FM network outlets are better than AM outlets

There are many advantages of FM network sites compared with AM sites, which are mainly manifested in:

1. Eliminate the occurrence of "rhizome" The "rhizome" is the result of periodic structural interactions. Color printing is usually accomplished by accurately overprinting four separate screen images. These images are printed using four inks of cyan, magenta, yellow, and black respectively. The screens are screened using the amplitude modulation and screening technique. The singulation will inevitably produce screen angles, and inevitably produce "rhizome" in the process of overprinting. With the frequency modulation screening technology, the probability of network appearance is random, the arrangement of network points is irregular, and there is no regular spatial network structure. Therefore, after a few color plates are superimposed, there will be no “rhized pattern”. Interference fringes, it can also eliminate the possibility of "moiré" caused by some regular stripes of the image itself (such as the wood bars of the fence or shark's teeth) interfere with the screen.

2. Improve color reproduction capability Because the distribution of FM network points is irregular, there is no network line angle problem, and the problem of "rhizome" is solved. Therefore, colors other than cyan, magenta, yellow and black can be used to enlarge the color gamut range. That is, more than four colors are used to increase spot color ink printing and achieve high fidelity (HiFi) color printing, reducing the color gap between prints and originals, and improving color reproduction capabilities. This is extremely helpful for the printing business market to increase profits. In addition, due to the irregular distribution of FM network dots, the overlap of dots can be avoided, and the ink can be directly printed on the substrate as much as possible. Therefore, a larger amount of ink can be used and the effect of increasing the color effect can also be achieved.

3. Resolution High In the AM network technology, commonly used dot lines represent the fineness of the dot image, and the most basic unit of its subtle level is determined by the number of screen lines, according to the formula: grayscale number = (output resolution DPI/ Number of network lines LPI) 2+1

The number of network lines is much lower than the final resolution of the system. Obviously, AM sites must sacrifice their resolution to obtain sufficient levels of expressive force. However, this weakness does not exist in the FM network technology, because the FM network technology uses the denseness of the network points, that is, the number of network points per unit length (DPL) to represent the fineness of the network image, and the blackening point that constitutes the FM network point is to form an image. The “elements” of the hue are at the same time the most basic elements of the subtle level of expression. Therefore, it can be said that, under the condition of the same system resolution, the FM network points have higher resolution than the AM network points.

4. High-definition In the AM screening technology, the dot line number determines the sharpness. The higher the cable number, the smaller the dot area of ​​the output, and the better the sharpness. However, usually the number of network lines is too large and the copying technology is more difficult. Therefore, the output images generated by the amplitude modulation screening technology have to be emphasized at the subtle level, namely USM. Because the screen area used by FM screening is particularly small and the image reproduction is of high definition, the copying effect is close to the continuous adjustment of the photographic film, especially the subtle levels of highlights and shadows are well reproduced. High-quality images can also be obtained by adopting the frequency modulation dot spotting technique on the low-resolution imagesetter, while the amplitude modulation dot-matrix technology requires a higher resolution of the contrasting rowing machine. FM screening technology is a brand new screening technology with many advantages. It can be used not only in fine prints but also in low-precision newspaper printing. It is widely concerned by the printing industry and has great development prospects.


Guangdong Printing 2004 No. 4