Interactive overlay maps and technological field evolutions for US patent (USPTO) data

Detecting the technical information included in patent documents offers a window of opportunity for identifying current technology structures and tracing technological developments. In this paper, we attempt to build a basemap for the international patent classifications (IPCs) of USPTO citation data, with the aim that such a map might be used as a tool to benchmark and capture the changes in organizational innovation activities over time, or the patterns in technological changes for future investigations in other sectors. Additionally, we subdivided patent classifications into detailed technological fields, as opposed to the usual eight broad technical domains, then traced the direction of the information flow over time. Promising quantitative measures, based on the technological proximity of the specialization and integration of the classes, were introduced to further provide insights into the notable differences in technological change and knowledge fusion over the past 30 years. Our aim in constructing this interactive overlay, and tracing the evolution of these technological fields, is to understand the patent portfolios of countries, organizations, and new and emerging technologies in the context of the overall technological landscape.