JP2022028834A - Biological feature input device and biological feature input method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biological feature input device and a biological feature input method which can obtain even an image of a dry finger and a wet finger.

SOLUTION: A biological feature input device 10 includes: an irradiation system 20 for making light incident onto an inside of a finger FG from surrounding of the finger FG; a fiber plate 30 having on its upper portion an incidence plane 30a on which a finger print portion FP of the finger FG is placed and through which transmitted light irradiated from the finger print portion FP among transmitted light from the finger FG is made incident; a prism body 40 positioned in a lower portion of the fiber plage 30 and having a reflective coating surface 40a; and an image capturing system 50 for generating a reduced image of a finger print from the transmitted light reflected by the reflective coating surface 40a and for capturing an image of a finger print.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a biological feature input device and a biological feature input method.

Fingerprint authentication is often used for personal identification because the probability of humans having the same pattern is extremely low and the structure is easy to quantify according to many years of research.
As a biological feature input device that authenticates an individual by placing a finger, a reflection method is known in which a prism or the like is used to irradiate the finger with light and acquire a fingerprint image from the light reflected by the finger.
For example, Patent Document 1 discloses a biological feature input device using a finger fingerprint by a reflection method.

U.S. Pat. No. 6,381,347

The biological feature input device of Patent Document 1 obtains an image by contacting a ridge (convex portion) of a fingerprint with a prism glass and hindering total internal reflection on the contact surface. For this reason, in the case of a dry finger having poor contact or a wet finger in which the space between the ridges (valleys) of the fingerprint is filled with moisture or the like instead of air, the biological feature input device of Patent Document 1 is used. It may not be possible to obtain a fingerprint image.

An object of the present invention is to provide a biological feature input device and a biological feature input method capable of acquiring an image even with a dry finger or a wet finger.

In the biological feature input device of the first aspect, an irradiation system for injecting light from around the finger toward the inside of the finger and a fingerprint portion of the finger are placed, and the fingerprint portion of the transmitted light of the finger is placed. Reduced from the fiber plate having an incident surface at the top that captures the transmitted light emitted from, the prism body located at the bottom of the fiber plate and having a reflective coating surface, and the transmitted light reflected by the reflective coating surface. It is provided with an imaging system that generates a fingerprint image and captures the fingerprint image.

Further, the biological feature input method of the second aspect includes a fiber plate having an incident surface at the upper part, a prism body having a reflective coating surface at a position below the fiber plate, and an imaging optical system having a reduction optical system and an image pickup unit. Of the installation step of installing the fingerprint portion of the finger on the incident surface, the irradiation step of incident light from the periphery of the finger toward the inside of the finger, and the transmitted light of the finger. An imaging step of generating a reduced fingerprint image from the transmitted light emitted from the fingerprint portion, captured by the incident surface, and reflected by the reflective coating surface, and imaging the fingerprint image is performed.

According to one aspect of the present invention, an image can be acquired even with a dry finger or a wet finger.

It is a schematic diagram of the biological feature input device which concerns on 1st Embodiment of this invention. It is an overall view of the biological feature input device which concerns on 1st Embodiment of this invention. It is a figure explaining the fiber plate which concerns on 1st Embodiment of this invention. It is an overall view of the biological feature input device which concerns on the 2nd Embodiment of this invention. It is a top view of the light source which concerns on the 2nd Embodiment of this invention. It is an overall view of the biological feature input device which concerns on 3rd Embodiment of this invention. It is an overall view of the biological feature input device which concerns on 4th Embodiment of this invention. It is an overall view of the biological feature input device which concerns on 5th Embodiment of this invention. It is an overall view of the biological feature input device which concerns on the modification of the 5th Embodiment of this invention. It is a flowchart of the biological feature input method of each embodiment which concerns on this invention.

Hereinafter, various embodiments according to the present invention will be described with reference to the drawings.

<First Embodiment>
Hereinafter, the first embodiment of the biological feature input device according to the present invention will be described with reference to FIGS. 1 to 3.

The configuration of the biological feature input device 10 of the present embodiment will be described.
As shown in FIG. 1, the biological feature input device 10 includes an irradiation system 20, a fiber plate 30, a prism body 40, and an imaging system 50.
The irradiation system 20 is provided above the fingerprint portion FP of the finger FG, which will be described later, and irradiates light toward the inside of the finger FG.
The fiber plate 30 has an incident surface 30a at the upper part and an exit surface 30b at the lower part. The fingerprint portion FP of the finger FG is placed on the incident surface 30a of the fiber plate 30, and among the transmitted light of the finger, the transmitted light emitted from the fingerprint portion FP is taken in and emitted from the exit surface 30b.
The prism body 40 is located below the fiber plate 30 and has a reflective coating surface 40a.
The image pickup system 50 receives the transmitted light emitted from the fingerprint unit FP through the fiber plate 30 and the prism body 40, generates a reduced fingerprint image, and captures the fingerprint image.
Hereinafter, the direction from the tip of the finger FG to the base side is described as the + X direction, the upward direction is the direction orthogonal to the + Z direction, the + X direction and the Z direction, and the direction from the front side to the back side of the paper is also described as the Y direction.
The fiber plate 30, the prism body 40, and the image pickup system so that the light in the emission direction of the fiber plate 30 incident on the prism body 40 is reflected by the reflective coating surface 40a of the prism body 40 and is incident on the image pickup system 50. 50 is arranged.
Hereinafter, each configuration will be described with reference to FIGS. 2 and 3.

(Irradiation system)
As shown in FIG. 2, the irradiation system 20 has a light source 20a. In the present embodiment, the light source 20a is light having a wavelength of light transmitted through the finger FG, and irradiates light having a wavelength in the region from red to near infrared (around 600 to 1000 nm). The light source 20a is provided above the finger FG and irradiates from the claw side (dorsal side) of the finger FG in the periphery of the finger FG. In the present embodiment, the light source 20a is a point light source such as an LED.

(Fiber plate)
In the fiber plate 30, the light that invades the finger FG is scattered inside the finger FG, and the light radiated from the ventral side of the finger FG is guided to the prism body 40.
The fiber plate 30 extends from the tip of the finger FG to between the first joint FG1 and the second joint FG2 of the finger FG.
As shown in FIG. 3, the fiber plate 30 has a fiber bundle 31. The direction of the fiber bundle 31 of the fiber plate 30 coincides with the direction of the optical path L1. Here, the optical path L1 is an optical path in which each light emitted from the fiber plate 30 is reflected by the reflective coating surface 40a of the prism body 40 and is incident on the image pickup system 50.
As shown in FIG. 3, the axis Af of each fiber 31a of the fiber bundle 31 is inclined with respect to the Z direction. Therefore, the fiber plate 30 has an emission angle that is inclined with respect to the Z direction toward the reflective coating surface 40a.

Although not particularly limited, as the fiber plate 30, a fiber plate having a numerical aperture NA of 0.3 to 0.6 (= sin (2θ)) may be used. Further, although not particularly limited, the fiber plate 30 may be a fiber plate having an emission angle of 30 to 60 degrees.
If the opening angle of the fiber plate 30 is configured to be 0.3 to 0.6 and the emission angle is configured to be 30 to 60 degrees, the biological feature input device 10 efficiently captures an image of scattered light in the finger FG. It is possible to guide the light to.

(Prism body)
The prism body 40 has a reflective coating surface 40a on the side portion on the tip side of the finger FG, an incident surface 40b along the emission surface 30b of the fiber plate 30 on the upper portion, and a side facing the reflective coating surface 40a (the base side of the finger FG). ) With an exit surface 40c.
The prism body 40 is a translucent body. The light incident on the incident surface 40b from the emitted surface 30b of the fiber plate 30 passes through the inside of the prism body 40, is reflected by the reflective coating surface 40a, and is emitted to the emitted surface 40c. The light emitted from the emission surface 40c heads toward the reduction optical system 50A while being refracted by the emission surface 40c.
Similar to the fiber plate 30, the prism body 40 extends from the tip of the finger FG to between the first joint FG1 and the second joint FG2 of the finger FG.

(Imaging system)
The image pickup system 50 includes a reduction optical system 50A and an image pickup unit 50B. The image pickup system 50 is arranged so that the reduction optical system 50A and the image pickup unit 50B face the exit surface 40c.
The reduced optical system 50A has a lens group, and reduces the image of the light radiated from the ventral side of the finger FG to form an image on the image pickup unit 50B.
The image pickup unit 50B captures the imaged image as a fingerprint image.

(Action and effect)
The operation and effect of the biological feature input device 10 will be described.
The biological feature input device 10 of the present embodiment acquires a fingerprint image of the scattered light in the finger FG scattered in the finger FG and emitted from the finger. Therefore, unlike the reflection method of acquiring the fingerprint image from the light reflected by the finger, the biological feature input device 10 can acquire the fingerprint image of the dry finger or the wet finger because it is the scattered light method in the finger FG. can.
Therefore, even for a person who has difficulty in fingerprint authentication due to his / her constitution or environment, fingerprint authentication is possible.

Further, the biological feature input device 10 of the present embodiment emits the light scattered in the finger FG to the fiber plate 30 from the ventral side of the finger.
The fiber plate 30 is cut so that the fiber bundle 31 is oriented in the direction of the optical path L1. Therefore, the fiber plate 30 can block the light that is a cause of the non-directional contrast reduction by aligning the light from the inside of the finger FG as parallel as possible and guiding the fingerprint image.
Therefore, since the biological feature input device 10 of the present embodiment blocks light, which is a factor of non-directional contrast reduction, and acquires a fingerprint image, it is possible to efficiently obtain a fingerprint image by scattered light in the finger FG. can.

Further, since the biological feature input device 10 of the present embodiment uses a reduced optical system, a small area image sensor can be used for the image pickup system 50.
If the fingerprint image due to scattered light in the finger is directly guided to a two-dimensional image sensor with a size ratio of 1: 1 without using a reduction optical system such as a lens, a large image sensor equivalent to the area of the fingerprint is used. It is necessary and the manufacturing cost is high.
For example, a two-dimensional image sensor is preferably a C-MOS or CCD system of a silicon semiconductor substrate in terms of performance, but a large image sensor of a C-MOS or CCD system of a silicon semiconductor substrate is very expensive.
Even a relatively inexpensive TFT type image sensor that can be produced at a relatively low cost compared to the C-MOS or CCD method in terms of process will be more expensive than a small area image sensor using a reduced optical system. Further, it is technically difficult to make a TFT type image sensor with higher definition, higher sensitivity, and lower noise than a C-MOS or CCD type image sensor, and stable supply is not possible.
In comparison with this, since the biological feature input device 10 of the present embodiment uses the reduced optical system 50A, a small area image sensor can be used for the image pickup system 50. Therefore, the cost is reduced as compared with the method of directly obtaining an image by a two-dimensional image sensor while improving the authentication accuracy of the living body.

<Second embodiment>
Hereinafter, the biological feature input device according to the second embodiment will be described in detail with reference to FIGS. 4 and 5.

The biological feature input device according to this embodiment is basically the same as that of the first embodiment, except that a plurality of light sources are provided on the side surface of the finger.

The biological feature input device 10'includes an irradiation system 20', a fiber plate 30, a prism body 40, and an imaging system 50.
The irradiation system 20'is provided above the fingerprint portion FP of the finger FG, and irradiates light toward the inside of the finger FG.
The irradiation system 20'has a plurality of light sources 20a'. In the present embodiment, the light source 20a'is light having a wavelength of light transmitted through the finger FG, and irradiates light having a wavelength in the region from red to near infrared (around 600 to 1000 nm). In the present embodiment, the irradiation system 20'is provided on the upper part of the finger FG and irradiates from the claw side (dorsal side) of the finger FG. In the present embodiment, each light source 20a'is a point light source such as an LED.

As shown in FIGS. 4 and 5, the plurality of light sources 20a'are arranged so as to surround the finger FG.
FIG. 5 is a diagram showing only a plurality of light sources 20a'and a fiber plate 30 among the biological feature input devices 10'.
In the present embodiment, the plurality of light sources 20a'are 7 light sources each along both side surfaces of the finger FG, and 1 each on the tip side and the base side FB of the finger FG, for a total of 16 light sources 20a'. Surrounding.
Therefore, the irradiation system 20'irradiates the finger FG from the upper surface (the surface on the nail side) and the side surface of the finger FG.

Therefore, since the irradiation system 20'irradiates the finger FG with light from the upper surface and the side surface of the finger FG so as to surround the finger FG, the finger FG can be uniformly and multi-directionally irradiated.

<Third embodiment>
Hereinafter, the biological feature input device according to the third embodiment will be described in detail with reference to FIG.

The biological feature input device according to the present embodiment is basically the same as that of the first embodiment, except that blood vessel images can also be captured.

As shown in FIG. 6, the biological feature input device 100 includes an irradiation system 20, a fiber plate 30, a prism body 140 having a reflective coating surface 140a, an incident surface 140b, and an emitting surface 140c, a reduced optical system 150A, and an imaging unit. An imaging system 150 having a 150B and a mirror 60 are provided.
In the present embodiment, the mirror 60 has a mirror surface on the entire surface of one plate facing the lower surface of the finger FG.
The mirror surface of the mirror 60 faces the lower surface of the base side FB from the first joint FG1 among the lower surfaces of the finger FG.
The mirror 60 is provided below the prism body 140 so that the upper end of the mirror surface of the mirror 60 is aligned with the lower end of the exit surface 140c.

The fiber plate 30 and the prism body 140 extend from the tip of the finger FG to the space between the first joint FG1 and the second joint FG2 of the finger FG. The fiber plate 30 and the prism body 140 extend to the same position in the + X direction. Therefore, the end portion 30e of the fiber plate 30 on the base side FB of the finger FG and the exit surface 140c are at the same position in the X direction.
Therefore, at the tip of the finger FG from the end 30e of the fiber plate 30 on the base side FB of the finger FG, the transmitted light emitted from the finger FG passes through the fiber plate 30 and the prism body 140 along the optical path L1. On the other hand, the transmitted light emitted from the base side FB of the finger FG is not transmitted through the fiber plate 30 and the prism body 140 from the end portion 30e of the fiber plate 30 of the base side FB of the finger FG, and is along the optical path L2. , Is emitted toward the mirror 60. In other words, the transmitted light emitted from the FB at the base of the finger FG with respect to the emission surface 40c is emitted toward the mirror 60 through the + X direction side with respect to the emission surface 40c.

In the present embodiment, the reflective coating surface 140a reflects the light (transmitted light) emitted from the fingerprint portion FP via the fiber plate 30 so that the optical path L1 faces the lower portion of the emission surface 140c.
Therefore, the reflective coating surface 140a is configured to direct the optical path L1 to the lower portion of the exit surface 140c. That is, the angle between the incident surface 140b and the reflective coating surface 140a is larger than the angle between the incident surface 40b and the reflective coating surface 40a in the first embodiment.
The mirror 60 reflects a part of the transmitted light emitted from between the first joint FG1 and the second joint FG2 of the finger FG on the second joint FG2 side.

The image pickup system 150 scatters in the finger FG and captures the light emitted from the fingerprint portion FP as a fingerprint image.
The image pickup system 150 images a light that is reflected by the reflective coating surface 140a of the prism body 140 via the fiber plate 30 and travels through the optical path L1 incident on the image pickup system 150, and captures a fingerprint image.

The image pickup system 150 captures the light emitted toward the mirror 60 as a blood vessel image, which is scattered in the finger FG and does not pass through the fiber plate 30 and the prism body 140.
The image pickup system 150 forms an image of light reflected by the mirror 60 and traveling in the optical path L2 incident on the image pickup system 150, and captures a blood vessel image.
When the light transmitted through the finger FG is emitted from the ventral side of the finger FG on the base side FB from the first joint of the finger FG, the light is absorbed by the blood in the venous blood vessel. Since the image is shaded when the light is absorbed by the blood in the venous blood vessel, the biological feature input device 100 can also capture an image of the blood vessel.
Since the FB at the base of the finger from the first joint FG1 is not pressed by the fiber plate 30 as compared with the tip side of the finger FG, an image of a blood vessel can be imaged.

The biological feature input device 100 guides an image (fingerprint image) of light traveling along the optical path L1 (via the fiber plate 30 and the prism body 140) to the upper half of the effective angle of view of the imaging system 150, and follows the optical path L2. The image of the light (via the mirror 60) traveling (passing through the mirror 60) is guided to the lower half of the effective angle of view of the imaging system 150.
Therefore, the imaging system 150 can capture an image in which the fingerprint image and the blood vessel image of the finger FG reflected by the mirror 60 are simultaneously reflected.

<Fourth Embodiment>
Hereinafter, the biological feature input device according to the fourth embodiment will be described in detail with reference to FIG. 7.

The biological feature input device according to the present embodiment is basically the same as that of the third embodiment, except that it further includes an infrared transmission filter.

The biological feature input device 200 further includes an infrared transmission filter 70 in the optical path of the transmitted light of the finger FG. The infrared transmission filter 70 transmits light having a wavelength in the infrared region and removes light having a wavelength in another wavelength region.
As shown in FIG. 7, in the present embodiment, the infrared transmission filter 70 is provided between the emission surface 140c of the prism body 140 and the image pickup system 150. Further, the infrared transmission filter 70 is provided over the entire effective angle of view of the image pickup system 150.

The infrared transmission filter 70 can be a filter that transmits light in the wavelength range of near-infrared light having a wavelength of about 850 to 960 nm and removes light in another wavelength range.
Considering the enhancement of contrast due to absorption by hemoglobin of blood vessels and the resistance to dirt and ambient light, light having wavelength characteristics in near-infrared light having a wavelength of about 850 to 960 nm is important for acquiring blood vessel images. ..
Therefore, if a filter is used to transmit light in the wavelength range of near-infrared light having a wavelength of about 850 to 960 nm and remove light in another wavelength range, a blood vessel image can be acquired with high contrast and low noise.

The infrared transmission filter 70 is provided over the entire effective angle of view of the image pickup system 150, but as a modification, the infrared transmission filter 70 passes through the mirror 60 in the entire effective angle of view of the image pickup system 150. It may be provided only in the effective angle of view of the lower half, which is the effective angle of view of the light of the blood vessel image.

<Fifth Embodiment>
Hereinafter, the biological feature input device according to the fifth embodiment will be described in detail with reference to FIG.

The biological feature input device according to the present embodiment is basically the same as that of the first embodiment, except that an imaging system for capturing a blood vessel image is separately provided.

As shown in FIG. 8, the biological feature input device 300 includes an irradiation system 20, a fiber plate 30, a prism body 40, an imaging system 50, and an auxiliary imaging system 55.
The prism body 40 has a reflective coating surface 40a on the side of the base side FB of the finger FG, an incident surface 40b along the exit surface 30b of the fiber plate 30 on the upper portion, and a side facing the reflective coating surface 40a (the tip of the finger FG). It has an exit surface 40c on the side of the side).

The fiber plate 30 and the prism body 40 extend from the tip of the finger FG to between the first joint FG1 and the second joint FG2 of the finger FG. The fiber plate 30 and the prism body 40 extend to the same position in the −X direction. Therefore, the end portion 30e of the fiber plate 30 on the tip end side of the finger FG and the upper end portion of the reflective coating surface 40a are at the same position in the X direction.
Therefore, at the tip of the finger FG from the end 30e of the fiber plate 30 on the base side FB of the finger FG, the transmitted light emitted from the finger FG passes through the fiber plate 30 and the prism body 40 along the optical path L1. On the other hand, the transmitted light emitted from the base side FB of the finger FG is not transmitted through the fiber plate 30 and the prism body 40 from the end portion 30e of the fiber plate 30 of the base side FB of the finger FG, and is along the optical path L2. , Is emitted toward the auxiliary imaging system 55. In other words, the transmitted light emitted from the FB at the base of the finger FG with respect to the emission surface 40c is emitted toward the auxiliary imaging system 55 through the −X direction side with respect to the emission surface 40c.

The auxiliary imaging system 55 includes an auxiliary reduction optical system 55A and an auxiliary imaging unit 55B. The auxiliary imaging system 55 is arranged so that the auxiliary reduction optical system 55A and the auxiliary imaging unit 55B face the lower surface of the finger FG. The auxiliary reduction optical system 55A and the auxiliary imaging unit 55B face the lower surface of the base side FB from the first joint FG1 among the lower surfaces of the finger FG.
Therefore, the biological feature input device 300 can acquire a fingerprint image by the imaging system 50 and a blood vessel image by the auxiliary imaging optical system.

<Modification example>
In the fifth embodiment, the auxiliary imaging system 55 directly receives the transmitted light emitted from the finger FG, but may be configured as a modification such as the biological feature input device 400.
As shown in FIG. 9, the biological feature input device 400 further includes a mirror 65. The biological feature input device 400 horizontally folds the transmitted light emitted from the finger FG by the mirror 65 and takes an image with the auxiliary imaging system 55.

The light source of the second embodiment of FIGS. 4 and 5 is not limited to the first embodiment, and may be applied to other embodiments. When applied to other embodiments, it is possible to obtain a uniformly illuminated fingerprint image. When applied to other embodiments for obtaining a blood vessel image, a uniformly illuminated blood vessel image can be obtained.

In the fourth embodiment of FIG. 7, the infrared transmission filter 70 is provided between the emission surface 140c of the prism body 140 and the image pickup system 150, but as a modification, between the lower surface of the finger FG and the mirror 60. It may be provided in the optical path of. As another modification, it may be provided between the irradiation system and the finger FG.

In the fourth embodiment of FIG. 7, the infrared transmission filter 70 is provided in the biological feature input device 100 of the third embodiment, but as a modification, the infrared transmission filter 70 is provided in the biological feature input device of another embodiment. It may be provided.
When provided in another biological feature input device, the infrared transmission filter 70 may be provided in the optical path between the finger FG and the imaging system or the auxiliary imaging system, and the infrared transmission filter 70 may be provided with the irradiation system. It may be provided between the finger FG and the finger FG.
Further, when provided in the biological feature input device 400 of the modified example of the fifth embodiment, the infrared transmission filter 70 may be provided in the optical path between the mirror 65 and the auxiliary imaging system 55, or may be provided on the lower surface of the finger FG. It may be provided in the optical path between the mirror 65 and the mirror 65.

<Biological feature input method>
The biological feature input method of each embodiment according to the present invention will be described with reference to FIG.

First, a fiber plate having an incident surface at the upper part, a prism body having a reflective coating surface at the lower part of the fiber plate, an imaging optical system having a reduction optical system and an imaging unit, and a finger on the incident surface are installed. Install the fingerprint part (ST1: Installation step).
Next, light is incident from around the finger toward the inside of the finger (ST2: irradiation step).
Finally, of the transmitted light of the finger, a reduced fingerprint image is generated from the transmitted light emitted from the fingerprint portion, captured on the incident surface, and reflected on the reflective coating surface, and the fingerprint image is captured (ST3 :). Imaging step).

Although some embodiments of the present invention have been described above, these embodiments are shown as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof shall be included in the scope of the invention described in the claims and the equivalent scope thereof, as well as in the scope and gist of the invention.

10: Biological feature input device 10': Biological feature input device 20: Irradiation system 20': Irradiation system 20a: Light source 20a': Light source 30: Fiber plate 30a: Incident surface 30b: Exit surface 31: Fiber bundle 31a: Fiber 40: Prism body 40a: Reflective coating surface 40b: Incident surface 40c: Exit surface 50: Image pickup system 50A: Reduction optical system 50B: Image pickup unit 55: Auxiliary image pickup system 55A: Auxiliary reduction optical system 55B: Auxiliary image pickup unit 60: Mirror 65: Mirror 70: Infrared transmission filter 100: Biological feature input device 140: Prism body 140a: Reflective coating surface 140b: Incident surface 140c: Ejection surface 150: Imaging system 150A: Reduction optical system 150B: Imaging unit 200: Biological feature input device 300: Living body Feature input device 400: Biological feature input device FB: Root side FG: Finger FG1: First joint FG2: Second joint FP: Fingerprint part L1: Optical path L2: Optical path

Claims (8)

An irradiation system that injects light from around the finger toward the inside of the finger,
A fiber plate on which the fingerprint portion of the finger is placed, and of the transmitted light of the finger, an incident surface having an incident surface for taking in the transmitted light emitted from the fingerprint portion at the upper portion and an emitting surface at the lower portion.
An imaging system that generates a reduced fingerprint image from the transmitted light that has passed through the fiber plate and captures the fingerprint image.
A biological feature input device. Further comprising a prism body located below the fiber plate and having a reflective coating surface, an entrance surface and an exit surface.
The imaging system generates a reduced fingerprint image from the transmitted light reflected by the reflective coating surface, and images the fingerprint image.
The transmitted light emitted from the emission surface of the fiber plate at an emission angle inclined toward the reflection coating surface enters the incident surface of the prism body, is reflected by the reflection coating surface, and is reflected by the prism. The biological feature input device according to claim 1, wherein the fiber plate, the prism body, and the image pickup system are arranged so as to emit light from the exit surface of the body and enter the image pickup system. A mirror that reflects the transmitted light emitted from the base side of the first joint of the finger among the transmitted light of the finger is further provided.
The imaging system captures an image in which the fingerprint image and the blood vessel image of the finger reflected by the mirror are simultaneously reflected.
The mirror surface of the mirror faces the lower surface on the base side of the first joint of the finger.
The transmitted light emitted from the root side does not pass through the fiber plate and the prism body, but is emitted toward the mirror, reflects the mirror, and is incident on the image pickup system. The biological feature input device according to claim 2, wherein the fiber plate, the prism body, and the imaging system are arranged. Further equipped with an auxiliary imaging system for imaging the blood vessel image of the finger,
The auxiliary imaging system faces the lower surface on the base side of the first joint of the finger.
The auxiliary imaging system, the fiber plate, and the prism body so that the transmitted light emitted from the root side does not pass through the fiber plate and the prism body and is emitted toward the auxiliary imaging system. The biological feature input device according to claim 2, wherein the imaging system is arranged. The living body according to any one of claims 1 to 4, further comprising an infrared transmission filter that is arranged in the optical path of the transmitted light, transmits light having a wavelength in the infrared region, and removes light in another wavelength region. Feature input device. The biometric feature input device according to any one of claims 1 to 5, wherein the numerical aperture of the fiber plate is 0.3 to 0.6. The biological feature input device according to any one of claims 2 to 4, wherein the emission angle is 30 to 60 degrees. An installation step of installing a fiber plate having an incident surface on the upper part and an emitting surface on the lower part, an imaging system having a reduced optical system and an imaging unit, and installing a finger fingerprint portion on the incident surface.
An irradiation step in which light is incident from around the finger toward the inside of the finger,
An imaging step of generating a reduced fingerprint image from the transmitted light emitted from the fingerprint portion of the transmitted light of the finger and captured on the incident surface, and imaging the fingerprint image.
Biological feature input method to carry out.

Images