Non-impact Printers Research Articles

Environmental Issues and Non-Impact Printing

The emissions from low speed and high speed non-impact printers during their life cycle have been documented.This paper emphasizes key environmental aspects of toner materials including material constraints, air quality, recycling and end of life disposition details. The material constraints were apparently driven by regulatory agencies guidelines and customer perceptions. The requirements of regulatory agencies like OSHA, US EPA, Prop 65, JIS and Blue Angel will be reviewed. The maximum emission levels will be discussed for volatile organic compounds like benzene, Styrene, toluene, aldehydes etc.The regulatory agency requirements, test procedures and official test protocols for toner manufacturers, raw material suppliers, and end users will be discussed. The environmental requirements of two major types of toners (styrene-acrylate and polyester) will be reviewed. The styrene based toners have an historical performance database and polyester toners are gaining massive usage at the present time. With the advent of nano materials, they do pose newer challenges for this industry. These aspects will be discussed in this paper.

220 レーザプリンタの開発状況と今後の課題

Laser printers are most widely used non-impact printers that are primary output devices for PCs. The basis of the technology is digital electrophotography originally developed for copiers. In this paper, past, present, and future of the laser printer is reviewed with respect to basic electrophotography, digital technology, color technology, and environmental issue.

The development of high-speed non-impact printers by General Electric (failure) and Xerox (success): a dual case study

In this dual case, we discuss how two leading innovative corporations, with excellent R&D facilities and deep pockets, developed independently high-speed non-impact printers. We describe in parallel the tour stages and three milestones of the process of technological innovation within the two companies. We analyse the key technical, marketing, financial, organisational and managerial factors that contributed to failure at General Electric and to commercial and financial success at Xerox. We emphasise the importance of (1) the choice of technology, (2) market research and especially (3) internal entrepreneurship for achieving success. In both cases, we discuss the ambiguous role of higher management that ranged from initial enthusiasm to hostility and neglect and finally to belated support. We conclude with lessons learned and guidelines that may be useful to R&D managers, business managers and internal entrepreneurs who intend to develop major technological innovations within established companies.

Characteristics of an electro-rheological fluid valve used in aninkjet printhead

The demand for non-impact printers has grown considerably with theadvent of personal computers. For entry-level mass production, twodrop-on-demand techniques have dominated the market - piezoelectric impulseand thermal-bubble types. However, the high cost of the piezoelectricprinthead and the thermal problems encountered by the thermal-bubble jetprinthead have restrained the use of these techniques in an array-typeprinthead. In this study, we propose a new design of printhead with anelectro-rheological (ER) fluid acting as a control medium. The ER fluid valvecontrols the ink ejection. As a first step toward developing this newprinthead, the characteristics of an ER fluid valve which controls thedeflection of the elastic diaphragm are investigated. First, the response of aprototype is tested experimentally to prove the feasibility of using this ERvalve for the inkjet printhead. Then, the discretized governing equation ofthe ER valve is derived. Finally, the prototype of the ER valve is fabricated.The experimental measurement based on the sinusoidal response verifies boththe theoretical analysis and the controllability of the response of the ERvalve by the applied electric field.

Digital Halftoning Using Optimum Pattern Selection in Human Visual System

This paper proposes a new approach to the problem of producing high quality halftone images. In order to reproduce continuous-tone images on bilevel output devices such as non-impact printers, various halftoning techniques have been developed. Ordered dither and error diffusion (or minimum average error) are the typical methods widely used for the purpose. In these methods, decision of bilevel is made on each pixel bases. In this paper, a new method named “Optimum Pattern Selection” is proposed. In the proposed system, each non-overlapping block of n × n pixels is taken up from the original continuous-tone image. On the other hand, all the possible binary patterns of the same size, i.e. n × n pixels, are generated mathematically. Each of the binary patterns is then transformed to a reproduced continuous-tone image block by a lowpass filter, which is a simplified model of HVS (Human Visual System). The reproduced images are then compared to the original image block. The optimum binary pattern, which brings about the reproduced image most similar to the original image block, is selected. For the purpose of improving the halftone image quality further, the optional filter switching algorithm is introduced.

Digital Photography and Color Printing

Digital photography is a new electronic still imaging system that has appeared in the process of the electronization of photography. It is a fusion of electronic photography and hybrid photography, combining film images and image data. The main frame of this system consists of image pickup, manipulation, and output processes. In the image pickup process, three-dimensional images of objects and two-dimensional film images are recorded by electronic still cameras and scanners, respectively. The image manipulation is digital signal processing using the computer. The image output processes include both hardcopy printing and softcopy display. Digital color printers are the key equipment for hardcopy output. Recent useful applications are electronic picture retouching in photographic studios and desktop publishing for graphics engineers. At present, many small digital cameras have appeared on the consumer market. They are designed to be three-dimensional scanners in the peripheral equipment of personal computers. The development of color non-impact printers producing color prints has succeeded in the early stages, and these technologies have expanded the applications of color hardcopy. Digital photography integrates various imaging equipment and yields new technical problems in image quality. This report reviews the progress of digital photography and its contribution to the development of the hardcopy world, then discusses new problems of data coding and matching in image quality of softcopy and hardcopy prodcopy produced by the same image data.

Physical Considerations in the Development of Pressure-Sensitive Adhesive Sheets

Abstract A pressure-sensitive adhesive sheet is a special kind of paper used in non-impact printers which use a heating process to apply toner to paper. As a result, it needs special characteristics that general pressure-sensitive adhesive paper for labels do not require. One of these characteristics is that the edge of the folded paper used in non-impact printers must not incline after printing. This was done by making the degree of orientation of the fibers in the face stocks and the release liners low. The other characteristics are that adhesive must not ooze out from the edges during the slitting or guillotining process and that the labels must not come off of the release liner by themselves during the printing process. Ooze characteristics were found to be related to the adhesive coat weight. An adhesive paper with both a high peel strength and lower adhesive coat weight was developed by studying the dynamic viscoelastic properties of adhesives and release layers. The storage modulus of the release layer concerned with the release force was also found to be related to the self-peeling tendency of the labels. These points were considered during the development of pressure-sensitive adhesive paper used in non-impact printers which use a heating process to apply toner to paper.

Image Quality Metrics for Printers/Plotters

Today, non-impact printers have become a common office peripheral. With this increase in market acceptance, the understanding of computer imaging has left the realm of black magic, known only by a select group of scientists and engineers, and entered into the mainstream of computer literacy.Competitive bench marking articles in popular computer magazines no longer look at just the price of the printer, how clear the user manual describes using the software that comes with it and if the manufacturer's technical support department picks up the phone. They are beginning to look inside the device at the optical, mechanical and electronic precision as measured by output image quality.Today, manufacturers are beginning to use sophisticated machine vision software technology to evaluate image quality and set the standards for their design and manufacturing operations. Their marketing organizations are using the same technology to perform competitive analysis.Manufacturers of printers need to understand how this new technology is being applied to assure competitiveness, improve customer satisfaction and to be able to respond to the growing awareness and expectations in the marketplace regarding image quality standards.This paper will present a series of specific metrics for quantifying image quality for non-impact printers. Specific metrics will include Color registration, Color consistency, MTF, resolution, Streak noise, Text quality, Motion quality, Linearity, Sharpness, Smearing effects, Dot quality and others. Discussion will also present methods by which manufactures have achieved a fully automatic image quality testing process. Case studies and examples of current installations at major printer manufacturers will be discussed.

20/30 Hindsight: Forecasting the Impact of Nonimpact Printers—An Update

The author gives a retrospective about the work he and his coworkers had done about 1980 in support of Xerox's decision to enter the high-speed computer laser printer market.

Critical parameters in the measurement of the color of nonimpact printing

Abstract. The task of instrumental measurement of the color of non-impact printing is addressed. The majority of the instrument andsample parameters that can introduce systematic errors in the in-strumental readings are identified. For selected cases, proper mea- surement procedures are identified. In other cases, the user is warned of the problem and must devise a measurement methodol-ogy for minimizing the effects of the identified parameters. Without proper concern for these parameters, high-fidelity device- independent color reproduction is not fully achievable. 1 Introduction Overthe past few years, the quality ofthe output of nonimpactelectronic printers has consistently improved. Today, thereis less bleeding and wicking of the primaries into adjacentpixels, less pickup of the primaries by the platen, and bettertrapping of one primary onto the others. At the same time, there has been an increasing need for higher fidelity and repeatability in the printed images. Electronically printed im-ages are being used as design proofs and even as productionguides in desktop printing and publishing and in architecturalengineering and design. Nonimpact printers are also beingused in nonimaging applications, such as trademark colorsand product simulations in CAD systems. Recently, there hasbeen increased activity in documentary standards for device-independent color communications between the desktop andthe printer, image setter, or separator.2 This has necessitatedthe colorimetric characterization of scanners, displays, andprinters. When the control is closed ioop, the characteriza-

Colour printer operating systems and their identifying characteristics

Advances in computer graphic technology have had a dramatic influence on the design of colour printers in the 1980s. The principal operating mechanisms of dot-matrix, thermal and ink-jet colour printers are discussed. Close scrutiny of samples generated by several different impact and non-impact colour printers has disclosed certain characteristics which will assist in determining the possible source of a particular questioned document.

Character generation under grid constraints

An original and fast filling algorithm based on vertical scan line sweep and contour tracking of a presorted shape description allows filling of character shapes with real subpixel resolution. Identical parts of a character lying at a different phase in respect to the grid will have a dissimilar discrete look. Grid constraints are applied in order to force given parts of a character (stems, serifs) to attain identical phasing. So that several contraints may be applied, degrees of freedom are provided in the form of stretchable null-segments inserted at particular locations in the character outline description. Grid constraints are also applied to avoid discrete arcs with an isolated pixel or a long horizontal or vertical run. The type of constraints applied to parts of a character consists only of horizontal or vertical subpixel translations. The resulting character description therefore remains nearly identical to the original description. The processing time used to apply grid constraints is negligible, compared with the time needed for character scan-conversion and filling. Hence, this method is very well adapted for direct character generation on non-impact printers. It is also suitable for character rasterization in typographic computer-aided design systems.

Basic printers

Although nonimpact printers are exciting much interest, there are still appropriate applications for line or band printers. Technology in these machines continues to be improved. There are a number of considerations to be taken into account when buying a printer, such as price/performance, reliability and supplier services.

Fonts with transcription symbols and their standardization—a survey of prospects

Phonetic typesetting has always been a difficult undertaking. As long as typesetting was the business of professional typesetters, the ordinary transcriptionist did not have to worry very much about this. Today, typesetting techniques are downgraded by a variety of other textprocessing machines, ranging from electrostatic printers, or other non-impact printers that use digitized font information, to impact printers, such as print-wheel and selectric typewriters (see Hsu (1982)). It is the output of this kind of printer that can be used for camera-ready copy. Moreover, the area of influence of the author is extended since he himself has access to such textprocessing machines (see the TEX user group movement, explained below). Some years ago, most of the text-processing machines were quite inflexible; they could not cope with additional symbols or additional fonts. Early attempts to make phonological and phonetic data representable in such textprocessing systems had to accept existing symbols, and mappings between existing standard symbols (the ASCII code, for example) had to be established, sometimes on the basis of similarity (& for epsilon, for example) (see Millar/Oasa (1981), Wothke (1981), Roach (personal communication, 1981). Now that it is possible to define character sets for matrix representation (Pfeiffer-Rupp (1981a), (1982a), Neuhaus (1983)), both for printer representation and for representation on a visual display (Pfeiffer-Rupp (1981b)), it is no longer necessary to operate with such makeshift devices—which demand an additional level of coding within the same alphabet and often lead to the idea that the ASCII code is adequate for everybody's purposes, which is what the graphics industry would like to hear from us.

Computer-Printed Documents As Part of a Computer Crime Investigation

Abstract Research related to the investigation and the prosecution of computer crime is continuing. Detailed, highly technical expertise may be required of the document examiner in the comparison, examination, and identification of computer-printed documents produced by high-speed printers. Such research in the area of the identification of computer printouts, as part of the evidence in a computer crime-related case, is continuing. It is important for the investigator, document examiner, and prosecutor to understand the basic workings of the computer, the entry of data by computer personnel, the processing of information via technological advances, and the output of data by high-speed impact or nonimpact printers and to relate such complex workings in everyday language so that the judge and jury may understand the evidence involved.