A Survey of Print Copy and Its Technology Research (1)

Abstract: This article revolves around the important research and achievements of publishing and copying technologies at home and abroad. It summarizes the basic contents and development process of prepress technology, digital printing technology, CTP technology, digital workflow and cross-media publishing technology driven by digital technology. Application results.

Keywords: Printing Technology, Digital Technology, Prepress Technology, CTP, Cross-Media Publishing Workflow, Printing technology with a long history has undergone tremendous changes in the late 20th century. When human beings enter the era of information in which multiple kinds of communication media coexist, the development of science and technology has not only promoted the progress of printing and copying technology, updated the printing technology, but also expanded the space for print copy research. Reviewing the research on printing and copying technology in the past 20 years, each breakthrough progress has a profound technical background, which is the result of comprehensive application and development of multidisciplinary research results. With the rapid development of computer technology and informatization and networking technologies, variable printing technologies and equipment have become increasingly sophisticated, and the development of systematization, standardization, flow, digitization, and networking technologies for printing technologies is maturing. With the advancement of optoelectronic technology, automatic control technology and mechanical technology, the development of printing equipment and equipment is changing with each passing day. Since China's reform and opening up, the printing industry has been fully revitalized along with economic development and technological advancement. Chinese scientists and technicians pioneered the Chinese type laser typesetting process and realized the computerization of Chinese character information processing. This enabled us to say goodbye to the history of “lead” and “fire” and is now shifting to digital networking. In the past 20 years, under the impetus of scientific and technological progress, China's printing and copying technology has developed rapidly. In prepress technology research, we have also obtained research results with independent intellectual property rights and reaching the world's advanced level.

1 Digital Technology Drives the Development of Prepress Technology Research

In the past 20 years, the development of printing technology has been characterized by the application of digital and networked technologies, especially in the pre-press field, which has seen a change from one to another. These changes stem from a series of results of prepress technology research.

1.1 The rise and fall of the electronic scanning color separation machine

In the 1930s, humanity established the system of colorimetry, and the theory of color reproduction of printed images was established and made breakthroughs. Dr. Hadi, an MIT scientist from the United States of America, envisioned a color image reproduction device based on the three primary color reproduction theory. It can not only solve color equations, but also reproduce the three primary color separation films with correct color reproduction. This is the original idea of ​​the electronic color separation machine. .

The first color separation scanning device patent was obtained in 1937 by Alexander Murray and Richard Morse. In 1951, Kodak collaborated with Time to create the world's first prototype of electronic color separation machine and named it "TIME SCANNER". Since then, the United States PDI (Printing Development Incorporated) on the basis of the prototype has been improved, developed the first PDI electronic color separation machine that shocked the world's printing industry.

In the early 1980s, the electronic color separation machine revolutionized the technology and started to adopt the digital laser dot-screening mode of the dot network generator, and achieved multi-color scan recording, disk storage, and digital program control. Standardized modern electronic color separation platemaking process.

After 1982, the Klaus-Fürsfeld Company first introduced the M645 digital electronic color separation machine using digital image processing technology. Following this, Hull's DC380, CP345, and CP345T digital electronic color separation machines were introduced one after another. The screen company's SG688 digital electronic color separation machine and SITEX's Satlight and Smart digital electronic color separation machines also came out in succession. The digital electronic color separation machine adopts a brand-new image correction system, so that the colors, levels, and intelligibility of the duplicated images are independent and focus is emphasized. At the same time, the color pre-proofing system makes the operation easier and the copy quality is high and stable.

An important milestone in the history of the development of electric extensions is the application of CCD technology, which uses charge couplers instead of photomultiplier tubes, and changes roller-type scanning to planar scanning. The "Designmaster" of the American Ikonics Company pioneered the precursor of the fifth-generation electric extension. The Designmaster 8000 electric branch exhibited for the first time at the US Printing Exposition in 1982 was the first all-digital photodiode array (later to be replaced by a CCD) planar scanning electric extension. The machine does not use the traditional three-color CMY color coordinate system, but uses the CIE chromaticity coordinate system, but only when the final output, it is converted to the CMY coordinate output. The advantage of this is that the hierarchical curve is represented by the brightness and the color is represented by the color difference. The two are separated from each other. Therefore, the color can be influenced when the hierarchy is modified, and the hierarchy is not affected when the color is modified. In addition, all the advantages of all-digital electric extensions and the use of CCD instead of photomultipliers are also available. The basis of CCD technology is the CCD element. It consists of a chip coated with a photosensitive silicon coating and a silicon photocell arranged in rows. These photocells change their voltage under illumination, and their amount of change is governed by the amount of light, so they can be used as photoelectric sensors. Especially suitable for those who need to turn the image signal into a digital signal. Flat-type color separation scanner uses a CCD charge-coupled device for photoelectric conversion. The drum-type electric extension adopts a photomultiplier tube for photoelectric conversion. Since the CCD is linearly arranged, planar scanning is used, and the photomultiplier tube scans the image line by line, so plane scanning is performed. The input speed of the machine is usually faster than that of the drum type extension.

Electric extensions used vacuum tubes from the beginning, to desktop publishing systems using large-scale integrated circuits and multi-microprocessors, and then to general-purpose microcomputers and color monitors, indicating that as long as the software is updated, the performance of electric extensions can be continuously updated. The processing speed is faster, the operation is more convenient, the repeatability is better, and the self-diagnosis ability is stronger.

In the early 1990s, with the advent of research and application of desktop publishing systems, electrical extensions were gradually replaced by desktop publishing systems that had more graphic and textual mixing capabilities. Due to the excellent performance of the electrical extension, the high-end networking system of the electrical extension was successfully developed. The application of this system makes the electrical extension continue to play a very important role in the color reproduction technology. However, this role has not been maintained and electric extension manufacturers have finally stopped production completely. Since the 1990s, successful research on color desktop publishing systems has gradually replaced the status of electric extensions.

1.2 Research and Progress of Electronic Publishing System

The study of China's electronic publishing system was kicked off by the study of the text information processing system hosted by Professor Wang Xuan. In the field of printing and copying, the earliest research result was the text typesetting technology.
The study of text typesetting in the world began with the mechanical typing that was invented in the early 1920s. After that, it went through an optical type manual phototypewriter, a microcomputer-controlled semi-automatic phototypewriter, and later a fully automated laser-scanned phototypesetter.

After the liberation, China's printing and copying technology research has been in a state of slow development, in which the text typesetting technology still uses hand-type typesetting with thousands of years of history. In 1974, the National Bureau of Publication and the Ministry of Machines jointly issued a notice on “The task of arranging printing technology to urgently require the trial production of new products for key printing machinery”. The National Science and Technology Commission and the Ministry of Electronics Industry decided to develop a computerized Chinese character processing system and named this task "748" project. The project was listed as a national key scientific research project. Prof. Wang Xuan participated in this project. He invented the “Digital Storage and High Magnification Gage Information Compression and Output Restoration and Minimum Distortion Variability Technology” with bold ideas and originality. Insights gained social recognition and won national patents. The successful development of this technology laid the foundation for the application of computer typesetting technology in China.

In 1980, the Chinese-language laser photocopying system developed by the “748” project research team printed a sample book “The Sword of Wu Hao”. In the same year, the State Publishing Bureau issued the "Opinions on the Direction of the Development of Book Printing Technology" and clarified the scientific research direction of China's book printing technology. By 1985, the "Huaguang" electronic computer laser character editing typesetting system developed by Peking University and other institutions passed the appraisal. The system was rated as one of China's top 10 scientific and technological achievements that year and also won the 1986 Geneva International Invention Exhibition Gold Medal. In November 1987, given the achievements made by Wang Xuan in the study of the laser Chinese character editing system, the China Printing Technology Association awarded him the first Bi Sheng Award and the Shin Sawa Letter Printing Prize.

On May 22, 1987, the Huaguang III machine printed the first full-page output of a Chinese newspaper in the Economic Daily. Since then, the application of this technology has enabled China to bid farewell to the era of "lead" and "fire" and ushered in "light" and "electricity." It has not only contributed greatly to the transformation of our typesetting technology, but also created a huge economy. Benefits even more indicate the beginning of a new era.

At the same time, some well-known large companies in the world have also made gratifying achievements in the research of output devices. In 1977, Xerox developed the Xerox 9700 electronic printing system, which became the first electrostatic imager laser printer, in 1981. Also developed a system that can produce and print computer-generated text, business forms, and other images; the same year, Canon developed the LBP-CX laser printer chip. The birth of these technologies and the success of our country's computer typesetting technology have created success in the transformation of typesetting technology.

With the development of computer hardware technology and the advancement of color image processing technology, the study of electronic publishing has evolved from a desktop publishing system (DTP) in monochrome processing of text graphics to an electronic color publishing system (CEPS) in which color graphics and text are processed together. The results have completed the transition from analog to digital information processing.

With the advancement of research and development of related technologies such as image processing, pattern recognition, and computer vision, research on text information processing technology related to electronic publishing technology has also made gratifying achievements. For example, Chinese characters such as Chinese character communication system, office automation system, OCR system, etc., OCR technology has been applied to the input of printed characters. At present, OCR recognition software is mainly used to scan printed information on paper media and automatically recognize the text information and input it into the computer. The successful application of this technology research has effectively improved the input speed of printed text.

At the same time, the research of speech recognition and synthesis technology is also being carried out in many comprehensive universities. In the development of the printing and copying technology, the research of this technology can be used for speech input and automatic proofreading.

The successful research and application of CEPS brought about changes in the prepress process and the development of research, mainly in the following aspects.