JPS6128172A - Picture input device - Google Patents

Abstract

PURPOSE:To obtain a sharp picture by providing a prescribed guide to a reflected face of a prism on which an object to be checked is placed to attain ease of positioning of the object to be checked. CONSTITUTION:The direction of a long side of a rectangular reflected face 12 of a prism 1 with cut and tilted ridge 15 on which a finger 2 for finger print image of the object to be checked is placed is made nearly coincident with a ridge line 14 formed by the incident face 11 of the prism 1 and the lead face. The positioning of the finger 2 is executed easily by the guide of this shape and the finger print with a sharp picture based on the reflected light image is obtained.

Description

TECHNICAL FIELD The present invention relates to an image input device, and more particularly to an image input device that optically detects a pattern to be verified, such as a fingerprint, and generates an electrical signal.

Conventional systems that use fingerprints to identify individuals have extremely high reliability due to the characteristics of fingerprints, which are unique to all people and unchangeable throughout life. Various devices have been proposed for verifying identity with fingerprints registered in a registered file.

In such a fingerprint verification device, a fingerprint pattern is detected from the back side of the placement surface of a finger placed on the finger device surface of a glass prism using a light source and an imaging device such as an ITV, using changes in the optical boundary of the glass. It has a fingerprint input device that generates a photoelectric conversion image, and is disclosed, for example, in Japanese Patent Application Laid-Open No. 1982-69300 and Japanese Patent Application Publication No. 54-85600.

1A and 1B show the arrangement relationship between a prism 1 and a finger 2, which is an object to be inspected, in such an input device, and the prism 1 has a light entrance surface 11 and a finger 2. The reflective surface 12, which is a mounting surface on which the
It has three independent surfaces including a derivation surface 13 for deriving the reflected light from. In this case, the longitudinal direction of the fingerprint pattern of the finger (which is also the longitudinal direction of the finger 2) is the entrance surface 11 and the extraction surface 1.
3 and is positioned substantially perpendicular to the nazuryo line 14.

Therefore, as shown in FIG. 1(C), the obtained image pattern causes an image rise in the longitudinal direction of the pattern due to the triangular prism shape of the prism 1.

Purpose of the Invention The present invention has been made to eliminate the above-mentioned drawbacks of the conventional ones, and its purpose is to eliminate the blurring of collected images caused by the triangular prism shape and to obtain clear images. Another object of the present invention is to provide an image input device that can easily position an object to be inspected on a mounting surface.

Structure of the Invention The image input device according to the present invention includes a prism having three independent surfaces: a light entrance surface, a reflection surface that causes reflection of light that has passed through the entrance surface, and a derivation surface that derives the reflected light. An image input device that places an object to be inspected having a pattern to be matched and inspects the pattern by using light from an output surface, which is parallel to the ridge line formed by the entrance surface and the output surface of the prism. The present invention is characterized in that a guide means is provided for making the longitudinal direction of the pattern of the object to be inspected substantially coincident with the same direction.

Fire cover 1 The present invention will be explained in detail below using the drawings.

FIG. 2 is a diagram explaining the present invention in detail, and goes to (A) (
C) corresponds to (A) to (C) in Figure 1, and 1
Equivalent parts are indicated by the same reference numerals in both figures. That is, the finger 2 is placed on the entrance surface 1 of the prism 1 so that the longitudinal direction of the fingerprint pattern substantially coincides with the direction parallel to the ridge line 14 formed by the entrance surface 11 and the output surface 13 of the prism 1.
Place it on top of 2. By doing this, as shown in (C), the sampled image pattern is
It is possible to eliminate the blurring in the longitudinal direction of the pattern that is caused by the prismatic shape, and the subsequent signal processing processes of digitizing pattern image signals and extracting fingerprint features can be performed effectively without errors.

Therefore, the configuration of the embodiment of the present invention is shown in FIGS. 3 to 7, in which a finger 2, which is an object to be inspected, is placed on the mounting surface 12 of the prism 1 in the longitudinal direction of the fingerprint pattern and the prism 1. A so-called guide means is provided to place the ridge line 14 so that the ridge line 14 substantially coincides with the ridge line 14 .

In FIG. 3, as shown in (A) is a plan view and (B) is a front view, the peripheral edge 15 of the mounting surface 12 of the prism 1 is tilted in a curved manner, and the longitudinal direction of the finger 2 is It has a rectangular shape whose direction substantially coincides with the ridge line 14 on the plane 12 surrounded by this cut 15. In other words, the yj direction of the long side of the rectangle surrounded by this cut 15 is now aligned with the mausoleum line 14.

As shown in FIG. 4 (△) is a plan view and (B) is a front view, projections 16 are provided on the other three sides of the placement surface 12 of the prism 1 except for the side on which the finger 2 is inserted, This protrusion 16
The direction of the long side of the rectangle formed by the plane 12 surrounded by the ridge line 14 coincides with the ridge line 14.

FIG. 5 shows the mounting surface 12 of the prism 1. In this example, a narrow groove 17 is formed in the groove 17, and the long sides of the rectangle surrounded by this groove 17 are parallel to the ridge line 14.

In FIG. 6, the shape of a finger is drawn with a line 18 on the mounting surface 12 of the prism 1 along the ridge line 14 so that the longitudinal axis of the finger coincides.

FIG. 7 shows that after cleaning the prism 1, a cutout is provided on the turntable 18, and this notch is used as a guide for placing the finger 2. A fan-shaped compress 19 and a dry cloth 20 are pasted on the surface of the turntable 18 facing the prism mounting K@'I 2, and the turntable 18 is moved in the direction of the arrow □Δ after the armature. As it rotates, the wet cloth 19 first wipes the placement surface 12 of the prism 1, and then the dry cloth 20 wipes it.

At this time, the wet cloth 19 has been sprayed with a cleaning liquid in advance, so that the mounting surface 12 is cleaned with this cleaning liquid, and then the dirt is wiped off with the dry cloth 20 together with the cleaning liquid. Then, the turntable stops at a position just before the turntable 18 is lit and the prism 1 is covered.

When the user inputs the personal identification number (II number) using a keyboard (not shown) to perform fingerprint verification, the turntable rotates to the position shown and stops, allowing the user to place their finger along this notch. Just place it.

Note that the collection pattern is not only human finger prints, but also T P with fingerprint patterns and other desired patterns to be inspected.
It may also be a film (plastic thin film) or the like.

According to the present invention, on the finger device surface which is the reflective surface of the prism, the longitudinal direction of the pattern of the object to be inspected is guided so as to match the ridge line formed between the entrance surface and the output surface of the prism. The user only needs to place the object to be inspected, such as a finger, according to this guide, which eliminates blurring of the image and makes it possible to collect a good pattern. The positioning of the object to be inspected can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional image input device, FIG. 2 is a diagram explaining the operation of an embodiment of the present invention, and FIGS. 3 to 7 are diagrams showing embodiments of the present invention. Explanation of symbols of main parts 1... Prism 11... Incoming surface 12... Reflecting surface 13... Deriving surface 14... Ridge line

Claims (1)

[Claims] An object to be inspected having a pattern to be verified is placed on the reflective surface of a prism that independently has three surfaces: a light incident surface, a reflective surface that causes reflection of the light that has passed through the incident surface, and a derivation surface that derives the reflected light. an image input device for inspecting a pattern to be matched using light from the derivation surface, the image input device comprising: An image input device comprising a guide means for making patterns substantially coincident in a longitudinal direction.