In a tandem printer, local dot positioning errors at a first transfer, which likely occur in thick paper printing, are unacceptable problems.
In this study, the mechanism of generating local dot positioning errors is investigated by FEM analysis. At first, vibration characteristics of a transfer belt drive system are investigated experimentally. And then, motion and deformation of a belt, a paper and rollers with the vibration characteristics are analyzed by FEM. Finally, calculated belt velocity fluctuation is validated by comparison with experiments.
As a result, it is clarified that the local dot positioning errors by belt velocity fluctuation at the first transfer are generated by belt tension and torque fluctuations on the drive shaft caused by impacts when leading edge of the thick paper is fed into a second transfer nip region. It has been known that the impacts generate a torque fluctuation on the drive shaft in a belt drive system as well as a steel rolling mill system. However, it is found in the result that they also generate a belt tension fluctuation in a pre-nip region caused by a contact force between a belt and a paper.
Present calculations can also provide image quality deterioration levels affected by jitter since the practical velocity fluctuations are accurately simulated.

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Core-shell (C-S) particles having ultra-thin shell layers are prepared by a coacervation process using positively chargeable Polymethyl-Methacrylate (PMMA) particles with the size of approximately 9.5μm as the core particles. Negatively or positively chargeable ultra-fine particles are used to prepare single-shell and double-shell particles by a coacervation process using their aqueous suspensions. Their surface structure and the tribo-charging characteristics are studied. The tribo-charging characteristics of the single-shell C-S particles can be controlled by the small amount of shell layers less than 5000ppm. Double-shell C-S particles have also been obtainable by the coacervation on the single-shell particles. The amount of the positively chargeable outer shell required to shield the negative chargeability of the inner shell is 1000ppm. The amount of the outer shell to attain the steady positive charge is 5000ppm. This corresponds to the very thin outer layers of about 10nm. These results strongly suggest the possibility to control the tribo-charging characteristics independent of the chargeability of the inner shell and core materials.

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It introduces the OKI C300/C500 series A4 Color LED Printers which were developed with the concepts of compact, ecology and low price into the market segments of the desk top and small work group.

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The Color 1000 Press and Color 800 Press (the “Color Press”) are high-speed color publishing systems capable of printing 100 and 80 pages per minute, respectively. The Color Press suppresses image surface elevation and supports a wider color gamut for color reproduction by using EA-ECO toner, achieves higher image quality, reliability and robustness with newly developed photoreceptor, intermediate transfer belt and fusing unit technologies, and combines renowned high-resolution processing of 2400 dpi, IRECT processing, and paper control technology. It features a new paper-cooling device, clear toner as a 5^th color in addition to YMCK, a complete lineup of paper feeding/output devices, and a high-speed multifunction controller incorporating a quad CPU. With these features, the Color Press improves the work efficiency and productivity of users, and can expand business with its extended application to photo TansPromo marketing collateral packages.

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The design of an electrophotographic printing system (ColorStream^® 10000 Flex) that has been developed for color and efficient b/w production printing is described. To fulfill all requirements a multipass concept was chosen, resulting in optimum usage of key components and in productivity dependence on print mode (1/1 to 5/5). As well as b/w or process color printing, the mixable toner design allows specific customized color and, for example, a 2/2 color operation. The platform incorporates various key components which were specifically developed and are described below. The embedding of technology components in a powerful and flexible workflow and control system enables use in a wide spread of applications.

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The HP Indigo 7000 Digital Press incorporates many innovative breakthroughs in its liquid electrophotographic engine and other sub-systems to enable it to reach a 2.15m/s process speed, 76% higher than that of the previous generation Indigo presses. Significant changes include the use of a charge roller in place of scorotrons to charge the photoconductor and an external blanket heating system to prepare the marking ink for transfer to paper. Other improvements, such as a higher-throughput writing head and more precise and capable mechanical assemblies, also play large roles in enabling the increased performance. In this paper we discuss the general advances in the HP Indigo 7000 and some of its new subsystems in much more detail. These together enable the press to greatly increase productivity without compromise to the Indigo “offset look and feel” quality.

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Four years have passed since Digital Toner HD (DT-HD) was put on the market. Along with the spread of RGB workflow, there has been an increasing demand from the customers requiring to faithfully reproduce colors displayed in the working monitor onto a print. However, the color gamut of the display differs greatly from that of the standard printing, therefore, alternation of hue angles and improvement in saturation of colors for coloring materials are required in order to faithfully reproduce the displayed colors. We aimed to realize faithful color reproduction, by applying the color toner technologies which have been accumulated by Konica Minolta. Based on a molecular design technology, we have succeeded in developing high chroma toners containing copper chelate type magenta dyes and phthalocyanine type cyan dyes achieving the above-described properties. The newly developed dyes have been loaded in the toners for bizhub PRO C65hc. As a result, it has become possible to reproduce the hue of the working monitor more brilliantly and more clearly on paper, which have been hard to realize until now. Here, the characteristics of bizhub PRO C65hc toners and the developed technologies are described.

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In this article, the Ricoh Group's efforts toward reducing environmental impact and achieving the recirculating society are explained, and environmentally friendly products and Reusing/Recycling technology based on the concept “Comet circle” are explained by the Ricoh Group's actual cases.
The brief summary is as follows :
1) Direction of Ricoh Group aimed at reducing environmental impact
2) Environmentally friendly products <imagio MP C2500RC/MP C3500RC (Re-Conditioned machine)>
3) Reusing/Recycling technology for designing and manufacturing of Reused machine

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Recently, environment conscious efforts have been made in various business fields. Those efforts are being promoted also in business fields of copier and printer, such as energy saving countermeasures and adoption of biomass resins. While some companies limited emissions of CO₂, Sharp introduced digital MFP adopted Mycros toner EP^TMcomprising more than 25wt% of non-grain plant-based resins, which acquired the industry's first BP mark (Biomass Pla-mark) in June, 2010. We will explain about monochrome digital MFP, MX-M623/M753 and Mycros Toner EP^TM.

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The electrophotographic full color Multi-Function Printer imageRUNNER ADVANCE C2030 that Canon released in 2010, targeted the low-end zone of the office, and this developted compact color MFP is equal to B/W MFPs in a concept for space-saving, low price and usability with a high quality image. For achieving these concepts, we selected the new cleaner-less system which optimized to the high quality image pQ toner and the new toner transferring system.

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