DE19912160A1 - Method of producing color pictures from digitally available image, using simple, low-cost and environmentally friendly material - Google Patents

Abstract

The color picture or hologram is produced from a digitally available image. On a material with permanently embossable surface are embossed points with a max. dia. of 1000 microns, comprising a pattern of parallel lines with spacing between 100 and 2000 nm, dependent on the color to be produced. The points to be embossed are applied individually and sequentially. The points are applied by needle printers whose tips contain the required line pattern. The embossing depth is 200 to 2000 microns. Polymers or polymer coated materials are used for embossing.

Description

The invention relates to a method for producing a colored image starting from of a digitally available image, the method being a particularly simple, inexpensive and environmentally friendly material used.

To create colored pictures, the motif is usually first with a Camera or scanner. The recording medium can be a photo graphic film or an electronic memory chip. Starting from this any processed (developed) information carrier becomes the image information transferred to a carrier material and leaves one as original as possible in the colors true picture arise. This can be done, for example, by analog exposure from a photographic color negative to a photographic paper and its ent development or based on electronically stored information Driving an inkjet printer and printing on a corresponding carrier material or by laser exposure of a photographic material.

In these and other known processes, the finished product must be manufactured A number of chemically produced substances can be used in the image (e.g. color couplers in the photographic process and dyes in inkjet printing as well many auxiliaries and additives) which, in addition, in the photographic process is wet mixed processing (development) is added.

From J. Imaging Sci. Technol. (1997), 41 (3), 211-220, holograms and to produce optical elements through microstructures in which the image Impression is caused by diffraction effects. The as DOE's (diffraction embossed foils designated optical elements) can, according to the current status of Technology can only be produced by passing a given image through a multi-stage process converted into a superficially structured metal stamp,  with the subsequent picture by embossing plastic surfaces is reproduced.

The disadvantage of this method is that the production of images only once or to be reproduced a few times, disproportionately expensive is because a separate embossing stamp would have to be made for each image.

The object of the invention was to provide a new method for manufacturing color images, letters, numbers or characters based on a digital image available image that works with very simple material and in particular on Color couplers, dyes and inks and all related to them no auxiliary materials.

This object is achieved in that on a material with permanent sticky surface with a maximum diameter of 1000 µm be embossed which have a pattern of parallel lines with that of the one to be generated Color dependent distances in the range between 100 and 2000 nm. The Assignment of the line widths to the colors obtained by diffraction is off US 3 957 354 and EP 632 296 are known.

The lines can be straight or curved, e.g. B. be wavy. The lines can have different structures, such as. B. sinusoidal, triangular, square, rectangular, multi-level. The point to be stamped is preferred divided into at least two areas, with the lines in one area the lines in the second area form an angle different from 0 and 180 °. The lines of 2 areas are preferably perpendicular to one another. Prefers is also that the point is divided into 3 areas, the lines of which each one Include an angle of 60 °.

The lines can also be one above the other at defined angles, preferably be arranged 90 ° or 60 °. This arrangement is preferably chosen  if the lines have different depths as described in US 3,957,354 ben.

The color that occurs on the lines due to interference depends on the structure of the Line, e.g. B. width and depth, and from the refractive index of the embossed material. For example, with a rectangular profile with the same line width create different colors by different depth.

In the case of a relief which is rectangular in section ( FIG. I), the three primary colors yellow, purple and blue-green can be obtained by the following relief data if the refractive index of the embossed material is 1.5.

The dots are placed close together. In particular, the Points applied so close together that the distance from which the picture is viewed, clear and delimited areas of color emerge, as this from Screen printing is known in which, for example, a fine screen for a book, however, a rough grid is used for a poster.

In a preferred embodiment, 6 points are different Line spacings are used which cause the colors blue, green, red, yellow, Generate purple and teal. In a further preferred embodiment, who  which also uses dots with line spacing caused by black interference produce.

Mixed colors from these colors are created by dots accordingly different line spacing can be applied side by side.

The application of the points can e.g. B. with known dot matrix printers or matrix printers whose needle tips have the desired line pattern and by printing this line pattern of the embossable surface gene.

The dot matrix printer can in a known manner from the memory in which the digi Tal available image is controlled.

The line pattern can be applied to the tips of a dot matrix printer known nanotechnology take place, see e.g. B. M. T. Gale, Replication Technology for Holograms and Diffractive Optical Elements, J. Imag. Sci. and Techn. 41 (3), Pp. 211-220 (1997).

The durability of the embossing can e.g. B. generated by the fact that the upper surface consists of an organic polymer, for example after embossing is cured by heating or UV radiation or by the fact that the polymer Embossed surface above the glass temperature and then as quickly as possible below the Glass temperature is cooled.

Polymer layers

Polymers or polymer-coated papers or fabrics are suitable for embossing. Thermoplastic polymers such as PE and PVC are particularly suitable. PC, cellulose acetate, PMMA, polyester, PP, PS, polyvinyl alcohol, polyvinyl pyrrolidone and Gelatin. The polymers can be used as chemically uniform compounds or as  Mixtures are used. The polymers preferably contain additives such as Plasticizers or matting agents such as titanium dioxide.

In another embodiment, polymers with reactive groups are used det after the stamping process by a subsequent reaction, such as irradiation with UV light or electron beams can be networked in order to make the impression as permanent as possible get pictures.

The embossing is preferably at temperatures above the glass transition temperature temperature (TG) of the polymer. This happens because the polymer is heated in the areas to be embossed.

In another embodiment, the needles of the printer are heated so that only the area of the polymer to be embossed is heated becomes.

In a further embodiment, the polymer is preheated as well the needles of the embossing tool are preheated.

In a further embodiment, the polymer is made by adding a soft machers lowered in the glass temperature. After the embossing, the glass temperature rises by evaporation of the plasticizer. This embodiment is preferred at Polymers such as PVA or gelatin are used when water is used as a plasticizer can be used.

Claims (4)

1. A method for producing a colored image or hologram based on a digitally available image, characterized in that points with a maximum diameter of 1000 microns are embossed on a material with a permanently embossable surface, which have a pattern of parallel lines with the color to be generated dependent distances in the range between 100 and 2000 nm. 2. The method according to claim 1, characterized in that to apply the points are applied one after the other. 3. The method according to claim 1, characterized in that for application of dot matrix printers are used, the needle tips of which have the desired line pattern. 4. The method according to claim 1, characterized in that the depth of the Embossing is 200 to 2000 µm.