Patent laws are different in many countries, and inventors are sometimes at a loss to understand which basic requirements should be satisfied if an invention is to be granted a patent. This is particularly true for inventions implemented on a computer. While roughly a third of all applications (and granted patents) relate, in one way or another, to a computer, applications where the innovation mainly resides in software or in a business method are treated differently by the major patent offices in the US (USPTO), Japan (JPO), and Europe (EPO). The authors start with a thorough introduction into patent laws and practices, as well as in related intellectual property rights, which also explains the procedures at the USPTO, JPO and EPO and, in particular, the peculiarities in the treatment of applications centering on software or computers. Based on this theoretical description, next they present in a very structured way a huge set of case studies from different areas like business methods, databases, graphical user interfaces, digital rights management, and many more. Each set starts with a rather short description and claim of the "invention", then explains the arguments a legal examiner will probably have, and eventually refines the description step by step, until all the reservations are resolved. All of these case studies are based on real-world examples, and will thus give an inexperienced developer an idea about the required level of detail and description he will have to provide. Together, Closa, Gardiner, Giemsa and Machek have more than 70 years experience in the patent business. With their academic background in physics, electronic engineering, and computer science, they know about both the legal and the subject-based subtleties of computer-based inventions. With this book, they provide a guide to a patent examiners way of thinking in a clear and systematic manner, helping to prepare the first steps towards a successful patent application.