In the mono-component development process, transportation of toner on the developing roller and thickness control of toner layers are the most important factors to consider when attempting to form toner layers of uniform and proper thickness
We have improved earlier observation methods to observe directly and analyze the toner transportation and toner behavior in the layer thickness control area, and using the improved method, we have experimented systematically with the various kinds of toner transportation and layer thickness control systems.
Above all, we concentrated on disruption of toner layers by contaminant infiltration.
As a result, the position of a slip Plane existing between static toner and flowing toner in the proximity of the metering area, was found to be most important in preventing a contaminant from entering the metering area.
Based on these results, we have found highly stable layer-forming method, called the “Contact Blade Method”, which minimizes the effects of infiltration by contaminants, and has succeeded in putting it into practical application.

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The phenomenon that ink ingredients are thermally decomposed and deposited on the surface of bulbble jet thin-film heaters (“kogation”) is investigated. Several experimental techniques are examined, including optical and scanning electron microscopy, ion milling. Auger spectroscopy, enhanced phase-measurement interferometry, and diamond-stylus surface profiling. The stylus surface profiling technique appears to be an efficient and accurate method for measuring the thickness of kogation on top of heaters. Kogation patterns of several inks are examined, and effects of miscellaneous ink ingredients on kogation are experimentally studied. It is found that kogation may cause both “soft” and “hard” failures of the bubble jet heater device. It is also shown that heater lifetime depends on both the nature and the thickness of the kogation layer, and that dye is one of the most important ingredients determining kogation characteristics. Possible kinetics of kogation is also discussed.

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A study has been made on the effect of He dilution on the stmcture and photoconductivity of hydrogenated amorphous silicon carbide (a-Si_1-xC_x:H) films prepared by RF plasma CVD method using SiH₄ and C₂H₂ as source gases. The concentration of SiH₂ and CH bonds in the films decreases and the deposition rate increases due to the He dilution. The film density increases with decreasing the concentration of SiH₂ and CH bonds. The photoconductivity is enhanced with an increase in the film density. The dense a-Si_1-xC_x:H films of x = 0.2 have high photoconductivity (ημτ = 10^-6 cm²/V) as the a-Si:H. The energy transfer of He atoms in the metastable states to the growing surface during deposition seems to play the most important role in obtaining dense films.

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In this paper, the measurement of quantum efficiency of double layered organic photoreceptor by the transient surface potential drop method is reported.
The quantum efficiency is dependent on light intensity and charge carrier transport layer thickness. The surface voltage drop should be measured at the low level of light intensity and for the sample with layer thickness from 5 μm to 10 μm.
The total quantum efficiency is a product of carrier generation and injection efficiencies from the charge carrier generation layer to the charge carrier transport layer. The quantum efficiencies under the high and low electric fields reflect the carrier generation and injection behaviors, respectively. The thermalization length r₀ and the initial dissociation probability φ₀ are calculated as 45 Å and 5.3 × 10^-2 using the value of quantum efficiency, respectively.

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We have carried out a computer simulation based upon a trap-limited transport mechanism in order to reexamine the hole transport properties of amorphous selenium (a-Se) thin films. It is shown that the temperature dependence of transit pulse shapes, and the electric field and temperature dependence of hole drift mobilities in a-Se can be quantitatively explained by considering the gap-state distribution consisting of an exponential tail of states upon which a Gaussian feature has been superimposed. Usually, the hole transport behavior in a-Se above 200 K has been attributed to a mechanism in which the carrier now occurs in the valence band with frequent interruption by trapping in discrete levels energetically close to the band edge. In the framework of this transport mechanism, the electric field dependence of hole drift mobility activation energies has been interpreted in terms of the Poole-Frenkel effect. However, we conclude from the present results that the gap states in a-Se are not discrete but distributed as used in the simulation, and that the electric field dependence of the activation energy arises from the multiple trapping of the transiting carrier in the distributed gap states rather than from the Poole-Frenkel effect.

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Chemical vapor deposition of a-SiGe:H films, which utilizes a microwave-excited plasma produced at pressures lower than 1 mTorr, has been investigated as a function of deposition pressure and source gas composition. Changes in film properties depending upon deposition pressure were discussed with respect to the effect of atomic hydrogen and ionic deposition precursors. The structural change of Si-H bonds depending upon source gas composition was also discussed referring to the ionization potential and the electron-molecule inelastic collision cross-section of source gases.

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