JPH0795343B2 - Fingerprint collection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] In a fingerprint collecting device, by providing a means for illuminating a transparent flat plate or a prism with which a finger is in contact only while the finger is in contact with the transparent flat plate or prism, an eye by a laser beam from a light source is provided. To prevent danger and improve safety.

[Industrial application field]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fingerprint collecting device, and more particularly, to a fingerprint collecting device that prevents a danger due to a laser beam from an illumination light source and enhances safety.

Recently, various technologies related to security of information processing systems have been developed along with the progress of advanced information society. For example, in order to manage entry into a computer room or the like that requires confidentiality, a personal identification system that uses a fingerprint or the like instead of a conventional ID card or a personal identification number is beginning to be introduced. Therefore, a fingerprint sensor using a prism, a hologram, or the like has been proposed as a personal information input means such as a fingerprint.

[Conventional technology]

FIG. 4 is a diagram showing a conventional fingerprint collecting device. This is because the hologram 2 is provided on the transparent flat plate 1, the illumination laser light source 3 and the image pickup device 4 are separately provided, and the light 6 reflected from the convex portion of the fingerprint of the finger 5 brought into contact with the transparent flat plate 1 is totally reflected. Under the conditions, the light propagates through the transparent flat plate 1, the light is guided to the outside by the hologram 2, and the light is detected by the image pickup device 4.

[Problems to be solved by the invention]

In the above-mentioned conventional fingerprint collecting device, even when the transparent flat plate 1 is not in contact with the finger 5, as shown in FIG.
However, there is a drawback in that it is dangerous to the human eye 8 because it leaks to the outside.

The present invention was created in view of the above points, and an object thereof is to provide a fingerprint collecting device having a high degree of safety.

[Means for solving problems]

Therefore, in the present invention, the illuminating laser light source 10, the transparent flat plate 11 or prisms 12 and 13 for contacting with a finger, the hologram 14, and the image sensor 15, the scattered light from the convex portion of the transparent flat plate. In the fingerprint sampling device that detects a fingerprint by utilizing the fact that the scattered light from the concave portion travels only within a certain incident angle range due to the presence of air while the light propagates in all directions inside As a means to illuminate a fingerprint only while it is in contact with 13, two triangular prisms 1
The prisms 2 and 13 are opposed to each other, a spring 16 is inserted therebetween, and a coupling liquid 21 is held on the surface of one prism 12 facing the other prism 13 and a prism facing the coupling liquid 21. A space is provided between the prism 10 and the surface, and the spring 16 is compressed by the contact pressure of the finger to eliminate the space, whereby the prisms 12 and 13 are optically coupled by the coupling liquid 21 and the light source 10 is formed. The feature is that the light from the light travels straight.

[Action]

By providing the means for illuminating the fingerprint only while the finger is in contact with the transparent flat plate or prism, it is possible to prevent the laser light from leaking to the outside except when the finger is in contact, and it is possible to improve safety.

〔Example〕

FIG. 1 is a diagram for explaining the first embodiment of the present invention.

In this embodiment, as shown in FIG.
A transparent flat plate 11, a hologram 14, and an image sensor 15 that are brought into contact with a finger
It is similar to the conventional example described in FIG. 4, and the main point of this example is that the transparent flat plate 11 is floated by the spring 16.
In addition, a movable contact 17 is provided at one end of the movable contact 17, and a fixed contact 18 is provided so as to face the movable contact.
Is inserted in the circuit of the light source 10 and the power supply 19.

In this embodiment having such a configuration, the movable contact 17 and the fixed contact 18 are normally separated by the spring 16 and the light source 10 is in the OFF state. Next, as shown in FIG. 1b, when the finger 20 is brought into contact with the transparent flat plate 11 to take a fingerprint, the contact pressure causes the spring to move.
16 is compressed and the contacts 17 and 18 come into contact, and the light source 10 is turned on.
As described above, the light source 10 is turned on only when the finger 20 contacts the transparent flat plate 11, and is turned off when the finger 20 is not contacted, so that the laser light does not leak to the outside. Therefore, the safety is higher than in the conventional case. The operation of detecting the fingerprint image in this embodiment is the same as that of the conventional example described in FIG.

FIG. 2 is a diagram for explaining the second embodiment.

In this embodiment, as shown in FIG. 2a, a laser light source 10 for illuminating a finger, a triangular prism 12 arranged to let the illumination light escape by total reflection, a prism 13 for inputting a fingerprint, a prism
A spring 16 and a prism 12 and 13 that provide a space between the prism 12 and 13.
And a hologram for extracting fingerprint information light into the air and an image pickup element (both not shown because they are provided at positions vertically away from the paper surface). ing.

In this embodiment having such a configuration, light 22 from the light source 10 passes through the prism 12 because air is present between the prism 13 and the coupling liquid 21 when the finger is not in contact with the prism 13. The light is totally reflected on the surface of and is released in the A direction. Therefore, the light does not go upward from the fingerprint input surface of the prism 13. Next, when the finger 20 is brought into contact with the prism 13 as shown in FIG.
13 contacts the coupling liquid 21 and is optically coupled to the prism 13. Therefore, the light 22 from the light source 10 travels straight to illuminate the finger 20, further reflects, passes through the hologram, and a fingerprint image is collected by the image pickup device.

As described above, also in the present embodiment, the illumination laser light 22 does not leak from the fingerprint input surface and is safe when the finger does not contact the prism 13.

FIG. 3 is a diagram for explaining the third embodiment of the present invention.

This embodiment has substantially the same structure as the second embodiment as shown in FIG. 3a. The difference is that the lengths of the left and right springs 16 are changed and the space between the prisms 12 and 13 is wedged. It is a shape. However, it is necessary that the B surface of the prism 12 and the C surface of the prism 13 are parallel to each other in the state shown in FIG.

The operation and effect of this embodiment configured as described above are similar to those of the previous embodiment, and when the space between the prisms 12 and 13 is wedge-shaped, the finger 20 is pressed against the prism 13. , The air layer above the coupling liquid 21 can easily escape,
There is an advantage that no bubbles remain between the prism 13 and the coupling liquid 21.

〔The invention's effect〕

As described above, according to the present invention, it is possible to improve the safety of the fingerprint collecting device with an extremely simple structure, and it is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a first embodiment of the present invention, FIG. 2 is a diagram for explaining a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention. FIG. 4 is a diagram showing a conventional fingerprint collecting device. FIG. 5 is a diagram for explaining the drawbacks of the conventional fingerprint collecting device. In FIGS. 1, 2, and 3, 10 is a laser light source for illumination, 11 is a transparent flat plate, 12 and 13 are prisms, 14 is a hologram, 15 is an image sensor, 16 is a spring, 17 is a movable contact, 18 Is a fixed contact, 19 is a power supply, 20 is a finger, and 21 is a coupling liquid.

Front page continuation (72) Inventor Yushi Inagaki 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) References JP-A-60-121422 (JP, A) JP-A-59-139481 (JP, A) JP-A-58-201178 (JP, A)

Claims (1)

[Claims] 1. A projection comprising a laser light source (10) for illumination, a transparent flat plate (11) or prisms (12, 13) for contacting a finger, a hologram (14), and an image sensor (15). The scattered light from the light travels in all directions in the transparent flat plate, while the scattered light from the recesses advances only a certain incident angle range due to the presence of air. As means for illuminating a fingerprint only while a finger is in contact with the transparent flat plate (11) or prism (13), the hypotenuses of two triangular prisms (12, 13) are opposed to each other, and a spring (1
6) is inserted, and while holding the coupling liquid (21) on the surface of the one prism (12) facing the other prism (13), the coupling liquid (21) faces the prism surface facing the other. By providing a space between them and compressing the spring (16) by the contact pressure of the finger to eliminate the space,
Connect both prisms (12,13) to the coupling liquid (21)
A fingerprint collection device characterized in that the light from the light source (10) is caused to go straight by being optically coupled by.