Notes from 3/11/2011

Claims:

• most important part of a patent
• define boundaries of property right
  

Interpreting the claims for 2 reasons

1. with respect to the prior art to determine validity
2. with respect to some possibly infringing thing

Term used, does the claim "read on" the prior art or possibly infringing device?
A claim reads on something if everything (elements and relationship among them) appears in that thing. It does not matter if other things are present in the other thing.

Example 1

I claim a chair comprising

• a seat
• a back attached to the seat
• legs attached to the seat.

Infringing:

• chair that has a seat, a back, legs, plus armrests
• chair with seat, back, and legs where the seat is removable

Comprising: something is made up of a list of things, but could include other things
Consisting: exactly the list of things and no more Not infringing:

• a stool with legs and a seat, but no back

Example 2

I claim a stool comprising

• seat
• legs attached to the seat

All chairs infringe on the stool patent.
No stools infringe the chair patent.
If the stool were patented first, the improved stool with back (which is a chair) would be patentable. The chair patent owner could not make, use, or sell chairs without the permission (license) of the stool patent owner.
Correspondingly

• the stool patent owner can not add backs to the stools without the permission of the chair patent holder
• limited testing by each side is allowed
• result: incentive to (cross-)license

In order to patent a stool when a chair already exists, then one would have to add to the list:

• no back

This makes stool patentable even with chairs in prior art. However, claims with no are problematic.