Mathematical Formula in International Business Machines Corporation v Commissioner of Patents (1991) 22 IPR 417

The use of a mathematical formula in a computer to produce an improved curve image was held to be patentable, since the production of the improved curve image is a commercially useful effect in computer graphics.  Specifically Burchett J found:

“Although there was nothing new about the mathematics of the invention what was new was the application of the selected mathematical methods to computer, and, in particular, to the production of the desired curve by the computer.  This involved steps which were foreign to the normal use of computers and, for that reason, were inventive.  A method of producing that by computer, which is novel and inventive, is entitled to the protection of the patent laws.”

The use of floating point arithmetic was common for processing such algorithms for generating curves (having problems of lack of speed and inaccuracy).  This invention however, claimed that calculations were performed without the use of floating point arithmetic.  At the time of the invention it was new and non-obvious to perform such mathematical algorithms in a computer, using something other than floating point arithmetic (more specifically, integer arithmetic).  This integer arithmetic, as described in the specification, comprised a particular way of performing calculations using components of a computer that changed the way a computer normally worked. It followed that the claim was directed to a process containing steps that was foreign to the normal use of computers.