JP2005177166A - Camera apparatus and iris imaging camera apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera apparatus which can pickup an image of a subject in good focus without making a mechanism and a circuit complicate. <P>SOLUTION: An iris imaging camera apparatus 1 include an iris image acquiring apparatus 10 to acquire the iris images photographed in each of the first and the second photographing modes with different characteristics of focus on the iris, and an iris certifying apparatus 60 which judges a distance to the iris by a judging section of a distance to a subject 63 on the basis of the difference of the focus of the image of the iris photographed in the first and the second photographing modes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a camera device for capturing a subject image with a high degree of focus.

  2. Description of the Related Art Conventionally, an iris imaging camera device that performs authentication using an image of a human iris is known. In this iris imaging camera device, an iris image is picked up by an iris image acquisition device, and the iris is authenticated by collating it with a previously registered iris image. As described above, since the iris imaging camera apparatus performs authentication using the iris image, it is desired that the iris image is a clear image with a high degree of focus. In order to capture a subject image with a high degree of focus, it is necessary to match the focus position of the camera device with the position of the subject.

  In a conventional general camera device, in order to obtain a subject image with a high degree of focus automatically without depending on the operation of the camera device by the user, an autofocus function is provided, and by performing automatic focusing, An image with high focus is obtained. Since the iris imaging camera device has this autofocus function, a clear iris image in focus on the subject's iris can be obtained (see, for example, Patent Document 1).

  In addition, as an iris imaging camera device that captures a highly focused iris image without using the autofocus function, the distance to the imaged person is measured, and the distance to the in-focus position and the distance to the imaged person are An iris imaging camera device having a guidance guidance function for guiding the person to be imaged so that the iris is positioned at the in-focus position based on the difference is known (see, for example, Patent Document 2).

JP 2002-94865 A (page 3-4, FIG. 9) Japanese Unexamined Patent Publication No. 2003-141517 (page 5-6, FIG. 1)

  However, a conventional iris imaging camera device having an autofocus function requires a lens drive mechanism and a control circuit for autofocus, and there is a problem that the mechanism and circuit of the device become complicated. In addition, even a conventional iris imaging camera device having a guidance guidance function requires a distance measuring sensor for measuring the distance to the person to be imaged in order to guide the person to be imaged, and the circuit is complicated as described above. There was a problem of becoming.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a camera device that can capture a subject image with a high degree of focus without complicating a mechanism and a circuit.

  The camera device of the present invention includes an image acquisition unit that acquires subject images captured in a plurality of imaging modes having different focus degree characteristics on a subject, and a degree of focus of the subject images captured in the plurality of imaging modes. Distance determining means for determining the distance to the subject based on the difference.

  With this configuration, since the distance to the subject is determined based on the difference in the focus level of the subject images captured in a plurality of imaging modes having different focus level characteristics, the focus level is high using the determined distance. A subject image can be captured.

  In addition, the camera device of the present invention has a common optical axis in a region where the subject is located, a plurality of branched optical axes branched from the common optical axis, and each branched optical path of the plurality of branched optical axes Each has imaging optical means having a plurality of different focusing ranges on the common axis. The plurality of imaging modes are imaging modes in which a subject image is formed through the plurality of branch optical paths to capture the subject image.

  With this configuration, since the imaging optical means has different focusing ranges on the common optical axis, a focused subject image can be obtained if the subject is located in any of a plurality of focusing ranges. A subject image in focus can be obtained over a wide range.

  In addition, the iris imaging camera device of the present invention includes an iris image acquisition unit that acquires an iris image captured in a plurality of imaging modes having different focus degree characteristics to the iris, and an iris image acquired in the plurality of imaging modes. Guidance for guiding the person to be imaged so that the iris falls within at least one of a plurality of focus ranges corresponding to the focus degree characteristics of each of the plurality of imaging modes based on the difference in focus degree Means.

  With this configuration, based on the difference in the degree of focus of the plurality of iris images captured in the plurality of imaging modes having different characteristics of the degree of focus on the iris, the object is placed in at least one of the plurality of focus ranges. Since the photographer is guided, an iris image with a high degree of focus can be obtained.

  Furthermore, in the iris imaging camera device of the present invention, the plurality of in-focus ranges are adjacent and different in the front-rear direction. The guiding means is a location where the iris is not included in any of the plurality of focusing ranges and is imaged in an imaging mode corresponding to a focusing range on the near side from the apparatus. When the in-focus level of the iris image is higher than the in-focus level of the second iris image captured in the imaging mode corresponding to the focus range on the back side, the subject is guided away, and the second When the degree of focus of the first iris image is higher than the degree of focus of the first iris image, the person to be imaged is guided closer.

  With this configuration, the person to be imaged is guided to move away or approach based on the difference in the degree of focus of the plurality of iris images captured in the plurality of imaging modes, and enters the at least one of the plurality of focus ranges. Thus, the person to be imaged can be guided. Note that a plurality of in-focus ranges that are adjacent and different from each other may or may not overlap each other.

  Furthermore, in the iris imaging camera device of the present invention, the guiding means guides the person to be imaged by at least one of display and sound.

  With this configuration, the person to be imaged can be guided by guidance guidance of at least one of display and sound.

  In the present invention, the distance to the subject is determined based on the difference in the focus level of the subject images captured in each of the plurality of imaging modes having different focus level characteristics. Therefore, the focus level is determined using the determined distance. It is possible to provide a camera device having an effect of being able to capture a subject image having a high height.

  Hereinafter, an iris imaging camera device according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows an iris imaging camera device according to a first embodiment of the present invention. In FIG. 1, the iris imaging camera device 1 includes an iris image acquisition device 10 and an iris authentication device 60. The iris image acquisition apparatus 10 includes an imaging optical system 11, an imaging element 12, an image processing unit 13, light shielding plates 14 and 15, and a switching unit 16.

  The imaging optical system 11 includes two half mirrors 111 and 112, two mirrors 113 and 114, and a lens group 115. The lens group 115 is a single-focus lens group in which each lens is fixed, and has a depth focusing range. The half mirrors 111 and 112 are disposed on an extension line of the optical axis of the lens group 115. The half mirror 111 is held in a direction in which a part of incident light from the subject side is reflected downward, and the half mirror 112 is in a direction in which a part of incident light from below is reflected in the direction of the lens group 115. Is retained.

  The mirror 113 is disposed at a position where the reflected light from the half mirror 111 is incident, that is, below the half mirror 111, and holds the reflected light from the half mirror 111 in a direction in which the reflected light is reflected in a direction parallel to the optical axis of the lens group 115. Has been. The mirror 114 is disposed at a position where the light reflected by the half mirror 111 and the mirror 113 is incident, that is, at the same height as the mirror 113, and is held in a direction in which the reflected light from the mirror 113 is reflected upward.

  With the above configuration, in the imaging optical system 11, the first branch optical system is configured by the half mirror 111, the half mirror 112, and the lens group 115, and the half mirror 111, the mirror 113, the mirror 114, the half mirror 112, and the lens. The group 115 constitutes a second branch optical system. Hereinafter, the optical axes of the first and second branch optical systems are referred to as first and second branch optical axes, and the optical paths along the first and second branch optical axes are referred to as first and second branch optical paths. .

  The imaging optical system 11 has a common optical axis outside the area where the subject is present, that is, outside the iris image acquisition apparatus 10, and the common optical axis is the first and second half mirrors 111 that are branch points. Branches to the branch optical axis. And the 1st and 2nd branch optical axis is joined by the half mirror 112 which is a joining point.

  The first branching optical system passes light from the iris located on the common optical axis through the first branching optical path that passes through the half mirror 111, the half mirror 112, and the lens group 115 and reaches the image sensor 22. It is configured. In the second branch optical system, the light from the iris located on the common optical axis passes through the half mirror 111, the mirror 113, the mirror 114, the half mirror 112, and the lens group 115 and reaches the image sensor 12. It is configured to pass through two branched light paths. Comparing the first branching optical path and the second branching optical path, the second branching optical path is the same as the distance between the half mirror 111 and the mirror 113 and the distance between the mirror 114 and the half mirror 112. It is longer than the branched optical path.

  The imaging device 12 is a solid-state imaging device that photoelectrically converts a projected iris image and outputs an electrical signal. The image processing unit 13 has a function of performing processing such as A / D conversion on the electrical signal output from the image sensor 12 and generating image data of an iris image.

  The shielding plate 14 is disposed on the first branch optical axis, and the shielding plate 15 is disposed on the second branch optical axis. The shielding plates 14 and 15 are driven by a driving mechanism (not shown) and move between a position where the branching optical path is blocked (blocking position) and a position where the branching optical path is not blocked (retracted position). The switching unit 16 has a function of controlling the movement of the shielding plates 14 and 15 based on a switching control signal from a switching control unit 65 of the iris authentication device 60 described later. The switching unit 16 moves both shielding plates so that when one of the shielding plates 14 and 15 is in the blocking position, the other is in the retracted position, that is, only one of the shielding plates blocks the branching optical path. To control.

  The iris image acquisition apparatus 10 configured as described above has first and second imaging modes, and images the iris that is the subject in each imaging mode. That is, the state where the shielding plate 14 is located at the retracted position, the shielding plate 15 is located at the shielding position, and the light from the iris passes through the first branch optical path, and an iris image is formed on the imaging device 12. Is the first imaging mode. Then, the shielding plate 14 is positioned at the blocking position, the shielding plate 15 is positioned at the retracted position, and light from the iris passes through the second branch optical path and an iris image is formed on the image sensor 12. Is the second imaging mode. In the present embodiment, the first imaging mode and the second imaging mode are selectively switched by the movement of the shielding plates 14 and 15 by the switching unit 16.

  FIG. 2 is a diagram illustrating the focus degree characteristic according to the distance to the iris that is the subject in the first and second imaging modes. In FIG. 2, the horizontal axis is the distance from the iris image acquisition device 10 to the iris that is the subject, and the vertical axis is the degree of focus of the iris image captured in each imaging mode. As described above, since the first branching optical system and the second branching optical system share the lens group 115, the focusing degree characteristics of both the branching optical systems have substantially the same shape. As described above, since the lengths of the first branch optical path and the second branch optical path are different, the focus degree characteristic of the first imaging mode and the focus degree of the second imaging mode are different. The characteristic is shifted by a difference in length between the first branch optical path and the second branch optical path on the common optical axis outside the iris image acquisition device 10. That is, the iris image acquisition device 10 has a focus degree characteristic that is substantially the same shape and deviated from each other as the focus degree characteristic according to the distance from the iris image acquisition apparatus 10 to the subject. have.

  In the focus degree characteristics of the first and second imaging modes, a range of a predetermined area including a point where the focus degree is maximum is the focus range. In the present embodiment, the imaging optical system 11 is configured so that the difference between the first and second branch optical paths is smaller than the size of the focusing range in each imaging mode. As a result, as shown in FIG. 2, the focusing range 7 in the first imaging mode and the focusing range 8 in the second imaging mode are adjacent to each other in a partially overlapping manner, and both focusing is performed. An enlarged focusing range 9 is formed by combining the ranges. Therefore, in the iris image acquisition apparatus 10, if the iris is within the enlarged focusing range 9, a clear iris image in focus can be obtained in either the first or second imaging mode.

  Further, in the present embodiment, the depth of the focus range is set so that the iris image within the range has a predetermined size suitable for iris authentication. That is, in the lens group 115, when the iris is at the farthest end of the focusing range 7, the size of the iris image obtained in the first imaging mode is set to the minimum size necessary for iris authentication. And when the iris is at the closest end of the focusing range 7, the size of the iris image obtained in the first imaging mode is the maximum size allowed for the iris authentication. Designed. Since the first branching optical system and the second branching optical system share the lens group 115, the second imaging is performed when the focusing range 7 in the first imaging mode satisfies the above condition. The focus range 8 of the mode also satisfies the above conditions.

  Returning to FIG. 1, the iris authentication device 60 of the present embodiment includes an image capture unit 61, a focus determination unit 62, a subject distance determination unit 63, a guidance guidance unit 64, a switching control unit 65, an iris authentication processing unit 67, An iris database 68 and an authentication result output unit 69 are provided. The image capture unit 61 has a function of capturing the image data of the iris image captured by the iris image acquisition device 10 as image data for iris authentication and outputting the image data to the focus determination unit 62 and the iris authentication processing unit 67. Yes.

  The focus determination unit 62 has a function of calculating the focus degree of the image data output from the image capture unit 61 and outputting the calculated degree of focus to the subject distance determination unit 63. The focus determination unit 62 converts the image data into a spatial frequency by Fourier transform, and calculates an integral value of the predetermined spectral component as the focus degree. The in-focus degree determination unit 62 further performs in-focus determination by comparing the calculated in-focus degree with a threshold value stored in advance, and the determination result is used as a subject distance determination unit 63, an iris authentication processing unit. 67 and the switching control unit 65. This threshold value is set corresponding to the focusing ranges 7 and 8 shown in FIG.

  The subject distance determination unit 63 receives the degree of focus of the image data of the iris image captured in the first and second imaging modes from the focus determination unit 62, and the subject distance based on the difference in the degree of focus It has a function to determine the distance to the iris.

  With reference to FIG. 2, the structure which determines the distance to an iris in the object distance determination part 83 is demonstrated. As already described, the focusing degree characteristic in the first imaging mode and the focusing degree characteristic in the second imaging mode are substantially the same shape and deviate from each other. Therefore, when the subject is at a distance farther than the distance L4 at which both the focus degree characteristics intersect, the image obtained in the first imaging mode has a higher degree of focus than the image obtained in the second imaging mode. Become. On the other hand, when the subject is at a position closer than the distance L3, the image obtained in the second imaging mode has a higher degree of focus than the image obtained in the first imaging mode.

  Here, the position (position of distance L4) where both the in-focus degree characteristics intersect is the center of each position (position of distance L3 and position of distance L5) where the in-focus degree peaks in both in-focus degree characteristics. Yes, this position is the center of the enlarged focus range 9. Therefore, by comparing the in-focus levels of the images obtained in both imaging modes and determining which in-focus level is higher, the subject is closer to the front side than the center of the enlarged focus range 9. Or on the back side.

  If the subject distance determination unit 63 stores the focus degree characteristics of the first and second imaging modes illustrated in FIG. 2, the focus degree and the second degree of the image obtained in the first imaging mode are stored. Based on the degree of focus of the image obtained in the imaging mode, a specific distance to the iris that is the subject can be obtained.

  For example, when the focus degree of the image acquired in the first imaging mode is a2, the distance to the iris is L2 or L7. When the distance to the iris is L2, the focus degree of the lower iris image that is an image acquired in the second imaging mode is a3 that is higher than the focus degree of the upper iris image. When the distance to the iris is L7, the focus degree of the lower iris image is a1 lower than the focus degree of the upper iris image. Thus, based on the difference between the focus degree of the upper iris image and the focus degree of the lower iris image, it can be determined whether the distance to the iris is L2 or L7.

  When the focus degree of the upper iris image is a2 and the focus degree of the lower iris image is a3, the subject distance determination unit 63 determines whether or not to the iris based on the stored focus degree characteristic. It can be determined that the distance is L2, and when the focus degree of the upper iris image is a2 and the focus degree of the lower iris image is a1, the distance to the iris can be determined to be L7. As described above, the subject distance determination unit 63 determines the distance to the iris based on the focusing characteristics of the first imaging mode and the second imaging mode and the focusing degree of the image captured in each imaging mode. Can be determined.

  The subject distance determination unit 63 further provides a signal for guiding the person to be imaged closer based on the determination result of the distance to the iris and the degree of focus output from the focus determination unit 62 (approach guidance signal). , A signal for guiding the person to be imaged away (a distance guidance signal), a signal indicating that the position of the iris is appropriate (guidance unnecessary signal), or a signal indicating that the determination result is unknown (determination impossible signal) ) To the guidance guidance unit 64.

  The subject distance determination unit 63 indicates that the result of the focus determination from the focus determination unit 62 indicates that the degree of focus of the iris image captured in any imaging mode is lower than the threshold value. When it is determined that the iris is not within the in-focus range 9, it is determined whether the iris is on the near side or the back side with respect to the in-focus range 9, and the approaching signal or the away-inducing signal is sent. Output.

  Specifically, the subject distance determination unit 63 has a lower degree of focus of the iris image captured in any imaging mode than the threshold value, and the degree of focus of the iris image captured in the first imaging mode. When the degree of focus of the iris image picked up in the second image pickup mode is higher, the position is outside the enlarged focus range 9 and far from the center L4 of the enlarged focus range 9, that is, the enlarged focus range. It is determined that the iris is located farther than the farthest end L6. In this case, the subject distance determination unit 63 outputs an approaching guidance signal. Further, the degree of focus of the iris image captured in any imaging mode is lower than the threshold value, and the degree of focus of the iris image captured in the first imaging mode is captured in the second imaging mode. When the degree of focus of the iris image is lower, the position is outside the enlarged focus range 9 and closer to the center L4 of the enlarged focus range 9, that is, closer to the closest end L1 of the enlarged focus range 9. It is determined that the iris is located. In this case, the subject distance determination unit 63 outputs a distance guidance signal.

  Further, the subject distance determination unit 63 indicates that the focus degree of the iris image captured in any one of the imaging modes is higher than the threshold value as a result of the focus determination by the focus determination unit 62. When it is determined that the iris is in the enlarged focus range 9, a guidance unnecessary signal is output. When the distance to the subject is unknown, the subject distance determination unit 63 outputs a determination impossibility signal.

  FIG. 3 is a diagram illustrating a configuration of the guidance guidance unit 64. The guidance guidance unit 64 includes a display unit 641 and an audio output unit 642. The display unit 641 is a close-up guide lamp 643 for guiding the person to be imaged to approach the iris image acquisition apparatus 10, and a distance guide for guiding the person to be imaged away from the iris image acquisition apparatus 10. The lamp 644 includes a good lamp 645 indicating that the distance of the iris is appropriate.

  The guidance guidance unit 64 has a function of turning on the proximity guidance lamp 643, the distance guidance lamp 644, and the good lamp 645 in response to the proximity guidance signal, the distance guidance signal, and the guidance unnecessary signal output from the subject distance determination unit 63. doing. When the guidance guidance 64 receives a determination impossible signal from the subject distance determination unit 63, none of the lamps are turned on.

  The guidance guidance unit 64 also provides voice guidance for guiding the person to be imaged to approach the iris image acquisition device 10 in response to the approaching guidance signal, the distance guidance signal, and the guidance unnecessary signal, and the person to be imaged. Voice guidance for guiding the user to move away from the iris image acquisition device 10 and voice guidance indicating that the position of the iris is appropriate are stored. The guidance guidance unit 64 has a function of receiving a guidance signal, a distance guidance signal, or a guidance unnecessary signal from the subject distance determination unit 63 and outputting voice guidance corresponding to them from the voice output unit 642. The guidance guidance 64 does not output any voice guidance when it receives a determination impossible signal from the subject distance determination unit 63.

  Returning to FIG. 1, if the switching control unit 65 indicates that the focus degree of the iris image is lower than the threshold value in the focus determination result output from the focus determination unit 62, Based on the determination result, it has a function of outputting a switching control signal for moving the shielding plates 14 and 15.

  The iris database 68 stores iris images of registrants. Based on the result of the focus determination output from the focus determination unit 62, the iris authentication processing unit 67 captures an iris image having a degree of focus higher than the threshold value from the image capture 61 as image data for iris authentication. Has the function of performing iris authentication and outputting the authentication result to the authentication result output unit 69. The iris authentication processing unit 67 performs iris authentication by extracting an iris portion included in the image data and collating it with an iris image stored in the iris database 68.

  The authentication result output unit 69 outputs an authentication result signal (authentication success signal or authentication unsuccess signal) based on the authentication result output from the iris authentication processing unit 67. This authentication result signal is a control signal for unlocking or locking the door key when the iris imaging camera device 1 is used in an entrance / exit management system, for example. Further, when a notification device such as a monitor is attached to the iris authentication device 60 and the authentication result is notified to the person to be authenticated, the authentication result signal is used as a notification signal of the authentication result.

  In the iris camera device 1, the iris image acquisition device 10 and the iris authentication device 60 may be configured integrally or may be configured separately. When both devices are configured as separate bodies, the iris authentication device 60 may be configured by installing software on a general-purpose computer.

  The operation of the iris imaging camera device 1 configured as described above will be described with reference to FIG. First, the switching unit 16 positions the shielding plate 14 at the retracted position and the shielding plate 15 at the blocking position, and sets the iris image acquisition apparatus 10 to the first imaging mode (step S41). The iris image acquisition apparatus 10 images the iris in the first imaging mode, and the image processing unit 13 generates image data.

  Next, the image capture unit 61 of the iris authentication device 60 captures the image data (first image data) of the iris image captured in the first imaging mode from the image processing unit 13, and sends it to the focus determination unit 62. Output (step S42). The focus determination unit 62 calculates the focus degree of the iris image and performs focus determination (step S43). At this time, the focus determination unit 62 outputs the calculated degree of focus to the subject distance determination unit 63 and outputs the result of the focus determination to the subject distance determination unit 63 and the iris authentication processing unit 67. Then, as a result of the focus determination by the focus determination unit 62, it is determined whether the focus degree is higher than the threshold value, that is, whether the iris is within the focus range of the first imaging mode (step S44). When the degree of focus is higher than the threshold value, that is, when an in-focus iris image is obtained in the first imaging mode (YES in step S44), the iris authentication processing unit 67 is an image capture unit. The first image data is fetched from 61 and an authentication process is performed (step S45).

  As a result of focus determination by the focus determination unit 62, when it is determined that the focus degree is lower than the threshold value, that is, when an in-focus iris image is not obtained in the first imaging mode. (NO in step S44), focus determination unit 62 outputs the result to switching control unit 65. Then, the switching control unit 65 outputs a switching control signal to the switching unit 16 of the iris image acquisition device 10 based on the determination result. The switching unit 16 moves the shielding plates 14 and 15 based on the switching control signal to switch the imaging mode of the iris image acquisition device 10 to the second imaging mode (step S46). Then, the iris image acquisition apparatus 10 images the iris in the second imaging mode, and the image processing unit 13 generates image data. At this time, the focus determination unit 62 outputs the focus degree and the result of the focus determination to the subject distance determination unit 63.

  The image capture unit 61 captures the image data (second image data) of the iris image captured in the second imaging mode from the image processing unit 13 and outputs it to the focus determination unit 62 (step S47). The focus determination unit 62 calculates the focus degree of the iris image and performs focus determination (step S48). At this time, the focus determination unit 62 outputs the calculated degree of focus to the subject distance determination unit 63 and outputs the result of the focus determination to the subject distance determination unit 63 and the iris authentication processing unit 67. Then, as a result of the focus determination by the focus determination unit 62, it is determined whether or not the focus degree is higher than the threshold value, that is, whether the iris is within the focus range of the second imaging mode (step S49). When it is determined that the degree of focus is higher than the threshold value, that is, when an in-focus iris image is obtained in the second imaging mode (YES in step S49), the certificate processing unit 67 Image data is captured from the image capture unit 61 and authentication processing is performed (step S45).

  When both of the first image data and the second image data are lower than the threshold value, that is, when the iris is not within the enlarged focus range (NO in step S49), the subject distance determination unit 63 performs the iris measurement. Is determined (step S50), and it is determined whether the determined distance to the subject is farther from the farthest end of the enlarged focusing range or closer to the nearest end of the enlarged focusing range (step S51). ).

  When the distance to the iris is closer than the closest end of the enlarged focus range (NO in step S51), the subject distance determination unit 63 outputs a guidance signal away from the guidance guidance unit 64. Then, the guidance guidance unit 64 turns on the distance guidance lamp 644 based on the distance guidance signal, and voice guidance for guiding the person to be imaged away from the iris image acquisition device 10 from the voice output unit 642. Is output (step S52).

  When the distance to the iris is far from the farthest end of the enlargement focus range (YES in step S51), the subject distance determination unit 63 approaches the guidance guidance unit 64 and outputs a guidance signal. Then, the guidance guidance unit 64 turns on the guidance lamp 643 based on the approach guidance signal, and guides the person to be imaged to approach the iris image acquisition device 10 from the voice output unit 642. Is output (step S53).

  After step S52 or step S53, it is determined whether a predetermined time limit has elapsed since the start of the process (step S54). If the time limit has not yet elapsed (NO in step S54), the process returns to step S41. If the time limit has elapsed (YES in step S54), the authentication process is not performed and the process ends. .

  According to the iris imaging camera device 1 of the first embodiment of the present invention as described above, the difference in the degree of focus between the iris images captured in each of the first and second imaging modes having different focus degree characteristics. Since the distance to the subject is determined based on this, based on the determined distance, the person to be imaged can be guided to an appropriate position, and an iris image with a high degree of focus can be obtained.

  The iris image acquisition apparatus 10 has a focus range that is shifted from each other on the common optical axis. If the iris that is the subject is located in any of the plurality of focus ranges, a focused iris image is formed. As a result, it is possible to obtain an in-focus iris image in a wide range of the distance to the iris with a simple configuration without an autofocus function.

(Second Embodiment)
Next, an iris imaging camera device 2 according to a second embodiment of the present invention is shown in FIG. The iris imaging camera device 2 of the present embodiment is a modification of the first embodiment, and the iris image acquisition device 20 includes a rotating mirror 216 instead of the half mirror 112 of the first embodiment. I have. Since the configuration of the iris authentication device 60 is the same as that of the first embodiment, description thereof is omitted.

  The iris image acquisition apparatus 20 further includes a support shaft 27 to which the rotation mirror 216 is fixed and a motor 28 that rotates the support shaft 27. In the iris image acquisition device 20, the first branch optical system is configured by the half mirror 211 and the lens group 215, and the second branch is formed by the half mirror 211, the mirror 213, the mirror 214, the rotating mirror 216, and the lens group 215. An optical system is configured. The rotating mirror 216 is provided in the vicinity of the junction of the first and second branch optical axes. The rotating mirror 216 selectively validates the first branching optical path or the second branching optical path by changing the angle by the rotation.

  FIG. 5 shows a state in which the first branch optical path by the first branch optical system is validated by the rotating mirror 216. In this state, the rotating mirror 216 is retracted to a position that does not block the first branch optical path, so that light from the iris passes through the first branch optical path, that is, the half mirror 211 and the lens group 215. And projected onto the image sensor 22. Then, the light traveling in the second branch optical path is reflected in a direction different from the direction toward the lens group 215 by the reflecting surface of the rotating mirror 216. Therefore, this light does not reach the image sensor 22 through the lens group 215.

  FIG. 6 is a diagram illustrating a state in which the second branch optical path is activated. In this state, the light from the iris reflects the second branch optical path, that is, the half mirror 211, the mirror 213, and the mirror 214, and the reflection surface of the rotating mirror 216 at the confluence of the first and second branch optical axes. And is incident on the lens group 215 and projected onto the image sensor 22. The light traveling through the first branch optical path is blocked by the back surface of the rotating mirror 216 and does not enter the lens group 215.

  In this way, the rotating mirror 216 is between the angle that activates the first branch optical path (first optical path validation angle) and the angle that validates the second branch optical path (second optical path validation angle). Rotate. The iris image acquisition device 20 is in the first imaging mode when the rotating mirror 216 is at the first optical path validation angle, and the second imaging mode when the rotating mirror 216 is at the second optical path validation angle. Imaging mode. The rotation operation of the rotation mirror 216 is performed by the switching unit 26 controlling the motor 28. The switching unit 26 receives the switching control signal from the switching control unit 65 of the iris authentication device 60 and controls the motor 28 based on the switching control signal.

  Also in the present embodiment, in the first imaging mode and the second imaging mode, the focus degree characteristic according to the distance to the iris that is the subject is shifted, and the iris image acquisition device 20 is configured to measure the distance to the iris. And a plurality of imaging modes having different focus degree characteristics according to.

  In the iris image acquisition device 20, when the rotation mirror 216 is at the second optical path activation angle as shown in FIG. 6 in the second imaging mode, the angle of the rotation mirror 216 is slightly changed. Multiple imaging may be performed. As a result, it is possible to capture a range that is shifted up and down, and to expand the range in which the iris can be captured in the vertical direction.

  The iris imaging camera device 2 configured as described above operates in the same manner as in the first embodiment. However, the setting of the first imaging mode in step S41 and the setting of the second imaging mode in step S46 are performed by driving the motor 28 by the switching unit 26. That is, when the switching unit 26 drives the motor 28 and the rotation mirror 216 is set to the first optical path activation angle, the first imaging mode is set, and the rotation mirror 216 activates the second optical path. By setting the angle, the second imaging mode is set.

  According to the iris imaging camera device 2 of the second embodiment of the present invention as described above, the difference in focus degree between the iris images captured in the first and second imaging modes having different focus degree characteristics. Since the distance to the subject is determined based on this, based on the determined distance, the person to be imaged can be guided to an appropriate position, and an iris image with a high degree of focus can be obtained.

  The iris image acquisition apparatus 20 has a focus range that is shifted from each other on the common optical axis. If the iris that is the subject is located in any of the plurality of focus ranges, an in-focus iris image is formed. As a result, it is possible to obtain an in-focus iris image in a wide range of the distance to the iris with a simple configuration without an autofocus function.

(Third embodiment)
Next, an iris imaging camera device according to a third embodiment of the present invention is shown in FIG. The iris image acquisition apparatus 30 according to the present embodiment includes an imaging optical system 31, a first imaging element 321, a second imaging element 322, a first image processing unit 331, and a second image processing unit 332. .

  The imaging optical system 31 includes a half mirror 311, a mirror 312, a first lens group 313, and a second lens group 314. The half mirror 311 is disposed on an extension line of the optical axis of the first lens group 313, and is held in a direction in which a part of incident light from the subject side is reflected upward. The mirror 312 is disposed on the extended line of the optical axis of the second lens group 314 and above the half mirror 311, and the reflected light from the half mirror 311 is directed toward the second lens group 314. Is held in the direction of reflection.

  The half mirror 311, the mirror 312, the first lens group 313 and the second lens group 314 are the distance between the half mirror 311 and the first lens group 313 and between the mirror 312 and the second lens group 314. Are arranged so that their distances are equal. The first lens group 313 and the second lens group 314 have the same configuration.

  The first image sensor 321 and the second image sensor 322 are solid-state image sensors that photoelectrically convert the projected iris image and output an electrical signal. The first image processing unit 331 and the second image processing unit 332 perform processing such as A / D conversion on the electrical signals output from the first image sensor 321 and the second image sensor 322, respectively, It has a function to generate data.

  In the present embodiment, the half mirror 311 and the first lens group 313 constitute a first branch optical system, and the half mirror 311, the mirror 312 and the second lens group 314 constitute a second branch optical system. ing. The position of the half mirror 311 is the branch point of the optical axes of both branch optical systems. The imaging optical system 31 has a common optical axis outside the iris image acquisition device 30.

  The first branching optical system passes the first branching optical path where the light from the iris located on the common optical axis passes through the half mirror 311 and the first lens group 313 and reaches the first image sensor 321. It is configured to pass. In the second branch optical system, the light from the iris located on the common optical axis passes through the half mirror 311, the mirror 312 and the second lens group 314, and reaches the second image sensor 322. It is configured to pass through two branched light paths. Comparing the first branching optical path and the second branching optical path, the second branching optical path is longer than the first branching optical path by the distance between the half mirror 311 and the mirror 312.

  The iris image acquisition apparatus 30 also has first and second imaging modes, as in the first embodiment, and takes an iris image in each imaging mode. That is, the state in which an iris image is formed by the first image pickup device 321 by the first branch optical system is the first image pickup mode, and the iris by the second image pickup device 322 by the second branch optical system. A state in which an image is formed is the second imaging mode.

  As described above, in the imaging optical system 31 of the present embodiment, since the first and second lens groups 313 and 314 have the same configuration, the focusing ranges 7 and 8 of the first and second branch optical paths are the same. The deviation is equal to the difference in length between the first branch optical path and the second branch optical path in the imaging optical system 31. In this embodiment, since the distance between the half mirror 311 and the first lens group 313 and the distance between the mirror 312 and the second lens group 314 are equal, the difference between the lengths of the two branched optical paths. Is the distance between the half mirror 311 and the mirror 312.

  In the present embodiment, the imaging optical system 31 is designed so that the difference between the lengths of the two branched optical paths is equal to the depth of the focusing ranges 7 and 8, so that the focusing range in the first imaging mode and the first focusing mode are the same. The focusing ranges of the two imaging modes are adjacent to each other without overlapping, and the entire focusing area is in focus in any of the imaging modes.

  The iris authentication device 70 includes an image capture unit 71, a focus determination unit 72, and a selector 75. The focus determination unit 72 is connected to both of the two image processing units 331 and 332 of the iris imaging camera device 30. The focus determination unit 72 has a function of calculating the focus degree of the image data output from each of the image processing units 331 and 332 and performing focus determination. The focus determination unit 72 outputs the calculated focus degree and the result of the focus determination to the subject distance determination unit 73. Further, the focus determination unit 72 has a function of outputting the result of focus determination to the selector 75.

  The selector 75 is also connected to both of the two image processing units 331 and 332 of the iris imaging camera device 30, and image data is input from both the image processing units 331 and 332. The selector 75 has a function of outputting the focused image data to the image capture unit 71 according to the result of the focus determination output from the focus determination unit 72. The image capture unit 71 has a function of taking in-focus image data selected by the selector 75 as image data for iris authentication and outputting the image data to the iris authentication processing unit 77.

  The iris authentication device 70 includes a subject distance determination unit 73, a guidance guidance unit 74, a comprehensive determination processing unit 75, an iris authentication processing unit 77, an iris database 78, and an authentication result output unit 79. Since this is the same as the iris authentication device 60 of the embodiment, the description thereof is omitted.

  The operation of the iris imaging camera device 3 configured as described above will be described with reference to FIG. First, the first and second image processing units 331 and 332 output image data to the focus determination unit 72, respectively. The focus determination unit 72 first calculates the degree of focus of the image data (first image data) output from the image processing unit 331, and performs focus determination (step S81). Then, as a result of the focus determination by the focus determination unit 72, it is determined whether or not the focus degree is higher than the threshold value, that is, whether the iris is within the focus range of the first imaging mode (step S82). When the image data output from the image processing unit 331 has a degree of focus equal to or greater than the threshold (YES in step S82), a determination result indicating that the second image data should be selected is selected by the selector. It outputs to 75 (step S83).

  On the other hand, when the degree of focus of the image data is lower than the threshold value in the focus determination in step S82, that is, when an in-focus iris image cannot be obtained in the first imaging mode (step S82). NO in S82), the degree of focus of the image data (second image data) output from the second image processing unit 332 is calculated (step S84). Then, the focus determination unit 72 determines the focus of the image data (step S85). When the focus degree is equal to or higher than the threshold value (YES in step S85), the image data should be selected. A determination result indicating the presence is output to the selector 75 (step S86).

  When the first image data is selected in step S83 or the second image data is selected in step S86, the image capture unit 71 captures the selected image data from the selector 75, and the iris authentication processing unit. (Step S92). The iris authentication processing unit 77 performs iris authentication using the image data output from the image capture unit 71 (step S93), and the process ends.

  When the degree of focus of the second image data in addition to the first image data is lower than the threshold value, that is, when the iris is not within the enlarged focus range (NO in step S85), the subject distance determination unit 73 Determines the distance to the iris (step S87), and determines whether the determined distance to the subject is farther from the farthest end of the enlarged focusing range or closer to the nearest end of the enlarged focusing range. (Step S88).

  When the distance to the iris is closer than the closest end of the enlarged focus range (NO in step S88), the subject distance determination unit 73 outputs a guidance signal away from the guidance guidance unit 74. Then, the guidance guidance unit 74 turns on the distance guidance lamp based on the distance guidance signal, and outputs voice guidance for guiding the person to be imaged away from the iris image acquisition device 30 from the voice output unit. (Step S89).

  When the distance to the iris is far from the farthest end of the enlarged focus range (YES in step S88), the subject distance determination unit 73 approaches the guidance guidance unit 74 and outputs a guidance signal. Then, the guidance guidance unit 74 turns on the guidance lamp on the basis of the approach guidance signal, and outputs a voice guidance for guiding the imaged person to approach the iris image acquisition device 30 from the voice output unit. (Step S90).

  After step S89 or step S90, it is determined whether a predetermined time limit has elapsed since the start of the process (step S91). If the time limit has not yet elapsed (NO in step S91), the process returns to step S81. If the time limit has elapsed (YES in step S91), the authentication process is not performed and the process ends. .

  As with the first embodiment, the iris imaging camera device 3 according to the third embodiment of the present invention captures an image in each of the first and second imaging modes having different focus degree characteristics. Since the distance to the subject is determined based on the difference in the degree of focus of the iris image, the person to be imaged can be guided to an appropriate position based on the determined distance.

  Furthermore, the iris image acquisition apparatus 30 has a focusing range that is shifted from each other on the common optical axis, as in the first embodiment, and the iris that is the subject is in the first and second focusing ranges. If it is located in any of the positions, an in-focus iris image can be obtained. Therefore, an in-focus iris image can be obtained with a simple configuration without an autofocus function in a wide range to the iris.

(Fourth embodiment)
Next, an iris imaging camera device according to a fourth embodiment of the present invention is shown in FIG. The iris imaging camera device 4 of the present embodiment is a modification of the third embodiment, and the configuration of the imaging optical system 41 of the iris image acquisition device 40 is different from that of the third embodiment. Since the configuration of the iris authentication device 70 is the same as that of the third embodiment, description thereof is omitted.

  The imaging optical system 41 of this embodiment includes a half mirror 411, a first lens group 412, and a second lens group 413. The first lens group 412 and the second lens group 413 are arranged so that their optical axes are orthogonal to each other. The half mirror 411 is disposed at a point orthogonal to both optical axes, and is held in a direction in which a part of incident light from the subject side is reflected by the second lens group 413. The first lens group 412 and the second lens group 413 are arranged so that the distance to the orthogonal point of the optical axis, that is, the distance to the half mirror 411 is equal.

  The first lens group 412 and the second lens group 413 have different distances to the focusing ranges 7 and 8. The focusing range 7 of the first lens group 412 is the second lens group 413. It is farther than the focusing range 8. In addition, the two lens groups 412 and 413 have different depths of the focusing range, and the focusing range 7 of the first lens group 412 is shallower than the focusing range 8 of the second lens group 413. Further, although both lens groups 412 and 413 have different magnifications, as in the first embodiment, the iris image of the iris at the farthest end of each focusing range is smaller than the smallest size that can be recognized by the iris. And the iris image of the iris at the closest end of the focus range is set to be smaller than the maximum size that can be handled by the iris authentication process.

  In the iris image acquisition device 40, a first branch optical system is configured by the half mirror 411 and the first lens group 412, and a second branch optical system is configured by the half mirror 411 and the second lens group 413. The position of the half mirror 411 becomes a branch point of the optical axes of both branch optical systems. Further, the imaging optical system 41 has a common optical axis outside the iris image acquisition device 40.

  The first image sensor 421 and the second image sensor 422 are solid-state image sensors that photoelectrically convert the projected iris image and output an electrical signal. Then, the first image processing unit 431 and the second image processing unit 432 perform processing such as A / D conversion on the electrical signals output from the first image sensor 421 and the second image sensor 422, respectively. And a function of generating image data.

  Similarly to the third embodiment, the iris image acquisition device 40 has first and second imaging modes, and images the iris as a subject in each imaging mode. That is, a state in which an iris image is formed on the first imaging element 421 by the first branching optical system is the first imaging mode, and an iris is formed on the second imaging element 422 by the second branching optical system. A state in which an image is formed is the second imaging mode. Also in the present embodiment, in the first imaging mode and the second imaging mode, the focus degree characteristic according to the distance to the iris that is the subject is deviated, and the iris image acquisition device 40 has a distance to the iris. And a plurality of imaging modes having different focus degree characteristics according to.

  The iris imaging camera device 4 configured as described above operates in the same manner as in the third embodiment.

  As with the first embodiment, the iris imaging camera device 4 according to the fourth embodiment of the present invention captures an image in each of the first and second imaging modes having different focus degree characteristics. Since the distance to the subject is determined based on the difference in the degree of focus of the iris image, the person to be imaged can be guided to an appropriate position based on the determined distance.

  Furthermore, the iris image acquisition device 40 has a focusing range that is shifted from each other on the common optical axis, as in the first embodiment, and the iris that is the subject is in the first and second focusing ranges. If it is located in any of the positions, an in-focus iris image can be obtained. Therefore, an in-focus iris image can be obtained with a simple configuration without an autofocus function in a wide range to the iris.

(Fifth embodiment)
Next, an iris imaging camera device according to a fifth embodiment of the present invention is shown in FIG. The iris image acquisition apparatus 50 according to the present embodiment includes an imaging optical system 51, an imaging element 52, and an image processing unit 53.

  The imaging optical system 51 includes a half mirror 511, mirrors 512 to 516, a first lens group 517, and a second lens group 518. The first lens group 517 and the second lens group 518 have the same configuration, and both are single-focus lens groups having a depth focusing range. The first and second lens groups 517 and 518 are arranged so that their optical axes are parallel to each other.

  The half mirror 511 is disposed on an extension line of the optical axis of the first lens group 517, and is held in a direction in which a part of incident light from the subject side is reflected downward. The image sensor 52 is arranged so that the iris image formed by the first lens group 517 is projected onto the upper region. The mirrors 512 to 514 are arranged so that the light reflected by the half mirror 511 is sequentially reflected and enters the second lens group 518. The mirrors 515 and 516 are arranged so that the light transmitted through the second lens group 518 is reflected in order and projected onto the lower region of the image sensor 52 in a direction parallel to the optical axis of the second lens group 518. Has been.

  The image sensor 52 is composed of a solid-state image sensor that converts an iris image projected on the imaging surface into an electric signal. The image processing unit 53 has a function of performing processing such as A / D conversion on the electrical signal output from the image sensor 52 and generating image data of an iris image.

  In the present embodiment, the first branch optical system is configured by the half mirror 511 and the first lens group 517, and the second branch optical system is configured by the half mirror 511, the mirrors 512 to 516, and the second lens group 518. It is configured. The position of the half mirror 511 becomes the branch point of the optical axes of both branch optical systems. The imaging optical system 51 has a common optical axis outside the iris image acquisition device 50.

  The first branching optical system passes through the first branching optical path where the light from the iris located on the common optical axis passes through the half mirror 511 and the first lens group 517 and reaches the upper region of the image sensor 52. It is configured to pass. The second branch optical system allows light from the iris located on the common optical axis to pass through the half mirror 511, the mirrors 512 to 514, the second lens group 518, and the mirrors 515 and 516. It is configured to pass through the second branch optical path that reaches the lower region.

  The iris image acquisition device 50 configured as described above has first and second imaging modes, and images the iris that is the subject in each imaging mode. That is, the state in which the light from the iris passes through the first branch optical path and the iris image is formed by the imaging device 52 is the first imaging mode, and the light from the iris passes through the second branch optical path. The state in which an iris image is formed by the image sensor 52 is the second imaging mode. In the present embodiment, the iris image acquisition device 50 simultaneously performs the imaging of the iris image in the first imaging mode and the imaging of the iris image in the second imaging mode.

  In the present embodiment, the imaging optical system 51 is designed so that the difference between the optical path lengths of the first and second branch optical paths is equal to the depth of the focusing range of the first and second branch optical systems. The focusing range of the first imaging mode and the focusing range of the second imaging mode are adjacent to each other without overlapping, and the entire focusing range is in focus by any imaging mode. .

  FIG. 11 is a diagram showing image data acquired by the iris image acquisition device 50 of the present embodiment. As described above, in the present embodiment, the focus range 7 in the first image capture mode and the focus range 8 in the second image capture mode form an enlarged focus range continuously. When an iris is within this enlarged focusing range, an in-focus iris image is obtained in one of the upper and lower regions of the image data, and a defocused iris image is obtained in the other region. In the example of FIG. 11, image data obtained when the iris that is the subject is located within the focusing range 7 of the first imaging mode is illustrated. The upper region of the image data is a focused iris image, and the lower region is a blurred iris image.

  Returning to FIG. 10, the iris authentication apparatus 80 according to the present embodiment includes an upper focus degree determination unit 821, a lower focus degree determination unit 822, an overall determination unit 85, and a cutout unit 89. The upper focus determination unit 821 and the lower focus determination unit 822 use the image data output from the image capture unit 81 to perform upper region and lower region images (upper iris image and lower iris image) in the image data. It has a function of calculating the degree of focus and outputting it to the subject distance determination unit 83. The upper focus degree determination unit 821 and the lower focus degree determination unit 822 further perform the focus determination by comparing the calculated focus degree with a threshold value stored in advance, thereby determining the focus degree. Is output to the subject distance determination unit 83 and the comprehensive determination unit 85.

  The subject distance determination unit 83 receives the degrees of focus of the upper iris image and the lower iris image from the upper focus determination unit 821 and the lower focus determination unit 822, and the iris that is the subject based on the difference between the focus levels. It has the function to determine the distance to. The subject distance determination unit 83 further includes a close-in guidance signal and a away-inducing signal based on the determination result of the distance to the iris and the focus determination results output from the upper focus determination unit 821 and the lower focus determination unit 822. In addition, it has a function of outputting a guidance unnecessary signal or a determination impossible signal to the guidance guidance unit 84. The iris for outputting these signals is the same as that in the first embodiment. The subject distance determination unit 83 also outputs a guidance unnecessary signal to the general determination unit 85 when outputting a guidance unnecessary signal to the guidance guidance unit 84.

  When the comprehensive determination unit 85 receives a guidance unnecessary signal from the subject distance determination unit 83, the comprehensive determination unit 85 has a function of fetching the result of the focus determination from the upper focus determination unit 821 and the lower focus determination unit 822 correspondingly. ing. When the upper focus determination unit 821 determines that the upper region is an in-focus image, the general determination unit 85 outputs an upper cut-out signal to the cut-out unit 86, and a lower focus determination unit. When it is determined in step 822 that the lower region is an in-focus image, it has a function of outputting a lower cutout signal to the cutout portion 86. In the iris image acquisition device 50 of the present embodiment, as described above, the focusing range 7 in the first imaging mode and the focusing range 8 in the second imaging mode are adjacent to each other without overlapping. In addition, an in-focus image is not obtained in both the upper and lower regions.

  When the cutout unit 86 receives the upper cutout signal or the lower cutout signal, the cutout unit 86 cuts out an iris image from the upper region or the lower region of the image data output from the image capture unit 81 in accordance with those signals, for iris authentication. The image data is output to the iris authentication processing unit 87 as image data.

  The iris authentication device 80 includes a guidance guidance unit 84, an iris authentication processing unit 87, an iris database 88, and an authentication result output unit 89, and these configurations are the same as the iris authentication device 60 of the first embodiment. Since there is, explanation is omitted.

  The operation of the iris imaging camera device 5 configured as described above will be described with reference to FIG. First, the image capture unit 81 captures image data from the image processing unit 53 and outputs the image data to the upper focus degree determination unit 821 and the lower focus range determination unit 822 (step S121). Then, the upper focus determination unit 821 and the lower focus determination unit 822 calculate the degree of focus of the upper iris image and the lower iris image in the image data, further perform the focus determination, and calculate the calculated focus. The result of the degree and focus determination is output to the subject distance determination unit 83 (step S122).

  The subject distance determination unit 83 determines the distance to the iris based on the difference in focus between the upper iris image and the lower iris image calculated by the upper focus determination unit 821 and the lower focus determination unit 822 ( Step S123), based on the results of the focus determination by the upper focus determination unit 821 and the lower focus determination unit 822, it is determined whether or not the distance to the iris is within the expanded focus range (Step S124). . If the iris is not within the enlargement focus range (NO in step S124), it is determined whether the distance to the iris is farther from the farthest end of the enlargement focus range or closer to the nearest end of the enlargement focus range. (Step S125).

  When the distance to the iris is closer than the closest end of the enlarged focus range (NO in step S125), the subject distance determination unit 83 outputs a guidance signal away from the guidance guidance unit 84. Then, the guidance guidance unit 84 turns on the distance guidance lamp based on the distance guidance signal, and outputs voice guidance for guiding the person to be imaged away from the iris image acquisition device 50 from the voice output unit. (Step S126).

  When the distance to the iris is far from the farthest end of the enlarged focus range (YES in step S125), subject distance determining unit 83 approaches guide guidance unit 84 and outputs a guide signal. Then, the guidance guidance unit 84 turns on the guidance lamp based on the proximity guidance signal, and outputs a voice guidance for guiding the person to be imaged to approach the iris image acquisition device 50 from the voice output unit. (Step S127).

  Next to step S126 or step S127, it is determined whether a predetermined time limit has elapsed since the start of processing (step S128). If the time limit has not yet elapsed (NO in step S128), the process returns to step S121, and the image data acquired by the iris image acquisition device 50 is captured again. Then, after calculating the degree of focus in step S122 and determining the subject distance in step S123, it is determined in step S124 whether or not the iris is within the enlarged focus range. When the person to be imaged moves according to the guidance in step S126 or step S127, the iris of the person to be imaged falls within the enlarged focus range.

  If it is determined that the iris is within the enlarged focus range (YES in step S124), an authentication process is performed using comprehensive determination unit 85, cutout unit 86, iris authentication processing unit 87, and iris database 88, An authentication result signal is output from the authentication result output unit 89 (step S129), and the process ends. Further, when the time limit has elapsed without being determined that the iris is within the enlarged focusing range (YES in step S128), the authentication process is not performed and the process ends.

  In the above example, the first and second branch optical systems include the first and second lens groups 517 and 518, respectively, and an image formed by both lens groups is projected onto the image sensor 52. However, the present invention is not limited to this. That is, a common lens group is provided in the first and second branching optical systems, the light transmitted through the half mirror 511 is incident on the upper region of the common lens group, the half mirror 511 is reflected, and the mirrors 512 to 512 are reflected. A configuration may be adopted in which the light reflected from 514 is incident on the lower region of the common lens group. If the depth of field of the common lens group is sufficiently wide, the image sensor provided behind the common lens group forms an image in the upper region in the first branch optical path as shown in FIG. The iris image is projected, and the iris image formed in the second branch optical path is projected on the lower region.

  Also with the iris imaging camera device 5 according to the fifth embodiment of the present invention, the first and second focus degree characteristics differ according to the distance to the iris, as in the first embodiment. Since the distance to the subject is determined based on the difference in focus between the iris images captured in each of the imaging modes, the person to be imaged can be guided to an appropriate position based on the determined distance.

  Furthermore, the iris image acquisition apparatus 50 has a focusing range that is shifted from each other on the common optical axis, as in the first embodiment, and the iris that is the subject is in the first and second focusing ranges. If it is located in any of the positions, an in-focus iris image can be obtained. Therefore, an in-focus iris image can be obtained with a simple configuration without an autofocus function in a wide range to the iris.

  In the above description, the example in which the iris image acquisition devices 10 to 50 have the first and second imaging modes has been described. However, the iris image acquisition device has three or more imaging modes. Also good.

  In the above description, the example in which the camera device of the present invention is a camera device that captures an image of a human iris for iris authentication has been described. It may be a general camera device used for a non-limiting purpose.

  Furthermore, in the above description, the focus degree characteristics of the first and second modes are shifted by about the depth of the focus range, and the focus range of the first image capture mode and the focus of the second image capture mode are the same. Although an example in which the ranges are adjacent has been described, the present invention is not limited to this. That is, if the focus degree characteristics according to the distance to the subject are different for each of the plurality of imaging modes, the degrees of focus of the images captured in those imaging modes are different, and the degree of focus is If the difference is used, the distance to the subject can be determined as described above. Therefore, the distance to the subject can be determined even if the focusing range in the first imaging mode and the focusing range in the second imaging mode are not adjacent to each other.

  As described above, the camera device according to the present invention determines the distance to the subject based on the difference in the degree of focus of the subject image captured in each of the plurality of imaging modes having different focus degree characteristics. This has the effect of being able to capture an image with a high degree of focus using the measured distance, and is useful as an iris imaging camera device that images the iris for iris authentication.

1 is a configuration diagram of an iris imaging camera device according to a first embodiment of the present invention. The figure which shows the focusing degree characteristic of the 1st and 2nd imaging mode in the 1st Embodiment of this invention The block diagram of the guidance guidance part in the 1st Embodiment of this invention The flowchart for operation | movement description of the iris imaging camera apparatus in the 1st Embodiment of this invention Configuration diagram of iris imaging camera apparatus in second embodiment of the present invention Configuration diagram of iris imaging camera apparatus in second embodiment of the present invention The block diagram of the iris imaging camera apparatus in the 3rd Embodiment of this invention Flow chart for explaining the operation of the iris imaging camera apparatus in the third embodiment of the present invention The block diagram of the iris imaging camera apparatus in the 4th Embodiment of this invention The block diagram of the iris imaging camera apparatus in the 5th Embodiment of this invention The figure which shows the image data produced | generated with the iris image acquisition apparatus in the 5th Embodiment of this invention Flow chart for explaining the operation of the iris imaging camera apparatus in the fifth embodiment of the present invention

Explanation of symbols

1, 2, 3, 4, 5 Iris imaging camera device 7, 8 Focusing range 9 Enlarged focusing range 10, 20, 30, 40, 50 Iris image acquisition device 60, 70, 80 Iris authentication device 63, 73, 83 Subject distance determination unit 64, 74, 84 Guidance guidance unit 62, 72 Focus determination 641 Display unit 642 Audio output unit 821 Upper focus determination unit 822 Lower focus determination unit

Claims (5)

Image acquisition means for acquiring subject images captured in a plurality of imaging modes having different characteristics of the degree of focus on the subject;
Distance determining means for determining a distance to the subject based on a difference in focus degree of the subject image captured in the plurality of imaging modes;
A camera device comprising: The area where the subject is located has a common optical axis, and has a plurality of branched optical axes branched from the common optical axis, and is different from each other on the common axis for each branched optical path of the plurality of branched optical axes. An imaging optical means having a plurality of focusing ranges;
2. The camera device according to claim 1, wherein the plurality of imaging modes are imaging modes in which a subject image is formed through the plurality of branch optical paths to capture the subject image. An iris image acquisition means for acquiring an iris image captured in a plurality of imaging modes having different characteristics of the degree of focus on the iris;
The iris is included in at least one of a plurality of in-focus ranges corresponding to the in-focus degree characteristics of each of the plurality of imaging modes based on a difference in in-focus degree of the iris images acquired in the plurality of imaging modes. Guiding means for guiding the person to be imaged to enter,
An iris imaging camera device comprising: The plurality of focus ranges are adjacent to each other and are different from each other in front and back.
The guiding means is a first iris image captured in an imaging mode corresponding to a focusing range on the near side from the apparatus, where the iris is not included in any of the plurality of focusing ranges. When the in-focus level is higher than the in-focus level of the second iris image imaged in the imaging mode corresponding to the in-focus range, the user is guided away and the second iris is The iris imaging camera device according to claim 3, wherein when the degree of focus of the image is higher than the degree of focus of the first iris image, guidance is performed to bring the person to be imaged closer. The iris imaging camera device according to claim 3 or 4, wherein the guide means guides the person to be imaged by at least one of display and sound.

Images