Hidden raster printed image
The invention relates to a latent raster printed image on a substrate, which shows, in particular, the multi-color reverse image under the influence of ultraviolet rays, and also to a method for producing such images. The image obtained additive method of mixing colors using the coloring matter of blue, red and green and fluorescent under ultraviolet rays substances. Raster printed image contains preferably several pigments, fluorescent under ultraviolet rays. This provides the possibility of applying hidden monochromatic or multicolored and a complex of images and patterns on products for applications, in particular for advertising purposes. 2 AD. and 2 C.p. f-crystals.
The present invention relates to a latent raster printed image on the substrate, which means displays one - or multi-color image, the method of its production and its use in advertising or for promotional purposes and for purposes of marketing products.
There is a need to label items such as products on the circumstances. For example, for advertising design product images and stories such hidden marking is of interest, so as thereby creating unexpected and particularly attractive optical effects that benefit for advertising marked products.
Patent WO 88/01288 describes a method of marking a substrate for security purposes, for example to protect a cheque cards from forgery, in which the first substrate is applied photochromic dye (i.e. paint, which is colorless in daylight and change color under the influence of ultraviolet rays and then the paint layer is coated with the protective layer, for example, from plasticized PVC. Preferably, the photochromic dye is applied by a screen printing method. Patent WO 88/01288 does not describe the marking of products with complex images and motifs of images for advertising purposes.
Another way to protect sensitive to the dangers of the subject, such as a cheque card, using a hidden marking describes the patent EP-A-0279526. By printing on the substrate in two different bundles of lines that intersect in the same place creates a moire pattern, which is difficult to forge. Applied printed to the ne only under the influence of ultraviolet rays. But in this case, the application for the purpose of advertising is not disclosed.
The patent US-A-5289547 describes a method of authentication, for example, banknotes, in which the applied photochromic compound, which may be visible or invisible to the human eye. The application of the photochromic compound is made by screen method.
In the patent EP-A-0327788 disclosed photochromic printing inks, which are used, in particular, for printing documents. Photochromic printing ink containing photochromic compounds, protected from oxygen and other components of the ink and which under the influence of ultraviolet rays give reversible color scheme. The printing ink may be different printing methods.
Patent WO-A-90/06539 also considers protective marking items photochromic compounds, which under the influence of ultraviolet rays give a visible image, and in this case, to improve the life of the photochromic compounds and for protection from sunlight is applied sunscreen layer.
From the patent GB-A-2272861 known device for producing and/or read documentone the invention aims to create a product that allows you to equip items hidden single or multi-color, as well as comprehensive images and designs for promotional purposes.
This task is solved hidden on the substrate a raster image, which under the influence of visible and/or fluorescent light (or, at most, only schematically) invisible to the human eye and shows single or multicolored image only under the influence of ultraviolet rays. Image reversal, that is, as soon as the ultraviolet rays have no effect, disappears the image after repeated UV exposure is made visible again. While it is preferable that this color image was multicolored. By applying the latent image by means of printing raster form, in contrast to the prior art, printing on the substrate complex of images and patterns, in particular for advertising purposes.
Color and multi-color bitmaps known for a long time. Get them traditional printing methods (see, for example, N. M.Speirs, "Introduction to Printing Technology", British Printing Industries Federation, 4. Aufl., 1992, Kapitel 2), commonly used raster ways (see, for example, H. M. Speirs, "Int ink next to each other and one above the other and arising due to the mixing of paint and change of intensity creates a visual effect. Educated in such a way bitmaps are easily visible to the human eye, i.e. under the influence of visible light (e.g. daylight), in other words, light with a wavelength range from approximately 400 to 700 nm, they show black and white or one - or multi-color image.
In addition, layers of paint, which under the action of visible light do not show colorful images, even if they are exposed to ultraviolet rays in the wavelength range from about 190 to 400 nm. Such images are called “hidden images”, as they are under normal light conditions are not distinguishable and only focused excitation become visible as images. These paint layers contain so-called fluorescent dye. Fluorescent dye is in an energetically excited state; under the influence of, for example, radiation fluorescent dye enters a state of low energy, and excess energy is given due to the emission of quanta of light of a certain wavelength. If the wavelength of the emission is in the visible range, given the radiation is perceived by human eyes is the value of people. So, in the entertainment places it is customary to apply a paying visitor at the entrance, for example, stamp a small number of latent luminescent paint on the skin (e.g., palm). This staining in the “normal” light is invisible, but visible under ultraviolet irradiation, so that the visitors entertainment, you can easily check paid whether they are input and applied whether hidden paint by briefly finding the area of skin under the ultraviolet lamp. Similarly, elections can find out the fact that the voters voted only once.
This painting up to the present time applies only monochromatic, that is, the observer under the influence of ultraviolet rays perceives only the monochromatic image. It is also not known, their use in promotional purposes.
In addition, from the patent DE 3216568 A1 famous image is a photographic technique in which the material for a photographic record containing at least one layer of photosensitive silver halide and at least one luminescent compound, fine exposed and developed to obtain a latent luminescent image is tsya fluorescent spectroscopic method and electronically recorded in the form of a monochrome fluorescent signals; the method provides single and multi-color image. This notation does not give a bitmap image and is not used for covert marking objects colourful image.
Usually a bitmap image in accordance with the invention contains at least one dye that is fluorescent under ultraviolet rays. The fluorescent dyes are used to dye substances which under the influence of ultraviolet rays first pass in an energetically excited state and then also under the influence of ultraviolet rays are stimulated to emission of light quanta and quanta of light are emitted with wavelength, in the visible range of the spectrum. The human eye in this case takes only paint that matches the wavelength of the emitted photon, and only when the bitmap is exposed to ultraviolet rays.
Fluorescent under ultraviolet rays dyes are in themselves known and marketed compounds (see Lacke und Druckfarben, 1998, S. 355 keyword "Leuchtfarbstoffe"). We are talking about, for example, those described in WO 88/01288 in cacertificate rays, described in WO 98/32799, DE-A-19512773 and DE-A-19651712. As printing inks containing fluorescent dyes, can be applied, for example, printing ink company SICPA-AARBERG, Switzerland, with the designation INNOVA 62-LC (Lumi-Color).
Preferably they give luminescence when exposed to ultraviolet radiation in the wavelength range from 240 to 380 nm, in particular at about 366 nm.
Dot raster print images are preferably 60 to 120 dots/cm, and in a given raster number of points does not depend on the size of the points. By varying the size of the halftone dots is generated optical modulation deepening of the image. If the plotted points are larger, they can come into contact with the adjacent points so that it can be obtained complete coverage of the surface.
Ways to use additive blending of colors (see, for example, E. D. Stiebner, "Bruckmann''s Handbuch der Drucktechnik", Bruckmann, 5. Aufl., 1992, p. 100-103; H. M. Speirs, "Introduction to Printing Technology, 4. Aufl., 1992, p. 76-78) is particularly preferable to obtain raster print images in accordance with the invention in comparison with also a possible way subtractive mixing of colors when the substrate a raster of the printed image is not enough white color is trafilerie rays, come basically in a dark environment, but also to increase the effect of UV illumination (night clubs, entertainment venues, and so on), you must reckon with the fact that the white color as an integral part for subtractive mixing of colors created (composed) multicolor raster print images is often missing. It is the absence of white light can be overcome by using additive blending colors to obtain a multicolor raster printed image. This method can be used everywhere where there is no radiation with white light or no emission of white light from the one used for printing the substrate material. The white paper or white cardboard emits, for example, by ultraviolet rays (i.e., radiation of light, no white component), only white light, when manufacturing of the substrate material were applied optical brightening tools. For reasons of environmental optical brightening tools are often undesirable. For example, it has been completely eliminated for the manufacture of paper and cardboard used in the tobacco industry. The absence of this source for white light is rytych multicolor raster print images, for example, polypropylene film, can be recovered by the application of additive mixing of colors to build the image. The darker the background, the better you can see the obtained printed image in accordance with the invention, obtained by the additive method. Raster printed image in accordance with the invention has in this case blue, red and green and another dye, fluorescent under ultraviolet rays. The alternative is also possible subtractive method, in this case on a substrate applied luminescent colors Magenta (red), Cyan (blue), yellow, and optionally black (for better contrast). Condition for the visibility of the image is white or light as part of the irradiating light or the presence of optical brightening funds, reflecting white light under ultraviolet radiation.
Raster print images according to the invention can be obtained by any suitable printing method (see, for example, N. M. Speirs, "Introduction to Printing Technology, 4.Aufl., 1992, p. 7-10), in particular offset printing, lithography, flexography, high printing or gravure printing. In order to avoid interfering moire pattern is preferred to use a bitmap which these images can be made from any suitable material, preferably it is composed, for example, of paper, cardboard, textile materials, or foil, or foil made of natural or synthetic polymers (e.g. polypropylene). So, scanning the printed image can be applied, for example, polypropylene, as it is usually applied to a transparent foil for cigarette packaging. Raster printed image can be applied, or on a separate substrate (e.g., label, gummed foil or label), and this substrate is then connected to the referent item. Or raster printed image is applied directly to the product, which is the substrate, such as an external polypropylene shell, paper, or cardboard box or on the inner liner of a pack of cigarettes, postcard, Poster, curtains or even on the packaging, in particular the gift and food packaging. Manufacturers can apply more typical of a printed image or logo, but also complex graphical forms for promotional purposes. When this raster printing dots of different layers can contain different y under the influence of ultraviolet rays, coloring matter, so that the multi-color bitmap is giving raster print images in advertising. For example, a conventional package, such as a cigarette pack, can have, as described, scanning a printed image in accordance with the invention. It's a raster printed image is not visible to an observer in daylight or visible light. Only under the influence of ultraviolet rays, for example, in the entertainment institution becomes visible multicolored image. Printing on so-called material point-of-sales, for example at the Postern, are also possible.
1. Hidden raster printed image on the substrate, which means shows multicolored image under the influence of ultraviolet rays and which additive obtained by the method of mixing colors using the coloring matter of blue, red and green and, if necessary, of one substance, fluorescent under ultraviolet rays.
2. Hidden raster printed image under item 1, and the substrate of the printed image consists of paper, cardboard, fabric or film or foil made of natural or synthetic polymer.
3. Hidden raster printed image under item 1 or 2, which is intended for use for promotional purposes and for the purpose of sale of goods is esteem ultraviolet rays, method of printing with a bitmap form, and apply the dye blue, red and green and, if necessary, another substance that is fluorescent under ultraviolet rays, according to the additive method of mixing colors.