The purpose of this work is to identify the technologies at the origin, the technological problems encountered and the solutions proposed which lead to the particular technology under study. Our methodology is based on the hypothesis that the documents cited in the search reports by patent examiners against patent applications in a particular (new) technology link the new emerging techniques to the conventional existing ones, and therefore an analysis of these documents will point to the roots of that (new) technology. Furthermore, it uses at different levels two main elements of the body of patent literature, namely prior-art lists of documents and classification codes. Firstly, identifying patents related with the particular technology using classification codes, then going backwards in time through the network of associated citations and finally, identifying technologies using again classification codes at different levels of aggregation. We have focused on patent publications because they have two features that in our opinion make patents particularly attractive for the study of the evolution of technology, namely each patent is published with classification codes and with a list of related prior-art documents. Both features are given by the patent examiner after an examination (the “search report”) totally independent of the author. Our methodology seems new and complements works based on the pioneers experience and academic sources. Although for illustrative purposes we have applied our methodology to find the roots of computer graphics, it appears to have the potentiality to be applied to find the roots of other technologies.