JP2007219624A - Blood vessel image input device and personal identification system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce size and cost, and to much more stably acquire detail image by reducing a saturation region in an image. <P>SOLUTION: This blood vessel image input device is provided with an image pickup means having an image reading part for one or more lines and an image formation means for forming the partial image of the finger in the image pickup means, and configured to scan an image pickup region by moving the finger for acquiring a series of partial images, and to acquire the blood vessel image of the whole finger from the series of partial images. This blood vessel image input device is provided with an illumination means where a plurality of light emitting parts for emitting the rays of light to be transmitted through the inside of the finger are arranged in a cross-sectional direction at the side face side of the finger and a means for controlling the light emission quantity and light emission patterns of the plurality of light emitting parts in the illumination means according to the partial image. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a blood vessel image input device that acquires a blood vessel image of a finger and a personal authentication system using the same.

  In particular, the present invention relates to a blood vessel image input in which an image of a finger blood vessel irradiated by illumination means and illuminated by light transmitted through the finger is received by the image sensor by relatively moving the position of the finger and the image sensor. The present invention relates to a device and a personal authentication system using the same.

  In recent years, as economic activities such as electronic commerce spread due to remarkable progress in information technology, the necessity of digitizing personal authentication for the purpose of preventing unauthorized use of information is also increasing. Therefore, as a personal authentication method that does not require a mobile phone like a key, is highly convenient, and is less likely to be illegally exercised due to loss or theft, a living body that uses a part of the body of a person such as a fingerprint, iris, or blood vessel pattern as a key Certification is attracting attention. In particular, the authentication method using a blood vessel pattern has little psychological resistance because it is not associated with criminal investigations like fingerprints or irradiates light directly on eyes like irises, and is easily observed. There is an advantage that it is difficult to forge because of the internal characteristics rather than the surface of the living body.

  Such a blood vessel pattern inside a living body is obtained by illuminating a target site with a near-infrared light source and photographing it with an imaging system such as a camera or an image sensor sensitive to near-infrared light. Hemoglobin in blood absorbs near-infrared light well, so light is absorbed in blood vessels and appears darker than surrounding tissues. The pattern due to the difference in brightness becomes a blood vessel pattern.

  As a blood vessel image input apparatus using a blood vessel pattern, there are an apparatus using a vein image of the back of the hand described in Patent Document 1 and an apparatus using a vein image of the palm described in Patent Document 2. In these blood vessel image input devices, the image sensor is a two-dimensional solid-state image sensor to acquire a large area image such as the back of the hand or the palm, and the imaging object becomes larger than the image acquisition by the imaging optical system. There was a problem that the whole apparatus became quite large.

  A blood vessel image input device for inputting a blood vessel image of a finger of a hand in order to avoid an increase in the size of the imaging device is disclosed in Patent Documents 3, 4 and 5. The finger has a smaller imaging area than the back and palm of the hand, and the imaging device can be made smaller in that respect.

  In the devices described in Patent Documents 3 and 4, a light source unit that illuminates a finger and a camera unit are arranged to face each other, at least one of them is not in contact with the finger, and a two-dimensional image sensor is used in the camera unit. It has been. For this reason, it was not sufficient for the downsizing of the imaging device.

  In view of this, there has been devised a device that places a finger on the device and illuminates it from the side as disclosed in Patent Document 5.

  FIG. 10 is a schematic diagram of an image input device for finger blood vessel images described in Patent Document 5.

In the blood vessel image input device 100, there are a light source unit 104 that illuminates the finger on the left and right of the guide groove 108 on which the finger 102 is placed, and a button switch 118 at a portion that contacts the fingertip. Light from the near-infrared light source 114 on the light shielding plate 116 in the light source unit 104 enters the finger 102 through the light source opening 106. A blood vessel image is photographed by using the light beam that has passed through the inside of the finger by the camera unit 112 through the photographing opening 110.
JP-A-10-295664 JP 2004-062826 A JP 7-21373 A JP 2001-273497 A JP 2004-265269 A

  Although the imaging means in the configuration of FIG. 10 of Patent Document 5 is not particularly specified, it is a two-dimensional solid-state imaging device and corresponds to the length of the finger in order to image from the tip of the finger to the base of the finger. An imaging area is required.

  FIG. 11 is a schematic diagram showing an imaging region of a finger by this two-dimensional solid-state imaging device.

  As can be seen from FIG. 11, the camera unit 112 forms an image on the image sensor 120 as a blood vessel image reflecting the vein pattern VP of the finger 102 with the image sensor 120 composed of a two-dimensional solid-state image sensor and the light transmitted through the inside of the finger. A lens optical system 121 as an imaging optical system. The camera unit 112 needs to be placed apart from the finger in order to secure an imaging area of the entire finger. In general, a two-dimensional solid-state imaging device is required to be as small as possible from the viewpoint of cost, and the reduction ratio of the lens optical system tends to be large, and as a result, the distance between the finger and the solid-state imaging device tends to be large. It is also necessary to increase the lens diameter and wide angle of view.

  Patent Document 5 discloses a folding structure of an optical system using a mirror for miniaturization. However, a two-dimensional solid-state imaging device is used as the solid-state imaging device, and the disclosed optical configuration is not in a direction suitable for folding, and it cannot be said that sufficient optical examination has been added. Although proposals have been made in consideration of downsizing of the apparatus in this way, downsizing with the above configuration is still insufficient.

  Also, an example is disclosed in which light sources are arranged obliquely above and below the finger side surface in order to reduce the feeling of finger pressure during authentication. In particular, when it is arranged below, a problem has been pointed out that a saturated region of the image signal is formed on the side surface of the finger. That is, a region where the light is directly applied to the finger side surface and reflected and the luminance is saturated at the maximum value appears, and a part of the blood vessel pattern is lost (see FIG. 5 described later). In order to solve this problem, the light shielding plate 116 is provided. However, since the light shielding property varies depending on the thickness of the finger, an example in which the inclination of the light shielding plate 116 is automatically adjusted and an example in which the light is reflected by a movable mirror are provided. Presented. However, when these mechanisms are incorporated, there is still a problem that the entire apparatus becomes large and leads to an increase in cost. In addition, a driving method is disclosed in which left and right light sources are alternately turned on to synthesize an unsaturated portion from two images, but this is limited to a two-dimensional solid-state imaging device. .

  The present invention has been made in view of such conventional circumstances, and aims to reduce the size and cost of the apparatus, and to acquire a more stable and fine image with less saturated areas in the image. Objective.

  In order to solve the above problems, a blood vessel image input device of the present invention includes an imaging unit having an image reading unit of one line or more, and an imaging unit that forms an image of a finger on the imaging unit. Is a blood vessel image input device that acquires a series of partial images by scanning the imaging region and acquires a blood vessel image of the entire finger from the series of partial images, and emits light that passes through the inside of the finger Illuminating means in which a plurality of light emitting portions are arranged in a cross-sectional direction on the side surface side of the finger, and means for controlling the light emission amount and the light emission pattern of the plurality of light emitting portions in the illumination means according to the partial image. It is characterized by that.

  According to the present invention, the imaging means is simplified, the blood vessel image of the entire finger is reconstructed from the partial image of the finger using the image processing means, and the saturated region of the blood vessel image is reduced, which is more than that of the conventional apparatus. It is small and can acquire a stable and fine image with a small saturation region in the image. Thereby, a blood vessel image input device with an improved authentication rate and a personal authentication system using them can be provided at low cost.

  Hereinafter, embodiments of a blood vessel image input apparatus according to the present invention will be described with reference to the drawings.

[First Embodiment]
(Device configuration)
1 is a side view of a blood vessel image input apparatus according to a first embodiment of the present invention, FIG. 2 is a perspective view of a basic part of the blood vessel image input apparatus, and FIG. 3 is a light source of the blood vessel image input apparatus. It is sectional drawing which shows arrangement | positioning.

  The finger 1 is scanned along the guide plate 2, that is, moved in a certain direction (horizontal direction indicated by an arrow P in the figure) to scan the imaging region. A subcutaneous vein pattern VP (blood vessel image) existing mainly in a portion including the first joint and the second joint of the finger 1 is photographed through an imaging optical system. A visible light cut filter 3 is installed in the slit-shaped image capturing portion of the guide plate 2.

  As an imaging optical system that is an imaging means, a gradient index lens array 6 is disposed via a reflecting mirror 5. As a result, the imaging optical system can be arranged in the scanning direction of the finger 1, so that the apparatus can be greatly downsized. However, since the subcutaneous veins are distributed three-dimensionally, the depth of field of the imaging optical system is selected as deep as possible. Further, when using the reflecting mirror 5 and a bending optical system, the size can be reduced even by using a short focus lens. The body image pickup device 7 which is an image pickup unit having an image reading unit arranged in the image forming portion preferably takes a strip shape in consideration of the scanning range and image pickup range of the finger 1 and the arrangement of the optical system. In the present embodiment, a strip-shaped one consisting of one line or more than one line is used. As a result, the overall size of the apparatus can be made very small.

  The finger 1 is scanned while illuminating the finger 1 with the light source 4 that is an illumination means arranged on the side surface of the finger 1 to acquire a partial image (image for each frame) of a series of finger vein images. The entire vein image is reconstructed using the acquired series of partial images. A vein pattern is extracted from this, and authentication is performed using a feature point extraction algorithm or the like.

  The light source arrangement, which is a feature of the present invention, will be described with reference to FIG. As the near-infrared light, generally 700 to 1000 nm which is not easily absorbed by living bodies other than blood vessels and easily obtains blood vessel contrast is used. In this embodiment, the light source 4 using a wavelength of 950 nm is disposed on the side surface of the finger 1. As the light source 4, LEDs (light emitting diodes) are arranged in three stages in the cross-sectional direction of the finger 1, that is, in a substantially vertical direction.

  In order to visualize the vein pattern inside the finger with sufficient contrast using infrared light, sufficient scattered light within the finger is required. These serve as background light, and an optical signal of a vein image can be obtained by illuminating the vein.

  For this reason, there is a configuration in which a powerful light source is arranged on the back surface of the finger (opposite side of the solid-state imaging device) as described in the related art. In this arrangement, the user often feels pressure on the finger. Furthermore, since the veins used for authentication are near the surface of the finger, when they are illuminated from the back, it is necessary to transmit the entire thickness of the finger 1. When performing backside illumination in the form of using a two-dimensional solid-state imaging device, a configuration such as arranging a large number of LEDs is necessary in order to secure the light amount of the light source. On the other hand, in the configuration in which the light source is arranged on the side surface by the method of scanning the finger, it is only necessary to provide the light source in the vicinity of the slit-shaped image capturing portion, so that it can be a further open type. Even if a finger is placed at the time of authentication, there is little feeling of pressure. The number of LEDs can be reduced, and the optical path length from the side surface to the vein pattern is shorter than that from the back surface, so that the total light quantity can be reduced.

  This reduces the LED drive current, thus extending the life of the LED and simplifying the power supply. By these, further downsizing and cost reduction of the entire apparatus can be realized. These LEDs are controlled by a light source control circuit (not shown). If the solid-state image sensor is a CMOS-type solid-state image sensor using the CMOS process, the LED control circuit can be easily formed on the same substrate as the solid-state image sensor. Not give.

  Near-infrared light from the LED is irradiated onto the side surface of the finger 1, and the veins inside the finger are illuminated by the near-infrared light scattered and transmitted through the inside of the finger. An arrow Q indicates scattered and transmitted light in the finger. The transmitted near-infrared light including the vein image that has come out from the finger enters the imaging optical system via the visible light cut filter. At this time, scattered light from the finger surface is prevented from entering the imaging optical system as much as possible.

(Image acquisition and lighting means control method)
Next, an image acquisition method based on the light source arrangement and the light source lighting control of the present invention will be described.

  4 is a schematic diagram for explaining an image reading method when there is no finger floating, FIG. 5 is a schematic diagram for explaining an image reading method when there is a finger floating, and FIG. 6 is a drawing according to the present invention. It is the schematic explaining the image reading method in the case.

  In FIG. 4, this is a normal case where the finger 1 does not float when the finger 1 is scanned. At this time, the finger 1 is scanned in contact with the guide plate 3. To increase the amount of transmitted light, increase the amount of light emitted from all LEDs as much as possible.

  FIG. 4A is a schematic diagram showing the cross-sectional direction of the finger, and FIG. 4B is a schematic diagram of a finger image after scanning the finger (entire image reconstructed by a reconstruction method described later).

  The light source 4 on the side surface of the finger irradiates obliquely above the finger 1, and light enters the finger from here. This light is scattered within the finger and illuminates a vein near the finger surface. Intra-finger scattered light including a vein image exits from the finger 1, enters the imaging optical system through the visible light cut filter 3, and is detected by the solid-state imaging device 7. Scattered and reflected light generated in the vicinity of the light incident point at an obliquely upper part of the finger 1 shows particularly strong scattering in the surface structure of the finger 1. Nearly 40% of the light scattered at this portion is reflected as reflected light to the outside through the surface, and the rest is transmitted through the finger as scattered light within the finger. Since this scattered reflected light does not enter the imaging optical system, it does not affect the vein image.

  Next, FIG. 5 shows a case where the finger floats during finger scanning.

  FIG. 5A is a schematic diagram showing a cross-sectional direction, and FIG. 5B is a schematic diagram of a finger image after scanning a finger (entire image reconstructed by a reconstruction method described later).

  For the sake of simplicity, description will be made assuming that a certain amount of floating occurs during scanning. In this case, if the LED is turned on in the same manner as in the normal case of FIG. 4, light enters the lower side of the floating finger, and a part of the scattered reflected light generated in this portion is connected via a visible light cut filter. Incident on the image optical system. As a result, a saturated region due to scattered reflected light is generated in the entire image reconstructed as shown in FIG. The scattered reflected light has a large spectral amount without attenuation in the finger compared to the scattered light in the finger, and when it enters a solid-state image sensor that matches the intensity of the scattered light in the finger, it easily saturates, and the vein image of this part is Unusable.

  Therefore, in the present invention, the plurality of light sources are individually controlled in the finger cross-sectional direction, that is, the floating direction to suppress saturation.

  FIG. 6 is a schematic diagram for explaining an image reading method when there is a float according to the present invention.

  When the finger 1 floats, the case where the saturation region is reduced by controlling the light source 4 is shown. Here, for the sake of simplicity, description will be made assuming that a certain amount of floating occurs during scanning. FIG. 6A is a schematic diagram showing a cross-sectional direction, and FIG. 6B is a schematic diagram of a finger image after scanning a finger (entire image reconstructed by a reconstruction method described later).

  When the finger 1 floats, the scattered reflected light from the lower LED of the light source 4 becomes a problem, so this light amount is reduced or turned off. In order to secure the overall light amount, the upper light amount is increased. Scattered and reflected light from the upper LED does not enter the solid-state imaging device 7, so that even if the amount of light is increased, there is no problem. As a result, as shown in FIG. 6B, the saturated region due to the scattered reflected light is sufficiently reduced, and the vein image is not adversely affected. If the finger float is even larger, the scattered reflected light from the middle stage LED also becomes a problem, so this light amount is reduced and the same adjustment is performed. In the above description, the case where the finger float is constant during scanning has been described. However, since the actual float amount changes during the finger scan, the light emission amount and light emission pattern of the plurality of LEDs installed in the finger cross-sectional direction described above. Is adjusted for each frame. For this purpose, it is necessary to grasp the floating amount for each frame and control the light emission amount and light emission pattern of the LED by feedback in real time based on the result.

  The solid-state imaging device performs photoelectric conversion, and the luminance in each pixel is proportional to the photoelectrically converted output. As a feedback method, in this embodiment, the output average value of the solid-state imaging device for each frame is monitored, and when the value exceeds a certain threshold, it is determined that a saturated region has occurred, and the next frame is determined according to the amount. The LED light emission amount and light emission pattern are controlled by the above method. The relationship between the output average value and the saturation region is obtained in advance, and the threshold value is calculated from the result. As a result, the floating of the finger can be detected in advance, and the light emission amount and light emission pattern of the LED can be optimized for each frame.Therefore, even if the floating occurs, the saturated area does not spread over the image, and the vein image is adversely affected. I don't give it.

  These output average values are monitored and thresholds are determined by a microcomputer on an external substrate connected to the solid-state image sensor 7. The resulting control signal is sent to the LED control circuit on the solid-state image sensor 7 to adjust the light emission amount and light emission pattern of the LED. In the present embodiment, the floating is detected using the output average value of each frame, but more precise control can be performed by monitoring the output distribution in the longitudinal direction of the frame image instead of the simple average value. In other words, the saturation starts from the end portion in the longitudinal direction, and from the distribution, it can be determined how much the floating has progressed.

(Image reconstruction method)
FIG. 7 is a diagram showing a partial image of a vein image acquired by the blood vessel image input apparatus and a method for realizing reconstruction of the entire image using the partial image.

  FIG. 7A shows a partial image of a series of vein images. Here, fingerprints and wrinkles are shown together with the vein image, but these can be shown by changing the illumination condition of the light source, for example, the irradiation angle to the finger 1. FIG. 7B shows an entire vein image reconstructed from the partial image of FIG. 7A by using the overlap information of the partial images. FIG.7 (c) shows the result of having taken out only the vein pattern from FIG.7 (b).

  When the image reading is started, the strip-shaped solid-state imaging device 7 having a plurality of lines is used for scanning at a certain period (constant frame rate) while scanning a finger. As shown in FIG. A strip-shaped partial image is obtained. The predetermined period is determined so that the solid-state imaging device 7 can capture a finger range including a part of the previously captured finger range every time even when the finger is scanned at the maximum expected scanning speed. .

  Next, a vein image of a desired finger region is reconstructed from these partial images of the vein. Since each of these partial images has an overlapping portion with an adjacent partial image, processing for matching the images based on the relative position information of the overlapping portion is performed by a processing circuit (not shown), as shown in FIG. 7B. The entire image can be reconstructed. A vein pattern used for authentication is extracted by removing unnecessary surface images such as wrinkles and fingerprints from the reconstructed whole image.

  In the present embodiment, the LED row has a configuration in which the LED rows are arranged in three stages, one on each side of the finger. However, in order to increase the light amount or to realize a finer light amount distribution pattern, two or more LED rows are arranged. May be placed on the side of the finger.

  Further, as described in the third embodiment, authentication can be performed by using separately extracted fingerprints and wrinkle images, and authentication accuracy can be improved together with vein authentication. In the vein pattern and the fingerprint / wrinkle pattern, the former Fourier-transformed spatial frequency component is distributed on the low frequency side and the latter is distributed on the high frequency side, so that both can be separated.

[Second Embodiment]
The basic configuration of the blood vessel image reading apparatus is the same as that of the first embodiment. In the present embodiment, the light emission amount and the light emission pattern of the LED of the light source 4 are changed at regular intervals for each frame, regardless of actual floating. For example, when a partial image is acquired at a reading speed such that three or more images have the same overlap, the light emission amount and the light emission pattern of the LED are changed in a cycle of three frames. Since the three frames always have an overlapping portion, it is possible to extract a partial image of at least one frame having no saturation region, that is, having no adverse effect, and use this frame as a representative partial image used for reconstruction. The other two frames can be discarded. Typical emission amounts and emission patterns include the following.

(I) Pattern to increase the amount of light emitted from all LEDs as much as possible (ii) Pattern to lower or turn off the light emitted from the lower LED, and increase the amount of light in the middle and upper (iii) Light emitted from the lower and middle LEDs The pattern (i) corresponds to the light emission pattern when there is no float, and the light emission when the float increases according to patterns (ii) and (iii) It becomes a pattern. Patterns (i), (ii), and (iii) are repeated every three frames to obtain partial images. Even if floating occurs during finger scanning, for example, the partial image acquired by the pattern (ii) is a partial image with no or reduced saturation region. Therefore, this partial image may be employed as a representative, and other partial images may be selected in the same manner, and the entire image may be reconstructed using the selected partial images.

  In the present embodiment, the amount of floating is monitored in real time, and control is not performed to feed back to the light emission amount and light emission pattern of the LED. It is not necessary to detect in real time whether or not floating has occurred, and it is possible to obtain a partial image with no saturation region or with reduced saturation only by controlling the light emission amount and light emission pattern of the LED. Although some data is wasted, it is not necessary to synthesize a partial image from which a saturated region is removed, and only the optimum partial image is extracted, so that the control of the entire apparatus is simplified. Regardless of the three-frame period, the LED emission amount and emission pattern are controlled in multiple frame periods, and the optimum partial image with a reduced saturation region is extracted from the obtained partial image as a representative, and the entire image is reconstructed. Just do it.

[Third Embodiment]
Next, an embodiment of a personal authentication system using the blood vessel image input device will be described.

  FIG. 8 is a block diagram of a personal authentication device that constitutes a third embodiment of the present invention, and FIG. 9 is a block diagram of a blood vessel image input device that constitutes the embodiment.

  The personal authentication system shown in FIG. 8 includes a blood vessel image input device 200 having an imaging unit 201 composed of the solid-state imaging device 7 described above, a peripheral circuit unit 202 thereof, and an LED 203 mounted on an LED chip, and the blood vessel image input device. 200 is connected to the blood vessel image matching device 300.

  The solid-state image sensor 7 is a CMOS solid-state image sensor using a CMOS process. By using the CMOS process, the imaging unit and the peripheral circuit (logic unit or the like) can be easily formed on the same substrate. Also in this embodiment, the peripheral circuit unit 202 is formed on the same substrate as the solid-state imaging device 7. As shown in FIG. 9, the peripheral circuit unit 202 includes a control circuit (drive circuit) 1021, a clamp circuit 1022, an A / D converter 1023, a communication control circuit 1024, a register 1025, an LED control circuit 1026, Timing generator 1028.

  The control circuit 1021 controls the operation of the imaging unit 201. The A / D converter 1023 converts an analog imaging signal corresponding to an image related to a finger blood vessel image output from the imaging unit 201 from an analog signal to a digital signal via the clamp circuit 1022. The communication control circuit 1024 to which the register 1025 is connected is for data communication of the digital signal converted by the A / D converter 1023 as an image signal of a blood vessel image to an external device (interface or the like). The LED control circuit 1026 controls the light emission of the LED 203. The timing generator 1028 generates a control pulse for controlling the operation timing of the circuits 1021 to 1026 based on the reference pulse supplied from the external oscillator 1027.

  The circuit including the peripheral circuit unit 202 is not limited to the above, and may include other types of circuits. On the other hand, a part of the circuit may be a separate chip (not shown).

  The blood vessel image matching device 300 includes an input interface 211, an image processing unit 212 that is a blood vessel image matching unit, a blood vessel image database 213 that is a blood vessel image registration unit, and an output interface 214.

  The input interface 211 receives communication data output from the communication control unit of the peripheral circuit unit 202, and the image processing unit 212 is connected to the input interface 211. A blood vessel image database 213 and an output interface 214 are connected to the image processing unit 212. The output interface 214 is connected to an electronic device (including software) that requires personal authentication in order to ensure security during use or login.

  Here, in the blood vessel image database 213, blood vessel images of the finger of the subject to be personally authenticated are registered in advance. The target person here may be one person or multiple persons.

  The target person's blood vessel image is input in advance from the blood vessel image input device 200 via the input interface 211 at the time of initial setting or when the target person is added as personal authentication information of the target person.

  The blood vessel image read by the blood vessel image input device 200 is input to the image processing unit 212 via the input interface 211. The image processing unit 212 collates whether or not it matches the registered image in the blood vessel image database 213 based on a known blood vessel image matching image processing algorithm, and outputs a matching result of matching or mismatching of the blood vessel images as a personal authentication signal. Output via the interface 214.

  In this example, the blood vessel image input device 200 and the blood vessel image matching device 300 are configured as separate devices. However, the present invention is not limited to this, and at least a part of the functions of the blood vessel image matching device 300 is performed as necessary. The peripheral circuit unit 202 of the blood vessel image input apparatus 200 may be integrated. In addition, the personal authentication system of this example may be configured integrally with an electronic device that requires personal authentication, or may be configured separately from the electronic device.

  In the personal authentication system using the blood vessel image input device according to the first and second embodiments, a fingerprint image can be acquired at the same time. Therefore, personal authentication can be performed using both the fingerprint image and the blood vessel image. For example, security can be improved when the blood vessel image matches the registered blood vessel image and when the fingerprint image matches the registered fingerprint image. When the authentication rate is low only by the image authentication of the blood vessel image or the fingerprint image, it is possible to acquire both images, perform authentication that one of the images matches, and lower the authentication error rate. In this case, the blood vessel image input device 200 and the blood vessel image collation device 300 are devices for both the fingerprint image and the blood vessel image.

1 is a side view of a blood vessel image input device according to a first embodiment of the present invention. The perspective view about the basic part of the blood vessel image input device Sectional drawing which shows arrangement | positioning of the light source of the blood vessel image input device Schematic explaining the image reading method when there is no finger lift Schematic explaining the image reading method when there is a finger lift Schematic explaining an image reading method when there is a float according to the present invention The figure which shows the whole image reconstruction method from a partial image The block diagram of the personal authentication apparatus which comprises the 3rd Embodiment by this invention Block diagram of a blood vessel image input device constituting the embodiment Schematic diagram of conventional finger blood vessel image input device Schematic diagram showing the imaging region of the finger by the conventional two-dimensional solid-state imaging device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Finger 2 ... Guide board 3 ... Visible light cut filter 4 ... Light source 5 ... Reflector 6 ... Refractive index distribution type lens array 7 ... Solid-state image sensor

Claims (11)

  An imaging unit having an image reading unit of one line or more and an imaging unit that forms an image of a partial finger image on the imaging unit. The imaging region is scanned by moving the finger, and the series of partial images is obtained. A blood vessel image input device that acquires and acquires a blood vessel image of an entire finger from a series of the partial images, emits light that passes through the inside of the finger, and has a plurality of light emitting units arranged in a cross-sectional direction on the side of the finger A blood vessel image input device comprising: an illuminating unit configured to control a light emission amount and a light emission pattern of the plurality of light emitting units according to the partial image.   In the means for controlling the light emission amount and the light emission pattern of the plurality of light emitting units according to the partial image in the illuminating means, the light emission amount and the light emission pattern of the plurality of light emitting units are feedback controlled by the output for each partial image. The blood vessel image input device according to claim 1.   The blood vessel image input device according to claim 2, wherein the output for each partial image is obtained by monitoring an average value of the outputs of the partial images.   The blood vessel image input apparatus according to claim 2, wherein the output for each partial image is obtained by monitoring an output distribution in a longitudinal direction of the partial image.   In the means for controlling the light emission amount and the light emission pattern of the plurality of light emitting units according to the partial image in the illumination unit, the light emission amount and the light emission pattern of the plurality of light emitting units are periodically changed for each partial image, and a blood vessel image The blood vessel image input device according to claim 1, wherein a partial image having a small saturated region is employed.   The blood vessel image input device according to claim 1, wherein the illuminating unit is disposed on the left and right side surfaces of the finger.   The blood vessel image input device according to claim 1, wherein the plurality of light emitting units in the illuminating unit are arranged in a plurality of rows in a cross-sectional direction of the finger.   The blood vessel image input device according to claim 1, wherein the image processing unit further acquires a surface image of the entire finger.   Illuminating means that emits light that passes through the inside of the finger and has a plurality of light emitting units arranged in a cross-sectional direction on the side surface of the finger, imaging means having an image reading unit of one line or more, and a partial image of the finger An imaging unit that forms an image on the imaging unit, scans the imaging region by moving the finger, acquires a series of partial images, and obtains a blood vessel image of the entire finger from the relative position information of the series of partial images. A blood vessel image input method to be obtained, further comprising controlling the light emission amount and the light emission pattern of the plurality of light emitting units of the illumination unit according to the partial image.   A blood vessel image registration unit that pre-registers a blood vessel image of the entire finger read by the blood vessel image input device according to claim 1 as identification information of a subject, and a blood vessel of the entire finger read by the blood vessel image input device A personal authentication system comprising: a blood vessel image collating unit that collates whether or not an image matches a registered image of the blood vessel image registration unit and outputs the collation result as a personal authentication signal.   9. An image registration means for previously registering the blood vessel image and the surface image of the whole finger read by the blood vessel image input device according to claim 8 as identification information of a subject, and the whole finger read by the blood vessel image input device A personal authentication system, comprising: an image collating unit that collates whether or not a blood vessel image and a surface image of the image coincide with a registered image of the image registration unit and outputs the collation result as a personal authentication signal .

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