JPH10269344A - Fingerprint reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fingerprint reader which increases the degree of freedom of a mounting direction by voluntarily selecting the direction of placing a finger on the fingerprint collecting plane of a prism. SOLUTION: This device includes a prism 11 which has a fingerprint collecting plane 11, an image pickup device 14 which detects light that proceeds into the prism from a light source 12 and is reflected by the fingerprint collecting plane and a case 18 that surrounds the prism, the light source and the image pickup device, and the case 18 has a finger placed guide 19 that is constituted of a recessed part which shows a finger placed position on the fingerprint collecting plane of the prism in the direction of a prescribed finger placing, and the center C of the recessed part is coincided with the light axis of an optical system 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fingerprint reading device having a surface that contacts a fingerprint and optically reading an image of the fingerprint that is in contact with the surface.

[0002]

2. Description of the Related Art In recent years, information processing technology has been applied to society as a whole, and with the spread of information processing technology, it has become necessary to manage various systems and to ensure safety. At present, in the information processing field, input of personal identification number, magnetic card
It is a common practice to identify each individual using an IC card or the like. In addition, in the personal living environment, applications of these information processing technologies are also attracting attention for ensuring the security of keys of houses and automobiles, keys of lockers, and the like. This is because it is impossible to avoid the dangers of forgetting the personal identification number and losing, stolen, forgery, and the like of the key, the magnetic card, the IC card, and the like using the conventional method. Therefore, as a method for avoiding these dangers, it is advantageous to secure the system management and the security by identifying the individual by fingerprint collation using the unique and invariant fingerprint of the individual. It is.

Conventionally, such a fingerprint matching device is configured as shown in FIG. 6, for example. In FIG. 6, a fingerprint collation device includes a right-angle prism having a fingerprint sampling surface 1a disposed diagonally, a light source 2 and a prism 1 disposed on one (lower surface in the illustrated case) side of the prism 1.
And a fingerprint reading device 5 including a lens group 3 and a photoelectric conversion element 4 such as a CCD (charge coupled device) arranged on the other side (right side in the case of the drawing), and a fingerprint image from the photoelectric conversion element 4. Is processed into fingerprint image data for collation. The fingerprint image data for collation is compared with the fingerprint image data for reference registered in advance, and a fingerprint image data processing unit 6 for performing fingerprint collation is processed. Have.

In the fingerprint collating apparatus having such a configuration, when an operator touches a finger on the fingerprint collecting surface 1a, light emitted from the light source 2 enters the prism 1 and the fingerprint on the fingerprint collecting surface 1a. Reflected by This reflected light exits from the prism 1, passes through the lens group 3, and enters the photoelectric conversion element 4. Then, it is photoelectrically converted by the photoelectric conversion element 4, and is taken in as fingerprint image data for collation by the fingerprint image data processing unit 6. Further, the fingerprint image data processing unit 6 compares the fingerprint image data for collation with the fingerprint image data for reference registered in advance, and performs fingerprint collation.

Here, since only the convex portion of the fingerprint comes into contact with the fingerprint collecting surface 1a, incident light is not totally reflected but irregularly reflected at this convex portion. Therefore, in the photoelectric conversion element 4,
The portion corresponding to the convex portion is identified as a dark portion, and the portion corresponding to the concave portion is identified as a bright portion.

[0006]

However, in such a fingerprint collating device, the finger placement direction of the right-angle prism 1 with respect to the fingerprint collecting surface 1a is prism 1, light source 2,
The direction is determined in one direction by being restricted by the optical system including the lens group 3 and the photoelectric conversion element 4. For this reason, in the fingerprint reading device 5, the mounting direction of the unit including the prism, the light source 2, the lens group 3, and the photoelectric conversion element 4 with respect to various devices in which the fingerprint matching device 1 is incorporated is uniquely determined. There was a problem that the degree of freedom was small.

On the other hand, if the finger placement direction required for the fingerprint reader 5 is determined, the mounting direction of the fingerprint reader 5 to various devices is determined. There was a problem that the place was restricted.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a fingerprint reading apparatus in which a finger placement direction of a prism with respect to a fingerprint collecting surface can be arbitrarily selected, thereby increasing a degree of freedom in a mounting direction. And

[0009]

According to the present invention, there is provided, according to the present invention, a prism having a fingerprint collecting surface, and an imaging means for detecting light reflected from the fingerprint collecting surface after entering the prism from a light source. And a case for accommodating an optical system composed of these prisms, a light source, an image sensor, and the like, wherein the case shows a finger placement position in a predetermined finger placement direction on a fingerprint collection surface of the prism. This is achieved by a fingerprint reading device having a guide, wherein the center of the finger placement guide passes through the optical axis of the optical system.

[0010] According to the above arrangement, the fingerprint of the finger in contact with the fingerprint collecting surface of the prism is illuminated by the light beam from the light source, and the light beam reflected by the fingerprint is incident on the light receiving surface of the image sensor. Then, fingerprint image data is obtained. In this case, since the center of the finger placement guide is configured to pass through the center of the optical system, the finger placement on the fingerprint collection surface of the prism follows the finger placement guide with respect to the optical axis of the light beam from the light source. It is accurately positioned at a predetermined position. Therefore, the finger rest guide is
The finger placement direction can be set in any direction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. still,
Since the embodiments described below are preferred specific examples of the present invention, various technically preferred limitations are added.
The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

FIG. 1 shows an embodiment of a fingerprint reading apparatus according to the present invention. In FIG. 1, a fingerprint reader 10 includes a right-angle prism 1 having a fingerprint collection surface 11a.
1, a light source 12 disposed on one side (lower surface) with respect to the right-angle prism 11, a lens group 13 disposed on the other side (right side) with respect to the right-angle prism 11, and And a photoelectric conversion element 14.

The right-angle prism 11 is disposed so that one of the surfaces at right angles to each other faces downward, and the slope thereof constitutes a fingerprint collection surface 11a. The light source 12 is disposed so as to face substantially the center of the lower surface of the right-angle prism 11.

Further, the lens group 13 comprises two lenses 13a and 13b and an aperture 13p in the case shown. And these lenses 13a, 1
The lens 3b and the aperture 13p are integrally held by the holders 13d and 13e with respect to the lens barrel 13c (see FIG. 2), respectively.
It is attached to the substrate 15 via 13e.

The photoelectric conversion element 14 is, for example, a CCD (Charge Coupled Device) or the like as an image pickup element. The photoelectric conversion element 14 is attached to a holder 14a and fixed and held to the substrate 15 via the holder 14a. I have. Further, the photoelectric conversion element 14 is electrically connected to a connector 14b attached to the holder 14a, and the connector 14b is connected to the connector 16b by a cable 16 via a second connector 15a attached to the substrate 15. It is configured to be pulled out.

The light source 12 and the right-angle prism 1
The optical system 17 including the lenses 13a and 13b, the aperture 13p, and the optical conversion element 14 is positioned so that these optical axes L coincide with each other on a straight line. A housing 18 is provided for the optical system 17 including the right-angle prism 11, the light source 12, the lens group 13, and the photoelectric conversion element 14 so as to cover the entire optical system 17. I have.

The case 18 is entirely formed of, for example, plastic, and is configured to cover the entire optical system 17. This fingerprint reader 10
The case 18 accommodating the optical system is not limited to the illustrated shape, and various shapes are selected according to the mounting space of the device and the mode and structure of the mounted equipment. Further, the case 18 includes a finger placement guide 19 formed in a region facing the fingerprint collecting surface 11a of the prism 11.

As shown by a chain line in FIG. 1, the finger placement guide 19 is arranged such that the fingertip 20 is positioned upward from the left side of the case 18 near the upper edge of the fingerprint collecting surface 11a of the prism 11. It is formed so as to regulate the finger placement direction and the finger placement position of the finger to be fingerprinted.

Specifically, as shown in FIG. 3, the finger placement guide 19 is provided on the fingerprint collecting surface 1 of the prism 11 of the case 18.
It comprises a concave portion 19a formed on the slope facing the surface 1a. The center C of the concave portion 19a is set so as to coincide with the optical axis L in FIG. Furthermore, the recessed part 1
9a is preferably formed along the shape of the periphery of the finger to receive the tip including the abdomen of the finger to be fingerprinted.

Further, the finger rest guide 19 is used to detect the fingerprint of the fingertip 20 from which the fingerprint is to be collected.
A window 19b is provided so as to be able to make contact with a. As a result, the finger placement guide 19 is moved to the fingertip 20 where the fingerprint should be collected.
The finger placing direction and the finger placing position can be regulated so as to match a predetermined position on the fingerprint collecting surface 11a of the prism 11, preferably the optical axis of the light beam from the light source 12. Here, a finger placement guide 19 is formed on the case 18 and the center C of the finger placement guide 19 is coincident with the optical axis L, so that the fingertip on the case 18 is different from that in FIGS. The shape of the recess may be determined so as to be placed in a different direction.

That is, the center of the finger placement guide 19 is
Therefore, basically, the fingerprint can be read accurately regardless of the direction in which the finger is placed.
For this reason, it is possible to configure a fingerprint reading device in which the finger placement direction is not restricted.

The fingerprint reader 10 according to the present embodiment
Is configured as described above. When the operator inserts the fingertip 20 obliquely from the lower left in FIG.
Based on the shape of No. 9, the light comes in contact with the fingerprint collecting surface 1a of the prism 11 near the optical axis of the light beam from the light source 12. Thereby, the light emitted from the light source 12 enters the prism 11 and is reflected by the fingerprint on the fingerprint collection surface 11a. The reflected light exits from the prism 11 and is transmitted to each of the lenses 13a and 13b of the lens group 13 and the aperture 13p.
And enters the photoelectric conversion element 14. Then, the image signal is photoelectrically converted by the photoelectric conversion element 14, and the image signal is output from the connectors 14 b and 15 a to the outside via the cable 16. Thereafter, for example, in a fingerprint image data processing unit (not shown), the data is captured as fingerprint image data for collation,
The fingerprint image data processing unit compares the fingerprint image data for collation with the fingerprint image data for reference registered in advance, and performs fingerprint collation.

In this case, the fingertip 20 is
As a result, the fingertip 20 is guided to a predetermined position on the fingerprint collection surface 11a of the prism 11, so that the contact position of the fingertip 20 on the fingerprint collection surface 11a is guided to an appropriate predetermined position. Will be performed. Here, in the case of the illustrated finger placement guide 19, the fingertip 20
Restricts the finger placement direction so as to be located near the upper edge of the fingerprint collecting surface 11a of the prism 11 from the left.

On the other hand, when it is desired to restrict the finger placement direction in the opposite direction, the fingerprint reading apparatus 10 having the case 21 formed as shown in FIGS. used. In FIG. 4, the fingerprint reading apparatus 10 includes the optical system 17 shown in FIGS.
, The prism 11, the light source 12, the lens group 1
3 and the photoelectric conversion element 14 are used.
Only the finger placement guide 22 has a different configuration. Here, similarly to the case 18 illustrated in FIG. 3, the case 21 is entirely formed of, for example, plastic, and is configured to cover the entire optical system 17.
Further, the case 21 includes the fingerprint collecting surface 11 of the prism 11.
The finger placement guide 22 is formed in a region opposing a.

The finger placement guide 22 is formed such that the fingertip 20 is positioned downward from the upper side near the lower edge of the fingerprint collecting surface 11a of the prism 11, as indicated by a chain line in FIG. As shown in FIG. 5, the finger placement guide 22 includes a concave portion 22 a formed on a slope facing the fingerprint collecting surface 11 a of the prism 11 of the case 21.
The center C of the concave portion 22a is configured to coincide with the optical axis L in FIG. The shape of the concave portion 22a is configured along the shape of the fingertip in that state such that the fingertip 20 to be fingerprinted faces downward near the lower edge of the fingerprint collection surface 11a of the prism 11. Further, the concave portion 22a
The window 22 b is provided so that the fingerprint of the fingertip 20 can contact the fingerprint collecting surface 11 a of the prism 11. Thereby, the finger placing guide 22 sets the finger placing direction and the finger placing position of the fingertip 20 to be fingerprint-collected, the finger placing direction from the lower left diagonally in FIG. 1, and the predetermined position of the fingerprint collecting surface 11a of the prism 11, preferably. Can be regulated near the optical axis of the light beam from the light source 12.

When using the case 21 provided with the finger placement guide 22 having such a configuration, the operator inserts the fingertip 20 into the finger placement guide 22 of the case 21 from diagonally upper right in FIG. The fingertip 20 is a finger rest guide 2
Based on the shape of No. 2, it comes into contact with the fingerprint collecting surface 1a of the prism 11 near the optical axis of the light beam from the light source 12.

In this case, the fingertip 20 is
As a result, the fingertip 20 is guided to a predetermined position on the fingerprint collection surface 11a of the prism 11, so that the contact position of the fingertip 20 on the fingerprint collection surface 11a is guided to an appropriate predetermined position. Will be performed.

Thus, the fingerprint reader 10 can be used in the opposite directions by appropriately selecting and using the case 18 or 21 in response to the restriction on the installation direction on various devices and the finger placement direction depending on the installation location. By using the finger placement guide 19 or 22 having the finger placement direction, the contact of the prism 11 of the fingertip 20 with the fingerprint collecting surface 11a at the designated position is guaranteed. As described above, the fingerprint reading device 10 includes the case accommodating the optical system and the finger placement guide formed in the case, and the optical axis of the optical system is made to coincide with the center of the finger placement guide. The finger placement direction can be selected. For example, by selectively using the case 18 or 21, the degree of freedom in mounting the fingerprint reading device 10 and the like can be increased.

That is, by preparing a plurality of types of cases each having a finger placement guide having a different finger placement direction, the finger placement in an appropriate finger placement direction can be performed according to the installation location and installation direction of the fingerprint reading device. By selectively using a case having a guide, the degree of freedom in the installation location and the mounting direction of the fingerprint reading device is increased. Therefore, a general-purpose fingerprint reader that can be attached to various devices can be easily and easily manufactured by simply replacing a plurality of types of cases and using the configuration of an optical system including a light source, a prism, and an image sensor as it is. It will be obtained at cost.

In the above-described embodiment, a right-angle prism is used as the prism having the fingerprint collecting surface 11a. However, the present invention is not limited to this, and a prism having a fingerprint collecting surface for obtaining a fingerprint image by total reflection is used. Obviously, a prism having the shape shown in FIG. Further, in the above embodiment, two types of cases having finger placement guides in opposite finger placement directions are shown. However, the present invention is not limited to this, and other finger placement directions, for example, a horizontal orientation shifted by 90 degrees. A case having a finger placement guide in the finger placement direction may also be prepared.

[0031]

As described above, according to the present invention, the finger placement direction of the right-angle prism with respect to the fingerprint collection surface is arbitrarily selected, so that the degree of freedom in the mounting direction is increased. An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a configuration of an embodiment of a fingerprint reading device according to the present invention.

FIG. 2 is an exploded perspective view showing an optical system in the fingerprint reader of FIG.

FIG. 3 is a perspective view of a case having a first type of finger placement guide in the fingerprint reader of FIG. 1;

FIG. 4 is a schematic side view showing a configuration in a case where a case having a second type of finger placement guide is used in the fingerprint reading device of FIG. 1;

FIG. 5 is a perspective view of a case having a second type of finger placement guide in the fingerprint reading device of FIG. 4;

FIG. 6 is a schematic side view showing an overall configuration of a fingerprint matching device using an example of a conventional fingerprint reading device.

[Explanation of symbols]

10 fingerprint reader, 11 right-angle prism, 11a fingerprint collection surface, 12 light source, 13
..Lens group, 14 ... Photoelectric conversion element (imaging element),
15 ... substrate, 16 ... cable, 17 ... optical system, 18 ... case, 19 ... first type finger placement guide, 20 ... fingertip, 21 ... case, 22 ...
-A second type of finger rest guide.

Claims (3)

[Claims] A prism having a fingerprint collecting surface; an image pickup means for entering the prism from a light source and detecting light reflected on the fingerprint collecting surface; and an optical system comprising the prism, the light source, the image pickup device and the like. The case has a finger placement guide indicating a finger placement position in a predetermined finger placement direction on the fingerprint collection surface of the prism, and the center of the finger placement guide is A fingerprint reading device, wherein the fingerprint reading device is configured to pass through an optical axis of the optical system. 2. The fingerprint reading device according to claim 1, wherein the finger placement guide comprises a concave portion formed in accordance with a shape of a finger from which a fingerprint is to be collected. 3. A plurality of types of cases having finger placement guides corresponding to different finger placement directions are prepared as the case, and an appropriate finger placement direction is set in accordance with the installation location and installation direction of the fingerprint reading device. 2. A case having a finger placement guide is selected and used.
A fingerprint reading device according to claim 1.