The first NIP Congress was entitled Advances in Non-Impact Printing Technologies. It was held in Venice, Italy a little more than 20 years ago. One of its highlights was a panel discussion with the presumptuous title “Future Directions of Non-Impact Printing Technologies”. The panel consisted of seven experts who covered electrophotography, electrostatic, thermal, ink jet, magnetic and related materials technologies. Fortunately, there is a documented record of the panelists' presentations, the opening remarks by the moderator, himself an expert, and brief recapitulations of some of the many questions and comments from the attendees.The predictions offered by the panelists and their moderator will be combined with projections contained in individual papers presented at this same Congress. They will be put into context by describing the technical status of the various non-impact printing technologies in 1981. Applications and approximate market penetration will also be covered.Current (2001) technical and applications status will be compared with the 1981 predicted future directions for each non-impact printing technology thereby highlighting the clairvoyance, or lack thereof, of the predictions. The most significant advances, technical and non-technical, that account for the current status of non-impact printing will be described briefly.The “Back to the Future” part of the presentation will consist of technical and applications extrapolations based on the author's experience, knowledge, imagination, and intuition.

Imaging systems tend at first to simulate the opponent yellow and blue vision channels (YB) even if that perceptibly violates trichromatic simulation of opponent red and green channels (RG). The preference is biologically traced: 8% male population are deficient in RG vision and only 0.003% in YB vision. The YB pair is not the usually assumed alternating combination of M, L, and S-cone responses (say, L+M-S): it is independent of RG sensations (L-M). The complementary yellow (570) and blue (465 nm) are seen after the RG pair has disappeared with decreasing illumination. The yellow is not seen after the 650-nm sensitivity limit of rhodopsin even if the red is over 50 nm more. The ‘blue-cone monochromats’ and some protanopes, having no M and L-cones, see the YB pair. Yellow adaptation eliminates the YB sensations but hardly influences the RG pair. Reflectometry of living retinas shows the ‘M and S-cone pigments’ rather to be long-living products of iodopsin (L-pigment) and rhodopsin.

This paper gives an overview on the state of the art in print production systems and methods, applied printing technologies and their positioning within the graphic arts, communication and media/multimedia industry including the description of trends for further developments (figs. 1, 4, 10, 23, 24, 25, 26, 27, 28).Digitalization allows the linking of the production/workflow sections prepress, press and postpress and can lead to print production systems which include all these three conventional sections (figs. 8, 15, 23).The high quality of print media and their economical production is based on powerful printing technologies and systems. Conventional printing technologies for high productivity which use plates (figs. 1, 2, 5) as well as masterless NIP (non-impact printing) technologies (figs. 1, 3, 15, 16, 25) are realized in commercial systems. The combination of several different printing processes (Figure 11) leads to hybrid printing systems which are optimized for special applications and versions for print media (e.g. offset and ink jet, Figure 13) for personalization/customization and print quality improvements etc. (figs. 2, 12, 14).New technologies make distributed, print on demand production and fully variable printing page per page possible and economical (figs. 9, 10). The driving force for doing this was the digitalization in prepress, digitalization of workflow, equipment, processes and tools to describe the print product to be produced completely with one data file (Figure 22), as well as advanced printing and finishing systems, networking (Figure 8) and the communication techniques (Figure 35) which are available. Printing via the net, measurement and automation control techniques and systems, remote proofing, all the computer to … – technologies (Figure 4, 32) for digital print production and the production of multimedia products (Figure 23), are established and secure high quality multicolor print media (figs. 17, 18, 19, 20, 21) within the world of E-commerce and global communication.All in all, print media do not compete with electronic media, only some partial replacement effects for special print products and applications, e. g. dictionaries, can be observed; the synergy effects between both kind of media support each other and lead also to cross-publishing and multimedia products (Figure 37). The demand for print media is growing continuously, also as an effect of the high growth rate of electronic media (Figure 24). Premedia as a new section in the workflow – in front of prepress – creates and provides a digital master for producing printmedia and/or electronic media (Figure 23). A hybrid / multimedia product is, for example, a conventional book which includes a CD-ROM, especially with search functions and animations added to the file, describing the content of the book itself.The power of print can be clearly recognized by the high quality which is available at relatively low costs, the great volume and demand of printed products and their high variety (figs. 25, 26, 33, 34). The power of print is also confirmed by the innovations in technologies, systems and applications, with realization and the strong demand for different systems for digital printing (Figure 28).Synergies and innovations allow the creation of new components within a printing system and continuous improvements. Image processing, new materials, optoelectronic and micromechanical components are being developed in the labs worldwide and used in improved or new systems. Short comments/information about “X”-graphy (Figure 1) – new NIP-technologies like Elcography, TonerJet, Direct Imaging Printing, Zurography and “Ink mist jetting” are given.There is a wide field of interest in interdisciplinary scientific, research, engineering, system and product design and for customer-friendly solutions and applications within the graphic arts and communication industry; these are challenges and chances to enter the market with new ideas and systems in time, successfully for all partners – users, suppliers and customers (Figure 39).The presentation covers this wide field of subjects and gives an overview on the state-of-the-art status and the future trends (figs. 24, 25, 27, 33, 34, 38). A selection of examples are shown and explained for the different printing and production systems optimised for several applications. This especially for offset and flexographic printing including direct imaging techniques (figs. 2, 5, 6, 13) as well as for the leading NIP-technologies electrophotography and ink jet (figs. 3, 14, 15, 16, 25).Examples for innovative new technologies and product concepts which are “on the road” to be checked and used in practice are mentioned like E-book, E-ink, E-paper (figs. 29, 30, 31), erasable and rewritable substrate/surfaces with storage capability (fig. 6, 7), OLEDs, MEMSs (e. g. digital micro mirror devices) and PLZT-light valves for designing new imaging systems, etc. as well as improved and new print production techniques and systems.

We have developed a colour prediction model and an ink-spreading model. The present study aims at confirming the validity of both models for the case of ink-jet prints using cyan, magenta and yellow inks.Our colour prediction model, augmented by the ink-jet spreading model, predicts accurately the reflection spectra of halftoned samples printed on an HP printer and on an Epson printer. For each printer, the reflection spectra of 125 samples uniformly distributed in the CMY colour cube were computed. The average prediction error between measured and predicted spectra is about ΔE = 2.5 in CIELAB. The model requires the estimation of a set of parameters which are deduced from a small set of measured samples. Such a model simplifies the calibration of ink-jet printers, as well as their recalibrations when ink or paper is changed.

Due to its simplicity, the theory of Kubelka-Munk [1] has found a wide acceptance for modeling the optical properties of light scattering materials. However, the concept is not explicitly adapted to predict halftone prints on paper. In this respect, a recent improvement was given by Berg [2]. Our approach is an extension of Berg's model in order to reduce the gap between the mathematical description of the paper's point spread function and the experimental results of simple reflectance measurements.

Decolorable ink developed by Toshiba consists of leuco dye, developer, and eraser. The key to fabricating an effective imaging material is to find a balance among these three components. There is equilibrium between colored leuco dye and colorless leuco dye. Because the equilibrium is dominated by colorless state in a solution, an addition of solvent to the ink instantly make it colorless. A similar decoloring process is performed by heating. This decolorable ink technology could be applied to almost all imaging materials.

We present a novel error-diffusion technique for halftoning color-separated images. The method correlates the different ink planes in a pixelwise manner and minimizes the overlap of dots from different colors to optimize the color halftone with respect to graininess.It is a two-step error diffusion: in a first step it is determined how many ink drops should be placed at a particular pixel without specifying the color of these drops. In a second step the color of these ink drops is determined.

Digital printing will be beneficial to the industrial printing market - labels & packaging, decorative printing - because lead times will be shorter, job lengths can be longer and there is the added benefit of fully variable data printing. A high throughput is needed and the output has to be similar to traditional printing while the substrates vary from very thin to very thick foils, films, aluminum and paper.The development of UV curable jetting inks and robust grayscale IJ printheads make it possible to build an industrial digital multi-color press. To achieve the necessary throughput (currently 800 sq.m/hr) a single pass system is needed.A single pass system has different requirements and specifications for the printheads, and requires specific tolerances in the assembly while the complete solution has to be efficient and economically optimized. The use of low viscosity UV ink drops in a raster has its own particularities. These requirements and the current solutions are discussed.

As xerography moves to intercept offset printing, image quality becomes a key ingredient of success. Classic halftoning methods, which generally deliver good, low noise halftone dots, have fixed positions in the scan field that hinder several possible improvements to these printing systems.First, exact halftone frequencies and angles would result if dot positions could be adjusted with arbitrary precision. This would improve the design of screen-sets that limit or reduce multiseparation moiré, or allow screen-sets that exhibit the classic rosette structure associated with offset printing.Second, electronic registration systems could emerge if the halftone dot positions could be adjusted in response to actuation commands from the printer. Such systems would automatically compensate for mechanical distortions caused by bent mirrors, elliptical rollers, and tandem color print stations, for instance, and thus save manufacturing costs for the mechanical system.Normally, the dot positions are fixed to small integer offsets (the angle corresponds to a “rational tangent”) in the scan field, thus preventing the occurrence of single separation moiré. When fractional dot positions are allowed (irrational tangent), moiré can result. Thus, if the moiré problem can be eliminated for irrational halftoning, the frequency and angle restrictions associated with rational tangent halftoning disappear.I will present one solution to this problem that subsamples a halftone cluster function stored in a look-up table to produce reduced moiré separations while printing. Halftone dot locations are computed by hardware, and dot cluster shapes typically do not repeat. I will show a simulation of a three-separation image printed on a 600 spi digital printer that uses irrational offsets (m30°, c75°, and k45°) designed to produce a classic rosette structure. I will also show a simulation of these same dots being electronically registered, or warped.