One of the biggest challenges in writing the written description is that it is almost impossible to guess how the invention might be used over the next twenty years, which is the life of the patent. Especially in developing technologies, what makes sense today may be turned on its ear by changes in technology or the market. However, reading that crystal ball is essential for good patent protection.
There are a number of cases where limitations from the specification are read into the claims by the courts. In the Phillips v. AWH Corporation case before the Federal Circuit, the lower courts read a limitation into a claim because the drafter described ‘the’ advantage of the invention had a special feature. The drafter seemed to me to be describing only ‘an’ advantage of a particular embodiment. However, the applied the feature to all the claims. If the drafter had used ‘an advantage’ rather than ‘the advantage’, it is likely that the case would not be in front of an en banc Federal Circuit and would have been settled a long time ago.
The best way to deal with this situation is to eliminate any mandatory language from the written description. Use terms like ‘may’ and ‘could’ rather than ‘must’ and ‘should.’ Give every alternative embodiment that can be imagined, and especially examples at the outlying extremes of the invention.
Many times, the inventors see their specific embodiment as the most logical and rational of the possibilities. What is an optimal embodiment today may be obsolete in three years. I see the invention as a combination of several elements, regardless of the embodiment. When writing the written description, I try to take each element to its logical extreme and cover every possibility for that element. After going through each element in as much detail as possible with as many examples as possible, the entire field of various embodiments should be covered.
Remember, the purpose of the written description is not only to support the claims, but to give as much breadth and scope to the claims as possible. Additionally, a broad written description effectively keeps other inventors from attempting to patent a close invention, one that may turn out to be even better than the inventor’s optimized embodiment of today.