JPS6358708B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to radiographic reproductions suitable for viewing in transmitted light.

Direct and indirect photography methods using X-rays and X-ray photographs obtained by these methods are widely used as a means of confirming the condition of an affected area from the outside without making an incision. However, the X-ray photographs obtained by X-ray imaging are condensed three-dimensional shapes of the affected area into a flat shape, and it takes many years to examine the X-ray photographs and accurately understand the condition of the affected area. This requires experience and knowledge, and if typical examples of various symptoms are prepared in advance for reference, by comparing the details with such reference X-ray photographs,
It helps in understanding the condition of the affected area, and is also useful as a teaching material for training doctors and X-ray photography experts.

The original of such reference radiograph is the hospital;
You can carefully select from past X-ray photographs stored at research institutions, etc., but the selected X-ray
Conventionally, when copying line photographs, the following problems have been encountered.

First, the method of duplicating an X-ray photograph by repeating the process of contact printing and developing it using a silver halide film twice or in one process using an autopositive film requires the use of an expensive silver halide film and then the printing and developing process. The process is inefficient and unsuitable for mass reproduction, and therefore reproductions using silver halide photography have little utility.

Next, the method of duplicating X-ray photographs using a printing method is a method suitable for mass duplication, but the printed reproductions obtained by a general printing method are suitable for viewing with reflected light. A view similar to a line photo (such as a diffuser plate placed in front of a white light source)
If you place it in front of the screen and use it for viewing with transmitted light, the optical transmission density of each halftone dot itself is low, so the gradation and details cannot be expressed, so the original X
It cannot be said that a line photograph has been reproduced, and therefore reproductions simply printed by ordinary methods have little utility value.

In view of the above conventional drawbacks, the present inventor has conducted various studies and found that it is possible to reproduce an original X-ray photograph by printing on a transparent substrate using an ink composition with a high pigment concentration. In particular, if the maximum optical transmission density of the formed image layer is 1.2 or more, the X-ray photographic reproduction has a color tone that is almost the same as the original when compared using the viewer described above. The present invention is based on the fact that a dot image layer having a maximum density of 1.2 or more, which is obtained by hatching an X-ray photograph, is provided on the surface of a transparent substrate by printing. . This invention relates to an X-ray photographic reproduction for transmitted light observation.

The present invention will be explained in detail below.

First, to explain the transparent substrate used in the present invention, when observing the part of the X-ray photograph using the original silver halide photographic film where the silver has disappeared, it looks somewhat matte due to the presence of the emulsion layer, and is not completely transparent. However, when the present inventor printed and evaluated various types of plastic films in order to prototype X-ray photographic reproductions, it was found that as long as they were observed under transmitted light using a viewer etc., even if a matte-like plastic film was used, Alternatively, a smooth and transparent plastic film may be used. Therefore, a smooth transparent plastic film is sufficient from the point of view of observation using transmitted light, but a matte-like plastic film is preferable in order to express some degree of realism when viewed using reflected light. Other than the above-mentioned transparent smooth or matte finish, any transparent plastic film can be used as long as it is transparent, rigid, has excellent printability, and does not deform due to heat when observed with a viewer. For example, polypropylene film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polyethylene terephthalate film, polycarbonate film, nylon film, polystyrene film, ethylene vinyl acetate copolymer film, ethylene vinyl alcohol copolymer film, ionomer film. ,
Cellulose diacetate film, cellulose triacetate film, polysulfone film,
Examples include polyimide films. Among the above, polyethylene terephthalate film is preferred in consideration of price, durability, strength, weather resistance, light resistance, etc. These plastic films may be transparent and smooth, so-called clear films.
Also, a semi-matte or matte film may be used, and the semi-matte or matte film may be a kneaded matte film by a kneading method or a sand matte film by a sandblasting method, or coating, although it requires a separate process and is not advantageous. Coating matte film may also be used. Other papers with high light transmittance, such as tracing paper and parchment paper, can also be used as the transparent substrate, but when these papers are used, the transmission density is lower than that of a transparent plastic film.

A halftone dot image layer having a solid density of 1.2 or more, which is formed by hatching an X-ray photograph taken by X-ray photography, is provided on the transparent substrate as described above by a printing method. The original X-ray photograph is converted into a halftone positive or halftone negative using a photolithography method to express the tone by the size of halftone dots, and a printing plate is created, which is then printed using known printing techniques. The method is used to print on the surface of a transparent substrate.

When printing on the surface of a transparent substrate using normal ink using a normal plate-making method, the transmitted optical density of the halftone dots themselves is low, and when using a viewer, the color appears faded, and the transmitted optical density is about 0.6 to 0.7 at most. It's nothing more than that. However, since the transmitted optical density of an X-ray photograph of an original is approximately 2.5 to 3.0 at most, in normal printing, although the original is reproduced when observed with reflected light, the original is reproduced when observed with transmitted light. It cannot be reproduced. Strictly considering the reproducibility of originals, it is necessary to set the maximum value of transmitted optical density to 2.5 to 3.0, but as the density increases, identification becomes progressively more difficult, so setting the maximum value to 1.2 or higher is practical. It can be seen as a reproduction of the original. In order to make the maximum value of transmitted optical density 1.2 or more, the following means may be used.

(b) Two or three times using the same color ink and the same plate
Repeated overprinting (b) So-called duotone printing using different color inks and different plates Among them, the above method (b) has the advantage of widening the density range and usually producing a somewhat bluish tinge. It takes advantage of the fact that the original X-ray photograph can be reproduced using black ink and sepia or iris ink.

Further, in addition to carrying out the photolithography using a conventional contact screen, it is preferable to carry out the photolithography using an electrophotographic machine called a scanner, since the gradation can be controlled.

The printing ink used in the above is preferably adjusted to have a high optical transmission density of halftone dots, for example, 2.0 or higher, and an ink containing a high concentration of a coloring agent such as a dye or pigment is used. is desirable, and it is preferable to use a pigment with hiding properties.

In principle, any printing method may be used as the printing method used above, but in order to express delicate details, offset printing method and gravure printing method are preferable. Among them, offset printing method has good reproducibility of details and Moreover, it is preferable for this type of printing of a wide variety of products and relatively small lots.

In addition, since the X-ray photographic reproduction of the present invention is frequently used, the halftone image layer tends to be abraded, so the ink itself may be of an ultraviolet curing type, or a protective layer may be provided using an ultraviolet curing paint. You may. In addition, the protective layer may be a suitable transparent plastic film formed on the halftone image layer via a transparent adhesive layer, and can be applied not only from one side but also from both sides as described above. good.

Since the X-ray photographic reproduction of the present invention has the above configuration, it is possible to express the same gradation details as the original X-ray photograph even when observed with transmitted light from a viewer, etc. It can be used as a reference for engineers or as a training text.

Claims (1)

[Scope of Claims] 1. An X-ray photographic reproduction for transmitted light observation, in which a halftone image layer with a maximum density of 1.2 or more, formed by hatching an X-ray photograph, is provided on the surface of a transparent substrate by printing. thing. 2. The X-ray photographic reproduction according to claim 1, wherein the halftone image layer comprises two layers of different hues provided by a duotone printing method. 3. The X-ray photographic reproduction according to claim 1 or 2, wherein the transparent substrate is a transparent plastic film.