Estoppel
Festo: Big issue—How does history change our use? If you disclaimed something can you get it back through DOE?
1.    W-J creates prosecution history estoppel for patent that is amended for “a substantial reason related to patentability”.
a.    Amended claims that are for purpose of avoiding prior art: This clearly should be estopped under W-J, falls within scope of earlier cases.
b.    Claims amended for other reasons: Are you going to be estopped from DOE every time examiner says you need to do X, no matter what X is?
(A)    Lots of reasons why you might make change besides dodging prior art (avoiding 101, 112 problems).
(B)    Can you argue, when you make a change you refocus on language, so literal language better be good?
(1)    How does that help with advances in technology? Maybe we should do that and ask “was it foreseeable?” if you touched it again, hold to literal language unless something impossible to foresee: change in technology, etc.
(2)    Problem: We’ll now fight over what was foreseeable.
(3)    Do you really look at it all that more closely when you make a change, want people to take all claims seriously. Seems like assault on DOE, doesn’t really seem related to making change.
(4)    Do we care about substance or procedure?
c.    Another idea: Every time you make a change that narrows claim, you narrow what qualifies for DOE.
(A)    You gave it up, can’t get it back.
(B)    Gives notice, lets you know what to worry about, don’t have to decide why they made a change just need to know that they narrowed.
- Problem: But that only shifts argument to whether they narrowed vs “redefined” or “shifted”.
So perhaps doesn’t save us anything.
2.    Should voluntary claim amendments create prosecution history estoppel?
a.    If you change voluntarily why is that different then getting it right the first time?
b.    Court: Treats the same as other amendments. If a voluntary amendment narrows the scope of a claim for a reason related to the statutory requirements for a patent, this will give rise to prosecution history estoppel. i.e. evidence of a surrender of subject matter
3.    If estoppel history is created, what range of equivalents are available under DOE?
a.    Orig filing was sloppy—said steel with tensile strength of 8.0. Now claim is sloppy and amended to read steel w/tensile strength of 7-9. Amendment (7-9) triggers bar. Can person claim plastic under DOE?
b.    Fed says this creates absolute bar, Lichtman thinks they mean to say you don’t apply DOE along dimension sacrificed (but not clear this is the case from what they said).
4.    What if we don’t know why claim was amended? Then prosecution history estoppel completely bars application of DOE.
5.    [Court doesn't get to fifth issue].