| The goal of the research detailed here is to develop a simulation model of the electrophotographic development process. This model, written in Matlab ®, takes various parameters that define a printer from the user as input, calculates electric fields and developed toner mass/area (DMA) based on a user-specified grid pattern, and displays the results in 3-dimensional plots.; Toner mass measurement capability from scanned images is developed. This method allows direct measurement of DMA from digitized images obtained using a video microscopy system. Various statistics of gray level data are analyzed and subsequently DMA at the camera pixel level is obtained.; Conventionally, electric fields in a development nip are often calculated for well-defined patterns (solid areas and isolated lines) or for a given charge distribution on the photoconductor surface. The field calculation technique presented in this dissertation uses a set of laser and photoconductor parameters to compute the exposure energy on the photoconductor surface, and the corresponding photoconductor surface potential. The surface potential is then used as a boundary condition for solving Poisson's equation. The normal and horizontal fields are subsequently obtained by taking the negative gradient of the voltage. The normal and horizontal fields obtained from this method are used to estimate DMA of a given pattern. The estimation procedure is phenomenological, but it exploits the physics governing toner movement in the development nip to account for observed feature size dependence of toner development.; The DMA estimation technique presented in this dissertation first scales the work done on toner by the electric and other forces in the gap based on measured developed toner mass data to obtain base DMA. The horizontal fields are then utilized to determine horizontal toner displacement. Estimated DMA specifies developed mass at each point in the calculation grid. Thus, for any input bitmap, DMA at the subpixel level can be accurately predicted over the entire image. Using various patterns and three printer engines, simulations and experimental results are presented and the phenomenological model is validated. |
