Patent Claims and Infringement (JWB)

• Claims:
  • most important part of a patent
  • define the boundaries of the property right
• Interpreting claims for two reasons
  • with respect to the prior art, to determine validity
  • with respect to some possibly infringing thing
• Term used for interpreting: does the claim “read on” the prior art or possibly infringing device?
  • A claim reads on something if everything (elements and relationship among elements) in the claim appears in the something. It does not matter if other things are present in that something
    • Example:
      • I claim a chair comprising

a seat;

a back attached to the seat; and

legs attached to the seat.

• • • • Infringing:
        • a chair that has a seat, back, and legs, plus armrests
        • a chair with a seat, back, and legs, with foldable seat part
      • Non-infringing:
        • stool with seat and legs, but no back
    • Example 2:
      • I claim a stool comprising

a seat;

legs attached to the seat; and

no back – this claim would make this stool patentable even with chair in prior art

• • • • all chairs infringe stool patent
      • If the stool were patented first, the improved stool with a back (i.e. chair) would be patentable, but the chair patent owner could not make, use, or sell chairs without permission of stool patent owner
      • Correspondingly, stool patent owner cannot add backs to his stools without permission of chair patent owner
      • Limited testing by each side is allowed
      • Result: incentive to cross-license
• Claims “consisting” means exactly the list of things claimed and no more, rather than “comprising”
• Means and function language in claims
  • As it’s described in the specification in the earlier part of the patent
  • “Doctrine of Equivalence” = trivial changes still infringe
  • Dependent claims: add elements
    • Example: claim 1 – seat and legs, dependent claim 2 – add back
      • everything owned in claim 2 would be owned in claim 1 (claim 1 is broader, more likely to be found invalid)
      • claims 2, 3, 5, 6 get more narrow (and thus harder to find invalid)