Patent litigation is a balance between validity and infringement
In a patent infringement lawsuit, the patent owner must prove that the alleged infringer’s conduct or product is covered by the patent owner’s patent. To do so, the patent owner may have to broadly interpret their patent’s claims to find infringement. Unfortunately, in doing so, the validity of the patent claims may be placed in jeopardy. The balance during litigation is between validity and infringement.
During prosecution, the same issue exists except that the balance is between broad claim scope and allowability (i.e., patentability). The patent’s claims should ideally be broad enough to prevent competitive alternatives (i.e., design arounds). However, claims that are too broad are likely to be rejected by the examiner (i.e., not patentable). The key is to differentiate your claimed invention from the prior art just enough to overcome the cited prior art.
In Ibormeith v. MBZ (Fed. Cir. Oct. 22, 2013), the patent owner (USPN6313749) obtained a patent directed to detecting a driver who is sleepy. The claims required a “computational means” wherein software computed a number of factors to determine whether the driver is sleepy or not. In interpreting the computational means limitation, the court looked to the specification to determine how this computation means is implemented.
The patent described a number of factors used to compute a number that reflects the sleepiness of the driver. Table 10 of the specification indicated that the number might be computed in the following manner:
S mod = S cir. + S zerox + S rms + S light + S temp + S sleep + S road + S trip
S mod is an objective number that could be used to trigger an alarm based on the variables on the right hand side of the equation. This equation could be interpreted as a simple summation of the various variables. However, such a simple reading would mean that the defendant’s product is not infringing the patent’s claims.
Instead, the patent owner and its expert took the position that the equation “equally covered all ways of taking into account the listed variables, or some subset of the variables, that a skilled artisan would find appropriate.” (emphasis added). Unfortunately, the court held that reading Table 10 in this manner “leaves the disclosure without an algorithm whose terms are defined and understandable.”
The patent owner attempted to persuade the court that two other figures provided the needed guidance to make the computational means definite and understandable. The court was not persuaded. “At best, the two figures provide raw circadian information that a person of ordinary skill in the art could use to design his or her own method of weighting. A description of an algorithm that places no limitation on how values are calculated, combined, or weighted is insufficient to make the bounds of the claims understandable.” (emphasis in original). Hence, the court held the claims to be indefinite, and invalid.
I invite you to contact me with your patent questions at (949) 433-0900 or [email protected]. Please feel free to forward this article to your friends. As an Orange County Patent Attorney, I serve Orange County, Irvine, Los Angeles, San Diego and surrounding cities.