Optical Microscopy has long been the preferred method for rapid dispersion analysis because of its relative simplicity. Reflective Light Microscopy with automatic image processing has become a standard tool for evaluating filler dispersion of agglomerates in the micron range, and is often referred to as macro dispersion. Many researchers, however, recognize the need to study particles and aggregates in the nano-scale, and have therefore used more costly and complicated methods such as Atomic Force Microscopy, and Electron Microscopy. Optical microscopy’s shortcomings in ultra high resolution measurements are due to the electromagnetic diffraction limit, which confines resolution of white light to approximately 1 micron. In this work a new reflected light method is discussed which provides resolution of less than 1 micron, but also avoids the diffraction limit of visible light by mechanically moving a sample in small increments.
In the following paper a detailed description of a new microscope where sub-micron imaging is possible will be described, as well as two models which explain the theory behind sub-pixel resolution. This is the first part of a two part study, and does not include a detailed experimental section, which will be presented in a future works.