JP2010035912A - Apparatus for photographing fingerprint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for photographing fingerprint which prevents an increase in the size of the entire apparatus. <P>SOLUTION: The apparatus for photographing fingerprint is equipped with a light source 3 for irradiating a sample surface including a fingerprint with light, a photographing device 11 for photographing an image including the fingerprint 5 on the sample surface 4, and a cylindrical light shield 2 having one end side 2a which supports the photographing device 11, and the other end side 2b positioned on the side of the sample surface and is characterized by placing the light source 3 in the neighborhood of the surface of a photographing lens 10 of the photographing device 11. The light source 3 is set to have a size smaller than an aperture of the photographing lens 10 and is preferably disposed in a central part of the photographing lens 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fingerprint imaging apparatus including a light source for irradiating light on a specimen surface including a fingerprint and a photographing machine for capturing an image including a fingerprint on the specimen surface.

  As a method for determining a suspect from a leftover item left at a crime scene or confirming its identity, a method of detecting a fingerprint remaining on the surface of the leftover item is widely used.

  Human skin is constantly secreting moisture, other inorganic substances such as sodium chloride, potassium and calcium, organic substances such as amino acids and lactic acid, and sebum. Fingerprints left on the surface of these objects are these secretions. Is formed by being transferred from the fingertip to the object surface. The fingerprint formed on the object surface is divided into a visible manifest fingerprint and a latent fingerprint that cannot be seen with the naked eye but can be detected by special means.

  The manifest fingerprint is transferred directly to gelatin paper or collected using a special photographing method. For detection of latent fingerprints, a powder method (solid method) in which a fine powder such as aluminum is attached to the latent fingerprint component, and a solution containing ninhydrin or the like is attached and reacted with the latent fingerprint component. A solution method (a liquid method) that reveals, a gas method that manifests by reacting iodine gas, cyanoacrylate gas, or the like with a component of a latent fingerprint is used (for example, Patent Document 1).

  The manifest fingerprint and the manifest latent fingerprint may be photographed for evidence preservation. However, for example, although the fingerprints treated with the cyanoacrylate gas described above are made visible, they cannot be easily visually observed. When photographing these fingerprints, light is obliquely illuminated. And shoot with shadows on the fingerprint ridges. Therefore, the photographing work requires a great deal of time and labor. In addition, if latent fingerprints are made obvious by methods such as the solid method, liquid method, and gas method described above, it will be necessary to add some hands to the original fingerprint, making it impossible to store the fingerprint as it is. .

  As means for solving this problem, the following Patent Document 2 discloses that a light source that irradiates light inside an external light blocking hood that blocks external light and light emitted from the light source is converged lightly. A fingerprint imaging apparatus comprising: an optical system arranged so that light is regularly reflected on a specimen surface and incident on a photographing machine; and a photographing machine that detachably fixes to the external light shielding hood and photographs a specimen including a latent fingerprint. Are listed. According to this fingerprint photographing device, the fingerprint can be easily seen by removing the photographing machine, and a blurred fingerprint that is difficult to visually observe can be photographed in a short time with a simple operation.

  Patent Document 3 below also describes a fingerprint imaging device in which an ultraviolet light source, a lens, a solid-state imaging device (corresponding to a camera), and the like are arranged in a housing that blocks external light.

JP-A-60-502088 Japanese Patent Laid-Open No. 6-147852 JP 2001-34738 A

  The problems in the prior art are as follows. That is, in Cited Document 2, a half mirror is provided for introducing light from the light source to the specimen surface, and the light path for the light source (left and right direction) is configured to be orthogonal to the optical path (vertical direction) of the imaging device. Therefore, the entire apparatus becomes large, and it is necessary to support the attached apparatus so as not to lose the balance when photographing. Therefore, there is room for improvement in terms of operability.

  In Cited Document 3, a half mirror is not provided. However, since the optical path for imaging and the optical path for the light source are set in an inclined state, the apparatus must be increased in size. Also, if the imaging optical path is set obliquely, it is difficult to focus on the entire surface of the specimen surface, and a blurred fingerprint image may be captured.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fingerprint imaging apparatus that can suppress an increase in size of the entire apparatus.

In order to solve the above-described problems, a fingerprint imaging apparatus according to the present invention includes:
A light source for irradiating light on a specimen surface including a fingerprint, a photographing machine for photographing an image including a fingerprint on the specimen surface, one end side supporting the photographing machine, and the other end side positioned on the specimen surface side A cylindrical light-shielding body having
The light source is arranged in the vicinity of the surface of the photographing lens of the photographing machine.

  The operation and effect of the fingerprint imaging apparatus having this configuration will be described. A photographing machine is supported on one end side of the cylindrical light shielding body, and the other end side is positioned on the sample surface during photographing. In addition, since the light source is disposed in the vicinity of the surface of the photographing lens of the photographing machine, the photographing optical path and the light source optical path can be configured to match or substantially match. Therefore, it is not necessary to provide a member such as a half mirror, and the overall size of the apparatus can be suppressed. Furthermore, since it is arranged in the vicinity of the surface of the taking lens, it is possible to take a fingerprint image with good sharpness without reflecting the shape of the light source.

  In the present invention, it is preferable that the light source is set to a size smaller than the aperture of the photographing lens and is disposed at the center of the photographing lens. By disposing at the center, the optical path of the light source can be made coincident with the imaging optical path, and the specimen surface can be illuminated uniformly. Moreover, since a light source smaller than the aperture of the lens is used, the subject light can be captured by the photographing lens.

  An example of an embodiment of a fingerprint photographing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an external configuration of a fingerprint photographing apparatus. FIG. 2 is a schematic diagram showing the internal configuration of the fingerprint imaging apparatus. FIG. 3 is a front view showing the configuration of the light source. The fingerprint imaging apparatus A mainly includes an imaging unit 1 and a light shielding unit 2 (corresponding to a cylindrical light shielding body).

<Configuration of First Embodiment>
An example in which a photographing machine 11 is used as the photographing unit 1 is shown in the figure. As the photographing device 11, a still camera, a CCD camera, a video, or the like can be used. In addition, a macro lens 10 (corresponding to a photographing lens) capable of macro photographing is attached to the photographing machine 11.

  As shown in FIG. 2, the light shielding unit 2 has a cylindrical shape and has a function of blocking external light. In addition, about a shape, it is not limited above, You may form in the shape of a square tube. The macro lens 10 of the photographing machine 11 is supported on one end side 2 a of the light shielding unit 2. As a method of supporting the photographing machine 11, for example, a filter mounting screw formed at the tip of the macro lens 10 may be used, or a configuration in which the camera 11 is simply placed may be employed.

  The other end side 2 b of the light shielding part 2 is positioned on the specimen surface 4. The light-shielding part 2 is positioned so that the fingerprint 5 existing on the specimen surface 4 is in the middle. The center of the light-shielding part 2 and the optical axis of the macro lens 10 are in agreement.

  The light source 3 is for irradiating the specimen surface 4 with light, and is attached to one end side 2 a of the light shielding unit 2. The light source 3 is provided in the vicinity of the surface of the lens 10 a located at the forefront among the lens group constituting the macro lens 10. The light source 3 is attached to the one end side 2a via the support portion 3a, and is located at the center of the lens 10a. A power supply line and the like to the light source 3 are performed via the support portion 3a.

  An image of the specimen surface 4 including the fingerprint 5 is captured by an imaging element such as a CCD or a film located on the imaging plane 12. At this time, since the light source 3 is arranged in the vicinity of the surface of the lens 10 a, the shape of the light source 3 does not form an image on the imaging surface 12. Therefore, even if the light source 3 is positioned at the forefront of the lens 10a, the image of the fingerprint 5 can be clearly taken.

  Further, when the image is confirmed with the finder of the photographing machine 11, the shape of the light source 3 is not imaged, so that there is no trouble in focusing operation and other operations.

  Note that the shape of the light source 3 is smaller than the aperture of the macro lens 10, and subject light can be taken into the macro lens 10.

  As a specific example of the light source 3, a light source using LEDs is preferable. In order to capture a fingerprint image clearly, it is necessary to irradiate light as perpendicular to the specimen surface 4 as possible and diffusely reflect it at the location where the fingerprint 5 is formed. Therefore, it is preferable to use an LED having relatively strong directivity as a light source. Of course, the light source 3 is not limited to the LED, and an EL light source or a fluorescent lamp may be used.

  According to the above configuration, the fingerprint imaging apparatus A can be configured with a simple configuration. Unlike the prior art, the light-shielding part 2 can be formed in a simple cylindrical shape, so that the center of gravity is located in the vicinity of the optical axis, so that it is possible to photograph in a stable state. In addition, since the light source 3 is disposed on the one end side 2a of the light shielding unit 2, the light shielding unit 2 can be reduced in size, and the size of the entire fingerprint imaging apparatus A can be suppressed.

<Configuration of Second Embodiment>
Next, an embodiment in which the arrangement of the light sources 3 is different will be described with reference to FIGS. In this embodiment, the light source 6 has a ring shape, and a hole for allowing subject light to pass therethrough is formed in the middle. The light source 6 is attached to one end side 2 a of the light shielding unit 2.

<Another embodiment>
The arrangement configuration of the light source 3 is not limited to that described in the present embodiment, and various modifications can be considered. For example, in FIG. 3, the light source 3 is disposed at the center of the lens 10a, but it may be disposed at the periphery instead of the center. Further, the light source 3 may be attached to the macro lens 10 instead of being attached to the light shielding unit 2. For example, you may make it attach using the filter attachment screw of the macro lens 10. FIG.

  The drive circuit for the light source 3 is not shown but can be provided separately. Alternatively, a driving circuit may be provided inside the photographing machine 11.

The perspective view which shows the external appearance structure of a fingerprint imaging device Schematic diagram showing the internal configuration of the fingerprint camera Front view showing the configuration of the light source The figure which shows embodiment from which the arrangement configuration of a light source differs Front view showing the configuration of the light source

Explanation of symbols

A fingerprint imaging device 1 imaging unit 2 light shielding unit 2a one end side 2b other end side 3 light source 3a support unit 4 specimen surface 5 fingerprint 6 light source 10 macro lens 11 photographing machine 12 imaging plane

Claims (2)

A light source for irradiating light on the specimen surface including the fingerprint;
A photographing machine for photographing an image including a fingerprint on the specimen surface;
A cylindrical light-shielding body having one end side that supports the imaging device and the other end side that is positioned on the specimen surface side,
A fingerprint photographing apparatus, wherein the light source is disposed in the vicinity of a surface of a photographing lens of the photographing machine. 2. The fingerprint photographing apparatus according to claim 1, wherein the light source is set to a size smaller than the aperture of the photographing lens and is disposed at a central portion of the photographing lens.

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