This study is intended to clarify gloss development mechanisms in electrophotographic printing in comparison with offset printing technology. In the present work, the influence that some fusing parameters and toner penetration have on the formation of the printed surface topography while the toner fuses between heated rolls and matte-coated paper was discussed.
The relationship between pre-printing and post-printing surface topographies was compared among three different parameters;the load and temperature of the nip and the passing speed of a sheet. For all the parameters, as the fusing energy given to the toner is reduced, the printed surface topography was formed to be influenced greatly by the paper surface topography. In addition, it was confirmed that the paper surface with unfused toner has a characteristic roughness distribution in the same frequency range with that of the paper surface. These results suggest that the transfer of toner maintains the paper surface topography, but the printed surface topography is formed by applying heat and pressure and becomes different from paper surface topography. The relationship between pre-printing and post-printing surface topographies was compared using coated papers with different levels of liquid absorbency. Fused toner penetration by capillary force hardly influenced printed surface formation.

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Properties of toner charge and toner mass amount on a developing roller for non-magnetic mono-component developing system have been investigated with a compact draw-off type instrument for measuring toner charge and toner mass amount. Pushing pressure of the blade to the developing roller, surface roughness of the roller, and external additives on toner surface affect toner mass amount of the toner layer on the roller as well as toner charge of the toner layer. These influences were examined in this study. As a result, the following were clarified. (1)In the case of changing the pushing pressure of the blade and the surface roughness of the roller, the toner charge on the developing roller is increased when the toner mass amount is decreased. Therefore, the area charge, which is defined by a product of the toner charge and the toner mass amount, was almost constant. (2)When the content of the small diameter silica used as the external additive in this study is increased, both of the toner charge and the toner mass amount are increased. Therefore, the amount of the area charge is also increased. (3)The area charge is very important to determine charging properties of toner particles in the mono-component developing system.

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We have developed new electron transport materials, which have the structure of naphthalene-tetracarboxylic diimide. These compounds showed good compatibility to a polycarbonate and good solubility in common organic solvents. Electron transport properties of these compounds were investigated by the conventional time-of-flight method. Electron drift mobilities have been measured as a function of the concentration and electric field. The values of electron mobility ranged from 10^-8 to 10^-4cm²/Vs as the molecular concentration was varied from 20 to 60wt%. These mobilities are comparable to hole mobility of triphenylamine derivative, TPD.

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The new oil-less full color toner using polyesters as its binder was developed by ester elongation polymerization. (Color P×P Toner).
We attained low temperature fixing, heat-resistance, and moderate glosses by controlling molecular weight distribution of polyester binders and wax dispersion. In addition, high image qualities were achieved by its small particle size as well as narrow particle size distribution. Moreover blade cleaning systems were realized through shape control techniques for producing dimple form particles. The Color P×P Toner was able to reduce consumption of toner by about 26% due to its higher image density and improved transfer efficiency compared to a conventional pulverized color toner. Also the Color P×P Toner method is able to reduce CO₂ emission from toner production by about 35% compared to the conventional pulverized toner production method.

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We investigated about the fading characteristics of dyes using edible, cosmetics and dyed goods and also proposed the design of coated paper on new rewritable system using discharge treatment. From the experimental results, we note that:(I)the fading performance improves with an decrease of ionization potential of dye, (II)the inorganic particles with dye adsorption of about 1g or more is more effective in the fading process by the discharge treatment, (III)the dyes alternatively adsorb to the inorganic particles but to no pulp and the loss of chromophore in dye is attributed to electrophilic reaction by oxidation gas, i.e., ozone, (IV)the fading performance on leaving time after print is closely related to the photoelectron yield, resulting in aggregation of monascus dyes. In addition, it can achieve to the CO₂ reduction target of about 1% provided that the system is applied to all PPC paper be in Japanese use.

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[in Japanese]

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Full Color Digital Multi-Function Products (DP-C322/C262) which has been developed by our company, has:1)“Angle-Adjustable Operational Panel” and “Voice Guidance” to improve usability considering Universal Design Concept. 2)“Belt IH Fusing System” which is our unique idea and the strong point to establish 15 seconds worm up time, and this is the fastest worm up time of A3 Color Digital Multi Function Products category in the world. Above make our product to establish significant energy-saving, because this system is not required any pre-heating power during Stand-By status. Following are detailed technical report of our unique and strong points which was established for our Full Color Digital Multi-Function Product (DP-C322/C262)

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We introduce The MICROLINE 9600PS series and MICROLINE 9800PS series developed to meet the requirements of high-quality and high-speed color printer for DTP and On-demand printing on the enterprise.
VDC-way Digital LED head, which realizes representation over offset printing quality by increasing up to maximum 32level grayscale per 1 dot first in the world, was installed, and the superior printing, which can be utilized for final printed matter in commerce, was made possible by adopting new technology which was newly developed polymerized toner, a new fusing unit, and so on.
As for the mechanism side as well, improving usability was realized by new technology which was Basket mechanism, high-reliability multi purpose tray, waste toner mechanism, and so on.

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Multi function color copiers at present have not been acceptable in general office market, because they are not convenient for both warm-up time and first copy output time. DocuCentre-II/ApeosPort-IIC4300 series has been developed to replace mono-chrome copiers to color copiers by focusing on the same convenience as that of mono-chrome copiers. This report introduces the development scenario and transition of C4300 series product, with technical summary.

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Developed from the same design and platform, the MP C4500 and MP C3500 series are positioned as midrange to high-end digital multifunctional printers, and realize the main features necessary to succeed in this market high productivity, high reliability, high image quality, and user friendliness. Specifically, the major features of these products are as follows.
1. A new image system that realizes excellent image quality through the use of color P×P toner.
2. The most accurate color image positioning available on any Ricoh product, made possible by new auto image positioning technology.
3. A high-reliability, high-productivity mainframe engine.
4. A paper transport mechanism and paper feed trays that feature user-friendly design, which enable to load paper tray easily and to remove jammed paper easily.
5. A large, quick-response LCD for more simplified operations.
6. IH fusing technology, which reduces machine warm-up time to one-quarter that of previous products.

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Full Color multifunction printer iRC-5180 that CANON released in July 2006, equipped with New fusing system <TBF>. A concept of iRC-5180 is ｢High-productivity｣,｢Down-sizing｣&｢High-resolution image｣, at the same time offering comfortable docu'ment-work-flow for office.
I'd report an outline of key technologies mainly about technology on <TBF>.

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Konica Minolta's bizhub PRO C6500 is a high-speed color MFP that provides 65-ppm color and B&W productivity. With wide range of inline finishing options which feature versatile booklet creation and finishing functions, professional output job is performed on demand as a production printing system.
The bizhub PRO C6500 incorporates various technologies to further adapt to light production printing environment. Presented here are the outline of system configuration and the newly-developed technologies for image forming process including paper feeding, fixing, and imaging, to improve the ability to print coated paper stock that is a great demand in this market.

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