JPH0754543B2 - Image input device - Google Patents

Description

The present invention relates to an image input device, and more particularly to an image input device for optically inputting a collation pattern of an object to be inspected.

[Conventional technology]

Generally, fingerprints have the properties of “universal” and “lifetime invariant”. For this reason, the fingerprint collation system that uses image processing and pattern recognition technology to fix the individual by collating the identity of the input fingerprint with the registered fingerprint that has been registered in advance has extremely high reliability. Various systems have been proposed.

In such a fingerprint collation system, it is necessary to optically detect a fingerprint pattern to be fingerprint collated and convert it into an electric signal. An image input device of this type is, for example, JP-A-54- As seen in the 85600 publication,
For the finger placed on the prism mounting surface, the optical boundary change is used from the back side of the mounting surface to detect the light source and ITV (I
An image input device that generates a photoelectric conversion image of a fingerprint pattern by an image pickup device such as an industrial television is known.

FIG. 3 (A) is a plan view showing the positional relationship between the prism 1 and the finger 2 as the object to be inspected in such an image input device, and FIG. 3 (B) is a front view thereof, not shown. The optical path from the light source is also shown.

The prism 1 independently has three surfaces: a light incident surface 11, a reflecting surface 12 that is a mounting surface on which the finger 2 is mounted, and a lead-out surface 13 that guides the reflected light from the reflecting surface 12.

FIG. 3C is an example of a fingerprint pattern obtained from the derivation surface 13. The fingerprint pattern is registered using the fingerprint pattern in the state shown in FIG. 3 (C).

By the way, in the case of the above-mentioned conventional image input device, if no restriction is placed on the placement of the finger 2, the finger is placed on the prism 1 in a user's arbitrary orientation. When the finger 2 is placed on the prism 1 at a certain angle instead of being straight as shown in FIGS. 4 (A) and 4 (B), the fingerprint pattern obtained is as shown in FIG. 4 (C). Three
The fingerprint pattern in FIG. 6C is rotated by a certain angle. Also, for example, as shown in FIGS.
Is placed too far from the predetermined position, the fingerprint pattern obtained is a parallel translation of the fingerprint pattern of FIG. 3C as shown in FIG. . When the input fingerprint is collected in the above-described manner, a collation with a fingerprint pattern such as that shown in FIG. 3 (C) that has been registered in advance is complicated in consideration of parallel movement and rotation of both patterns. Positioning processing is required as pre-processing.

Therefore, the present inventor first applied for a patent (Japanese Patent Application No. 61-271328).
No.), an image input device is proposed in which guides are provided on the reflecting surface of a prism along at least both sides and an end of a finger as an object to be inspected. According to this image input device, the placement of the finger in the form shown in FIGS. 4A and 4B and the placement of the finger in the form shown in FIGS. 5A and 5B are prevented by the guide. As a result, the finger placement condition can be made to be the same to some extent, and the alignment process between the input fingerprint pattern and the registered pattern can be simplified by that much.

[Problems to be Solved by the Invention]

However, the guide along at least both side portions and the end portion of the finger to be inspected has to have a relatively complicated shape, which causes a problem when the manufacturing cost increases, and can be surrounded by the guide. Moreover, dust and the like are likely to be accumulated on the surface on which the fingerprint is placed, and the cleaning thereof cannot be performed easily.

The present invention has been made in view of such circumstances,
The purpose is that the guide with an extremely sensitive structure makes it possible to make the placement condition of the finger, which is the object to be inspected, almost constant, and dust is hard to collect on the placement surface of the prism, and cleaning is also possible. An object is to provide an easy image input device.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention is provided on the reflecting surface of a prism which independently has three surfaces of a light incident surface, a reflecting surface for reflecting the light passing through the incident surface, and a derivation surface for deriving the reflected light. In an image input device for inputting a collated pattern having a mounted inspection object by using light from the derivation surface, an arc-shaped concave portion on which a first joint portion of a finger, which is the inspection object, is placed. It has a structure in which the provided finger joint part mounting guide to be inspected is provided at a predetermined position near the reflection surface of the prism.

[Action]

In the image input device of the present invention, the finger to be inspected is placed in the arc-shaped concave portion of the finger joint placement guide to be inspected provided at a predetermined position in the vicinity of the reflecting surface (mounting surface) of the prism. When the first joint is placed, the orientation of the finger and the position in the front-back direction are substantially constant, and the placing conditions of the finger that are repeatedly performed become substantially equal.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, an embodiment of the image input device of the present invention is configured such that an incident surface 11 of light from a light source (not shown), a reflecting surface 12 for reflecting light passing through the incident surface 11 and a reflection from the reflecting surface 12 are reflected. An object to be inspected is placed at a predetermined position near the reflecting surface 12 on the upper panel 4 of the image input apparatus body in which the prism 1 having the three derivation surfaces 13 for guiding the light to be input to the image pickup device (not shown) is incorporated. A guide 3 for placing a finger joint part to be inspected on which the first joint part of a finger as a physical object is placed is provided.

The guide 3 of this embodiment is formed by forming a part of a thin plate into an arc shape, and in use, the plan view of FIG. 2 (A), the front view of FIG. 2 (B) and the FIG. 2 (C). As shown in the side view of FIG. 3, the fingerprint portion of the finger 2 is pressed against the reflecting surface 12 of the prism 1 while the first joint portion of the finger 2 is properly placed on the guide 3. By doing this, the finger 2
The direction is fixed, and the finger is not placed diagonally as shown in FIGS. 4 (A) and 4 (B). Further, the position of the finger 2 in the front-rear direction is also defined by the guide 3 so that the finger 2 will not go too far forward or, as shown in FIGS. As a result,
The fingerprint pattern to be input is shown in FIG. 4 (C) and FIG. 5 (C).
It is possible to suppress such rotation and parallel movement as described above, and it is possible to reduce the alignment processing performed prior to the subsequent matching processing.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various other additions and changes can be made. For example, in order to secure a stable placement of the finger to be inspected, at least one of the fingers on both sides of the finger or the other fingers are described in the attached specification and drawings of Japanese Patent Application No. 61-271328 previously filed. A structure for guiding with a placement guide for a single finger may be adopted, and further, a plane for placing not only the finger but also the palm is provided, and the palm is fixed, and then the finger joint part to be inspected according to the present invention is placed. The fingerprint pattern may be input according to the user guide.

〔The invention's effect〕

As described above, the image input device of the present invention has the finger joint to be inspected having the arc-shaped recess for placing the first joint portion of the finger to be inspected at a predetermined position near the reflecting surface of the prism. Since it has a part placement guide, it is possible to make the orientation of the finger and the position in the front-back direction almost always constant when placing the finger repeatedly over a plurality of times. Has an effect that an extremely simple structure is sufficient, and since the fingerprint placement surface of the prism is open, it is difficult to collect dust and the like and can be easily cleaned.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of an embodiment of the present invention, FIG. 2 is a view showing a usage state of the embodiment of FIG. 1, and FIG. 3 is a description of a conventional image input device. FIG. 4, FIG. 5 and FIG. 5 are explanatory views of problems of the conventional image input device. In the figure, 1 ... Prism 2 ... Finger 3 ... Guide 4 ... Top panel of image input device 11 ... Incident surface 12 ... Reflection surface 13 ... Derivation surface

Claims (2)

[Claims] 1. An object to be inspected, which is placed on the reflecting surface of a prism, which independently has a light incident surface, a reflecting surface for reflecting the light passing through the incident surface, and a derivation surface for deriving the reflected light. In an image input device for inputting a collation pattern of an object using light from the derivation surface, a finger joint part to be inspected having an arc-shaped concave part for mounting a first joint part of a finger to be inspected An image input device comprising a mounting guide at a predetermined position near the anti-slope of the prism. 2. The image input device according to claim 1, further comprising a flat surface for fixing a palm of a hand including the finger.