 101-2 is provided at a position corresponding to the tip of the ring finger 113, and the light source 101-5 is provided at a position corresponding to the base of the ring finger 113.

[0020] The light source 101 can emit wavelength light of a single wavelength band, and the wavelength light emits near-infrared light, which is invisible light, or visible light (e.g., blue light or green light). The light source 101 can also emit wavelength light of multiple different wavelength bands. When the light source 101 emits multiple wavelength light, the wavelength light includes visible light (e.g., blue light or green light) and near-infrared light, which is invisible light. In this embodiment, the light source 101 emits only near-infrared light of a single wavelength. Note that the visible light is used to photograph the skin surface of the finger to obtain finger surface image data, and the near-infrared light is used to photograph the blood vessels of the finger to obtain finger vascular image data. Note that the light source 101 can emit multiple wavelength light simultaneously or at different timings. The light source 101 is, for example, an LED (light-emitting diode), and has a maximum light intensity value (upper limit) determined by its rating.

[0021] The imaging unit 102 is provided inside the housing 100A. The imaging unit 102 includes an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The imaging unit 102 is disposed such that the imaging surface of the imaging element faces the top panel 100B of the housing 100A so as to capture an image of an area illuminated by light emitted by the light source 101.

[0022] Furthermore, a light-transmitting plate 105 that transmits light emitted from the light source 101 and reflected by the fingers 111 to 113 is provided in an area of ​​the top panel 100B facing the imaging unit 102. The light-transmitting plate 105 is made of a transparent material such as acrylic or glass. A film that transmits only light of a specific wavelength may be attached to the light-transmitting plate 105. This makes it difficult to see inside the main body 100 from the outside.

[0023] A first optical filter 103 is provided between the imaging unit 102 and the top plate 100B of the housing 100A, and a second optical filter 104 is provided on the optical path of the light emitted from the light source 101 on the top plate 100B.

[0024] The first optical filter 103 and the second optical filter 104 are bandpass filters that transmit light in the same wavelength band as the light emitted from the light source 101. In this case, the image capturing unit 102 is prevented from receiving unnecessary light, and noise in the biometric image data can be suppressed. The first optical filter 103 and the second optical filter 104 may also be polarizing filters. In this case, it is possible to reduce the specular reflection component of the light reflected by the fingers 111 to 113, which is specularly reflected from the skin surface, and thus it is possible to obtain clearer finger blood vessel image data.

[0025] In the +Z direction from the second optical filters 104 corresponding to the light sources 101-1 and 101-4, a fingertip presentation board 1400 is provided in the housing 100A so that its longitudinal direction is parallel to the Y axis. The fingertip presentation board 1400 is a transparent plate-like member made of acrylic, glass, or the like, and fingers 111 to 113 can be placed on it. This allows the positions of the fingertips of the hand 110 presented by the user to be guided to the fingertip presentation board 1400. Therefore, even when a finger is placed on the fingertip presentation board 1400 or held over it without contact, the imaging unit 102 can capture an image of the entire finger.

[0026] With the above configuration, light emitted from light source 101 is reflected by fingers 111 to 113 of hand 110 presented above top plate 100B of casing 100A via second optical filter 104, and the reflected light is received by the imaging surface of imaging unit 102 via light-transmitting plate 105 of top plate 100B and first optical filter 103. The light received by imaging unit 102 is then photoelectrically converted and output as image data. Imaging unit 102 is connected to data memory 106, and the photoelectrically converted image data is stored in data memory 106.

[0027] The image data includes finger vein image data that shows the blood vessels of the finger, and finger surface image data that shows the unevenness of the skin surface such as a fingerprint, or the color of the skin surface based on differences in the light absorption characteristics of skin tissue such as melanin and keratin. The finger vein image data and finger surface image data are sometimes collectively referred to as finger image data.

[0028] The controller 107 is connected to the light source 101 and the data memory 106. In the example of Fig. 1, the controller 107 is provided outside the housing 100A.

[0029] The controller 107 has a function as a control unit that controls the light source 101 and the imaging unit 102 to cause the main body unit 100 to acquire finger image data, and a function as an authentication unit that extracts feature data indicating features such as blood vessels and fingerprints of the fingers 111 to 113 from the finger image data and performs biometric authentication of the person to be authenticated based on the feature data.

[0030] Fig. 2 is a block diagram showing a more detailed example configuration of the image capturing device 108 shown in Fig. 1. As shown in Fig. 2, the image capturing device 108 has the main body 100 and the controller 107 as shown in Fig. 1. The controller 107 also has a light source control unit 300 and a computer 310.

[0031] The light source control unit 300 controls the timing at which the light source 101 is turned on and the amount of light emitted in response to instructions from the computer 310 .

[0032] The computer 310 includes a processor 311, a storage device 312, an input device 313, an output device 314, and a communication IF (Interface) 315. The processor 311, the storage device 312, the input device 313, the output device 314, and the communication IF 315 are connected to one another via a bus 316.

[0033] The processor 311 reads a program stored in the storage device 312 and executes the read program to control the entire main body 100 and the controller 107. The storage device 312 is a non-transitory recording medium that stores various programs that define the operation of the processor 311 and data used by the processor 311. The storage device 312 is also used as a working area for the processor 311. The storage device 312 is, for example, a read-only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a flash memory.

[0034] The above programs include, for example, an image processing program and a light source control program. The image processing program is a program for performing image processing on image data generated by the imaging unit 102. The light source control program is a program for controlling the light source 101. Note that at least a part of the functions realized by each program may be realized by a dedicated circuit or the like. The programs may be provided from a portable storage medium such as a removable medium (CD-ROM, flash memory, etc.) on which the programs are stored and stored in the storage device 312. The programs may be provided via a network from a storage medium of an external device on which the programs are stored and stored in the storage device 312.

[0035] The input device 313 receives various data from an administrator of the image capturing apparatus 108, etc. Examples of the input device 313 include a keyboard, a mouse, a touch panel, a numeric keypad, and a scanner. The output device 314 outputs data. Examples of the output device 314 include a display, a printer, and a speaker. The communication IF 315 is connected to an external device (not shown) and transmits and receives data to and from the external device. If the controller 107 does not have a function as a control unit, image processing and light source control may be performed by an external device connected to the communication IF 315.

[0036] Fig. 3 shows another example of the configuration of the image capturing device 108. The image capturing device 108 shown in Fig. 3 has a configuration in which the computer 310 shown in Fig. 2 is provided in the main body 100, and the computer 310 controls the light source 101 without going through the light source control unit 300 shown in Fig. 2.

[0037] <Finger image data capture process procedure> FIG. 4 is a flowchart for explaining an example of an image capturing process for acquiring biometric image data (finger image data) by the image capturing device 108. When the image capturing process is started in step S401, the light source 101 is controlled by light source control in step S402 to emit light. At this time, the light source 101 emits light of a single wavelength. Note that, if this is the first time that light is emitted, the light intensity value of the light source 101 is set to an arbitrary initial light intensity value. Next, in step S403, the image capturing device 108 captures an image and acquires image data Is. Next, in step S404, the image capturing device 108 performs image processing on the image data Is acquired in step S403, thereby performing finger detection processing.

[0038] In the finger detection determination in step S405, the image capturing device 108 determines whether a finger has been detected based on the result of the finger detection process in step S404. If it is determined that a finger has not been detected in the finger detection determination (step S405) (step S405: No), the process returns to the light source control in step S402 and repeats the finger detection process. On the other hand, if it is determined that a finger has been detected (step S405: Yes), the process proceeds to the finger region luminance calculation process in step S406, and the image capturing device 108 calculates the luminance within the finger region of the image data Is acquired in step S403. For convenience, the finger region may also be referred to as the "biological region."

[0039] In step S407, the image capturing device 108 calculates the light intensity value of each of the multiple light sources 101 for the next image capturing based on the luminance of the finger area calculated in step S406. In determining whether image capturing is to be terminated in step S408, the image capturing device 108 determines whether image capturing should be terminated based on, for example, whether the luminance of the finger area matches a target value or whether a timeout has occurred for the image capturing time. If it is determined that image capturing should be terminated (step S408: Yes), the image capturing device 108 terminates image capturing in step S409, and if it is determined that image capturing should not be terminated (step S408: No), it repeats the light source control in step S402.

[0040] In the light source control of step S402, if the light intensity value of each light source 101 has been calculated in step S407, the image capturing device 108 causes each light source 101 to emit light at the calculated light intensity value, and performs image capture in step S403.

[0041] The amount of reflected light from light source 101 is likely to be insufficient near the contours of the sides of fingers 111 to 113 in arrangement direction Y. The area near the contours of the fingertips has a three-dimensional shape with many curved surfaces, so the amount of reflected light from light source 101 is particularly likely to be insufficient, and the area near the fingertips in finger image data tends to be very dark. Therefore, light sources 101-1 and 101-2 corresponding to the fingertip side and light sources 101-4 and 101-5 corresponding to the finger bases are each illuminated with different amounts of light. By illuminating light sources 101-1 and 101-2 on the fingertip side with a stronger amount of light than light sources 101-4 and 101-5, the imaging unit 102 can capture images of the entire fingers 111 to 113 with uniform brightness.

[0042] <Step S407> In calculating the light intensity value of each light source 101 in step S407, the ratio of the light intensity values ​​of each light source 101 is determined in advance so that the entire finger can be photographed with uniform brightness, thereby enabling faster light source control and image capture. For example, the ratio of the light intensity values ​​of light sources 101-1 and 101-2 corresponding to the fingertip side to the light intensity values ​​of light sources 101-4 and 101-5 corresponding to the finger base is set to a:b (a>b), and the base light intensity value for determining the light intensity value of each light source 101 is set to n (for example, n is an integer value ranging from 0 to 255). In this example, the light intensity values ​​of light sources 101-1 and 101-2 are the same, and the light intensity values ​​of light sources 101-4 and 101-5 are the same.

[0043] 5A, the horizontal axis represents the base light intensity value n and the vertical axis represents the average luminance value I of multiple fingers, and the relationship between them is determined, and then the base light intensity value n corresponding to the target average luminance is determined.The light intensity value of each light source 101 for the next image capture is set based on the determined base light intensity value n and the preset coefficients a and b.

[0044] In the example of FIG. 5A, it is assumed that the relationship between the base light intensity value n and the average brightness I can be linearly approximated. However, if the ratio between the light intensity values ​​of the light sources 101-1 and 101-2 corresponding to the fingertip side and the light intensity values ​​of the light sources 101-4 and 101-5 corresponding to the base of the finger is a:b (a>b), then in reality, as shown in FIG. 5B, the relationship between the light intensity value n and the average brightness I changes at a certain point (referred to as the "fluctuation boundary point (Pb)") of the base light intensity value n.

[0045] Specifically, because the light intensity value a*n of each of the light sources 101-1 and 101-2 is always greater than the light intensity value b*n of each of the light sources 101-4 and 101-5, increasing the base light intensity value n causes the light intensity values ​​of the light sources 101-1 and 101-2 to reach the upper limit value (fluctuation boundary point) that can be set first. If a base light intensity value n greater than the fluctuation boundary point is set, the light intensity values ​​of the light sources 101-1 and 101-2 remain at their upper limit values, and only the light intensity values ​​of the light sources 101-4 and 101-5 increase. Because the relationship between the base light intensity value n and the average luminance of the finger area changes depending on whether the base light intensity value n is smaller or larger than the fluctuation boundary point, assuming a simple linear relationship as in FIG. 5A results in a large error from the actual relationship, which can lead to problems such as an inability to accurately determine a light intensity value corresponding to the target luminance and a long time required for image capture.

[0046] When the base light intensity value n is increased, a fluctuation boundary point is assumed where the light intensity values ​​of some of the light sources 101 among the multiple light sources 101 reach an upper limit, and by assuming that the relationship between the base light intensity value n and the average brightness of the finger area changes depending on whether the base light intensity value n is smaller or larger than the fluctuation boundary point, it becomes possible to more accurately and quickly determine the base light intensity value n corresponding to the target brightness and capture a finger image.

[0047] The base light intensity value of the fluctuation boundary point can be calculated by dividing the upper limit light intensity value max of each of the light sources 101-1 and 101-2 by a (that is, by "upper limit light intensity value max / a").

[0048] <Calculation of light intensity value of light source taking into account fluctuating boundary points> Specifically, it is assumed that the base light intensity value n and the average brightness of the finger area have different linearities when the base light intensity value n is smaller than the fluctuation boundary point and when it is larger than the fluctuation boundary point, and these can be approximated by lines with different slopes and intercepts.By approximating the relationship between the brightness of the finger image obtained from a single image capture and the base light intensity value n by different lines when the base light intensity value n is smaller than the fluctuation boundary point and when it is larger than the fluctuation boundary point, it becomes possible to control the light source quickly and accurately with fewer captures.

[0049] FIG. 6A illustrates a light source control method when the base light intensity value n when the average brightness of the finger area is observed is smaller than the fluctuation boundary point. A line with a slope of α1 passing through a predetermined intercept β1 is calculated from the observed average brightness and the current base light intensity value n. As shown in FIG. 6A, for base light intensity values ​​n greater than the fluctuation boundary point Pb, the relationship between the average brightness and the base light intensity value n is approximated by a line with a slope of α2. The line with slope α2 can be calculated by multiplying the slope α1 by a coefficient γ1 (γ1<1) set in advance based on experience. Alternatively, an intercept β2 through which the approximated line passes for base light intensity values ​​n greater than the fluctuation boundary point Pb can be set in advance based on experience, and the slope of the line passing through the intercept β2 and the point where the line with slope α1 intersects with point Pb can be set as α2.

[0050] FIG. 6B illustrates a light source control method when the base light intensity value n obtained when the average brightness of the finger area is observed is greater than the fluctuation boundary point. A line with a slope α2' passing through a predetermined intercept β2' is calculated from the observed average brightness and the current base light intensity value n. As shown in FIG. 6B, for base light intensity values ​​n smaller than the fluctuation boundary point Pb', the relationship between the average brightness and the base light intensity value n is approximated by a line with a slope α1'. The line with a slope α1' can be calculated by multiplying the slope α2' by a coefficient γ2 (γ2 > 1) set based on experience. Alternatively, an intercept β1' through which the approximated line passes for base light intensity values ​​n smaller than the fluctuation boundary point Pb' can be set based on experience in advance, and the slope of the line passing through the intercept β1' and the point where the line with a slope α2' intersects the fluctuation boundary point Pb' can be set as α1'.

[0051] The above example shows a case where the base light intensity value n and the average brightness of the finger area are linear, but the relationship can also be approximated using a quadratic or cubic function, or smoother function approximation can be performed using polynomial interpolation, spline interpolation, etc. More accurate function approximation is possible by performing polynomial interpolation or spline interpolation using the brightness of finger images obtained by capturing multiple images and the base light intensity value n.

[0052] <Specific operation of light intensity value calculation> The operation of the image capturing device 108 when calculating the light intensity value in step S407 will be described in more detail. As described above, the image capturing device 108 (controller 107) estimates functions (a first function representing the first relationship and a second function representing the second relationship) based on the observed values ​​(the observed average luminance and the current base light intensity value). The first relationship is the relationship between the average luminance and the base light intensity value of the finger region in the range where the base light intensity value is equal to or less than the fluctuation boundary point in the graph of FIG. 5B, and the first function is a function representing the first relationship. The second relationship is the relationship between the average luminance and the base light intensity value of the finger region in the range where the base light intensity value is greater than the fluctuation boundary point in the graph of FIG. 5B, and the second function is a function representing the second relationship.

[0053] The image capturing device 108 determines the base light intensity based on the target brightness and the brightness corresponding to the fluctuation boundary point (hereinafter referred to as "threshold brightness"), and calculates the light intensity value of each light source as follows. The target brightness is, for example, a predetermined brightness set in advance according to the desired brightness.

[0054] Specifically, when the target brightness is equal to or lower than the threshold brightness, the image capturing device 108 determines a base light intensity (n) from the target brightness using a first function. In this case, the image capturing device 108 calculates the light intensity values ​​of the light sources 101-1 and 101-2 corresponding to the fingertip side by a*n, and calculates the light intensity values ​​of the light sources 101-4 and 101-5 by b*n. The image capturing device 108 controls each light source 101 so that the light source 101 irradiates light at the calculated light intensity values ​​during the next image capturing (S402 and S403). For convenience, the control state in which the light intensity of each light source 101 is controlled in this manner may also be referred to as a "first control state."

[0055] When the target brightness is greater than the threshold brightness, the image capturing device 108 determines the base light intensity from the target brightness using the second function. In this case, the image capturing device 108 calculates the upper limit values ​​of the light intensity of the light sources 101-1 and 101-2 corresponding to the fingertip side as the light intensity values ​​of the light sources 101-1 and 101-2, and calculates the light intensity values ​​of the light sources 101-4 and 101-5 using the light intensity value b*n. The image capturing device 108 controls each light source 101 so that it irradiates light at the calculated light intensity value during the next image capturing (S402 and S403). For convenience, the control state in which the light intensity of each light source 101 is controlled in this manner may also be referred to as the "second control state."

[0056] To reduce the amount of calculation, the image capturing device 108 may determine a base light intensity and calculate the light intensity of each light source as follows: That is, the image capturing device 108 determines whether the target luminance and the observed average luminance are each equal to or less than a threshold luminance.

[0057] When both the target luminance and the observed average luminance are equal to or less than the threshold luminance, the image capture device 108 estimates only the first function representing the first relationship based on the observed values ​​(the observed average luminance and the current base light intensity). The image capture device 108 determines the base light intensity from the target luminance using the first function. In this case, the image capture device 108 calculates the light intensity values ​​of the light sources 101-1 and 101-2 corresponding to the fingertip side using a*n, and calculates the light intensity values ​​of the light sources 101-4 and 101-5 using the light intensity value b*n.

[0058] The image capture device 108 determines whether the target luminance and the observed luminance are each equal to or less than the threshold luminance. If both the target luminance and the observed luminance are greater than the threshold luminance, the image capture device 108 estimates only the second function representing the second relationship based on the observed values ​​(the observed average luminance and the current base light intensity). The image capture device 108 determines the base light intensity from the target luminance using the second function. In this case, the image capture device 108 calculates the upper limit values ​​of the light intensity of each of the light sources 101-1 and 101-2 corresponding to the fingertip side as the light intensity of each of the light sources 101-1 and 101-2, and calculates the light intensity value of each of the light sources 101-4 and 101-5 using the light intensity value b*n.

[0059] When the target luminance is greater than the threshold luminance and the observed average luminance is equal to or less than the threshold luminance, the image capture device 108 estimates a first function representing the first relationship and a second function representing the second relationship based on the observed values ​​(the observed average luminance and the current base light intensity). The image capture device 108 determines the base light intensity from the target luminance using the second function. In this case, the image capture device 108 determines the upper limit values ​​of the light sources 101-1 and 101-2 corresponding to the fingertip side as the light intensity values ​​of the light sources 101-1 and 101-2, and calculates the light intensity values ​​of the light sources 101-4 and 101-5 using the light intensity value b*n.

[0060] If the target luminance is equal to or less than the threshold luminance and the observed average luminance is greater than the threshold luminance, the image capture device 108 estimates a second function representing the second relationship and a first function representing the first relationship based on the observed values ​​(the observed average luminance and the current base light intensity). The image capture device 108 determines the base light intensity from the target luminance using the first function. In this case, the image capture device 108 calculates the light intensity values ​​of light sources 101-1 and 101-2 corresponding to the fingertip side using a*n, and calculates the light intensity values ​​of light sources 101-4 and 101-5 using light intensity value b*n.

[0061] <<Example 2>> Example 2 is an example in which light sources 101 emit a plurality of light beams with different wavelengths in Example 1. The imaging device has the same configuration as Example 1, and a description thereof will be omitted. For example, when light sources 101 emit light beams with two different wavelengths, one wavelength is near-infrared light for imaging blood vessels in a finger, and the other wavelength is light with a visible wavelength such as blue or green for imaging biological information on the skin surface, such as a fingerprint.

[0062] <Finger image capture processing> 7 is a flowchart showing a biological image capturing process procedure according to Example 2. When the capturing process starts in step S701, the capturing device 108 controls the light source 101 by light source control in step S702 to emit light. At this time, the light source 101 simultaneously emits light of multiple wavelengths.

[0063] Next, the image capturing device 108 captures an image in step S703, and performs wavelength separation processing on the acquired image data Is in step S704. As a result, the image data Is is separated into multiple wavelength-separated image data Ii and Ic corresponding to the components of light of each irradiated wavelength. Next, in step S705, the image capturing device 108 performs image processing on the image data Is acquired in step S703 and the wavelength-separated image data Ii and Ic generated in step S704, thereby performing finger detection processing.

[0064] In the finger detection determination in step S706, the image capturing device 108 determines whether a finger has been detected based on the result of the finger detection process in step S705. If it is determined that a finger has not been detected in the finger detection determination (step S706) (step S706: No), the process returns to the light source control in step S702 and repeats the finger detection process. On the other hand, if it is determined that a finger has been detected (step S706: Yes), the process proceeds to the finger region luminance calculation process in step S707, and the image capturing device 108 calculates the luminance within the finger region for each of the image data Is acquired in step S703 and the wavelength-separated image data Ii and Ic generated in step S704.

[0065] In step S708, the image capturing device 108 calculates the light intensity value of each of the multiple light sources 101 for the next image capture based on the luminance of the finger area calculated in step S707. In the image capture end determination in step S709, the image capturing device 108 determines whether to end image capture by, for example, determining whether the luminance of the finger area matches the target value or whether a timeout has occurred for the image capture time. If it is determined that image capture is to end (step S709: Yes), the image capturing device 108 ends image capture in step S710, and if it is determined that image capture is not to end (step S709: No), it repeats the light source control in step S702. In the light source control of step S702, if the light intensity value of each light source 101 has been calculated in step S708, the imaging device 108 causes each light source 101 to emit light at the calculated light intensity value, and performs image acquisition in step S703.

[0066] In calculating the brightness of the finger region in step S707, the image capturing device 108 obtains brightness information of the region within the finger region detected in the finger detection process in step S705, particularly the region from which biometric features are to be extracted, using the image data Is including RGB components captured in step S703 and the multiple wavelength-separated image data Ii and Ic generated in step S704.

[0067] In step S708, the luminance information is used to calculate the light intensity value of each light source 101, using the luminances Li and Lc of the wavelength-separated image data Ii and Ic. Alternatively, the luminance information may be used to calculate the luminance information of the RGB image data Is captured by simultaneously irradiating the image with light of multiple wavelengths using the luminances Lr, Lg, and Lb of the color component image data Ir, Ig, and Ib.

[0068] The calculation of the light intensity value of each light source 101 in step S708 calculates the light intensity value of near-infrared light based on the relationship between the luminance Li of the wavelength-separated image Ii and the light intensity value of near-infrared light, and calculates the light intensity value of visible light based on the relationship between the luminance Lc of the wavelength-separated image Ic and the light intensity value of visible light, thereby making it possible to simultaneously irradiate two wavelength lights while independently calculating the light intensity values ​​of each wavelength light.

[0069] In addition, by determining in advance the ratio of the light intensity values ​​of each light source 101 so that the two wavelengths of visible and near-infrared light are irradiated over the entire finger with uniform brightness, and then calculating the light intensity values, faster light source control and image capture become possible.

[0070] As in the first embodiment, for example, the ratio of the light intensity values ​​of light sources 101-1 and 101-2 corresponding to the fingertip side to the light intensity values ​​of light sources 101-4 and 101-5 corresponding to the finger base is c:d (c>d), and the base light intensity value of near-infrared light of each light source 101 is ni and the base light intensity value of visible light is nc. In this case, the light intensity values ​​of near-infrared light of light source 101-1 and light source 101-2 are c*ni and c*nc, respectively, and the light intensity values ​​of near-infrared light of light source 101-4 and light source 101-5 are d*ni and d*nc, respectively.

[0071] By adjusting the base light intensity values ​​ni and nc while keeping the preset coefficients c and d fixed, it is possible to acquire images Ii and Li having the luminance of the target brightness. Specifically, as shown in Fig. 8A, the horizontal axis represents the base light intensity value ni and the vertical axis represents the average luminance value Fi of multiple fingers in the wavelength-separated image Ii, and assuming that the relationship between the luminance value Fi and the base light intensity value ni changes when the base light intensity value ni is larger or smaller than the fluctuation boundary point Pbi where the light intensity value of the light source 101 on the fingertip side reaches its upper limit, the base light intensity value ni corresponding to the target luminance value is obtained, and the light intensity value of the near-infrared light is determined.

[0072] In Figure 8B, the horizontal axis represents the base light intensity value nc of the visible light light source 101, and the vertical axis represents the average brightness Fc of multiple fingers in the wavelength-separated image Ic.Assuming that the relationship between the brightness value Fc and the base light intensity value nc changes depending on whether the base light intensity value nc is larger or smaller than the fluctuation boundary point Pbc, where the light intensity value of the light source 101 on the fingertip side reaches its upper limit, the base light intensity value nc corresponding to the target brightness value is obtained, and the light intensity value of visible light is determined.

[0073] 8A and 8B, by assuming the fluctuation boundary points (Pbi, Pbc) and estimating the relationship between the brightness and the light intensity value, it is possible to determine the light intensity values ​​of the two wavelengths independently and acquire a biological image with the target brightness more quickly and accurately. The method for adjusting the base light intensity values ​​ni and nc is the same as in Example 1, so a description thereof will be omitted.

[0074] In the photographing process flow of Fig. 7, when light source 101 emits visible light and near-infrared light of a plurality of different wavelengths, in the configuration of photographing device 108 of Fig. 1, strong visible light emitted from light source 101 may be dazzling to the human eye. Therefore, before hand 110 is held over photographing device 108, light source 101 emits only invisible near-infrared light to acquire a biometric image, and after the finger is detected, light source 101 emits visible light and near-infrared light simultaneously, thereby making it possible to photograph a biometric image in a less dazzling state.

[0075] In the case where light source 101 simultaneously emits visible light and near-infrared light before a finger is detected, after the finger is detected, the light intensity values ​​of visible light and near-infrared light can be adjusted based on the brightness of the finger area of ​​the finger image in the next photograph, thereby making it possible to acquire a finger image with the target brightness.

[0076] On the other hand, if light source 101 emits only near-infrared light before a finger is detected, only the luminance of the finger area due to near-infrared light can be obtained from the finger image when the finger is detected. When calculating the light intensity value based on the luminance of the finger area, only the light intensity value of near-infrared light can be adjusted in the next capture, and if the light intensity value of visible light is set to an initial value, it becomes possible to calculate the light intensity value based on the luminance of the finger area due to visible light in the next capture.

[0077] If light source 101 is configured to emit only near-infrared light before a finger is detected, the timing at which visible light and near-infrared light are emitted simultaneously will be delayed, which poses a problem in that the start of adjustment of the light intensity value of visible light will be delayed accordingly.

[0078] Therefore, the correlation between the light intensity value of near-infrared light and the luminance Li of the wavelength-separated image Ii and the light intensity value of visible light and the luminance Lc of the wavelength-separated image Ic is calculated in advance, and the light intensity value of visible light is calculated based on this correlation when capturing an image after detecting a finger. Specifically, an image is captured using only near-infrared light, and the light intensity value of visible light is estimated from the next light intensity value of near-infrared light calculated based on the luminance Li of the finger image after the finger is detected, so that the luminance Lc of the wavelength-separated image Ic becomes the target value. This makes it possible to adjust the light intensity values ​​of visible light and near-infrared light at the same time, enabling high-speed biometric image capture.

[0079] By calculating the correlation between the light intensity values ​​of near-infrared light and visible light after taking into consideration the existence of boundary points of fluctuation in the relationship between the base light intensity value ni of near-infrared light and the average brightness Fi of multiple fingers in Figure 8A and the relationship between the base light intensity value nc of visible light and the average brightness Fc of multiple fingers in Figure 8B, it becomes possible to practically capture biometric images faster and more accurately.

[0080] For example, the relationship between the near-infrared light base light intensity value ni and the average brightness Fi in Fig. 8A is determined from the average brightness (observed brightness) and base light intensity value observed when photographing using only near-infrared light, and the relationship between the visible light base light intensity value nc and the average brightness Fc in Fig. 8B is determined from the above correlation. Thereafter, using the method described above, the near-infrared light intensity value of each light source at the time of next photographing is calculated from the target brightness and the relationship (two functions) in Fig. 8A, and the visible light intensity value of each light source at the time of next photographing is calculated from the target brightness and the relationship (two functions) in Fig. 8B. Note that the two functions representing the above relationship in Fig. 8A may be referred to as the "first function and second function" for convenience, and the two functions representing the relationship in Fig. 8B may be referred to as the "third function and fourth function" for convenience.

[0081] <<Example 3>> The third embodiment is an example in which, when a deviation occurs in the position where the finger is presented in the first and second embodiments, the amount of light emitted by the plurality of light sources 101 is controlled according to the position where the finger is presented.

[0082] In this embodiment, as in the first embodiment, a case will be described in which near-infrared light is emitted from the light source 101 as light of a single wavelength, but as in the second embodiment, light of a plurality of different wavelengths may be used.

[0083] 9 shows an example of a case where a finger is presented at a position shifted from the reference position. If the direction from light sources 101-4 and 101-5 corresponding to the base of the finger toward light sources 101-1 and 101-2 corresponding to the fingertip is defined as the +X direction, the finger is presented at a position shifted in the +X direction from the reference position. In Examples 1 and 2, assuming that the ratio of the light intensity values ​​of the light sources 101 is determined so that the light of the light sources 101 is uniformly irradiated onto the entire finger area when the finger is presented at the reference position, when the finger is presented at a position shifted from the reference position, the light emitted by the light sources 101 (101-1 and 101-2) closer to the finger becomes brighter, while the light emitted by the light sources 101 (101-4 and 101-5) farther from the finger becomes less bright. In the example of Figure 9, when the finger is presented shifted in the +X direction from the reference position, in finger image 1500, the finger becomes brighter with the light emitted by the closer light sources 101-1 and 101-2 and less bright with the light emitted by the farther away light sources 101-4 and 101-5.

[0084] 10A and 10B are explanatory diagrams showing Example 1 of light intensity adjustment according to a change in hand position according to Example 3. As in Example 1, when a base light intensity value n is used to determine the light intensity value of each light source 101, and the light intensity values ​​of light sources 101-1 and 101-2 are a*n and the light intensity values ​​of light sources 101-4 and 101-5 are b*n (a>b≧1), the base light intensity value n and the average luminance of the finger region of the finger image are considered to have a relationship as shown in FIG. 10A , taking into account the fluctuation boundary point. When the base light intensity value n is greater than the fluctuation boundary point, the light intensity values ​​of light sources 101-1 and 101-2 remain unchanged at their upper limit values, and only the light intensity values ​​of light sources 101-4 and 101-5 increase.

[0085] 9, since the finger is displaced in the +X direction from the reference position, the finger is unlikely to be brightened by the light emitted from light source 101-4 and light source 101-5, which are farther away from the finger. Therefore, if the relationship in FIG. 10A is that of a case in which the finger is presented at the reference position, when the base light intensity value n is actually greater than the fluctuation boundary point, as shown in FIG. 10B, the average brightness of the finger area is unlikely to increase even if the base light intensity value n is increased.

[0086] Specifically, as shown in FIG. 10B, it is assumed that the base light intensity value n and the average luminance of the finger area have different linearities when the base light intensity value n is smaller than the fluctuation boundary point and when it is larger than the fluctuation boundary point, and an example will be described in which the base light intensity value n and the average luminance of the finger area are approximated to lines with different slopes and intercepts.

[0087] When the base light intensity value n obtained when the average brightness of the finger region is observed is smaller than the fluctuation boundary point, a straight line with a slope α1 passing through a predetermined intercept β1 is obtained from the observed average brightness and the current base light intensity value n. As shown in FIG. 10B , for base light intensity values ​​n greater than the fluctuation boundary point, the relationship between the average brightness and the base light intensity value n is approximated by a straight line with an intercept β3 and a slope α3. For base light intensity values ​​n greater than the fluctuation boundary point when the finger is positioned at the reference position, the relationship between the average brightness and the base light intensity value n can be approximated by a straight line with an intercept β2 and a slope α2, as in the first embodiment. Using the predetermined line with intercept β2 and slope α2 as a reference, the slope α3 can be calculated according to the presented position of the finger. For example, the change rate V of the slope α2 and the slope α3 due to the movement of the presented finger from the reference position is determined in advance through an experiment, and the slope α3 is determined by multiplying the slope α2 by the change rate V corresponding to the moving position of the finger. It goes without saying that the relationship between the base light quantity value n and the average brightness can be approximated by a quadratic or cubic function, or by polynomial interpolation or spline interpolation, as in the first embodiment.

[0088] In this embodiment, the case where the finger is presented shifted in the +X direction from the reference position has been described. However, if the finger is presented shifted in the -X direction, the finger in the finger image 1500 is less likely to be brightened by the light emitted from the light sources 101-1 and 101-2, which are moving away, and is more likely to be brightened by the light emitted from the light sources 101-4 and 101-5, which are closer. Therefore, the slope of the approximation line when the base light intensity value n described in FIG. 10B is greater than the fluctuation boundary point is greater than the slope α2 when the finger is at the reference position. In this way, when the finger moves from the reference position in the Y direction, not just the X direction, it is possible to approximate the relationship between the base light intensity value n and the average brightness of the finger region when the base light intensity value n is greater than the fluctuation boundary point, depending on the positional relationship between each light source 101 and the presented finger.

[0089] In this way, by estimating the change in the relationship between the base light intensity value n and the average brightness of the finger area when the base light intensity value n is smaller or larger than the fluctuation boundary point according to the fluctuation from the reference position of the finger, it becomes possible to acquire a finger image with the target brightness more accurately and quickly.

[0090] FIG. 11 is a flowchart showing detailed processing procedures for calculating the light intensity value of each light source shown in FIGS. 4 and 7 (steps S407 and S708) in the third embodiment. After step S707, the position of the finger detected from the finger image is calculated (S1101). A variation indicating how much and in what direction the finger position calculated in step S1101 deviates from a preset reference position of the finger is calculated (S1102). Based on the variation from the reference position of the finger calculated in step S1102 and the luminance of the finger region calculated in step S707, a relationship between the base light intensity value and the luminance of the finger region is estimated for cases where the base light intensity value is smaller than the fluctuation boundary point and cases where it is larger than the fluctuation boundary point (S1103). Based on the relationship between the base light intensity value and the luminance of the finger region estimated in step S1103, a light intensity value of the light source 101 corresponding to the target luminance is determined (S1104).

[0091] <<Modifications>> The present disclosure is not limited to the above-mentioned criminal cases, and various modifications may be adopted within the scope of the present disclosure. Furthermore, the above-mentioned embodiments may be combined with each other without departing from the scope of the present disclosure. The biometric image capturing device of each of the above-mentioned embodiments may be used as a biometric authentication device that performs biometric authentication of a subject using biometric authentication information extracted from a biometric image of the subject captured by the biometric image capturing device.

[0092] In each of the above embodiments, the biometric image capturing device may capture a transmission image of the biometric body using light that has passed through the biometric body.

[0093] A biometric image capturing system may be configured that includes the biometric image capturing device according to each of the above embodiments and a server (computer) connected to the biometric image capturing device via a network so as to be able to transmit and receive information. In this case, the server may have functions as an image processing unit and a light source control unit, and may perform the image processing and light source control (calculation and control of the amount of irradiated light) described above.

[0094] The present disclosure may also have the following configuration.

[0095] [1] A first irradiation unit and a second irradiation unit are light sources that irradiate a living body with light of at least a single wavelength, and the first irradiation unit and the second irradiation unit are arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the living body; an image processing unit that acquires a biometric image, which is an image including the biometric organism, captured by irradiating light onto the biometric organism presented in a presentation area included in the irradiation range of light of the first irradiation unit and the second irradiation unit, and performs predetermined processing on the biometric image to detect a biometric area in the image; a control unit that controls an amount of irradiation light, which is an amount of light emitted by each of the first irradiation unit and the second irradiation unit, based on the detected luminance of the biological region; Equipped with The control unit a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit, and the amount of irradiation light of the first irradiation unit has not reached an upper limit value, and the ratio of the amount of irradiation light of the first irradiation unit to the amount of irradiation light of the second irradiation unit is constant; a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and the amount of irradiation light of the first irradiation unit has reached an upper limit value; In any of the control states, controlling the amount of light irradiated by the first irradiating unit and the amount of light irradiated by the second irradiating unit; Composed of Biometric imaging device.

[0096] [2] In the biometric imaging device according to [1], The first irradiation unit and the second irradiation unit are Irradiating the living body with light of two or more different wavelengths; The image processing unit A predetermined process is performed on the living body image captured by simultaneously irradiating the living body presented in the presentation area with the light of the plurality of wavelengths, thereby generating wavelength-separated images corresponding to the light of the plurality of wavelengths, and detecting a living body area in the wavelength-separated images based on the generated wavelength-separated images; The control unit For each of the plurality of wavelengths of light, controlling the amount of irradiation light of the first irradiating unit and the amount of irradiation light of the second irradiating unit in either the first control state or the second control state based on the luminance of the biological region detected in the wavelength-separated image; It was configured as follows: Biometric imaging device.

[0097] [3] In the biometric imaging device according to [1], The image processing unit Detecting a displacement of the detection position of the biometric area from a reference position of the presentation area based on the biometric image; The control unit In the second control state, the amount of light irradiated by the second irradiating unit is further controlled so that the amount of light irradiated by the second irradiating unit corresponds to the amount of fluctuation. It was configured as follows: Biometric imaging device.

[0098] [4] In the biometric imaging device according to [1], The control unit Based on observed luminance, which is the luminance of the biological region based on the captured biological image, and a base light amount, which is a light amount serving as a reference for calculating the amount of light irradiated by the first irradiating unit at the time of capturing and the amount of light irradiated by the second irradiating unit, a first function expressing a first relationship between the luminance of the biological region and the base light amount when the amount of light of the first irradiating unit has not reached an upper limit value, and a second function expressing a second relationship between the luminance of the biological region and the base light amount when the amount of light of the first irradiating unit has reached an upper limit value, In the first control state, the base light amount is specified based on a target luminance and the first function, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, which are calculated to be the ratio based on the specified base light amount, are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, In the second control state, the base light amount is specified based on the target luminance and the second function, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the light amount of the second irradiation unit calculated based on the specified base light amount is set as the irradiation light amount of the second irradiation unit. It was configured as follows: Biometric imaging device.

[0099] [5] [4] The biometric imaging device according to [4], The image processing unit Detecting a displacement of the detection position of the biometric area from a reference position of the presentation area based on the biometric image; The control unit As the second function, a function is estimated when the light amount of the first irradiating unit reaches an upper limit value, and further, a function representing a relationship between the luminance of the biological region according to the amount of variation and the base light amount is estimated. It was configured as follows: Biometric imaging device.

[0100] [6] [4] The biometric imaging device according to [4], the first relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, The second relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, and a rate of change in the luminance of the biological region with respect to a change in the base light amount is smaller than that of the first relationship. Biometric imaging device.

[0101] [7] [5] In the biometric imaging device according to the first relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, The second relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, and the rate of change in the luminance of the biological region with respect to a change in the base light amount is smaller than that of the first relationship, and the rate of change in the luminance of the biological region with respect to a change in the base light amount changes according to the amount of fluctuation. Biometric imaging device.

[0102] [8] [4] The biometric imaging device according to [4], The control unit When the observed luminance and the target luminance are equal to or less than a predetermined threshold luminance, estimating only the first function representing the first relationship; When the observed luminance and the target luminance are greater than the threshold luminance, only the second function representing the second relationship is estimated; When the observed luminance is equal to or less than the threshold luminance and the target luminance is greater than the threshold luminance, estimating the first function representing the first relationship and the second function representing the second relationship; When the observed luminance is greater than the threshold luminance and the target luminance is equal to or less than the threshold luminance, estimating the second function representing the second relationship and the first function representing the first relationship. It was configured as follows: Biometric imaging device.

[0103] [9] [2] In the biometric imaging device according to The control unit Based on the observed luminance, which is the luminance of the biological region based on the captured wavelength-separated image corresponding to light of one wavelength among the plurality of wavelengths, and the base light amount, which is a light amount serving as a reference for calculating the irradiated light amount of the first irradiating unit and the irradiated light amount of the second irradiating unit at the time of imaging, For the light of the one wavelength, a first function that represents a first relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; a second function representing a second relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; Estimate For each of the other wavelengths of light, a third function representing a third relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; and a fourth function representing a fourth relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; Estimate For each of the plurality of wavelengths of light, In the first control state, the base light amount is specified based on the target luminance and the first function or the third function corresponding to each of the light of the plurality of wavelengths, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, which are calculated to be the ratio based on the specified base light amount, are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, In the second control state, the base light amount is specified based on the target brightness and the second function or the fourth function corresponding to each of the light of the plurality of wavelengths, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the irradiation light amount of the second irradiation unit calculated based on the specified base light amount is set as the irradiation light amount of the second irradiation unit. It was configured as follows: Biometric imaging device.

[0104]

[10] In the biometric imaging device according to [1], The control unit the first irradiating unit and the second irradiating unit irradiate near-infrared light to a living body at a first timing, and irradiate the near-infrared light and visible light to the living body at a second timing after the first timing; The image processing unit generating a wavelength-separated image corresponding to components of the near-infrared light by performing a predetermined process on the biological image captured by irradiating the biological body presented in the presentation area with the near-infrared light at the first timing, and detecting a biological body area in the wavelength-separated image based on the generated wavelength-separated image; Based on the observed luminance, which is the luminance of the biological region based on the captured wavelength-separated image, and the base light amount, which is a light amount serving as a reference for calculating the irradiated light amount of the first irradiating unit and the irradiated light amount of the second irradiating unit at the time of imaging, Regarding the near-infrared light, a first function that represents a first relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; a second function representing a second relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; Estimate Regarding visible light, a third function representing a third relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; and a fourth function representing a fourth relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; Estimate When near-infrared light and visible light are irradiated onto the living body at the second timing, Regarding the near-infrared light, In the first control state, the base light amount is specified based on a target luminance and the first function, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit are calculated to be the ratio based on the specified base light amount, and are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit; In the second control state, the base light amount is specified based on a target luminance and the second function, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the irradiation light amount of the second irradiation unit calculated based on the specified base light amount is set as the irradiation light amount of the second irradiation unit, Regarding the visible light, In the first control state, the base light amount is specified based on a target luminance and the third function, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit are calculated to be the ratio based on the specified base light amount, and are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit; In the second control state, the base light amount is specified based on the target luminance and the fourth function, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the irradiation light amount of the second irradiation unit, calculated based on the specified base light amount, is set as the irradiation light amount of the second irradiation unit. It was configured as follows: Biometric imaging device.

[0105]

[11] In the biometric imaging device according to [1], the hand as the living body is presented in the presentation area, The first irradiating unit is arranged so as to be closer to the fingertip of the hand presented in the presentation area than the second irradiating unit. Biometric imaging device.

[0106]

[12] A first irradiation unit and a second irradiation unit are light sources that irradiate a living body with light of at least a single wavelength, and the first irradiation unit and the second irradiation unit are arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the living body; an image processing unit that acquires a biometric image, which is an image including the biometric organism, captured by irradiating light onto the biometric organism presented in a presentation area included in the irradiation range of light of the first irradiation unit and the second irradiation unit, and performs predetermined processing on the biometric image to detect a biometric area in the image; a control unit that controls an amount of irradiation light, which is an amount of light emitted by each of the first irradiation unit and the second irradiation unit, based on the detected luminance of the biological region; Equipped with The control unit a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit, and the amount of irradiation light of the first irradiation unit has not reached an upper limit value, and the ratio of the amount of irradiation light of the first irradiation unit to the amount of irradiation light of the second irradiation unit is constant; a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and the amount of irradiation light of the first irradiation unit has reached an upper limit value; In any of the control states, controlling the amount of light irradiated by the first irradiating unit and the amount of light irradiated by the second irradiating unit; Composed of Biometric imaging system. [Explanation of symbols]

[0107] 100A...housing, 100B...upper panel, 101...light source, 102...imaging unit, 103...first optical filter, 104...second optical filter, 105...light-transmitting plate, 106...data memory, 107...controller, 108...imaging device, 110...hand, 111...index finger, 112...middle finger, 113...ring finger, 120...installation surface, 300...light source control unit, 310...computer, 316...bus, 1400...fingertip presentation board, 1500...finger image

Claims

1. a first irradiation unit and a second irradiation unit which are light sources that irradiate a living body with light of at least a single wavelength, the first irradiation unit and the second irradiation unit being arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the living body; an image processing unit that acquires a biometric image, which is an image including the biometric organism, captured by irradiating light onto the biometric organism presented in a presentation area included in the light irradiation range of the first irradiation unit and the second irradiation unit, and performs predetermined processing on the biometric image to detect a biometric area in the image; a control unit that controls an amount of irradiation light, which is an amount of light emitted by each of the first irradiation unit and the second irradiation unit, based on the detected luminance of the biological region; Equipped with The control unit a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit, and the amount of irradiation light of the first irradiation unit has not reached an upper limit value, and the ratio of the amount of irradiation light of the first irradiation unit to the amount of irradiation light of the second irradiation unit is constant; a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and the amount of irradiation light of the first irradiation unit has reached an upper limit value; In any of the control states, controlling the amount of light irradiated by the first irradiating unit and the amount of light irradiated by the second irradiating unit; Consists of The image processing unit Detecting a displacement of the detection position of the biometric area from a reference position of the presentation area based on the biometric image; The control unit In the second control state, the amount of light irradiated by the second irradiating unit is further controlled so that the amount of light irradiated by the second irradiating unit corresponds to the amount of fluctuation. It was configured as follows: Biometric imaging device.

2. The biometric image capturing device according to claim 1 , The first irradiation unit and the second irradiation unit are Irradiating the living body with light of two or more different wavelengths; The image processing unit A predetermined process is performed on the living body image captured by simultaneously irradiating the living body presented in the presentation area with the light of the plurality of wavelengths, thereby generating wavelength-separated images corresponding to the light of the plurality of wavelengths, and detecting a living body area in the wavelength-separated images based on the generated wavelength-separated images; The control unit For each of the plurality of wavelengths of light, controlling the amount of irradiation light of the first irradiating unit and the amount of irradiation light of the second irradiating unit in either the first control state or the second control state based on the luminance of the biological region detected in the wavelength-separated image; It was configured as follows: Biometric imaging device.

3. A first irradiation unit and a second irradiation unit which are light sources that irradiate a living body with light of at least a single wavelength, the first irradiation unit and the second irradiation unit being arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the living body; an image processing unit that acquires a biometric image, which is an image including the biometric organism, captured by irradiating light onto the biometric organism presented in a presentation area included in the light irradiation range of the first irradiation unit and the second irradiation unit, and performs predetermined processing on the biometric image to detect a biometric area in the image; a control unit that controls an amount of irradiation light, which is an amount of light emitted by each of the first irradiation unit and the second irradiation unit, based on the detected luminance of the biological region; Equipped with The control unit a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit, and the amount of irradiation light of the first irradiation unit has not reached an upper limit value, and the ratio of the amount of irradiation light of the first irradiation unit to the amount of irradiation light of the second irradiation unit is constant; a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and the amount of irradiation light of the first irradiation unit has reached an upper limit value; In any of the control states, controlling the amount of light irradiated by the first irradiating unit and the amount of light irradiated by the second irradiating unit; Consists of The control unit Based on observed luminance, which is the luminance of the biological region based on the captured biological image, and a base light amount, which is a light amount serving as a reference for calculating the amount of light irradiated by the first irradiating unit at the time of photographing and the amount of light irradiated by the second irradiating unit, a first function expressing a first relationship between the luminance of the biological region and the base light amount when the amount of light of the first irradiating unit has not reached an upper limit value, and a second function expressing a second relationship between the luminance of the biological region and the base light amount when the amount of light of the first irradiating unit has reached an upper limit value, In the first control state, the base light amount is specified based on a target luminance and the first function, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, which are calculated so as to be the ratio based on the specified base light amount, are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, In the second control state, the base light amount is specified based on the target luminance and the second function, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the light amount of the second irradiation unit calculated based on the specified base light amount is set as the irradiation light amount of the second irradiation unit. It was configured as follows: Biometric imaging device.

4. The biometric image capturing device according to claim 3, The image processing unit Detecting a displacement of the detection position of the biometric area from a reference position of the presentation area based on the biometric image; The control unit As the second function, a function is estimated when the light amount of the first irradiating unit reaches an upper limit value, and further, a function representing a relationship between the luminance of the biological region according to the amount of variation and the base light amount is estimated. It was configured as follows: Biometric imaging device.

5. The biometric image capturing device according to claim 3, the first relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, The second relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, and a rate of change in the luminance of the biological region with respect to a change in the base light amount is smaller than that of the first relationship. Biometric imaging device.

6. The biometric image capturing device according to claim 4, the first relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, The second relationship is a relationship in which the luminance of the biological region increases as the base light amount increases, the rate of change in the luminance of the biological region with respect to a change in the base light amount is smaller than that of the first relationship, and the rate of change in the luminance of the biological region with respect to a change in the base light amount changes according to the amount of fluctuation. Biometric imaging device.

7. The biometric image capturing device according to claim 3, The control unit When the observed luminance and the target luminance are equal to or less than a predetermined threshold luminance, estimating only the first function representing the first relationship; estimating only the second function representing the second relationship when the observed luminance and the target luminance are greater than the threshold luminance; When the observed luminance is equal to or less than the threshold luminance and the target luminance is greater than the threshold luminance, estimating the first function representing the first relationship and the second function representing the second relationship; When the observed luminance is greater than the threshold luminance and the target luminance is equal to or less than the threshold luminance, estimating the second function representing the second relationship and the first function representing the first relationship. It was configured as follows: Biometric imaging device.

8. A first irradiation unit and a second irradiation unit which are light sources that irradiate a living body with light of at least a single wavelength, the first irradiation unit and the second irradiation unit being arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the living body; an image processing unit that acquires a biometric image, which is an image including the biometric organism, captured by irradiating light onto the biometric organism presented in a presentation area included in the light irradiation range of the first irradiation unit and the second irradiation unit, and performs predetermined processing on the biometric image to detect a biometric area in the image; a control unit that controls an amount of irradiation light, which is an amount of light emitted by each of the first irradiation unit and the second irradiation unit, based on the detected luminance of the biological region; Equipped with The control unit a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit, and the amount of irradiation light of the first irradiation unit has not reached an upper limit value, and the ratio of the amount of irradiation light of the first irradiation unit to the amount of irradiation light of the second irradiation unit is constant; a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and the amount of irradiation light of the first irradiation unit has reached an upper limit value; In any of the control states, controlling the amount of light irradiated by the first irradiating unit and the amount of light irradiated by the second irradiating unit; Consists of The first irradiation unit and the second irradiation unit are Irradiating the living body with light of two or more different wavelengths; The image processing unit A predetermined process is performed on the living body image captured by simultaneously irradiating the living body presented in the presentation area with the light of the plurality of wavelengths, thereby generating wavelength-separated images corresponding to the light of the plurality of wavelengths, and detecting a living body area in the wavelength-separated images based on the generated wavelength-separated images; The control unit For each of the plurality of wavelengths of light, controlling the amount of irradiation light of the first irradiating unit and the amount of irradiation light of the second irradiating unit in either the first control state or the second control state based on the luminance of the biological region detected in the wavelength-separated image; It is configured as follows: The control unit Based on the observed luminance, which is the luminance of the biological region based on the captured wavelength-separated image corresponding to light of one wavelength among the plurality of wavelengths, and the base light amount, which is a light amount serving as a reference for calculating the irradiated light amount of the first irradiating unit and the irradiated light amount of the second irradiating unit at the time of imaging, For the light of the one wavelength, a first function representing a first relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; a second function representing a second relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; Estimate For each of the other wavelengths of light, a third function representing a third relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; and a fourth function representing a fourth relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; and Estimate For each of the plurality of wavelengths of light, In the first control state, the base light amount is specified based on the target luminance and the first function or the third function corresponding to each of the light of the plurality of wavelengths, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, which are calculated to be the ratio based on the specified base light amount, are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit, In the second control state, the base light amount is specified based on the target brightness and the second function or the fourth function corresponding to each of the light of the plurality of wavelengths, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the irradiation light amount of the second irradiation unit calculated based on the specified base light amount is set as the irradiation light amount of the second irradiation unit. It was configured as follows: Biometric imaging device.

9. A first irradiation unit and a second irradiation unit which are light sources that irradiate a living body with light of at least a single wavelength, the first irradiation unit and the second irradiation unit being arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the living body; an image processing unit that acquires a biometric image, which is an image including the biometric organism, captured by irradiating light onto the biometric organism presented in a presentation area included in the light irradiation range of the first irradiation unit and the second irradiation unit, and performs predetermined processing on the biometric image to detect a biometric area in the image; a control unit that controls an amount of irradiation light, which is an amount of light emitted by each of the first irradiation unit and the second irradiation unit, based on the detected luminance of the biological region; Equipped with The control unit a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit, and the amount of irradiation light of the first irradiation unit has not reached an upper limit value, and the ratio of the amount of irradiation light of the first irradiation unit to the amount of irradiation light of the second irradiation unit is constant; a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and the amount of irradiation light of the first irradiation unit has reached an upper limit value; In any of the control states, controlling the amount of light irradiated by the first irradiating unit and the amount of light irradiated by the second irradiating unit; Consists of The control unit the first irradiating unit and the second irradiating unit irradiate near-infrared light to a living body at a first timing, and irradiate the near-infrared light and visible light to the living body at a second timing after the first timing; The image processing unit a predetermined process is performed on the living body image captured by irradiating the near-infrared light onto the living body presented in the presentation area at the first timing, thereby generating a wavelength-separated image corresponding to components of the near-infrared light, and detecting a living body area in the wavelength-separated image based on the generated wavelength-separated image; Based on the observed luminance, which is the luminance of the biological region based on the captured wavelength-separated image, and the base light amount, which is a light amount serving as a reference for calculating the irradiated light amount of the first irradiating unit and the irradiated light amount of the second irradiating unit at the time of imaging, Regarding the near-infrared light, a first function representing a first relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; a second function representing a second relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; Estimate Regarding visible light, a third function representing a third relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit has not reached an upper limit value; and a fourth function representing a fourth relationship between the luminance of the biological region and a base light amount when the light amount of the first irradiating unit reaches an upper limit value; and Estimate When near-infrared light and visible light are irradiated onto the living body at the second timing, Regarding the near-infrared light, In the first control state, the base light amount is specified based on a target luminance and the first function, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit are calculated to be the ratio based on the specified base light amount, and are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit; In the second control state, the base light amount is specified based on a target luminance and the second function, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the irradiation light amount of the second irradiation unit, calculated based on the specified base light amount, is set as the irradiation light amount of the second irradiation unit; Regarding the visible light, In the first control state, the base light amount is specified based on a target luminance and the third function, and the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit are calculated to be the ratio based on the specified base light amount, and are set as the irradiation light amount of the first irradiation unit and the irradiation light amount of the second irradiation unit; In the second control state, the base light amount is specified based on the target luminance and the fourth function, an upper limit value of the light amount of the first irradiation unit is set as the irradiation light amount of the first irradiation unit, and the irradiation light amount of the second irradiation unit, calculated based on the specified base light amount, is set as the irradiation light amount of the second irradiation unit. It was configured as follows: Biometric imaging device.

10. The biometric image capturing device according to claim 1 , the hand as the living body is presented in the presentation area, The first irradiating unit is arranged so as to be closer to the fingertip of the hand presented in the presentation area than the second irradiating unit. Biometric imaging device.

11. a first irradiation unit and a second irradiation unit which are light sources that irradiate a living body with light of at least a single wavelength, the first irradiation unit and the second irradiation unit being arranged at different positions from each other; an imaging unit that captures an image using light reflected from or transmitted through the living body; an image processing unit that acquires a biometric image, which is an image including the biometric organism, captured by irradiating light onto the biometric organism presented in a presentation area included in the light irradiation range of the first irradiation unit and the second irradiation unit, and performs predetermined processing on the biometric image to detect a biometric area in the image; a control unit that controls an amount of irradiation light, which is an amount of light emitted by each of the first irradiation unit and the second irradiation unit, based on the detected luminance of the biological region; Equipped with The control unit a first control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit, and the amount of irradiation light of the first irradiation unit has not reached an upper limit value, and the ratio of the amount of irradiation light of the first irradiation unit to the amount of irradiation light of the second irradiation unit is constant; a second control state in which the amount of irradiation light of the first irradiation unit is greater than the amount of irradiation light of the second irradiation unit and the amount of irradiation light of the first irradiation unit has reached an upper limit value; In any of the control states, controlling the amount of light irradiated by the first irradiating unit and the amount of light irradiated by the second irradiating unit; Consists of The image processing unit Detecting a displacement of the detection position of the biometric area from a reference position of the presentation area based on the biometric image; The control unit In the second control state, the amount of light irradiated by the second irradiating unit is further controlled so that the amount of light irradiated by the second irradiating unit corresponds to the amount of fluctuation. It was configured as follows: Biometric imaging system.

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