In Canada, a patentable invention must be useful, or have utility. Otherwise the patent issued for the invention is invalid.
A patented invention lacks utility if it will not operate at all, or if it will not do what was promised in the patent.
Where a patent does not promise any benefit of the invention, the utility requirement can be easy to meet. For example, it is generally sufficient if the invention provides any industrial or commercial value, or affords the public a useful choice.
However, if a patent promises a specific effect of the invention, then the utility of the invention will be measured against the explicit promise. This means that a patent may be invalidated for containing unsupported statements to the superiority or uniqueness of the claimed invention.
The patent owner must be in a position to establish utility as of the Canadian filing date of the patent. Utility can be established as demonstrated utility showing that the invention in fact works, or on the basis of a “sound prediction” that the invention will likely work. There is no requirement to prove utility in the patent itself. However, if the utility is based on sound prediction, the patent must include:
- a factual basis for the prediction;
- a sound line of reasoning from which the desired result can be inferred from the factual basis; and
- proper disclosure to support the prediction.
Making promises in a patent may create uncertainty in the validity of the patent. Therefore, patent applications should be drafted with no broken promise, or no promise at all.