In order to understand the imaging characteristics of xerography, it is essential to compare dot gains of various hardcopy output systems such as Chromalin, offset printing, etc. For such a purpose, the most desirable definition of dot gain is “Dot area expansion caused by the dot thickness reduction compared with the one at the solid area”. According to this definition, the amount of dot gain can be semi-quantitatively estimated both from the cross-sectional dot structures and by colorimetric measurements of halftone wedges because any thickness change in the colorant layer sifts the color of the image. The cross-sectional details of the dots were characterized by the observations with a TEM and an optical microscope, confirming the validity of the present colorimetric analysis.

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The purpose of this study is to clarify quantitatively the difference of thinking faculty between two conditions using softcopy and hardcopy. We have examined two working conditions—display medium placed horizontally and vertically—for both medium of LCD as a softcopy and printed paper as a hardcopy. A series of tests have been carried out by measuring calculation speed and correct answer rate to simple calculation tasks using five members of testees. The results have shown clear differences in the correct answer rate. In the horizontal states, the speed is faster when using hardcopy than using LCD, while they are almost the same in the vertical state. In addition, the speed of calculations in the vertical condition are faster than that of the horizontal condition. It is suggested that the advantage of hardcopy originates in its horizontal working condition.

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Non-magnetic single-component process is reported for basic development characteristics. For example, the characteristics of development mechanism using an elastic development roller depends on the resistance of a development roller, the mechanism of the thin toner layer formation by a doctor blade, the toner sticking phenomena on doctor blade and the ghost formation mechanism for the surface potential of the development roller using high resistance development roller.
The uniformity of development ability for halftone images is a significant subject in a contact single-component non-magnetic development system. In digital printing system, it is necessary to hold the development toner uniformity to the photo-conductor for each dot.
We analyze that the mass of the development toner to the photoconductor depends on the diameter of a toner particle using the elastic conductive development roller. And we found the ghost formation is explained by the difference of the toner particle on the surface of the development roller before the development process.

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