WO2017047091A1

WO2017047091A1 - Fingerprint reading device

Info

Publication number: WO2017047091A1
Application number: PCT/JP2016/004228
Authority: WO
Inventors: 輝幸樋口; 芳紀幸田
Original assignee: 日本電気株式会社
Priority date: 2015-09-18
Filing date: 2016-09-16
Publication date: 2017-03-23

Abstract

Provided is a fingerprint reading device that does not degrade the image quality of a fingerprint. The fingerprint reading device is provided with: a placement unit, on which a finger is placed; a pair of light sources that are provided to the placement unit and are arranged substantially on the same plane as the placement unit, so as to shine light on the finger touching a placement surface of the placement unit; and an imaging unit that is provided to the placement unit and captures an image of the fingerprint of the finger via the light that is scattered inside the finger and emitted from the surface of the finger. Relative to the placement surface, the pair of light sources are inclined toward the inner side of the placement surface.

Description

Fingerprint reader

The present invention relates to a fingerprint reader.

In this technical field, a fingerprint input device is known in which light from a light source is inserted into a finger, and a fingerprint image is formed using light that is scattered within the finger and then comes out of the finger surface again. ing. For example, Patent Document 1 discloses a fingerprint input device having a fiber optic plate having a finger contact surface and a light source that generates near-infrared light. This near-infrared light source is disposed in the lower left of the fiber optic plate at four locations on the left and right sides of the finger in addition to the vicinity of the first joint.

Patent Document 2 discloses a biometric authentication device that authenticates an individual using a blood vessel pattern of a hand or a finger. The biometric authentication device includes a housing for inserting a finger, LED arrays disposed on the inner side surface and the inner top surface of the housing, and a CCD image sensor disposed on the inner side surface and the inner bottom of the housing. Yes. Further, Patent Document 2 discloses a configuration in which two mirrors are arranged within an angle of view that can be photographed by a CCD image sensor so that a transmitted light image from three directions is photographed by one CCD image sensor. Yes.

Patent Document 3 discloses an authentication device for identifying an individual using a finger vein pattern. This authentication device has a light source that irradiates infrared light from the back side of the finger and an imaging device that converts light transmitted through the finger into an electrical signal. Furthermore, patent document 3 is disclosing the authentication apparatus which has a light source located in the side surface side of a finger | toe.

Patent Document 4 discloses a biometric authentication device having a tip placement unit for placing the tip of the finger belly, a root placement unit for placing the base of the finger belly, a spot light generation light source, and an imaging unit. . The tip placement part has a sensor for detecting the placement position of the finger. Then, the detection unit receives the output of the sensor, detects where the finger is placed, and teaches that the finger is correctly placed if it is the correct placement position. On the other hand, if the finger is not correctly arranged, the detection unit teaches that the finger is displaced.

Patent Document 5 discloses a mouse that is connected to a computer body and on which an IC card for fingerprint verification is mounted. The main body of the mouse is provided with a cover member that is rotated so as to open the opening. In addition, the IC card has a fingerprint detection unit to which the user's fingertip is pressed. The fingerprint detection unit has an imaging unit and a backlight that irradiates the pressure contact part of the fingertip.

Patent Document 6 discloses a finger imaging apparatus including a transparent plate on which a target finger is placed in order to obtain a fingerprint image, and a guide integrally formed at the front end of the apparatus. Furthermore, Patent Document 6 discloses a configuration in which a finger is pressed against a transparent plate by a deformed bag when the target finger is completely inserted.

Patent Document 7 discloses a biometric authentication device including a U-shaped finger channel and a coil spring attached so as to normally bias the finger channel.

Japanese Patent No. 3751872 International Publication No. 2009/019809 JP 2005-071118 A Japanese Patent No. 5598687 JP 2004-070831 A US Patent Application Publication No. 2004/0101171 International Publication No. 98/044447

In the devices disclosed in Patent Documents 1 to 7 described above, there is a problem that the image quality of the fingerprint is deteriorated depending on the emission direction of the light emitted from the side light source. An object of the present invention is to provide a fingerprint reading apparatus that solves the above-described problem that the image quality of a fingerprint is deteriorated depending on the emission direction of light emitted from a side light source.

In order to solve the above-described problem, a fingerprint reading apparatus as an example of the present invention includes a placement unit on which a finger is placed, and a finger that is provided on the placement unit and contacts the placement surface of the placement unit. By a pair of light sources arranged on substantially the same plane as the placement surface described above, and the light provided in the placement portion, scattered inside the finger and emitted from the surface of the finger An imaging unit that captures a fingerprint of the finger, and the pair of light sources are inclined toward the inside of the placement surface with respect to the placement surface.

This provides a fingerprint reader that does not degrade the image quality of fingerprints.

Further features of the present invention will become apparent from the following description of embodiments, given by way of example with reference to the accompanying drawings.

It is the schematic explaining the usage condition of a fingerprint reader. 1 is a schematic surface view of a fingerprint reading apparatus according to a first embodiment of the present invention. It is a schematic side view along the longitudinal direction of a fingerprint reader. It is a schematic sectional drawing along the longitudinal direction of the center of a fingerprint reader. It is explanatory drawing which shows the light radiate | emitted from a light source. It is explanatory drawing which shows the light radiate | emitted from a light source. It is a schematic back view of a fingerprint reader. It is a schematic surface drawing which shows the light source which concerns on another example. It is a schematic side view which shows the light source which concerns on another example. It is a schematic side view which shows the light source which concerns on another example. It is a schematic perspective view of the fingerprint reader which concerns on 2nd Embodiment of this invention. It is a schematic perspective view which shows the finger guide which concerns on another example. It is a schematic perspective view of the finger guide which concerns on 3rd Embodiment of this invention. It is a schematic perspective view of the finger guide which concerns on 3rd Embodiment. It is a schematic side view along the longitudinal direction of the fingerprint reader which concerns on 4th Embodiment.

Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, dimensions, materials, shapes, relative positions of components, and the like described in the following embodiments are arbitrary and can be changed according to the configuration of the apparatus to which the present invention is applied or various conditions. In addition, unless otherwise specified, the scope of the present invention is not limited to the embodiments specifically described below.

[First Embodiment]
FIG. 1 shows a usage mode of the fingerprint reading apparatus 100 according to the first embodiment. The fingerprint reading device 100 shown in FIG. 1 may be used by being inserted between the fingers of a child to be read by a fingerprint. This is because children, especially newborn babies and infants, may sleep while holding their fists, and read fingerprints without waking the sleeping child. A user who is an assistant for fingerprint reading grips the grip portion 1 of the fingerprint reader 100 and inserts the placement portion 2 into a gap between the child's thumb and forefinger, for example. Alternatively, the user places the finger on the placement unit 2 so that the child's finger contacts the placement surface of the placement unit 2.

Therefore, the fingerprint reading device 100 has a placement surface, a placement portion 2 on which a finger to be read is placed, and a grip portion 1 that extends from the placement portion and is gripped by a user during use. It has. The fingerprint reader 100 is connected to a computer by wire or wirelessly. When the user presses the reading switch 11 (illustrated with a dotted line), reading of a fingerprint is started, and a pair of light sources irradiate the finger with light. And the imaging part of the mounting part 2 images the light radiate | emitted from the surface of the finger | toe, and the fingerprint reader 100 transmits the data of the read fingerprint to a computer.

The computer displays a fingerprint image based on the fingerprint data received from the fingerprint reader 100 on a display connected to the computer. Thereafter, the user presses the reading switch 11 of the fingerprint reading device 100 at a timing when an appropriate fingerprint is displayed on the display. As a result, the computer stores the image data of the fingerprint displayed on the display. This fingerprint reading is preferably performed a total of six times for the thumb and index finger of both hands and the thumb of both feet. However, if it is difficult to read fingerprints, at least two readings may be performed on the thumbs of both hands.

Subsequently, the fingerprint reading apparatus 100 will be described with reference to FIGS. FIG. 2 shows the surface of the fingerprint reading device 100 and corresponds to the placement surface 21 side of the placement unit 2. 3 shows a side surface along the longitudinal direction of the fingerprint reader 100, and FIG. 4 shows a cross section taken along the line IV-IV in FIG. 5 corresponds to a cross section along a direction orthogonal to the longitudinal direction of the placement portion 2, and shows a state where the finger placed on the placement surface 21 is viewed from the front end side. FIG. 6 shows the back surface of the fingerprint reader 100. In addition, a back surface means the surface on the opposite side of the mounting surface 21, when the mounting surface 21 side is made into the surface. The fingerprint reader 100 has a symmetrical shape. Therefore, in description of the side surface along a longitudinal direction, only one side surface is demonstrated. However, the fingerprint reading apparatus 100 has substantially the same configuration on the other side surface where the description is omitted.

The fingerprint reader 100 includes a placement unit 2 on which a finger is placed. And the mounting part 2 is a pair of light sources arrange | positioned on the substantially same surface as the mounting surface 21 so that light may be irradiated to the mounting surface 21 which a finger contacts, and the finger which contacts the mounting surface 21 As shown, two side light sources 22 are provided. In FIG. 2, the side light source 22 is a linear light source that is disposed across the placement surface 21 and extends along a pair of opposite sides of the placement surface 21. Specifically, the linear light source is a plurality of

light sources

22a, 22b, 22c, and 22d arranged side by side along a pair of sides, for example, four near infrared LEDs (Light Emitting Diodes) along each of the pair of sides. )have. This linear light source is formed by wrapping a plurality of

light sources

22a, 22b, 22c, and 22d with a translucent plastic material. The plurality of

light sources

22a, 22b, 22c, and 22d irradiate near infrared light having a wavelength of, for example, 820 to 980 nm from both sides of the finger pressed against the placement surface 21 to both sides of the finger.

The side light source 22 is provided along a pair of sides extending in the longitudinal direction of the mounting surface 21. When a child places his / her finger on the placement unit 2, the finger may be placed near the end of the placement surface 21 (near the tip 31 of the fingerprint reading device 100). In other words, the finger may come into contact with the vicinity of the end on the side where the placement surface 21 is inserted with respect to the finger. Therefore, when the light source is arranged at a position facing the tip of the finger (the center side of the fingerprint reading apparatus 100), it is difficult to make a sufficient amount of light incident on the finger because the distance from the light source to the finger is long. Therefore, if the side light source 22 is provided along a pair of sides extending in the longitudinal direction, a sufficient amount of light can be incident on the child's finger. Note that the side light source 22 may be provided along a pair of sides extending in a direction orthogonal to the longitudinal direction of the placement surface 21 as long as a finger can be placed at the center of the placement surface 21. Further, the light source may be provided along the four sides so as to surround the rectangular mounting surface 21.

Further, the fingerprint reading apparatus 100 includes a grip unit 1 that functions as a user's handle when reading a fingerprint. And the holding part 1 is integrally formed with the mounting part 2 so that it may extend from the mounting part 2. FIG. Further, the grasping unit 1 is provided with a reading switch 11 (illustrated by a dotted line) that is operated by a user when starting to read a fingerprint. In addition, the grip unit 1 is provided with a power lamp 12, and light from the power lamp 12 passes through the casing of the fingerprint reader 100. Thereby, the user can visually recognize the power ON or the power OFF from the outside. The power lamp 12 is, for example, a green LED. Further, the power lamp 12 may be turned on during image reading. Further, the power lamp 12 may be turned on when the user starts reading a fingerprint with the reading switch 11. The color with which the power lamp 12 is lit can be different for each function.

As shown in FIG. 3, the grip portion 1 and the placement portion 2 are integrally formed with a resin casing 3. The holding unit 1 is provided with a reading switch 11, and the reading switch 11 is embedded so as to be flush with the back surface of the holding unit 1. Thereby, it is possible to prevent the user from erroneously pressing the reading switch 11 when gripping the grip portion 1. In FIG. 3, the reading switch 11 that cannot be seen from the side is shown by a dotted line for convenience. The housing 3 may be formed of metal, and the metal housing 3 can dissipate heat more efficiently than the resin housing 3.

The grip portion 1 and the placement portion 2 are formed so that their back surfaces are flush with each other. Therefore, when the user inserts the placement unit 2 between the fingers, the back surface of the housing 3 can be prevented from being caught by the fingers. On the other hand, on the surface side of the fingerprint reading device 100, the portion of the placement unit 2 where the side light source 22 is provided is thicker than the grip unit 1. That is, the side light source 22 protrudes from the surface of the grip portion 1. And as shown in FIG. 4, the side light source 22 protrudes also from the protective glass 23 which comprises the mounting surface 21 of the mounting part 2. As shown in FIG. On the back side of the protective glass 23, for example, a CMOS image sensor is arranged as the imaging unit 25.

Thus, at least the top of the side light source 22 protrudes from the mounting surface 21. Thereby, the light emission part of the side light source 22 can be brought closer to the back side of the finger, and a larger amount of light can be irradiated to the finger, so that deterioration in image quality can be prevented. In addition, the part below the light emission part of the side light source 22 is located in the side of the protective glass 23 or the imaging part 25 substantially.

The imaging unit 25 images a fingerprint by light scattered inside the finger and emitted from the surface of the finger. As indicated by arrows in FIG. 5B, the near-infrared light emitted from the side light source 22 is incident on the finger in contact with the protective glass 23, scattered therein, and emitted from the surface of the finger. The imaging unit 25 images near-infrared light that enters through the protective glass 23. However, in the fingerprint reading apparatus 100 shown in FIG. 5A, the side light source 22 is arranged with reference to the size of an adult finger illustrated by a dotted line. For this reason, when reading the fingerprint of a child's finger illustrated by a solid line, there is a possibility that a sufficient amount of light from the side light source 22 does not enter the finger. That is, since the finger of a child is thinner and thinner than the finger of an adult, when the side light source 22 emits light upward, a sufficient amount of light is not applied to the finger. This degrades the image quality of the fingerprint.

Furthermore, since the side light source 22 is arranged on the side of the finger, the light amount is lower at the center of the placement surface 21 far from the side light source 22 than at both sides of the placement surface 21. As a result, contrast is uneven between the central portion and both side portions of the fingerprint, and the image quality of the fingerprint is degraded. Therefore, in the first embodiment, the side light source 22 of the placement unit 2 is disposed on substantially the same plane as the placement surface 21 and is mounted on the placement surface 21 as shown in FIG. 5B. It is inclined toward the inside of the placement surface 21. In other words, the side light source 22 is arranged in a posture inclined with respect to the placement surface 21 toward the center in the placement surface 21 so as to emit light toward the back side of the finger. Thereby, since a sufficient amount of light can be irradiated to the child's finger, deterioration of the image quality can be prevented. Furthermore, since the amount of light scattered at the central portion of the finger increases, unevenness in contrast can be reduced and deterioration in image quality due to unevenness in contrast can be prevented. Note that the side light source 22 can be tilted so that the angle of the optical axis with respect to the placement surface 21 falls within a range, for example, greater than 0 degrees and less than 90 degrees.

At the contact portion where the finger is in contact with the protective glass 23, light is not emitted into the air, so light loss at the interface between the finger and the air layer is reduced. As a result, the contact portion is displayed brightly in the captured fingerprint image. On the other hand, in the non-contact portion where the finger is not in contact with the protective glass 23, light is emitted into the air, so that light loss occurs at the interface between the finger and the air layer. As a result, in the captured fingerprint image, the non-contact part is displayed darker than the contact part. Thereby, a fingerprint is shown as an image pattern of a dark part and a bright part. That is, the bright contact portion corresponds to the ridge line of the fingerprint, and the dark non-contact portion corresponds to the valley portion of the fingerprint.

Furthermore, the side light source 22 is inclined in a range where the emitted light does not directly enter the mounting surface 21. That is, as shown in FIG. 5B, the side light source 22 is arranged such that the placement surface 21 (protective glass 23) is not located within the range of the irradiation angle. Accordingly, it is possible to prevent the light emitted from the side light source 22 from directly entering the imaging unit 25 and causing unevenness in contrast. Instead of adjusting the inclination angle of the side light source 22, the irradiation angle may be adjusted using a light shielding member or a diaphragm.

Returning to FIG. 4, the fingerprint reader 100 will be described. The imaging unit 25 is electrically connected to the main body substrate 15 provided in the grip unit 1. Further, the side light source 22 of the placement unit 2 is also electrically connected to the main body substrate 15. A reading switch 11 is disposed on the main body substrate 15, and the fingerprint is read by the user operating the reading switch 11. In addition, a port 16 connected to, for example, a USB connector cable is disposed on the main body substrate 15 as a terminal cable. The fingerprint data imaged by the imaging unit 25 is output to a computer (not shown) via a terminal cable connected to the port 16. The port 16 is provided at the end of the fingerprint reading device 100 opposite to the placement unit 2.

A heat radiating member made of, for example, brass, aluminum, iron, copper, or the like is disposed as the heat sink 26 below the imaging unit 25. The heat sink 26 is in contact with the substrate of the imaging unit 25 and the housing 3. The heat generated from the imaging unit 25 is transmitted to the housing 3 via the heat sink 26 and released to the outside. In FIG. 6, three heat sinks 26 (illustrated by dotted lines) are arranged in a U shape so as to at least partially surround the imaging unit 25. However, the number of heat sinks 26 may be two or less, or four or more, and may be one heat sink 26 formed in a U shape. A part of the heat sink 26 may be exposed to the outside from the housing 3.

As shown in FIG. 6, the reading switch 11 provided in the grip portion 1 is exposed on the back surface of the fingerprint reading device 100. That is, the reading switch 11 is provided on the surface opposite to the placement surface 21. The reading switch 11 is a mechanical push button switch, but a switch constituted by an electrical, capacitive or pressure contact sensor may be used instead of the mechanical switch. A recess 13 is formed on the surface of the reading switch 11. Accordingly, the user can specify the position of the reading switch 11 without visually recognizing only the touch of the finger touching the recess 13.

Further, as shown in FIG. 7, in each of the side light sources 22, the amount of light can be increased in the tip side region R <b> 1 of the fingerprint reading apparatus 100 into which the finger is inserted, compared to the center side region R <b> 2. That is, in the side light source 22, when the region R1 near the tip of the fingerprint reading device 100 is compared with the region R2 near the center of the fingerprint reading device 100, the region R1 on the tip side can be brightened. The child sometimes places his / her finger at a position biased toward the front end side of the fingerprint reader 100. In this regard, a sufficient amount of light can be incident on the finger by brightening the region R1 on the front end side of the fingerprint reader 100. Further, since the finger of a child goes from the fingertip to the fingertip as it goes to the tip side of the fingerprint reading apparatus 100, the finger becomes thicker. Therefore, a sufficient amount of light does not reach the inside of the finger on the finger root side than the fingertip. In this regard, a sufficient amount of light can be incident on the finger by brightening the region R1 on the front end side of the fingerprint reader 100.

Specifically, the plurality of

light sources

22 a, 22 b, 22 c, and 22 d of the side light source 22 are such that the distance between the light sources in the region R <b> 1 on the distal end side of the fingerprint reading device 100 into which a finger is inserted is the center of the fingerprint reading device 100. It can arrange | position so that it may become narrower than area | region R2 of the side. Thereby, the density of the plurality of

light sources

22a, 22b, 22c, and 22d in the tip end region R1 is higher than that in the center region R2. Therefore, it is possible to increase the amount of light in the region R1 on the distal end side and to make a sufficient amount of light incident on the finger placed at a position biased toward the distal end side.

Further, the side light source 22 arranged to be inclined toward the placement surface 21 may be inclined toward the front end of the fingerprint reading apparatus 100 as shown in FIG. Thereby, the side light source 22 emits light upward toward the center of the tip. Therefore, it is possible to increase the amount of light in the upper space of the region on the front end side of the fingerprint reader 100 so that a sufficient amount of light is incident on the finger placed at a position biased toward the front end side. Note that the amount of light emitted from the light source in the tip region R1 may be set to be larger than the amount of light emitted from the light source in the region R2 on the center side.

According to the fingerprint reading apparatus 100 according to the first embodiment described above, it is possible to increase the amount of light scattered at the center portion of the finger, and to prevent deterioration in image quality due to contrast unevenness. In addition, the fingerprint reader 100 can accurately read fingerprints of children, in particular, newborns and infants.

Note that the linear side light source 22 of the fingerprint reading apparatus 100 only needs to emit light along the side of the mounting surface 21, and is not limited to a configuration in which a plurality of light sources are arranged in a line. For example, as shown in FIG. 9, the linear side light source 22 may include a light guide 22e and a light source 22f that emits light toward an end surface of the light guide 22e. In this case, the light guide 22e is configured to emit light that is incident from the end face and travels through the interior toward the finger.

[Second Embodiment]
Subsequently, a fingerprint reading apparatus 200 according to the second embodiment will be described with reference to FIG. The second embodiment is different from the first embodiment in that it includes a back light source 5 that irradiates light on the back of the finger and a finger guide 6 that guides the finger onto the placement surface 21. In the description of the second embodiment, differences from the first embodiment will be described, the same reference numerals will be given to the components described in the first embodiment, and description thereof will be omitted. Except where specifically described, the constituent elements having the same reference numerals perform substantially the same operations and functions, and the effects thereof are also substantially the same.

As shown in FIG. 10, the fingerprint reading apparatus 200 according to the second embodiment further includes a back light source 5 that irradiates light from a position facing the placement surface 21 toward the back of the finger. Further, the fingerprint reading device 200 includes a finger guide 6 facing the placement surface 21, and the back light source 5 is provided on the finger guide 6. The back light source 5 is a linear light source extending in the longitudinal direction, like the linear side light source 22 extending along a pair of sides of the mounting surface 21. Furthermore, the back light source 5 has, for example, three near infrared LEDs as a plurality of light sources arranged side by side along the longitudinal direction. And the back light source 5 is arrange | positioned in the finger guide 6 formed with the translucent plastic material. The back light source 5 irradiates near infrared light having a wavelength of, for example, 820 to 980 nm on the back of the finger from above the finger in contact with the placement surface 21.

In the central portion of the mounting surface 21 far from the side light source 22, the amount of light is lower than that on both sides of the mounting surface 21. As a result, contrast is uneven between the central portion and both side portions of the fingerprint, and the image quality of the fingerprint is degraded. In this regard, according to the fingerprint reader 200 according to the second embodiment, the back light source 5 irradiates light toward the back of the finger. Thereby, since a sufficient amount of light can be irradiated to the child's finger, deterioration of the image quality can be prevented. Furthermore, since the amount of light scattered at the central portion of the finger increases, it is possible to reduce the unevenness of contrast and prevent the image quality from being deteriorated.

Further, the finger guide 6 has a curved shape along the outer shape of the finger as shown in FIG. The finger guide 6 detachably attached to the fingerprint reading device 200 includes two terminal pins 61 electrically connected to the main body substrate 15, a base 62 provided with the terminal pins 61, and a base 62. And a guide portion 63 protruding on the mounting surface 21. The guide part 63 is made of a transparent plastic material that transmits visible light, and the back light source 5 is embedded in the guide part 63. The base 62 and the back light source 5 of the guide 63 are electrically connected by a wiring 64. Thereby, the back light source 5 is electrically connected to the main body substrate 15 via the wiring 64 and the terminal pins 61.

The user can attach the finger guide 6 to the fingerprint reading device 200 so that the child's finger is placed on the placement surface 21 so as to be covered from above the finger. In the attached state, the terminal pin 61 of the finger guide 6 is inserted into the two pin holes 17 formed in the grip portion 1. Thereby, the back light source 5 of the finger guide 6 is electrically connected to the main body substrate 15. In addition, the guide part 63 of the finger guide 6 has a size and a shape so as not to overlap the side light source 22 in a state where the finger is sandwiched. More specifically, the guide portion 63 is configured such that a gap through which light from the side light source 22 passes is generated between the guide portion 63 and the placement surface 21 when a finger is sandwiched. Thereby, it can prevent that the guide part 63 blocks the light which radiate | emits from the side light source 22, and injects into a finger | toe.

The user can hold the child's finger between the finger guide 6 and the placement surface 21 by pressing the finger guide 6 from above. As a result, the finger is pressed against the placement surface 21 via the finger guide 6, and thus the child's finger can be fixed at a position suitable for fingerprint imaging with a simple structure. In particular, since a child's finger is softer than an adult's finger, a part of the finger may be separated from the placement surface 21 simply by bringing the finger into contact with the placement surface 21. In particular, the child may move his / her finger without being able to stand still when reading the fingerprint. In this regard, according to the finger guide 6 according to the second embodiment, by holding the finger, the finger can be fixed to prevent image blurring.

Furthermore, a reflective layer that reflects near-infrared light may be formed in the region excluding the rear light source 5 on the placement surface 21 side of the guide portion 63. By this reflective layer, the light from the side light source 22 can be reflected toward the back of the finger. Thereby, since a sufficient amount of light can be irradiated to the child's finger, deterioration of the image quality can be prevented. Furthermore, since the amount of light scattered at the central portion of the finger increases, it is possible to reduce the unevenness of contrast and prevent the image quality from being deteriorated.

Also, the finger guide 6 can be fixed to the fingerprint reader 200. For example, as shown in FIG. 11, a finger guide 6 having a guide portion 63 protruding on the placement surface 21 and a back light source 5 can be fixed to the fingerprint reading device 200. Thereby, if a child's finger is inserted along the fixed finger guide 6, the finger can reach a correct position. Further, in the finger guide 6, the back light source 5 is electrically connected to the main body substrate 15 of the fingerprint reading device 200 by wiring (not shown) extending in the guide portion 63. In FIG. 11, for convenience of explanation, the grip portion 1 is omitted and only the placement portion 2 is illustrated.

The fingerprint reader 200 according to the second embodiment described above can also accurately read the fingerprints of children, particularly newborns and infants. In addition, the amount of light scattered at the central portion of the finger can be increased to prevent deterioration in image quality due to uneven contrast. Further, the finger guide 6 can fix the child's finger at a position suitable for imaging with a simple structure. The finger guide 6 can guide the child's finger to a position suitable for imaging.

In the second embodiment, the back light source 5 is provided in the center of the guide portion 63, but the back light source 5 may be provided on both end sides along the longitudinal direction of the guide portion 63. Further, the back light source 5 may be provided at the center and both ends of the guide portion 63, respectively. Further, in the rear light source 5, the light amount of the light source corresponding to the front end side of the fingerprint reader 200 may be larger than that of the light source corresponding to the center side.

[Third Embodiment]
Subsequently, a fingerprint reading device 300 according to the third embodiment will be described with reference to FIGS. 12A and 12B. The third embodiment differs from the first and second embodiments in that the finger guide 306 can be opened and closed. In the description of the third embodiment, differences from the first and second embodiments will be described, and the same reference numerals will be given to the components described in the first and second embodiments, and the description thereof will be made. Omitted. Except where specifically described, the constituent elements having the same reference numerals perform substantially the same operations and functions, and the effects thereof are also substantially the same. For convenience of explanation, FIGS. 12A and 12B show only the placement portion 2 with the grip portion 1 omitted.

The finger guide 306 according to the third embodiment has a movable portion 365 and can be opened and closed with respect to the placement surface 21. Specifically, as shown in FIG. 12A, the movable portion 365 of the finger guide 306 is hinged to the guide portion 363 and hinged to the grip portion 1. And in the open position shown to FIG. 12A, the guide part 363 is spaced apart from the mounting surface 21 in the position facing the mounting surface 21. FIG. On the other hand, in the closed position illustrated in FIG. 12B, the guide portion 363 and the movable portion 365 are in contact with the placement surface 21 at a position that covers the placement surface 21. The movable portion 365 and the guide portion 363 are made of a transparent plastic material that transmits visible light.

The user rotates the guide portion 363 of the finger guide 306 upward from the placement surface 21 when reading the fingerprint. As a result, the finger guide 306 rotates in a direction away from the placement surface 21 around an axis (not shown) located at a connection portion between the movable portion 365 and the fingerprint reading device 300. The movable unit 365 functions as a link that connects the fingerprint reader 300 and the guide unit 363. Therefore, when the finger guide 306 is rotated, the movable portion 365 stands up in a direction away from the placement surface 21 as the guide portion 363 is away from the placement surface 21. In the open position, the guide portion 363 and the movable portion 365 take a substantially L-shaped posture.

The user rotates the finger guide 306 toward the closed position so that the finger guide 306 is superimposed on the finger while the child's finger is in pressure contact with the placement surface 21. Then, by pressing the finger guide 306 from above the finger, the child's finger can be held between the finger guide 306 and the placement surface 21. As a result, the finger is pressed against the placement surface 21 via the finger guide 306, and thus the child's finger can be fixed at a position suitable for fingerprint imaging with a simple structure. Therefore, by holding the finger, the finger can be fixed to prevent image blurring. The guide portion 363 of the finger guide 306 has a size and a shape so as not to overlap the side light source 22 in a state where the finger is sandwiched. More specifically, the guide portion 363 is configured such that a gap through which light from the side light source 22 passes is generated between the guide portion 363 and the placement surface 21 when a finger is sandwiched. Thereby, it can prevent that the guide part 363 blocks the light which radiate | emits from the side light source 22, and injects into a finger | toe.

Furthermore, a reflection layer 366 that reflects near-infrared light is formed in a region on the mounting surface 21 side of the guide portion 363. By this reflection layer, the finger guide 306 reflects near infrared light emitted from the pair of side light sources 22 toward the placement surface 21. Then, the reflected near infrared light is applied to the back of the finger. Thereby, since a sufficient amount of light can be irradiated to the child's finger, deterioration of the image quality can be prevented. Furthermore, since the amount of light scattered at the central portion of the finger increases, it is possible to reduce the unevenness of contrast and prevent the image quality from being deteriorated.

Note that an urging member such as a torsion spring may be disposed on the movable portion 365 of the finger guide 306. Thereby, the biasing member can bias the finger guide 306 from the open position toward the closed position. Therefore, even if the user does not press, the child's finger can be held between the finger guide 306 and the placement surface 21.

The fingerprint reader 300 according to the third embodiment described above can also accurately read the fingerprints of children, particularly newborns and infants. In addition, the amount of light scattered at the central portion of the finger can be increased to prevent deterioration in image quality due to uneven contrast. Furthermore, the finger guide 306 can fix the child's finger at a position suitable for imaging with a simple structure.

[Fourth Embodiment]
Subsequently, a fingerprint reading device 400 according to the fourth embodiment will be described with reference to FIG. The fourth embodiment differs from the first to third embodiments in that the reading switch 11 is not provided. In the description of the fourth embodiment, differences from the first to third embodiments will be described, and the same reference numerals will be given to the components described in the first to third embodiments, and the description thereof will be made. Omitted. Except where specifically described, the constituent elements having the same reference numerals perform substantially the same operations and functions, and the effects thereof are also substantially the same.

FIG. 13 shows a side surface of the fingerprint reader 400 along the longitudinal direction. The fingerprint reader 400 has a symmetrical shape. Therefore, in FIG. 13, only one side is demonstrated. However, the fingerprint reading device 400 has substantially the same configuration on the other side, on which explanation is omitted. For convenience of explanation, the protective glass 23 that does not appear on the side surface is indicated by a dotted line.

The fingerprint reader 400 includes a placement unit 402 for placing a finger. And the mounting part 402 is a pair of light sources arrange | positioned on the substantially same surface as the mounting surface 21 so that light may be irradiated to the mounting surface 21 which a finger contacts, and the finger which contacts the mounting surface 21 As shown, two side light sources 422 are provided. In the fourth embodiment, the side light source 422 is a point light source arranged with the placement surface 21 interposed therebetween. And the side light source 422 has one near-infrared LED each wrapped with the translucent plastic material. Further, the side light source 422 is arranged so that the top portion thereof is substantially flush with the placement surface 21. That is, the side light source 422 is positioned so that the upper surface of the protective glass 23 and the top of the side light source 422 are substantially flush with each other.

Also, the fingerprint reading device 400 includes the grip portion 1 that functions as a user's handle when reading a fingerprint. The grip portion 1 is formed integrally with the placement portion 402 so as to extend from the placement portion 402. However, unlike the first to third embodiments, the grip 1 is not provided with the reading switch 11. On the other hand, as in the first to third embodiments, the mounting unit 402 includes the imaging unit 25 (not shown). And the imaging part 25 images a fingerprint with the light scattered inside the finger | toe and radiate | emitted from the surface of the finger | toe. Further, the side light source 422 is inclined toward the inside of the placement surface 21. That is, the side light source 422 is arranged in a posture inclined toward the center in the placement surface 21.

Also by the fingerprint reader 400 according to the fourth embodiment described above, the amount of light scattered at the central portion of the finger can be increased, and deterioration of image quality due to contrast unevenness can be prevented. Also, the fingerprint reader 400 can accurately read the fingerprints of children, in particular, newborns and infants.

As mentioned above, although this invention was demonstrated with reference to each embodiment, this invention is not limited to the said embodiment. Inventions modified within the scope not departing from the present invention and inventions equivalent to the present invention are also included in the present invention. In addition, the above-described embodiments and modifications can be combined as appropriate without departing from the scope of the present invention.

For example, the casing 3 of the fingerprint reading device 100 according to the first embodiment has a rounded shape so that it can be easily inserted between fingers, but has a corner portion having a substantially L-shaped cross section. It may be. Moreover, the front-end | tip of the mounting part 2 may have a taper shape. Further, the grip 1 may be provided with a non-slip to prevent the user's hand from slipping.

Also, the finger guide is formed of a material that transmits visible light, but may be formed of a material that blocks visible light. Thereby, when reading a fingerprint outdoors, the amount of sunlight incident on the imaging unit 25 can be reduced. Therefore, the occurrence of unevenness in contrast due to sunlight can be suppressed.

Furthermore, the fingerprint reading apparatus may include a light shielding member having an insertion portion into which a finger is inserted. By covering the placement unit 2 with this light shielding member, the amount of sunlight incident on the imaging unit 25 can be reduced. The protective glass 23 may have a transmission layer that transmits near infrared light and blocks or reflects visible light. Thereby, the amount of disturbance light incident on the imaging unit 25 can be reduced. Alternatively, the protective glass 23 may have an ND filter.

Some or all of the above embodiments can be described as in the following supplementary notes, but are not limited thereto.

(Appendix 1) a placement unit for placing a finger;
A pair of light sources arranged on the same plane as the previous placement surface, so as to irradiate light to a finger that contacts the placement surface of the previous placement portion.
An imaging unit that is provided in the placement unit and that captures the fingerprint of the finger by light scattered inside the finger and emitted from the surface of the finger;
The pair of light sources is a fingerprint reading device that is inclined toward the inside of the mounting surface with respect to the mounting surface.

(Supplementary note 2) The fingerprint reading device according to supplementary note 1, wherein each of the pair of light sources is a linear light source extending along a pair of opposing sides of the placement surface.

(Additional remark 3) The said linear light source is a fingerprint reader of Additional remark 2 which has several light sources arrange | positioned along with the said side.

(Supplementary note 4) The fingerprint reading device according to

Supplementary note

2 or 3, wherein, in each of the pair of light sources, a light amount is larger in a region on the front end side of the fingerprint reading device than in a region on the central side of the fingerprint reading device.

(Additional remark 5) The said several light source is arrange | positioned so that the space | interval of the said light sources in the area | region of the front end side of the said fingerprint reader may become narrower than the area | region of the center side of the said fingerprint reader. The fingerprint reader according to the description.

(Supplementary note 6) The fingerprint reading device according to any one of supplementary notes 1 to 5, further comprising a back light source that emits light toward the back of the finger from a position facing the placement surface.

(Supplementary note 7) The fingerprint reading device according to any one of supplementary notes 1 to 6, further comprising a finger guide facing the placement surface.

(Additional remark 8) The said finger guide is a fingerprint reader of Additional remark 7 which can be opened and closed with respect to the said mounting surface while having a movable part.

(Supplementary note 9) The fingerprint reading device according to supplementary note 7, wherein the finger guide is detachable from the fingerprint reading device.

(Appendix 10) The pair of light sources irradiates near infrared light,
10. The fingerprint reader according to any one of appendices 7 to 9, wherein the finger guide reflects the near infrared light emitted from the pair of light sources toward the placement surface.

As mentioned above, although this invention was demonstrated with reference to embodiment (and modification), this invention is not limited to the said embodiment (and modification). Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

Note that the entire contents of Japanese Patent No. 3751872 and Japanese Patent No. 5598687 are cited and made a part of this application.

This application claims priority based on Japanese Patent Application No. 2015-186011 filed on Sep. 18, 2015, the entire disclosure of which is incorporated herein.

2: placement unit, 5: back light source, 6: finger guide, 21: placement surface, 22: pair of light sources, 25: imaging unit, 100: fingerprint reader, 365: movable unit, R1: region on the tip side , R2: Central area

Claims

A placement unit for placing a finger;
A pair of light sources arranged on the same plane as the previous placement surface, so as to irradiate light to a finger that contacts the placement surface of the previous placement portion.
An imaging unit that is provided in the placement unit and that captures the fingerprint of the finger by light scattered inside the finger and emitted from the surface of the finger;
The pair of light sources is a fingerprint reading device that is inclined toward the inside of the mounting surface with respect to the mounting surface.
2. The fingerprint reading apparatus according to claim 1, wherein each of the pair of light sources is a linear light source extending along a pair of opposing sides of the mounting surface.
The fingerprint reader according to claim 2, wherein the linear light source has a plurality of light sources arranged along the side.
The fingerprint reading device according to claim 2 or 3, wherein, in each of the pair of light sources, the amount of light in the region on the front end side of the fingerprint reading device is larger than the region on the central side of the fingerprint reading device.
4. The fingerprint according to claim 3, wherein the plurality of light sources are arranged such that an interval between the light sources in a region on a front end side of the fingerprint reading device is narrower than a region on a central side of the fingerprint reading device. Reader.
The fingerprint reader according to any one of claims 1 to 5, further comprising a back light source that irradiates light toward the back of the finger from a position facing the placement surface.
The fingerprint reader according to any one of claims 1 to 6, further comprising a finger guide facing the placement surface.
The fingerprint reader according to claim 7, wherein the finger guide has a movable part and can be opened and closed with respect to the mounting surface.
The fingerprint reader according to claim 7, wherein the finger guide is detachable from the fingerprint reader.
The pair of light sources emits near infrared light,
The fingerprint reader according to claim 7, wherein the finger guide reflects the near infrared light emitted from the pair of light sources toward the placement surface.