Imaging apparatus and imaging method

Abstract

To widen a range of a distance to a subject that can be imaged.SOLUTION: An imaging apparatus comprises a distance measurement light emitting unit, a distance measuring unit, a light emitting unit, a plurality of lenses, an imaging element, and an image selecting unit. The distance measurement light emitting unit emits distance measurement light to a living body. The distance measuring unit measures a distance to the living body based on a distance measurement image that is an image of reflected light that the distance measurement light is reflected by the living body. The light emitting unit emits light to the living body. The plurality of lenses form images of the living body irradiated with light from the light emitting unit and are configured to each have a different focal length. The imaging element generates living body images that are a plurality of images of the living body, each of which captures the living body via the plurality of lenses. The image selecting unit selects one of the plurality of living body images based on the measured distance to the living body and an authentication available range that is a range in which authentication is available using each living body image captured via the plurality of lenses.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an imaging device and an imaging method, and more particularly to an imaging device and an imaging method for generating images of a living body. [Background technology]

[0002] In authentication devices that perform personal authentication, imaging devices are used that capture images of biological bodies such as finger vein images and fingerprint images. For example, an imaging device has been proposed that includes an imaging element, a lens array in which a plurality of lenses are arranged in an array, and an illumination means (see, for example, Patent Document 1).

[0003] In this conventional technology, each lens included in the lens array forms an image of a living body on an imaging element. This imaging element captures a compound eye image, which is a collection of images of a plurality of living bodies. The imaging device according to the conventional technology separates living body images corresponding to each of the plurality of lenses from the captured compound eye image. The separated plurality of biological images are formed by lenses having different planar positions, and image shift exists. The imaging device of the conventional technology generates a living body image from which the image shift has been removed by mutually computing these plurality of living body images. In addition, a part of the compound eye image is used to measure the illuminance of the surroundings and the distance to the subject. The on / off control of the lighting means is performed based on the distance to the subject. In addition, in this imaging device, imaging is started when the distance to the subject becomes equal to or less than a predetermined threshold. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-220035 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned conventional technology has a problem that the range of distances to the subject that can be captured is narrow because calculations are performed on multiple images, which means that the subject needs to be brought close to the imaging device to capture the image, resulting in a problem of reduced convenience.

[0006] Therefore, the present disclosure proposes an imaging device and an imaging method that widen the range of distances to a subject (living body) that can be imaged. [Means for solving the problem]

[0007] The imaging device of the present disclosure includes a light irradiation unit, a distance measurement unit, a plurality of lenses, an image sensor, and an image selection unit. The light irradiation unit irradiates light onto a living body. The distance measurement unit measures the distance to the living body. The plurality of lenses are configured with different focal lengths for forming an image of the living body irradiated with the light. The image sensor generates a plurality of living body images by capturing images of the living body through the plurality of lenses. The image selection unit selects one of the plurality of living body images based on the measured distance to the living body.

[0008] In addition, the imaging method of the present disclosure includes irradiating a living organism with light, measuring the distance to the living organism, generating a plurality of living organism images by imaging the living organism through a plurality of lenses having different focal lengths that form an image of the living organism irradiated with the light, and selecting one of the plurality of living organism images based on the measured distance to the living organism. Effect of the Invention

[0009] According to the imaging device and imaging method of the present disclosure, it is possible to expand the range of distances to a living body from which a living body image can be acquired. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of an authentication device according to an embodiment of the present disclosure. [Diagram 2]FIG. 2 is a diagram illustrating an example of the configuration of an imaging device according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is a diagram illustrating an example of capturing a biological image according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram illustrating a configuration example of an authentication device according to an embodiment of the present disclosure. [Figure 5A] FIG. 5A is a diagram illustrating an example of distance measurement according to an embodiment of the present disclosure. [Figure 5B] FIG. 5B is a diagram illustrating an example of distance measurement according to an embodiment of the present disclosure. [Figure 5C] FIG. 5C illustrates an example of distance measurement according to an embodiment of the present disclosure. [Figure 5D] FIG. 5D illustrates an example of distance measurement according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram illustrating an example of selection of a biometric image according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram illustrating an example of a method for capturing a biological image according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Authentication device configuration] FIG. 1 is a diagram illustrating an example of the configuration of an authentication device according to an embodiment of the present disclosure. The diagram is a diagram for explaining an overview of an authentication device 1. The authentication device 1 performs biometric authentication using biometric information of a human body. The authentication device 1 in the diagram illustrates an example of a standalone authentication device. Examples of biometric information include veins, fingerprints, irises, and face shapes. The authentication device 1 in the diagram illustrates an example in which veins in a person's palm are used as biometric information.

[0012] The authentication device 1 in the figure is configured by arranging a panel 2 and an imaging device 100 in a housing. The panel 2 is a display panel with a touch panel added. This panel 2 is used for inputting and outputting information to and from a user. The imaging device 100 generates an image of the veins in the palm of a user's hand. This imaging device 100 captures an image of the veins while irradiating the palm of the user with infrared light.

[0013] When a palm is held over the imaging device 100 in the figure, infrared light is irradiated from the imaging device 100 onto the palm. A part of the irradiated infrared light is reflected by the surface of the palm, and the rest penetrates the skin and cells of the palm, entering the inside, and is absorbed by hemoglobin in the blood in the veins. In other words, by irradiating infrared light, reflected light according to the shape of the veins can be obtained. As will be described later, the imaging device 100 includes an imaging element (imaging element 10) that is compatible with infrared light. By using this imaging element 10 to capture the light reflected from the palm, a vein image, which is an image of the vein pattern, can be generated. In this way, the authentication device 1 acquires the vein image in a non-contact manner. Based on this vein image, the authentication device 1 performs authentication.

[0014] [Imaging device] 2 is a diagram showing a configuration example of an imaging device according to an embodiment of the present disclosure. The figure is a plan view showing a configuration example of an imaging device 100. In the imaging device 100 in the figure, an imaging element 10, a light irradiation unit 30 (light irradiation units 30a, 30b, 30c, 30d, 30e, 30f, 30g, and 30h), and a distance measurement light irradiation unit 40 (distance measurement light irradiation units 40a, 40b, 40c, and 40d) are arranged on the surface of a substrate 101.

[0015] The light irradiating units 30a-30h irradiate the living body with light when capturing an image. The light irradiating units 30a-30h can be configured with light emitting diodes (LEDs) that irradiate infrared light. As shown in the figure, the light irradiating units 30a-30h can be arranged around the image capturing element 10.

[0016] The distance measurement light irradiating units 40a-40d irradiate the living body with light (hereinafter referred to as distance measurement light) used to measure the distance to the living body. The distance measurement light irradiating units 40a-40d can be configured with LEDs that irradiate infrared light. The distance measurement light irradiating units 40a-40d differ from the light irradiating units 30a-30h in that they focus emitted light. As shown in the figure, the distance measurement light irradiating units 40a-40d can be arranged at the four corners of the substrate 101.

[0017] The imaging element 10 generates a biological image. The imaging element 10 has a light receiving surface 11, which is an area where a plurality of pixels that convert light into an electrical signal are arranged. The imaging element 10 captures an image of light incident on the light receiving surface 11. The imaging element 10 in the figure captures an image of light irradiated from light irradiating units 30a-30h and reflected by the biological body, to generate a biological image. As shown in the figure, the imaging element 10 is disposed in the center of a substrate 101. For example, a CMOS (Complementary Metal Oxide Semiconductor) type or a CCD (Charge Coupled Device) type imaging element can be used for the imaging element 10.

[0018] [Biometric imaging] FIG. 3 is a diagram showing an example of capturing a biometric image according to an embodiment of the present disclosure. The figure is a schematic diagram showing an example of capturing a biometric image in the imaging device 100. The figure also shows a state in which a hand 301 is held over the imaging device 100. The dotted lines in the figure show infrared light irradiated to the palm of the hand 301. As shown in the figure, the light irradiating unit 30 irradiates light that is diffused over a wide range. In contrast, the distance measurement light irradiating unit 40 includes a lens that condenses light emitted from an LED, and irradiates light that is concentrated at one point on the hand 301. The light irradiated by the distance measurement light irradiating unit 40 corresponds to distance measurement light. In addition, the imaging device 100 in the figure has lenses (first lens 21 and second lens 22) that condense reflected light from the hand 301. These lenses can be arranged on a cover 102 (not shown in FIG. 2) that covers the imaging element 10.

[0019] [Image of authentication device] 4 is a diagram showing a configuration example of an authentication device according to an embodiment of the present disclosure. The figure is a block diagram showing a configuration example of an authentication device 1. The authentication device 1 in the figure includes an imaging device 100 and an authentication unit 200.

[0020] As described above, the imaging device 100 captures an image of a living body to generate a biometric image. The imaging device 100 in the figure captures an image of a hand (palm) of a living body, and generates and outputs a vein image, which is a biometric image.

[0021] The imaging device 100 includes an imaging element 10, a first lens 21, a second lens 22, a light emitting section 30, a distance measuring light emitting section 40, a distance measuring section 50, an image selecting section 60, and a control section .

[0022] As described above, the light irradiating unit 30 irradiates light onto a living body. The light irradiating unit 30 in the figure irradiates infrared light onto a hand, which is a living body. The light irradiating unit 30 irradiates light based on the control of the control unit 70.

[0023] The first lens 21 collects light from the living body to form an image. The first lens 21 in the figure collects light that is irradiated from the light irradiating unit 30 and reflected by the living body (palm) to form an image of the living body on the image sensor 10 (light receiving surface 11).

[0024] The second lens 22, like the first lens 21, collects light from the living body to form an image. The second lens 22 in the figure also collects light that is irradiated from the light irradiating unit 30 and reflected by the living body (palm) to form an image of the living body on the image sensor 10 (the light receiving surface 11 thereof).

[0025] The first lens 21 and the second lens 22 have different focal lengths. Specifically, the first lens 21 is configured to have a shorter focal length than the second lens 22. Therefore, the first lens 21 and the second lens 22 have different positions and ranges at which the living body, which is the subject, is focused. The focused range is an area close to the image sensor 10 in the first lens 21, and an area farther away than the first lens 21 in the second lens 22. The first lens 21 and the second lens 22 simultaneously form an image of the living body on the image sensor 10. Also, the first lens 21 and the second lens 22 in the figure are juxtaposed with respect to the light receiving surface 11 of the image sensor 10. Therefore, an image of the living body is formed on the image sensor 10 by each of the first lens 21 and the second lens 22.

[0026] The biometric image needs to be captured under a condition where at least one of the first lens 21 and the second lens 22 is in focus. This is because an out-of-focus, unclear biometric image causes problems in authentication. The range of distance to the biometric body where the biometric image captured through the first lens 21 and the second lens 22 can be used for authentication is approximately equal to the range of focus in the first lens 21 and the second lens 22. Since the first lens 21 and the second lens 22 have different ranges of focus, the range of distance to the biometric body that can be authenticated when using the biometric image captured through the first lens 21 and the second lens 22 is also different. As described later, the first lens 21 and the second lens 22 are used as lenses having focal lengths that bring about a state where the ranges of biometric distances where authentication is possible using the biometric images captured through the respective lenses partially overlap.

[0027] The imaging element 10 generates a biometric image as described above. The imaging element 10 in the figure generates a vein image. Light emitted from the light irradiation unit 30 and reflected by a living body, a hand, is incident on the imaging element 10 in the figure. The imaging element 10 captures an image of the veins of the hand using this reflected light. As described above, a biometric image is formed on the imaging element 10 by the first lens 21 and the second lens 22 arranged side by side. Therefore, the imaging element 10 generates an image including two biometric images corresponding to the respective lenses. The image generated by the imaging element 10 is output to the image selection unit 60.

[0028] The image sensor 10 also generates an image for distance measurement to measure the distance to the living body. This image is generated by capturing an image of light irradiated by the distance measurement light irradiating section 40 and reflected by the living body. Details of distance measurement will be described later.

[0029] As described above, the distance measurement light emitting unit 40 emits distance measurement light onto the living body. This distance measurement light is reflected by the living body and enters the imaging element 10 to be imaged. That is, the imaging element 10 captures the distance measurement light of the distance measurement light emitting unit 40 reflected on the living body. As described above, the distance measurement light is light that is concentrated at one point, so the imaging element 10 generates an image of multiple points corresponding to the distance measurement light of the multiple distance measurement light emitting units 40. Hereinafter, this image is referred to as a distance measurement image. This distance measurement image has a different shape depending on the distance of the living body. During distance measurement, the distance measurement image generated by the imaging element 10 is output to the distance measurement unit 50.

[0030] The distance measuring unit 50 measures the distance to the living body. The distance measuring unit 50 controls the distance measuring light emitting unit 40 to emit distance measuring light to the living body. After that, the distance to the living body is detected based on the distance measuring image output from the imaging element 10. The details of the distance measuring by the distance measuring unit 50 will be described later. The detected distance to the living body is output to the image selecting unit 60.

[0031] The image selection unit 60 selects a biometric image from the images generated by the imaging element 10 based on the distance to the biometric image. As described above, when generating a biometric image, the imaging element 10 outputs an image including two biometric images formed by the first lens 21 and the second lens 22, respectively. The image selection unit 60 selects one of them.

[0032] As described above, the first lens 21 and the second lens 22 have different focusing ranges and different ranges of distance to the biometric subject that can be authenticated. The image selection unit 60 compares the distance to the biometric subject with the authenticable ranges of the first lens 21 and the second lens 22. As a result, the image selection unit 60 can select a lens from the first lens 21 and the second lens 22 that focuses on the biometric subject at the measured distance, and select a biometric image captured through the lens. Next, the image selection unit 60 cuts out the selected biometric image from the image output from the imaging element 10 to generate a new biometric image. The generated biometric image is output to the authentication unit 200. The image selection unit 60 in the figure outputs a vein image as a biometric image. The biometric image output from the image selection unit 60 corresponds to the output from the imaging device 100.

[0033] The control unit 70 controls the entire imaging device 100. The control unit 70 controls the imaging element 10, the light irradiation unit 30, etc. by outputting control signals thereto.

[0034] In the imaging device 100, the distance measuring unit 50, the image selecting unit 60, and the control unit 70 can be configured by dedicated hardware using an FPGA (Field Programmable Gate Array) or the like. They can also be configured by a microcomputer equipped with firmware.

[0035] The authentication unit 200 performs personal authentication based on the biometric image output from the imaging device 100. The authentication result is output to a higher-level device or the like. The authentication unit 200 in the figure shows an example in which it is disposed in the authentication device 1, but other configurations can also be adopted. For example, the authentication unit 200 can be arranged in an external server or the like, and can exchange biometric images and the like with the imaging device 100 via a network.

[0036] [Distance measurement] 5A-5D are diagrams illustrating an example of distance measurement according to an embodiment of the present disclosure. The diagrams illustrate an example of distance measurement by the distance measuring unit 50.

[0037] FIG. 5A shows an image 401 generated by the image sensor 10. The image 401 includes a distance measurement image 402 captured through the first lens 21 and a distance measurement image 403 captured through the second lens 22. The distance measurement images 402 and 403 include a point-like image 404 output from the distance measurement light emitting unit 40. As described in FIG. 2, four distance measurement light emitting units 40 are arranged in the imaging device 100, so that four images 404 are formed in each of the distance measurement images 402 and 403. The shapes of the images 404 in the distance measurement images 402 and 403 change depending on the distance to the living body. This will be described by taking the distance measurement image 402 as an example.

[0038] 5B-5D are diagrams showing distance measurement images 402 when the distance to the living body changes. Fig. 5B, Fig. 5C, and Fig. 5D show distance measurement images 402 when the distance to the living body is long, medium, and short, respectively. In this way, the farther the living body is from the imaging device 100, the smaller the four images 404 of the distance measurement image 402 become. Therefore, the distance to the living body can be detected by measuring the size of the images 404 of the distance measurement images 402 and 403, the area occupied by the four images 404, and the like.

[0039] In order to perform such distance measurement, the distance measuring unit 50 is calibrated at the time of product shipment, etc. Specifically, distance measurement data, which is the relationship between the biometric distance and the size of the biometric image, is obtained for each of the first lens 21 and the second lens 22. This distance measurement data is stored in the distance measuring unit 50. After product shipment, the distance measuring unit 50 can calculate the distance to the biometric device based on the stored distance measurement data.

[0040] [Select a biometric image] 6 is a diagram showing an example of biometric image selection according to an embodiment of the present disclosure. The figure shows an example of biometric image selection in the image selection unit 60. In the figure, a first authenticable range 411 represents a range where authentication is possible using a biometric image captured through the first lens 21. Also, a second authenticable range 412 represents a range where authentication is possible using a biometric image captured through the second lens 22. The first authenticable range 411 based on the first lens 21, which has a short focal length, is set to an area close to the image sensor 10 (the near side), and the second authenticable range 412 based on the second lens 22 is set to an area farther away (the far side).

[0041] As shown in the figure, the first authenticable range 411 and the second authenticable range 412 have an overlapping area. Specifically, the lower limit distance of the second authenticable range 412 is closer to the image sensor 10 than the upper limit distance of the first authenticable range 411. This allows the entire authenticable range 410 in the image sensor 100 to be expanded to a range from the lower limit distance of the first authenticable range 411 to the upper limit distance of the second authenticable range 412. Seamless authentication is possible within this range of distance. In this way, by adopting lenses with focal lengths that cause the respective authenticable ranges to overlap as the first lens 21 and the second lens 22, the range of biometric distances that can be authenticated can be expanded. Hereinafter, the upper limit distance and the lower limit distance are abbreviated as upper limit and lower limit.

[0042] The authentication possible range based on the first lens 21 and the second lens 22 can be determined based on the size of the generated biometric image in addition to the range in which each lens is focused. When the distance to the biometric body is long, the image of the biometric body projected on the light receiving surface 11 of the image sensor 10 becomes small, causing the vein image to be crushed. This makes it difficult to extract the biometric information required for authentication. On the other hand, when the distance to the biometric body is short, the projected image of the biometric body becomes larger than the light receiving surface 11 of the image sensor 10. In this case, the captured biometric image is an image in which part of the biometric information is missing. Therefore, the authentication possible range can be set to the distance range to the biometric body that can obtain a biometric image of the size required for authentication. Even in this case, the authentication possible range based on the first lens 21, which has a short focal length, is closer to the image sensor 10 than the authentication possible range based on the second lens 22.

[0043] The image selection unit 60 determines whether the biometric subject is included in the first authenticable range 411 or the second authenticable range 412 based on the distance output from the distance measurement unit 50, and selects either the biometric image captured through the first lens 21 or the second lens 22. After that, the image selection unit 60 performs a process of cutting out the biometric image from the image output from the imaging element 10. This cutting out of the biometric image can be performed by image processing.

[0044] When the distance to the biometric information falls within an overlapping region of the first authenticable range 411 and the second authenticable range 412, the lens that is closer to the center of each authenticable range can be selected.

[0045] In order to select such a biometric image, the image selection unit 60 is calibrated at the time of product shipment. Specifically, the upper limit, center, and lower limit of the authentication possible range for each of the first lens 21 and the second lens 22 are obtained and stored in the image selection unit 60. After product shipment, the image selection unit 60 can select a biometric image based on the stored upper limit value, etc.

[0046] [Method of capturing biological images] FIG. 7 is a diagram showing an example of a method for capturing a biological image according to an embodiment of the present disclosure. Using the same figure, an example of a method for capturing a biological image in the imaging device 100 will be described. First, light is irradiated onto the biological body (step S101). This can be performed by the control unit 70 controlling the light irradiating unit 30 to irradiate light. Next, the distance to the biological body is measured (step S102). This can be performed by the distance measuring unit 50 controlling the distance measuring light irradiating unit 40 to irradiate distance measuring light, and then the distance measuring unit 50 detecting the distance based on the distance measuring image generated by the imaging element 10. Next, a biological body image is generated (step S103). This can be performed by the control unit 70 controlling the imaging element 10 to capture an image. At this time, the imaging element 10 captures an image of the biological body via the first lens 21 and the second lens 22.

[0047] Next, the image selection unit 60 determines whether the distance to the biometric information is equal to or greater than the lower limit of the authenticable range of the first lens 21 (first authenticable range 411 in FIG. 6) (step S104). If the distance to the biometric information is not equal to or greater than the lower limit of the authenticable range of the first lens 21 (step S104, No), the process from step S102 is executed again. On the other hand, if the distance to the biometric information is equal to or greater than the lower limit of the authenticable range of the first lens 21 (step S104, Yes), the process proceeds to step S105.

[0048] In step S105, the image selection unit 60 determines whether the distance to the biometric information is equal to or less than the upper limit of the authenticable range of the second lens 22 (second authenticable range 412 in FIG. 6) (step S105). As a result, if the distance to the biometric information is not equal to or less than the upper limit of the authenticable range of the second lens 22 (step S105, No), the process from step S102 is executed again. On the other hand, if the distance to the biometric information is equal to or less than the upper limit of the authenticable range of the second lens 22 (step S105, Yes), the process proceeds to step S106.

[0049] In step S106, the image selection unit 60 determines whether the distance to the biometric information is equal to or greater than the upper limit of the authentication range of the first lens 21 (step S106). If the distance to the biometric information is equal to or greater than the upper limit of the authentication range of the first lens 21 (step S106, Yes), the process proceeds to step S109. On the other hand, if the distance to the biometric information is not equal to or greater than the upper limit of the authentication range of the first lens 21 (step S106, No), the process proceeds to step S107.

[0050] In step S107, the image selection unit 60 determines whether the distance to the biometrics is closer to the lower limit of the authenticable range of the second lens 22 or the upper limit of the authenticable range of the first lens 21. As a result, if the distance to the biometrics is closer to the upper limit of the authenticable range of the first lens 21 than the lower limit of the authenticable range of the second lens 22 (Yes in step S107), the process proceeds to step S109. On the other hand, if the distance to the biometrics is not closer to the upper limit of the authenticable range of the first lens 21 than the lower limit of the authenticable range of the second lens 22 (No in step S107), the process proceeds to step S108.

[0051] In step S108, the image selection unit 60 selects a biometric image based on the first lens 21 (step S108). After that, the process proceeds to step S110.

[0052] In step S109, the image selection unit 60 selects a biometric image based on the second lens 22 (step S109). After that, the process proceeds to step S110.

[0053] In step S110, the image selection unit 60 outputs the selected biometric image (step S110).

[0054] Through the above-described processing, a biometric image can be captured by the imaging device 100. Note that the order of the processing for measuring the distance to the biometric body (step S102) and the processing for generating a biometric image (step S103) can be interchanged.

[0055] [Effects of the embodiment] In this way, the imaging device 100 according to the embodiment of the present disclosure captures an image of a living body through the first lens 21 and the second lens 22, generates an image including two living body images based on the respective lenses, and selects these living body images based on the measured distance to the living body. This makes it possible to expand the range of distances to the living body that allows for biometric authentication, thereby improving convenience.

[0056] Furthermore, the configuration of the imaging device 100 can be simplified compared to a method in which a lens having a focus adjustment mechanism is used to expand the range of distances to a living body that can be authenticated, because the focus adjustment mechanism and the like can be omitted.

[0057] In addition, since the first lens 21 and the second lens 22 simultaneously form an image of the living body on the imaging element 10, a plurality of living body images can be generated by one imaging element 10. The number of imaging elements 10 can be reduced, and the configuration of the imaging device 100 can be simplified.

[0058] The configuration of the imaging device 100 is not limited to this example. For example, a configuration in which three or more lenses are used to capture a biometric image can be adopted. In this case, the range of distance to the biometric subject that can be authenticated can be further expanded.

[0059] It is also possible to adopt a configuration in which an imaging element is arranged for each lens arranged in the imaging device 100. In this case, the image selection unit 60 can select an imaging element paired with a lens based on the distance to the living body, and obtain a living body image output from the selected imaging element.

[0060] Further, other methods, for example, a ToF (Time of Flight) method using the image sensor 10, can also be applied to measure the distance to the living body.

[0061] The imaging device 100 can also be used to generate images of a living body other than a hand or a living body image other than a vein image. For example, the imaging device 100 can also be used to generate finger vein images, fingerprint images, face images, iris images, etc.

[0062] It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained. [Explanation of symbols]

[0063] 1 Authentication device 10. Image sensor 21 First Lens 22 The Second Lens 30, 30a, 30b, 30c, 30d, 30e, 30f, 30g, 30h Light irradiation section 40, 40a, 40b, 40c, 40d Distance measurement light irradiation section 50 Ranging section 60 Image Selection Section 100 Imaging device

Claims

1. a distance measurement light irradiating unit that irradiates a living body with distance measurement light; a distance measuring unit that measures a distance to the living body based on a distance measuring image that is an image of the distance measuring light reflected by the living body; A light irradiation unit that irradiates light to the living body; A plurality of lenses each having a different focal length for forming an image of the living body irradiated with light from the light irradiation unit; an imaging element that captures images of the living body through the plurality of lenses to generate living body images that are a plurality of images of the living body; an image selection unit that selects one of the plurality of biometric images based on the measured distance to the biometric body and an authenticable range that is an authenticable range by each of the biometric images captured through the plurality of lenses; An imaging device comprising:

2. The imaging device according to claim 1 , wherein the distance measurement image is generated by the imaging element.

3. The living body is a hand, The biometric image is a vein image. The imaging device according to claim 1 .

4. The imaging device according to claim 1 , wherein the plurality of lenses form an image of the living body by light reflected by the living body from the irradiated light.

5. The imaging device according to claim 1 , wherein the authentication possible ranges corresponding to the plurality of lenses partially overlap each other.

6. The plurality of lenses each form an image of the living body on one of the imaging elements, The imaging element generates an image including a plurality of the biological body images captured through the plurality of lenses; The image selection unit selects one of the plurality of biometric images included in the generated image. The imaging device according to claim 1 .

7. a plurality of the imaging elements corresponding to the plurality of lenses, The image selection unit selects one of the biometric images generated by each of the plurality of image capture devices. The imaging device according to claim 1 .

8. The imaging device according to claim 1 , wherein the distance measurement light emitting section includes a lens that condenses the emitted light.

9. Irradiating a living body with distance measurement light from a distance measurement light irradiation unit; measuring a distance to the living body based on a distance measurement image which is an image of light reflected by the living body; Irradiating the living body with light from a light irradiation unit; generating a plurality of images of the living body by capturing images of the living body through a plurality of lenses having different focal lengths that form images of the living body irradiated with light from the light irradiation unit; selecting one of the plurality of biometric images based on the measured distance to the biometric body and an authenticable range that is an authenticable range by each of the biometric images captured through the plurality of lenses; An imaging method comprising:

Images