High resolution imaging by electrophotography can make it possible to make a bigger business market, for example in the field of “Print on Demand”, and the application of a liquid developing technology has been studied hard on this purpose. To realize a high resolution imaging by electrophotography, the resolution depends on not only developing technology but also the latent image on photoreceptors.As the results of this study, diffusion on the diffusion theory revealed the advantage of a positive-charge-type single–layer organic photoreceptor (OPC) due to the photoconduction mechanism. And also, the latent images developed by liquid toner on single-layer and a dual-layer OPC have supported the diffusion theory discussion as a single-layer OPC can only resolve the 100 pair lines / mm although the dual-layer can not. This means a single-layer OPC have an advantage for the high resolution imaging technology utilizing electrophotography.