This is the eagerly awaited fourth edition of Philip Grubb's acclaimed book on patent law and practice. It guides the reader through the legal and procedural complexities of the British, European, Japanese and US patent systems, and explains in detail the role of patent practitioners (both in-house and in private practice) in maximising the commercial potential of their client's or company's innovative products. This new edition provides vital updating to take account of the latest legal developments, while retaining the focus upon the relevant technology and industry practices in this sector that sets it apart from more general books on patent law and procedure.