John is a European and UK Patent Attorney with over 30 years’ professional experience. He drafts and prosecutes patent applications in the software, electronic and optical fields, with particular expertise in semiconductor device manufacturing equipment and processes. John’s clients range from large multinationals to smaller start-ups, including firms that have successfully progressed beyond the early stages to develop extensive foreign filing programmes. Clients appreciate John’s pragmatic and cost-conscious approach to prosecution as well as his ability to effectively capture the essence of an invention in drafting applications.
Protection of software inventions (often referred to as computer-implemented inventions) is a particular interest. John has written several articles on the EPO’s approach to this type of invention and has given many presentations on the topic to a variety of audiences. John’s approach is a practical one, seeking the best way to present an invention in drafting and argument to achieve useful protection as expeditiously as possible.
John is recommended by The Legal 500, where he is described as “an eminent patent attorney well versed in European computer-implemented inventions practices” and “ knowledgeable about software technology, including cutting-edge technologies such as AI”. IAM Patent 1000 says "John Leeming knows everything there is to know about computer-implemented inventions; he focuses on semiconductor device manufacturing and AI issues", and “finds clients a path to success even in cases when other attorneys would advise giving up”.
John also handles litigation and enforcement matters, having conducted IPEC and Patents County Court proceedings and assisted in various Patents Court proceedings over the years. Many matters have been successfully resolved without recourse to litigation, sometimes making use of alternative dispute resolution methods such as mediation and IPO Opinions. John’s approach is to take clear and decisive action early in correspondence to prevent a matter escalating to litigation.
He also successfully handled, on behalf of the opponent, a reference to the European Patent Office Enlarged Board of Appeal (G0004/97) that established that it is legitimate to file an opposition in the name of a strawman. John also has a wide variety of other EPO appeal proceedings, both inter partes and ex parte.
John has extensive experience in recovering lapsed patents and applications, using restoration and restitution procedures in the UK Intellectual Property Office (UK IPO), the EPO and elsewhere in Europe. The crucial factor in such proceedings is correct presentation of the evidence; viewed from the appropriate perspective an apparently hopeless case can become much more promising. He represented the proprietor in Ament’s Patent  RPC 647 which overturned the UK IPO’s practice that lack of funds could never be a ground for restoration of an inadvertently lapsed patent.
John joined J A Kemp in 1988 and became a partner in 1994. He is the chair of the firm’s management committee and is based in our London office.