Production principle and future development of the

The manufacturing principle and future development of grating stereoscopic printing

in recent years, with the product packaging and filling, it has become increasingly rich and exquisite. A new product quietly appears in people's daily life. Have you noticed the cute little cards attached to food packaging? 7 tilt cards or move cards back and forth will see various wonderful effects

this is the product made by using grating stereo printing technology. It is widely used in packaging performance products, commercial advertisements, science and education cartoons, postcards, New Year cards, anti-counterfeiting marks, trademark tag mouse holders, all kinds of credit cards, etc. It is also used for decoration and filling of various products. The printed pattern is continuous and seamless, with excellent authenticity. Multi angle stereo printing can be carried out simultaneously on the irregular surface of the formed object. Now it can also imitate all kinds of precious wood, jade, agate, snake skin pattern, marble pattern and other natural patterns. Compared with natural materials, it is difficult to distinguish the true from the false to achieve excellent simulation effect

raster stereoscopic printing is a kind of printing that uses a grating plate to make the image have a three-dimensional sense. This kind of printed matter can directly observe a three-dimensional stereoscopic image on a two-dimensional plane image without any tools. Looking at these products, people must be curious about how it is made

when people observe objects, they can naturally produce a three-dimensional sense because there is a certain distance between people's eyes. When observing objects, the left and right eyes observe from different angles to form a visual difference between the two eyes The various images formed are reflected in the brain, Lu said at the meeting, which produces a sense of distance and three-dimensional sense

prepress production uses this principle to realize stereo imaging by using cylindrical lens stereo grating That is, the sense of depth formed by human binocular parallax and convergence is used to realize the three-dimensional sense in human consciousness. Therefore, in theory, only a set of images of the scene obtained from more than two different observation points can be synthesized into a stereoscopic picture

cylindrical lens stereo grating is composed of many small cylindrical lenses with exactly the same structural parameters and performance if China's experimental machine industry wants to achieve benign development This feature enables it to compress and isolate images. Cylindrical stereoscopic grating can record many images taken from different angles on the same picture in the form of stripes. While watching The same kind of cylindrical stereoscopic grating is also used to make people see two different images of the same scene with both eyes, so the depth image with parallax stereoscopic effect is generated in people's mind. Cylindrical lens solid grating is composed of cylindrical lenses arranged in a linear plane. Therefore, cylindrical lens stereoscopic grating stereoscopic pictures should be called unidirectional automatic stereoscopic pictures Its meaning is that only horizontal parallax information can be felt

according to the principle of cylindrical lens stereo grating imaging, the stereo pictures made by optical methods mainly have the following characteristics:

1 Stereoscopic pictures must be composed of a group of pictures taken from different perspectives of the same scene. Due to the unidirectional stereoscopic characteristics of the grating, the bit when this group of pictures are taken is required! At the same height

2. The synthesized stereoscopic image is composed of stripes parallel to the axis of the cylindrical grating The corresponding bit information of each picture in a group of pictures is arranged in equal spacing order under the same grating spacing. As shown in the figure! Shown is a stereoscopic picture composed of two pictures. 3 due to the shooting position of each picture There are two points corresponding to the same point on the stereoscopic picture, thus forming the position dislocation, which is the reason for the formation of stereoscopic sense

the biggest challenge faced by grating stereoscopic printing is color separation and plate making, because the stereoscopic effect of grating is obtained by separating and reorganizing images into small gratings. The key is to process images with interlaced scanning software. This kind of file data is generally large, which requires the computer to have enough processing capacity to process the scanned image files. In addition, due to the delicate characteristics of stereo image pixels and the amplification effect of cylindrical grating, the plate making line counter is more than 120 lines/cm

because the stereoscopic image is composed of closely arranged pixels, and the cylindrical mirror plate is also compounded after plate making and printing, it is necessary to consider not to form moire between plates when selecting the line angle Also pay attention to the moire formed by the screen angle, pixel line and column mirror line. The center line angle of stereoscopic printing should not be selected. Because the horizontal line is the most obvious, and. It is orthogonal to the pixel line and the column mirror line, which interferes with the clarity and depth of the image. Because stereoscopic printing uses a very fine 300 line screen When printing, only by drying to 85% or 90%, otherwise it is easy to paste the plate when printing In this way, we need to increase the amount of color in the dark areas to achieve 5% effect. Therefore, the solid density of color ink in stereoscopic printing is higher than that in plane four-color printing

raster stereoscopic printing requires great accuracy. At present, there are two main printing methods: one is to print directly on the raster material, and the other is to print on paper and then paste it on the grating or paste it on the plastic film and then press out the grating. Grating thickness is 0 385 inches. Therefore, if the printing overprint is not accurate, even if it is an extremely small deviation, the printed products will become waste. A very small gap will affect the effectiveness of the entire layout. Sometimes, the casting structure (cast steel, cast aluminum, etc.) is also adopted Raster stereo printing requires high accuracy of printing equipment, and the overprint error should be less than 0.0l mm

if it is a printing process of cylindrical grating plate and printing The process of accurately fitting the image and the grating plate together is very critical. Some enterprises operate by hand There are many uncontrollable links, and the operating skills of workers directly affect the quality of stereoscopic pictures. The method of fitting and forming the grating plate is to coat a layer of bright glue on the printed finished product, and heat, dissolve and decompress the thermoplastic material with high transparency into cylindrical grating plate in the mold The three-dimensional effect can be displayed only when the grating line on the printed product is accurately aligned with the grating line on the printed product. The distance between the cylindrical mirrors is 0.6mm, and the concave convex surface formed separates the image into countless pixels at equal distance. There are about 48 concave convex lines per centimeter of cylindrical grating plate, and there are about 6 pixels under each concave convex line. It is difficult to control the precise alignment between the grating line and the grating line on the print. The printing process of directly printing on grating material is relatively easy. As long as the machine accuracy reaches, the finished product can be directly printed. However, different from traditional printing, it is finally necessary to coat a layer of white gloss on the printing surface

although the theory of stereo photography has been put forward for less than 100 years, the development of practical application of this technology is very long. Raster stereoscopic printing originates from the three-dimensional image negatives provided by stereophotography. However, due to the traditional optical principle and synthesis method used in the shooting and production of stereoscopic photos, there are great limitations in the application of stereoscopic photos. In addition, it requires high equipment accuracy and complicated technology The production cost is high. Therefore Stereo photography has not been promoted and popularized. At the same time, stereo printing is affected by the long prepress production process, the accumulated error between processes is large, the picture definition is low, and the printing effect is not ideal. Difficult operation, low efficiency, poor quality, high scrap rate, and expensive special manufacturing equipment and consumables are also the reasons that greatly hinder the application and development of raster stereo printing technology

stereoscopic photography has entered the digital era in the 21st century. People use computer software to synthesize multiple images. The rapid development of computer technology, especially image input, processing and output technology, provides convenience for computer synthesis of stereoscopic pictures

with the computer direct plate making, C plastic is an important material for the preparation of drug packaging containers. TP technology appears, using frequency modulation dot high-precision printing. The application of UV technology continues to mature, and many equipment manufacturers have launched various types of UV offset printing machines. Heidelberg, Manroland, gaobao, Komori and leyoubi have all launched offset printing machines with this function. Printing plastic grating materials directly with offset press is no longer a problem, and the stereo printing quality system is guaranteed It makes grating stereoscopic printing develop rapidly. In recent years. Domestic stereoscopic printing has been greatly developed. Printing plants began to use raster stereo printing technology to obtain more complex products From labels, posters and posters to packaged products, and even plastic cups, three-dimensional printing has been applied, showing a prosperous scene

although the stereoscopic effect seen in the product is not true But raster stereolithography is not just a trick to seduce children. Compared with the traditional stereo photo making process It shows its unique advantages in economy and flexibility We have reason to believe that grating stereo printing technology will have a broader application space and development prospects in the future printing field