Protection_Against_Counterfeiting
4 PROSPECTS OF HOLOGRAPHY
Classical holograms allow three-dimensional display, but they are limited to recording of immovable images. Moreover, the creation of a hologram is a laborious process using beams that are split in order to over-scan the object shape and then join again on the film. In early research to create a hologram the science required reflecting properties of the object, its total stability and size comparable to the recording medium. Even though there are some new variants of holograms (www.zebraimaging.com, 2006), for example, rainbow, colour, and holograms of unlimited size the prospects of holography are in "movable" holographic projections that can be used in holographic film and three-dimensional television. We can expect holography to be used more and more also in the field of protection of objects against counterfeiting, for identification of hidden objects and for data storage.
4.1 Protection Against Counterfeiting
Counterfeiting of brands destroys the reputation of legitimate companies and potentially puts consumers at risk. Constantly innovating and open reproduction techniques as regards colours, materials and resolution, provide counterfeiters with the perfect tool for making counterfeit which seems practically undistinguishable from originals in two-dimensional printing and graphics.
Product makers are currently amid a sea of choices for their brand protection – from glow-in-the-dark inks to radio frequency identification up to protecting products through holograms.
In the field of protection of papers and objects against counterfeiting, holography brings something quite new (Fiala et al, 1998). The level of security feature, is of course, driven by price. For example, the Nike golf balls have a hologram on the box, which is specific to that box; the holographic image of Jerry West is on all National Basketball Assn. paraphernalia.
The lowest level of holographic protection would be standard patterns like stars, cracked ice or bubbles. The next level, about 10 % to 20 % more expensive, is a hologram that contains a generic wording such as "secure" or "genuine". The next rung on the protection ladder would contain a custom image – a company logo; the next level up would use micro text, and the highest level would use a transparent holographic film (Fontelera, 2005).
Typically, a silver-backed substrate is used for holograms. With such film, about 70 % to 80 % percent of the image in the hologram could be captured through a scanner. With a transparent holographic film, only 20 % to 30 % percent of the image can be captured.
Protection by hologram brings the solution not only by making it impossible to copy by a common reproduction technique, but it also enables fast visual inspection. We use the image dynamic inspection of hologram (i.e. the image at the adjusted angle of vision or illumination changes its colour, position, shape or is completely replaced by other image). The three-dimensionality of the image is copied by common reproduction technique as blurred. Moreover, the hologram enables also special protection through code: for example, in the case of cryptograms there is on the elementary segment of a hologram caught also other hidden information.
Security holograms are mostly rainbow ones often designed with the aid of computer. A part of the protection is the technique of such hologram connection with the product, so that the safety component could not be removed from the paper or product without destroying the hologram. Holography is used to protect documents and security papers (notes, cheques, certificates, credit cards and other bank cards), identity papers (identity cards and personnel cards, passports, driving licences) and branded articles (video recordings, cassettes, CDs, software, alcohol, perfumes, cosmetics, glasses, china, etc.).
