A Brief Introduction of Anti-counterfeiting Principle of Holographic Marks

Generally referred to as holographic anti-counterfeit trademarks, it refers to holograms that record specific patterns and texts representing a certain commodity. The main principles that holograms can play anti-counterfeit effects are:

First, the production and replication of holograms are highly technical, require specialized personnel, and have complex processes. Holography itself is a new and high technology. It not only needs to equip with high-quality anti-shock tables, lasers, various optical components, and special chemicals, but more importantly, it needs to be handled by skilled and experienced professionals. Only qualified hologram masters can be produced. The grating density on the hologram is usually 1000 lines/mm, and the undulating height is only a few tenths of a μm, so a demanding electroforming process and a high-precision, high-quality molded copying apparatus and a hologram copying machine are required. Compared with conventional printing technology that can produce products by manual operation only by conventional equipment, the production of holographic marks reveals from many aspects such as technology, personnel, process, and equipment investment, making it difficult to reproduce and difficult to reproduce.

Second, holograms have their own structures that are difficult to copy. Most molded security labels today are rainbow holograms that record one or more two-dimensional planar patterns. Using holograms to reproduce the characteristics of a three-dimensional stereoscopic image, two (or more) plane patterns can be hierarchically recorded in the longitudinal direction in the hologram, thereby reconstructing planar images located at different depths and having an occlusion relationship with each other. Since rainbow holograms have the property of reproducing images with variable colors, false color coding techniques can be used to reproduce different colors in different patterns or different parts of the same pattern. And because the hologram itself is a complex grating with a very high density, even if the same person uses the same pattern in different places, two holograms with the same grating cannot be produced, and different people are more difficult to duplicate. The most obvious manifestation of this difference is the difference in the depth and color distribution of the reconstructed image, and of course, the differences in diffraction efficiency, viewing angle, and signal-to-noise ratio. Therefore, even with a full set of equipment and technology, imitation of other homes molded holographic anti-counterfeit labels, is not an easy thing.

Third, there is implicit encryption information. Encryption can be performed in holograms using special optical encoding techniques that can either change the size of the reconstructed object as the distance from the human eye to the hologram changes, or store additional points at some point in the hologram. The information, or the hologram itself, is generated by the computer, and so on. A hologram that uses a special three-dimensional object model as a target reproduces an exactly the same stereogram as the original. Due to the higher technical content of the above items, it is less likely to be copied.

Fourth, it has a material anti-copy function. Above we only analyzed the hologram's non-imitation from the perspective of holographic process. However, in real life, there is such an approach that uses the removed embossed hologram to use the film with the aluminum layer removed as a master, electroforms the metal template, and then performs embossing replication on the machine. Although the index of diffraction efficiency, signal-to-noise ratio, etc. of the molded hologram thus produced is reduced compared with the original product, the end result is that even though the anti-imitation method is used in the hologram, it is difficult to escape the artificial imitation. The bad luck. In order to solve this problem, tamper-evident and stamping-type anodized aluminum film molded holograms having a copy-proof function have been developed.

The basic anti-copying principle of the tamper-evident (also called disposable) molded hologram is: the lower surface of the resin layer connected to the hologram film polyester material is plated with a pressure-sensitive adhesive coated on the aluminum layer that has been molded and deformed into a grating carrier. The entire embossed hologram can be affixed to the bearer. When the hologram is peeled off, the upper polyester film will be separated from the resin layer and peeled off, while a portion of the aluminum layer will be adhered. There was no grating at all on the polyester film removed, and the hologram left on the receiver was incompletely damaged, so that imitation was impossible at all.

The hot stamping hologram structure is basically the same as the tamper-proof hologram. The difference is that the separation between the polyester film and the resin layer at the top of the former is very good at the time of hot stamping, and it is coated on the bottom layer. The heat-sensitive adhesive produces strong adhesiveness when subjected to heat, so that the aluminum layer and the resin layer with the grating will adhere tightly and completely to the accommodating material and cannot be peeled off at all.

Of course, from a philosophical point of view, there is neither an invincible spear nor an unbreakable shield in the world. Like all other things, there is always such a contradiction between security and counterfeiting. To make the holographic trademark have a much higher anti-counterfeiting performance than a trademark produced by other printing methods, it is necessary to continuously research and develop new technologies and develop new products in various aspects such as holographic plate making, printing processes, and material production.