On the latest screening technology of computer dir

  • Detail

Editor's note: there is no doubt that every printing factory believes that the computer direct plate making system can greatly improve the printing quality. Because it does not need to use film, but directly images on the printing plate, it can make the printing workshop cleaner, and allow people to use more accurate points, reducing the restrictions of four-color printing on the printing machine. In addition, the computer direct plate making system can reduce the point deformation and maximally compensate the point expansion on the printing machine. Under such a development trend, many manufacturers have launched random addition products for computer direct plate making systems

the traditional halftone addition is what we often call amplitude modulation addition. It is composed of a series of regularly arranged points, which reflect the difference between highlight or dark tone through the change of point size. Amplitude modulation plus has strong predictability, and the effect on the printing press is better than random plus. The limitation of this technology is that the printing plant must ensure that the image is not lost in the brightest and darkest places. With the increase of the number of lines added, it becomes more and more difficult to control the highlights and maintain the gap between the dim eyes

FM plus or random plus uses a completely different way from am plus. They can maintain the same size of points, but will change the distance between points. Because the dots are very small and closely arranged in many areas, FM plus can reproduce more details (middle tone) and reduce the chance of "moire" fringes. Images printed with FM plus technology can often achieve the quality of continuous tone photos. However, due to the use of non upper fixture, lower fixture, reducer, electronic control system, DC Electromechanical, frame, and the result that the maximum range is almost not used, the lead screw, workbench and other parts constitute a small point compared with the commonly used range, so the problem of highlight points often appears in the process of AM plus will also appear in most of the steps of FM plus. Before the advent of computer direct plate making technology, it was difficult to transfer micro dots from film to printing plate. Now, this problem can be easily solved

many emerging addition technologies are a mixture of AM and FM addition. Mixed addition uses traditional banner addition in most tonal areas, while FM addition technology is used in highlight and dark areas. Through mixed processing, offset printing plants can increase the number of lines added in the am processing area without bringing additional burden to the printing press. The following are some of the most common new products in the market (Agfa, artwork systems, Ascot, Fujifilm, Heidelberg, Kodak, rampage system, ripit and screen)


Agfa claims that its additive technology can combine the advantages of AM and FM. The company's: sublima is a patented product that integrates two technologies into one solution. It is also the first solution of AGFA to adopt XM patented technology. In the development process of sublima, two Agfa technologies are used: ABS (Agfa balanced screening) and cristalraster FM plus technology

let's take a look at how sublima works. In the middle tone area, sublima uses ABS Technology for clear and accurate replication. In the troublesome areas of high light and dark tone, sublima uses frequency modulation technology to reproduce the details of the image. But this software can't easily switch from one technology to another. It uses patented technology to determine the switching point between the two additive technologies, and can achieve a smooth transition without affecting the effect of the image. Although the FM plus area uses relatively small points, they will still be arranged according to the plus angle established by ABS. The final result of this is to generate a new target.: The number of additional lines that sublima can achieve is 210, 240, 280 and 340 LPI respectively

: sublima software takes into account all variables. It can calculate the minimum point size that the printing plate can print on each printing machine, so as to allow the printer to adjust on the printing machine - this is a place where it is stronger than FM

: the built-in calibration curve of sublima can automatically compensate for the expansion of different points. It can keep 1% to 99% of the dots in long edition printing. The biggest advantage of this technology is still reflected in prepress and printing. At the highest number of lines added - it can only rip at a resolution of 2400dpi. The printing effect of 340 LPI is no different from that of 150 LPI - including ink balance and plate performance

artwork systems

artwork systems is a leading professional prepress software supplier in the industry. They have developed concentric screening technology. According to the company, concentric screening is a revolutionary halftone addition technology, which can divide traditional circular points into more fine concentric rings. These concentric rings can reduce the thickness of the ink film on the printing plate, thus bringing users higher printing stability and color saturation. Convergent screening is the first halftone point with different internal shapes, and it is also the first "non stereo" halftone point in the world. Artwork's production printing plant can increase the number of extra lines - even double the original number - without worrying about spots, dot expansion and other problems caused by high number of extra lines

concentrate avoid the fluctuation of extrusion pressure caused by the fluctuation of plastic temperature. IC screening has all the advantages of the second generation FM plus technology. It has strong printability, is easy to use, and can achieve the smoothness that traditional am plus can achieve. Besides the covallis factory of HP, it can also be used in the nexus and odystar workflow launched by artwork systems


in September, 2006, Ascot launched a new perfecthighlights flexographic printing plus technology. It brings new tools to ASCO users, carton processing plants and label printing plants, so that they know how to achieve the best results in the silk printing process and plate making process. The printing factory can set the best parameters for the specific printing environment, ink, substrate and printing machine, so as to improve the value obtained by packaging buyers and bring them greater competitive advantage. Perfecthighlights can print 1% to 2% highlights in various ways. It can bring users the best intermediate and dark tone reproduction effect together with other addition technologies of ESCO

in addition, Ascot has also developed a variety of additive technologies, including sambaflex and groovy screens. Sambaflex and groovy screens are hybrid plus technologies. They use am dots in most areas of the image and FM dots in the line areas of highlights and darkens to improve the saturation of color and the stereo effect of the image. ESCO also has Highline am plus technology, which can produce a very high number of lines at a low output resolution. For example, it can produce 423 LPI points at a resolution of 2400 DPI

author/Yu Peng

(Jiagong electromechanical)

Copyright © 2011 JIN SHI