HU210844B - Method for making films and die plates suitable to the manufacturing special prints - Google Patents

Abstract

The present invention relates to the production of films for the production of special prints, preferably of securities, and optionally of printing presses, by creating a pattern on a substrate, and then by exposing the pattern to a laser beam and rendering it to a film by color, by retrieving the film and making a deduction, and, if necessary, the elaborate, - making a pre-sensitized press form of a controlled film. The invention is characterized in that an illuminated optical grid consisting of irregularly contoured points containing defective sites is produced on a transparent substrate, and the optical grid thus produced is illuminated in a known manner by means of a coded laser beam. EN 210 844 A Scope of the description: 4 pages

Description

The present invention relates to a process for the production of films and forms suitable for the production of special prints, preferably securities.

The production of securities usually requires the use of special printing techniques.

The advancement of printing and printer-level photocopying technology makes it possible for color copies of banknotes and securities to approach the originals almost perfectly and to be misused. The protection of securities against copying is provided by the use of watermarks, so-called security papers, or special-fiber papers, unique graphic elements, ink embossing or UV-excited ink component, or the use of special perforations.

Such special procedures are described in T. Kolossá, T. Szilágyi: Press on the Desk, Editoprint, Bp.

Printing techniques for making printing plates are also well known in the art.

One type of printing process is flat printing, including offset printing.

With this technology, the drawing and the non-drawing elements are on the same plane. The process steps for producing an injection mold are as follows.

The first step is to create the text or image and fix it on a magnetic disk or other medium such as film or paper.

The text or image on the substrate is transposed onto film by exposure, preferably by means of a laser exposure device.

The illuminators also perform grid and color decomposition.

The color film produced is then developed, usually using an automatic developer.

This will record the data recorded on the film.

It is expedient to make a control copy of the recorded films.

This process is called the Cromalin process, developed by Du Pont.

The process is usually repeated four times according to the colors used.

The completed proof is then checked and the errors are corrected.

Details of the above steps can be found in the following textbooks.

Peter-Szilágyi Offset Technology (Technical Publisher, Bp. 1978, pp. 158-165, pp. 165-170, pp. 177-182) and Szilágyi: Advanced Offset Technology, (Edito Print, 1991, 61-62) , 111-116,121-123, 150-151).

Verified, approved films are printed.

In this connection, the film is placed on a metal plate with a photosensitive layer, preferably on an aluminum plate. This is illuminated with a halogen lamp, the surface of the photosensitive layer is unaffected, and the die is fixed.

Known operations are described in detail in the "Technologie des Offsetdrucks" (Verlag Beruf u. Schule, Itzehoe, 1989, pp. 20-33, 84/87, 95, 76/82) and in Werner, Standardisierten Mehrfarben Offsetdruck (Polygraph Verlag, Frankfurt, Germany). 2, 21-23, 1982).

The purpose of the above operations is to produce a printing mold capable of producing prints that are faithful to the original. You can make any number of identical copies of these prints by copying them.

EP 0 273 526 describes a process for making security documents such as bonds and shares.

The essence of the procedure is to create a so-called "moire" pattern by applying offset grids.

Loyal copying of moire is very difficult on ordinary copiers.

The disadvantage of this process is that the moire created on the security provides a distracting look and is also faithfully reproducible on special copying machines, thus not providing complete protection against counterfeiting.

It is an object of the present invention to provide a process for producing a film or printing form which is not copied in the same way as the original.

The method of the present invention is based on the recognition that by creating a special optical grid with defective locations and illuminating it with a laser beam of a given resolution, a film can be produced which then produces prints that cannot be copied in the same way as the originals.

The commonly known "optical grid" consists of regular contour elements, such as dots and spaced apart, which are equally spaced.

Such an optical grid can be mapped to a substrate (such as a film) without the aid of the electronic scanner devices of our time, since such "regular" optical grids are rendered using the factory-supplied program of the device.

If light is transmitted through the regular contour points of a regular grid, the scattering of light behind each grid point will be the same magnitude and direction. This produces a pattern of regular dots on a substrate, such as a film or photosensitive disk.

Producing a print form from the film, the print forms produce the regular grid pattern and can be reproduced by photocopying.

However, in contrast to the above, the present invention provides an optical lattice where the contours of the lattice points are not regular (circular), but the contours are deformed, amorphous.

In addition, the optical grid created in accordance with the present invention also contains so-called "defect locations", i.e., some of the amorphous contour points are randomly missing. Thus, at these so-called error locations, the distance between points and point intervals is uneven.

The essence of the present invention is. if we pass the light beam through an optical grid with irregular contour points and defective locations instead of a regular optical grid,

EN 210 844 The scattering of light behind the case will be irregular and directional.

This irregular scattering results in light interference behind the grid. This interference-modified beam produces an irregularly arranged pattern on the substrate (film) behind the grid.

This irregular pattern is already an unstable grid because it disintegrates when re-exposed.

In the case of illumination (eg photocopying), another interference occurs and the pattern is disintegrated to varying degrees, so the copy will be different from the original.

As a result, the film or printing pattern produced by the present invention is not counterfeit by photocopying, and is thus well suited for the production of bonds and various securities.

The present invention relates to a process for producing films and optionally printing forms for producing special prints, preferably securities, by forming a pattern on a substrate, then lightening and color-mapping the pattern onto a film, recovering the film and then extracting said film. , from pre-sensitized printing to controlled film.

The method is characterized in that, on a transparent substrate, an optical grid of irregularly contoured dots containing defective locations is produced as a special original, and the optical grid thus produced is exposed by a laser beam encoded in a known manner.

According to the invention, the special optical grid is illuminated by an argon-ion laser beam having a resolution of 2000 to 8000 dpi.

The advantages of the process according to the invention are as follows.

There is an economical, simple procedure for producing copy-safe securities. Due to the large number of possible variations of the fault location design, the variation of the "grid codes" recorded on the film is almost infinite.

The "grid codes" can be stored on film and can later be safely identified.

In the process of the invention, the points of the optical grid may have any density, but the point size must be greater than the resolution pixel of the illuminator.

In our method, it is expedient to use a laser beam illumination that is at the line of sight.

The process of the present invention is illustrated by the following examples:

Example 1

An optical grid is created with a grid density of 80 lines / cm.

The optical grid is imaged on a film using a Dainippon Screen S-605 argon-ion laser beam at 7000 dpi in two machine revolutions.

A signal generator is connected to the device to draw a grid point on six applied Fuji Is 5000 film. The repeatability of the workflow precludes that the program setup switches of the unit are in a position where the mapping is not random, coded, but random. Random rendering will cause the grid points of the optical grid to be irregular.

The film is developed in a Dainippon F 305 developer with Fuji-Grandex system developer.

The special original thus produced is exposed to film in a known manner in encoded mode using the above apparatus. then the film is developed as described above.

We make a control copy of the developed film by Du Pont company Cromalin.

We apply a White Line Laminator to laminate the film, apply a toner to the ATM V, and then apply a Top Coat Laminat seal to the sandwich structure, which is exposed to UV light.

After illumination, the illuminated layer is peeled off the sandwich structure. We produce a film by color, which is superimposed on one another.

The extract is compared with the original and corrected if necessary.

We make the printing of controlled films.

The die is made from a pre-sensitized sheet 0.4 mm thick.

A controlled film is placed thereon and illuminated by a metal halide lamp with an emission spectrum of 300550 nm. The plate is then developed with an aqueous-alkaline developer, rinsed and dried.

After printing, the ink is suitable for offset printing.

The printing forms thus produced are used to print stocks.

On the surface of the stock, the points of the optical grid are clearly visible with a magnifying glass.

The stock is placed in a photocopier and copied.

Examining the copy with a magnifying glass shows that the copy does not contain the grid points on the original stock.

Example 2

All proceed as in Example 1, but using an argon ion beam laser at 8000 dpi.

Claims (2)

1. Procedure for special prints, preferably securities. can be used to make films and optionally printing molds, creating a pattern on a substrate, then lightening the pattern with a laser beam and color rendering onto film, evoking the film, and optionally producing a pre-sensitized printing film from said controlled film, on a clear media as a special original, with irregularities containing defects EN 210 844 An optical grid of contour points is prepared and the optical grid thus produced is exposed by a laser beam encoded in a known manner. Method according to claim 1, characterized in that the exposure is performed with an argon ion laser beam having a resolution of 2000-8000 dpi.