1、数字印刷翻译中文2490字Digital printingPhil GreenDigital printing is currently the most rapidly growing print sector, and one which is opening up new possibilities of short-run color work. It is also enabling entirely different relationships between the purchaser and supplier of printed products and making po
2、ssible all kinds of new products.The conventional printing processes described earlier in this chapter are mature technologies. The technological development of these processes will continue, but will tend to deliver only incremental improvements in performance. Digital printing, by comparison, is s
3、till at an early stage in its development and will continue to develop rapidly, opening up new markets and making increasing inroads into the conventional process.In the medium term at least, it is highly unlikely that digital printing will entirely replace the conventional processes. This is for tw
4、o fundamental reasons: The cost of colorants used makes unit prices too high to compete on longer runs; Modern printing equipment is designed around production economies of scale, with high speeds, large formats and inline processes such as folding and coating, and it will be some time before manufa
5、cturers build digital presses that can compete on high production volumes.The strength of digital printing is therefore largely in shorter print runs. However, the short-run market is expanding fast as print runs for all types of product are falling, and new products are made possible by integrated
6、digital production. A direct cost comparison between digital and conventional printing may not be relevant in every case as digital printing can often provide a better solution to a communication problem, adding value and generating savings elsewhere in the production cycle, for example, in administ
7、ration or distribution costs. This logic also applies to the print buyers when thinking of incorporating digital printing into their own operations, adding them to their existing design and prepress operations. To take a example in retailing, instore printing facilities linked to install and run tha
8、n purchasing from external suppliers, but the marketing benefits may outweigh the additional costs.The point at which digital and conventional printing breaks even tends to be at a run length of around 1000 copies(more for black and white and less for color). Run lengths that do not fall automatical
9、ly into the province of conventional or digital will be decided by the added value of the process: for digital printing this includes distributed printing and the ability to vary the image with each copy, while for conventional processes such as litho it will include the higher quality levels, the g
10、reater range of substrates that can be printed, and the availability of inline processes such as coating.Digital printing technologiesDigital printers currently fall into four basic types: Page printers that print flat sheets of paper, usually in A4 format but sometimes up to A3 (these range from de
11、sktop printers to high-speed copier/printers like DocuTech, and include high-quality continuous tone printers used mostly for proofs and presentation materials); Large-format devices that print on continuous rolls, mainly for short-run posters; Overprinting heads for adding product codes (mainly for
12、 packaging) that are mounted onto conventional presses or finishing equipment, or on packaging lines; Reel-fed machines that print at speeds comparable to conventional printing presses.A digital printer has two fundamental components: a marking engine that transfers colorant to the paper, and a fron
13、t-end that prepares the data used to drive the marking engine. The front end will include a RIP and a memory buffer. The page data is transferred directly to the front end without the need for films and plates, so there are large potential savings in costs.Because the digital printing device is driv
14、en by data and requires no plates, the image can be changed for each successive print. This variable image printing concept has great potential interest to publishers and advertisers who are interested in tailoring their communications more closely to what is known about their audience, often in con
15、junction with sophisticated marketing databases.Digital printing systems that operate at high speeds or high resolutions require dedicated front ends and large memory buffers, but low-end devices such as desktop printers can make use of software-based printer drivers that sit on the users host compu
16、ter.The most widely-used technologies in marking engines are ink jet, laser and dye sublimation.Ink jetInk jet printers deploy an array of nozzles to project ink droplets onto the paper surface. The nozzles are relatively cheap to produce, and wider arrays that can image a moving web of paper are cu
17、rrently in development. Ink jet print heads are found in all the types of digital printer listed earlier, and dominate the large-format and overprinting markets. They can print on the widest range of substrates (including cheaper grades such as part mechanicals).LaserLaser printers transfer toner to
18、 the paper surface electro-statically. An image is created on a photoconductive surface by adding or removing an electrical charge, and toner is attracted to the charged areas on this imaging surface (laser printers are perhaps more accurately known as electrostatic printers, since other energy sour
19、ces such as electron beams can also be used to alter the conductive properties of the imaging surface). Most systems use dry toner powder, but liquid toner systems are also available and deliver much better print quality: smaller particle sizes yield higher print resolution, and gloss resins can be
20、incorporated to make the finish more like that of a conventional print. Laser printers are mainly found in page printers and reel-fed printers.Dye sublimationDye sublimation printers vaporize a waxy colorant and transfer it to the paper surface. The unit cost of prints made by this process are extre
21、mely high, and as a result its use is restricted largely to one-off prints for proofing or presentation purposes. Quality can be extremely high, comparable to a glossy photographic print.With all the digital printing systems there is a trade-off between resolution and speed. The more device pixels t
22、here are to be imaged on a page, the slower the print speed will be in pages per minute.Digital workflow-the mainstream of developspeedy development of digital processing and internet information exchange All-digital workflows are on their way. They will soon replace the traditional analogue imaging
23、 and reliable digital performance in graphical processing, proofing, output, and transfer. It will also enable no-film involved Computer-To-Plate system to take the lead. Multi-media documental output is no longer a dream anymore. Pre-press production line has becoming more integrated, professional
24、and diversified. The main development trends of application software are openness, cross-platform functions, intelligence and standardization of documentation format.The implementation of digital workflow is the irresistible trend development in printing industry. Maturing printing technologies such
25、 as CopyDot scanning, digital proofing, computer-to-plate, and digital workflow gradually remove the obstacles to the implementation of digital technologies. Advanced output technology, together with intelligentization of digital workflow management will also improve the efficiency of digital printi
26、ng operation.The digital technology process has almost replaced the traditional technology. The design and pictures can be transferred by network or through electronic medium. The corporation of pan-region, pan-country, pan-continent will be a common thing. We can offer the need, exchange informatio
27、n, remote proofing, and production tracking etc. The product can be designed in somewhere of the world, and printed in another place of the world.Direct-to-pressOne of the success stories of digital printing is Heidelbergs Quickmaster DI, which uses digital imaging on an otherwise conventional press
28、 design. Machines have been installed in a large number of bureau-type operations, and deliver many of the advantages of digital printing at the quality and cost associated with litho.Anew production modelThe traditional model of print production can be summarized as print a large enough quantity of
29、 a product to make unit costs economic, and then distribute to the end-user. Digital technologies make it possible to completely rethink the way in which visual communications are produced and distributed.Print-on-demandBecause the amount of prepress work and press make-ready are minimal when compar
30、ed with conventional printing, production costs are almost entirely variable, with a very small fixed element. This means that they become cost-effective to print copies as they are needed, instead of producing for stock.Distribute, then printPrinted products are usually distributed over a wide geog
31、raphical area, and it can sometimes be more cost-effective to distribute the pages in digital form for local reproduction.Distribute electronically For items whose function is information rather than marketing, end-users will often accept the end product in electronic form (on disc or CD): the pages
32、 can be printed individually as required. This allows the originator of the product to focus on its content instead of its reproduction.Alternatively, it may be possible to use an online distribution medium such as the World Wide Web, and create pages that are intended for viewing on screen rather than reproduced on paper.Variable image printing As each page is imaged separately, and there is no physical printing plate, it is possible to change some or all of the page with each successive print. This enables, for example, each communication to be personalized for its intended recipi
