JPH06289495A - Image forming method - Google Patents

Abstract

PURPOSE:To faithfully reproduce a thin footprint or a fingerprint transferred to a gelatin paper by projecting and developing an original on which a footprint impression or a fingerprint impression is transferred by using a camera provided with a transmission exposure light source. CONSTITUTION:A transmission light source type photographing base is placed on an original platen 1; such a self-adhesive sheet for detection as the gelatin paper, a gelatin film, a triacetate film on which the footprint and the fingerprint left on a tatami mat, a floor, and a wall, etc., are taken is set on a glass on the transmission light source type photographing base, illuminated by the light sources A and B of the transmission light source type photographing base, and projected and developed on a photographic sensitive material by a process camera. Normal black and white silver halide photographic paper can be used as the photographic sensitive material to be used. However, in order to reproduce the footprint and the fingerprint having no brightness and darkness contrast in substance, a photosensitive material for silver complex salt diffusion transfer whose contrast (gradation) is high is desirable. Thus, the thin footprint and the fingerprint transferred on the gelatin paper, etc., can be easily and faithfully reproduced as a photographic picture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method.
In particular, the present invention relates to a method of photographing a thin footprint impression or fingerprint impression transferred to gelatin paper, gelatin film, triacetate film, electrostatic paper or the like with a photographic light-sensitive material and reproducing it as a photographic image.

[0002]

2. Description of the Related Art Obtaining footsteps and fingerprints left by a criminal on the scene is one of the important means for criminal investigation. Footprints and fingerprints of criminals are generally classified into those left on a tatami mat, floor, wall, or other hard surface and those left on a soft surface.For the former, a footprint detection adhesive sheet is used. For the latter, it is known that plaster is poured into the footprints and solidified.

The foot mark taken by the pressure-sensitive adhesive sheet for detecting a foot mark is then photographed by an ordinary camera, printed on black-and-white photographic paper, and stored. To reproduce the footprints of a criminal by taking pictures with a normal camera, it was a difficult problem to accurately reproduce the dimensions. That is, there has been no method for simply and accurately reproducing the size (size) of the foot print taken with the pressure-sensitive adhesive sheet for foot print detection as a photographic image.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image forming method which reproduces thin foot marks and fingerprints transferred on gelatin paper, gelatin film, triacetate film, electrostatic paper, etc., as a faithful photographic image. Is to provide.

Another object of the present invention is to provide an image forming method for reproducing traces or fingerprints as a faithful photographic image by a simple method using an existing plate making camera.

[0006]

The above-mentioned object of the present invention is characterized in that a document on which a footprint impression or a fingerprint impression is transferred is photographed on a photographic light-sensitive material using a camera equipped with a transmissive exposure light source and developed. Image forming method.

The details of the present invention will be described below with reference to the drawings of the embodiments.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view showing a typical example of an existing plate-making camera suitable for carrying out the present invention. Specifically, a diagraphica repro camera OS-6 manufactured by Mitsubishi Paper Mills, Ltd.
006V, 6006S, 5025V, 6026V, 60
26S etc. FIG. 2 is a perspective view of a transmission light source type photographing table suitable for carrying out the present invention.

The original table (original rack) 1 is of a usual type in which original paper is pressed by a glass plate. Each of the light source A and the light source B is, for example, a box type housing two halogen lamps of 400 W, and the box can adjust the angle and distance with respect to the platen.
It is not used in the image forming method of the present invention. The light applied to the original document strikes the photographic light-sensitive material of the photographing section 2 through the lens. As the photographic light-sensitive material, for example, a negative material for silver complex salt diffusion transfer (one-step T-NE, N manufactured by Mitsubishi Paper Mills, Ltd.) capable of obtaining a high-contrast image is obtained.
E, B-NE) is used.

Comparative Example A pressure-sensitive adhesive sheet for detecting footprints and fingerprints remaining on tatami mats, floors, walls, etc. is placed on the document table 1. Light source A and light source B were irradiated at the same angle (about 45 degrees) and distance (about 800 cm) with the pressure-sensitive adhesive sheet for detection, and images were taken with the negative material. This negative material and positive material (manufactured by Mitsubishi Paper Mills Co., Ltd. One Step 1
PGL, 1P, PC-100) was passed through an ordinary DTR processor for development processing, and peeled after about 20 to 60 seconds. The positive material is almost pure white, with a slight footprint,
The fingerprint traces were only partially recognized as a silver image.

EXAMPLE Next, as shown in FIG. 1, a transmission light source type photographing table was placed on a document table, and a gelatin paper was placed on the glass of the transmission light source type photographing table.
Set the footprints and fingerprints transferred on an adhesive sheet such as gelatin film, triacetate film, or electrostatic paper, and shoot with a light source of a transmission light source type shooting table. After photography, the film was developed in the same manner as above, and silver images of footprints and fingerprints were accurately, faithfully and clearly reproduced on the positive material.

Especially, there are thin footprints and fingerprints transferred by gelatin paper, gelatin film, triacetate film, electrostatic paper, etc., and it is necessary to adjust the exposure amount. By doing so, the appropriate exposure amount can be found relatively easily.

In the above-mentioned embodiment, the transmission light source type photographing table is placed on the original plate 1 of the existing plate making camera, but a plate making camera in which the original plate 1 itself is provided with a transmissive exposure light source may be used. .

As the light-sensitive material used in the present invention, ordinary black-and-white silver halide photographic printing paper can be used, but contrast (gradation) is reproduced in order to reproduce footprints and fingerprints which have substantially no contrast between light and dark. It is preferable to use a photosensitive material for silver complex salt diffusion transfer having a high temperature.

[0015]

INDUSTRIAL APPLICABILITY According to the present invention, particularly thin footprints and fingerprints transferred by gelatin paper, gelatin film, triacetate film, electrostatic paper and the like can be simply and easily obtained by using a transmission light source type photographing stand and a plate-making camera. It can be faithfully reproduced as a photographic image and contributes greatly to the promotion of criminal operations.

[Brief description of drawings]

FIG. 1 is a front view of a plate-making camera in which a transmission light source type photographing table is installed on a document table.

FIG. 2 is a perspective view of the transmission light source type imaging stand of FIG.

[Explanation of symbols]

 1 Manuscript table 2 Shooting section

Claims (1)

[Claims] 1. An image forming method comprising: photographing a document on which a footprint impression or a fingerprint impression is transferred onto a photographic light-sensitive material using a camera equipped with a transmissive exposure light source and developing the photographed material.