Monday, July 26, 2010

What Are Patent Claims?

Don’t rely on the dictionary for the definition of “claim”. When applied to patent law, a claim is formally worded sentence fragment that recites and defines the structure, or acts, of an invention in precise, exact terms.

Claims are used to determine if an invention is patentable over the existing prior art, and recite the bounds or scope of an invention. The patent specification shows how to build or make and use the invention and the claims define its scope.

When filing a patent application you must have at least 1 claim to obtain a filing date.

The legal statue that deals with claims is part of Section 112 of the patent laws (35 USC 112), which states the following:

2. The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as the applicant’s invention.’

3. A claim may be written in independent or, if the nature of the case admits, dependent form.

4. Subject to the following paragraph, a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers….

5. A claim in multiple dependent form shall contain a reference, in the alternative only, to more than one claim previously set forth and then specify a further limitation of the subject matter claimed. A multiple dependent claim shall not serve as a basis for any other multiple dependent claim. A multiple dependent claim shall be construed to incorporate by reference all the limitations of the particular claim in relation to which it is being considered.

6. “An element in a claim for a combination may be expressed as a means or step for perform a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.

The patent laws and rules are available in PDF format on the USPTO website.

Claims reduce the invention down to its simplest form eliminating anything not essential. One of the most difficult aspects of writing a claim is to keep it short and concise.

Ideally you won’t need very many dependent claims. Dependent claims “narrow” the scope of the independent claim. Try to keep the number of dependent claims below 20 unless the invention is very complex and actually needs that many dependent claims.

Since an infringing invention needs to have all the elements of a claim to infringe it, the shorter the claim and the fewer features claimed in a claim the broader the coverage. So when writing claims make them as short and concise as possible and cite the fewest features you can while still being novel over prior art.

A claim hast to reveal something “novel”, i.e. new and different, either hardware or process, or that no other prior art shows. Usually to overcome prior art one has to narrow the scope not broaden it. To narrow the scope of a claim one sites more elements, or by specifying the existing elements more narrowly.

Claims must also show that the invention is unobvious to someone having ordinary skill in the art, or in other words, it must show one or more features that are new and important and that produce new unexpected results.

There are unique grammatical rules for writing claims and if you are going to write your own claims you should get a good book about writing your own patent and learn to do it correctly.
For instance, a patent claim can have only one capital letter, one period, and no dashes quotes, parentheses, trademarks or abbreviations.

Many of the words used in claims have highly specific meanings and are not always obvious to laypersons in their meaning. Words like “means”, “said”, “whereby”, and “thereof”.

Independent claims are claims that do not refer to a preceding claim and can stand alone. It should define the invention completely on its own.

Dependent claims incorporate all of the elements and restrictions of the independent or dependent claim they are dependent on. It cites a narrower version of the preceding claim by either adding elements or describing the claim more narrowly.

In short, your patent claims should be clear, unambiguous, and all of the elements have to be shown in the patent drawings. The claims should be made as broad as possible with as few elements as possible and still show “novelty” and “unambiguousnous” over all previous patents and prior art.

Patent Basics more about patents.   

What is prior Art? All about prior art.  

Types of Patents  There are three types of patents, Plant, Utility, and Design