Anyone who has ever tried to read a patent knows that the exercise hardly qualifies as light reading. With densely written text and schematic drawings littered with numerals, a typical patent is a difficult read for the layperson.
The portion of a patent that is generally considered the most difficult to comprehend, however, is the claims section. This section contains a series of numbered paragraphs known as claims that textually define, in language that is usually obscure, the scope of the patent holder’s monopoly. In other words, the claims define the requirements for something to be considered an instance of the invention that is covered by the patent. As such, the claims are central to any patent infringement analysis.
In essence, a “two-finger test” is applied to determine whether a competitor’s product infringes a patent. For each feature of a patent claim, if it is possible to point to the feature within the claim language with one finger while simultaneously pointing to the feature in the product with another finger, the patent is generally considered to be infringed.
Nothing in the above description would appear to require the use of obscure language within a patent claim. The layperson may wonder why an invention cannot simply be described in the claims using plain English. Certainly, that would help the general public better understand the invention that the patent purports to protect.
The trouble with using plain English is that it tends to result in claims that are unnecessarily narrow. This may have the unintended consequence of excluding subtle variations of the invention from the scope of the patent.
Consider the original invention of the stool centuries ago. The inventor of the stool may have constructed a prototype that could be described in plain English as follows:
A stool consisting of a round wooden seat and four legs extending downwardly from an underside of the round wooden seat.
Yet, if that inventor had filed a patent application containing only one claim describing the prototype exactly as above, he would have done himself a disservice.
The reason is that by reciting very specific limitations in the claim (e.g., by requiring four legs, by requiring the seat to be round, and by requiring the seat to be made of wood), the inventor would have ensured patent coverage only for instances of the invention that are effectively identical to the prototype. A competitor wishing to circumvent the patent might have easily done so by modifying the claimed stool to omit at least one essential limitation or to replace an essential limitation with something else. For example, the competitor might have manufactured a stool having only three legs or having a square wicker seat instead of a round wooden one. Thus, the above claim language, while clear, would not have been very effective in blocking a competitor’s products.
A better approach would have been to use broader claim language that encompasses all variations of the prototype of which the inventor can conceive, such as the following:
A seating apparatus comprising a seat and at least three legs extending downwardly from an underside of the seat.
This claim differs from the original claim in several respects. Firstly, the term “stool” has been replaced with the more generic term “seating apparatus.” This is to prevent a competitor from adding a feature (e.g., a chair back) to his product and arguing that because the product is no longer a “stool,” it is outside the scope of the claim. Secondly, the language “at least three legs” has replaced “four legs” with a view to encompassing stools with three legs, four legs, or possibly even more. Thirdly, the seat is no longer described as being round and wooden, so that seats having different shapes or made from materials other than wood will be covered.
The broader claim language is more effective in blocking a competitor’s products than the original claim language. As long as a competitor’s product has at least three legs that extend from an underside of some kind of seat, it would infringe the patent according to the two-finger test. This would be true regardless of whether the competitor’s product has a chair back, the exact number of its legs, the material from which the seat is made or the shape of the seat. The broader claim is therefore preferable for protecting the patent holder’s interests.
Unfortunately, the superior protection afforded by the broader claim comes at the expense of diminished comprehensibility: the broader claim language is simply not as clear as the original claim language. For example, the term “seating apparatus” does not immediately conjure the same sort of image in the mind of the reader as the term “stool.” Similarly, the term “seat,” while descriptive, is not quite as descriptive as “round wooden seat.” Obscure claim language is simply the price to be paid for maximizing patent protection.
With the benefit of the foregoing justification for obscure patent claim language, it is interesting to consider how common household objects might be described in patent claims. To that end, the reader is invited to identify the objects described below (answers are provided at the bottom of this page):
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A gardening implement comprising an elongate handle and a thin flat blade extending transversely from an end of said handle.
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A handheld appliance comprising: a plastic body with a handle, an air inlet and an air outlet; an electric fan and heating element mounted within the body in a passage between the air inlet and the air outlet; and a switch for selectively activating the electric fan and heating element.
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A tool comprising a pointed metallic helix protruding from a handle.
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A utensil comprising a shallow bowl and a handle extending outwardly from an edge of said bowl.
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A utensil comprising a bowl and a handle extending upwardly from an edge of said bowl.
Peter A. Elyjiw, Toronto
Answers: 1. hoe 2. blow dryer 3. corkscrew 4. spoon 5. ladle
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