IP and Business: Quality Patents: Claiming what Counts

What are patent claims?

Claims are the heart of a patent application. Whereas the description of the invention contained in a patent document teaches how to make and use the invention, the claims define the scope of legal protection. The claims demarcate in words the boundary of the invention, much as a picket-fence defines the extent of land covered by a deed for a piece of land. Only the technology covered in the claims is protected by the patent. If the claims are not properly drafted, then any invention contained in the detailed description but not covered by the claims becomes part of the prior art when the granted patent is published. Anyone else would then be at liberty to use that unprotected information without the patent owner’s permission.

Broad versus narrow claims

The claims may be broad or narrow in their scope. Most patent agents would prefer to draft claims that are as broad as possible to cover all aspects of the invention found in the detailed description, its equivalents or likely future versions. On the other hand, a patent examiner in an IP office will not allow broad claims that cover more than the inventor actually invented, and will seek to narrow the claims to the actual invention. Further, the patentability of an invention defined by broad claims may be more easily refused based on a wider range of prior art. So, while broad claims are attractive to the business applicant because they cover a greater range of products or situations, it is more difficult to obtain and to enforce a patent with broad claims.

Narrow claims are generally specific to one particular invention in a product, and consist of more elements/limitations than broader claims. Patents with narrow claims tend to be easier to obtain and enforce. Conversely, they will prove less useful as a business tool since they allow competitors to gain easy access to the same market by producing products with only minor modifications to the patented product or service. From a business perspective, therefore, the most effective patent applications tend to include a large number of claims, including a mix of broad and narrow claims.

Tips on Writing Claims

The website of the Canadian Intellectual Property Office (CIPO) offers a clearly written, online tutorial to assist individuals and...