The touch-down development is one component process using charged toner. But there are many problems unsolved on the mechanism of this process.
In this paper, some analyses are given on the mechanism of this process using charged toner. The optimum toner thickness on the development roller and the optimum pressure between the photoconductive drum and the roller are given on the theory and the experimental results.

View full abstract

Magnetic brush development has been studied both theoretically and experimentally. In the analysis, the relations between developed toner mass and primary development factors, such as developer flow rate, toner layer potential, toner charge to mass ratio and recording layer capacity, have been investigated. The theoretical expression obtained agrees well with experimental data. Using this expression, the suitable parameter values needed to obtain the required optical density are clarified.

View full abstract

The magnetic brush developing method is widely employed in electrostatic recording facsimile equipment or electrophotographic recording copier.
However, several problms in designing magnetic brush developer still remain. This paper describes developing powder fatigue and reproduced image quality.
Experimental results show that quantity of spent toner and impairing influence upon reproduced image quality of the 5-pole sleeve type developer are less than those of the conventional 6-pole type developer.
Consequently, the 5~pole sleeve type developer is more successful than the conventional 6-pole type developer for facsimile equipment use.

View full abstract

Thermoplastic-photoconductor medium combines many advantages, such as dry and nearly instantaneous in-situ development, erasability, high diffraction efficiency, etc. But this medium is not so stable for the change of circumstances especially the variation of atmospheric temperature if the usual heating method is used to soften a plastic layer. The solvent vapour method, which uses a solvent vapour insteat of heating, has been developed in order to improve the defects originating in the Joule's heat of usual heating method.
The difference of sensitivity and maximum diffraction efficiency between the solvent vapour method and the heating method has been studied and the followings are found.
(1) The sensitivity on the solvent vapour method is higher than that of the heating method.
(2) The maximum diffraction efficiency on the solvent vapour method is higher than that of the heating method.
Research has been carried out to explain these features and it becomes clear that the main reason for these results is the difference of the transparent conductor-photoconductor interface conditions between the solvent vapour method and the heating method. Namely, the interface in the solven vapour method is analogous to that of the insulator-metal system, but it is analogous to that of the p-type semiconductor-metal system in the heatig metod. Anothr reasson is the edge effect in the solvent vapour meteod is stronger than that of the heatinsr method.

View full abstract