Application of Laser Holographic Anti-counterfeiting Technology Industry Class

Early laser holograms can only be reproduced by laser, that is, if you want to observe laser holograms, you can only use a laser as a light source to illuminate the holograms at a certain angle to observe the image. The commercialization of laser holograms requires white light reproduction, that is, laser holograms can be observed under ordinary light sources. The most commonly used white light reproduction laser holography for molded holography is two-step rainbow holography and one-step rainbow holography.

Laser holography has been successfully used in the fields of three-dimensional image display, interferometry and non-destructive testing, and the wider application of laser holography is after the invention of laser holography. Early hologram replication to laser as the light source, the photosensitive material as the carrier single copy, the process is complex, high cost, low efficiency.

The special photosensitive material for molding laser holography is photoresist. After the laser holographic exposure of the material, the relief phase hologram can be obtained by processing, that is, the master plate for making the embossed hologram. The surface of the master is filled with uneven interference fringes, and its density can reach more than one thousand per millimeter. Plating a certain thickness of metal nickel on the surface of the master to make a metal master that can be used for batch replication (printing), and the metal master replicates the interference fringes on the holographic master. The metal master is installed on the molding machine, the molded holographic film material (PET, BOPP, etc.) is heated, the metal master is pressed on the film material with a certain pressure, and the relief hologram on the metal master is imprinted on the molded holographic film material. This is a high-volume, high-speed, low-cost laser hologram replication method, to the application of laser holography has brought a leap.

The more mature molding laser holographic technology came out in the United States in the early 1980 s and was introduced into China in the mid-1980s. Early molding laser holographic technology is mainly used in image display (handicrafts), in the field of anti-counterfeiting, molding laser holographic technology has been rapid development.

In China, molded laser technology was first applied in the field of anti-counterfeiting in 1988. The reason why this technology can be applied to the field of anti-counterfeiting, in addition to factors such as low price and convenient identification, is mainly due to its strong information carrying capacity. The embossed hologram can record the state of the hologram, the nature of the optical elements used, the post-processing situation and the nature of the photosensitive material, and its complex optical characteristics cannot be effectively copied. Because of its strong information carrying capacity, microfilm technology, which is extremely difficult for ink printing methods, is much simpler for molded laser holography.

China's molding laser holographic technology from the early two-step color rainbow method, two-step color rainbow mask method, grating shining method developed low-frequency lithography, pixel lithography and so on. In terms of materials, from permanent molding materials to disposable molding materials and hot stamping molding materials, the pretreatment or post-treatment of materials has developed regular dealuminization, partial dealuminization, half-tone holography, perspective holography, etc. The combination with printing technology has also developed fluorescent ink printing, laser uncover logo, laser scratch logo, laser holographic hot stamping, etc; the combination of the two materials has developed a double-layer hidden logo; the combination with other anti-counterfeiting technologies has developed a laser holographic telephone code logo. The non-expert inspection of the authenticity of holographic anti-counterfeiting trademarks has also developed from simple visual inspection to card inspection, magnifying glass inspection, laser beam irradiation inspection, etc. The future trend is electronic identification inspection.

The early molded laser holographic logo has low brightness, small observation range, not bright enough color, and not clear enough pattern. The use of mask method improves the clarity of the pattern and makes the pattern observation convenient. The application of grating shining method improves the brightness and color vividness. The application of pixel lithography technology realizes the automation of holographic photography, and in a point-by-point burst of light, each pixel unit has different parameters to realize the colorful dynamic changes of our design. The further development of the two-step rainbow technology has realized the dynamic and three-dimensional dynamic of movie feeling. Although the molded laser holographic technology is non-counterfeit, it is quite difficult for ordinary consumers to identify the authenticity. Early holographic anti-counterfeiting is mainly based on exclusive anti-counterfeiting, with the promotion of holographic technology, exclusive has ceased to exist. In order to cope with the fierce competition and improve the identification ability of non-professionals, laser holographic technicians continue to develop new technologies such as first-line anti-counterfeiting technologies such as meteor light spots and magic pattern technology, second-line anti-counterfeiting technologies such as laser encryption and double card technology, and the direction of molded laser holographic identification is: fast electronic semi-automatic/automatic identification.

The use of disposable molding materials solves the problem of the secondary transfer of anti-counterfeiting trademarks and plays a huge role in the promotion of molding laser holographic trademarks. The use of hot stamping molding materials has realized the integration of packaging and anti-counterfeiting, and the process problems of domestic holographic hot stamping materials have affected its promotion speed, but this will become the largest application of molding laser holography. The invention of the wide molding machine has greatly improved the production efficiency. The pre-treatment and or post-treatment of holographic molding materials can produce regular dealuminized (regular disclosure) type, partial dealuminized type, positioning dealuminized type, hollow type molded holographic anti-counterfeiting identification, and half-tone holographic and perspective holographic anti-counterfeiting identification. When the rule-dealuminized or rule-exposed logo is pasted on the object to be pasted and opened, part of the aluminized layer falls off to the object to show the preset text or pattern; the part-dealuminized logo has a horizontal strip that takes off the aluminized layer and becomes transparent (also known as one-way positioning aluminized); the rule-dealuminized logo takes off the aluminized layer at the fixed position of the logo and becomes transparent (also known as two-way positioning aluminized); hollow-out type is used to print corrosion-resistant materials on the aluminum surface of aluminized film embossed with holograms. After etching, the aluminum layer on the aluminized film is regularly hollowed out to form characters or graphics (no positioning and dealuminization), which are mostly used for cigarette anti-counterfeiting cables. Halftone holographic products can be made by keeping the aluminized layer of the molded material in the form of dots 20-30 and removing the aluminized layer. For example, the laser holographic anti-counterfeiting technology used on the ID card is halftone hologram. The printed picture and text covered by the see-through holographic identification film can be observed through the holographic film without affecting the observation of the laser holographic image.