1. Patents VI Infringement & the Doctrine of Equivalents
Class Notes: March 17, 2003
Law 507 | Intellectual Property | Spring 2003
Professor Wagner

2. Today’s Agenda Literal Infringement The Doctrine of Equivalents
3/17/03
Law 507 | Spring 2003

3. The Basics of Infringement
The patent right: the right to exclude others from . . .
Making
Using
Selling
Offering to sell
Importing
Categories of Infringement
Direct Infringement
Indirect Infringement (direct + assistance)
3/17/03
Law 507 | Spring 2003

4. The Basics of Infringement (2)
Forms of Direct Infringement
Literal infringement
Infringement via the Doctrine of Equivalents
3/17/03
Law 507 | Spring 2003

5. Literal Infringement Basic rules of literal infringement:
all elements of the claim must be (identically) present in the accused device;
Additional elements in the accused device are (generally) not relevant to infringement;
Consider this claim . . .
A writing implement comprising:
A wooden cylinder with a hollow core
A cylinder of graphite in said hollow core
A small cylinder of eraser material attached to one end of the wooden cylinder
Which of the following infringes the claim?
A typical wooden pencil with a small metal clip for shirt-pocket storage
A plastic pencil (body made of plastic)
A pencil without an eraser
3/17/03
Law 507 | Spring 2003

6. Literal Infringement Larami Corp v Amron (Ed Pa 1993)
What is the key claim element? (Why?)
What does the accused device have instead?
Why does the court find no infringement as a matter of law? (Why isn’t this at least a jury question?)
How might TTMP have drafted the claim to cover the Supersoaker?
3/17/03
Law 507 | Spring 2003

7. The Doctrine of Equivalents
Recall: the basic rule of literal infringement:
all elements of the claim must be (identically) present in the accused device
The Doctrine of Equivalents:
Allows elements in an accused device to be “substantially equivalent” and still be ‘present’ for purposes of infringement
Thus, the basic rule of infringement changes to:
all elements of the claim must be (identically or equivalently) present in the accused device
3/17/03
Law 507 | Spring 2003

8. The Doctrine of Equivalents
Warner-Jenkinson v Hilton Davis (1997)
Key limitation: “a pH of approximately 6.0 to 9.0”
Accused process: pH of 5.0
The court reaffirms the DOE, though it notes an important limit on the doctrine –- prosecution history estoppel
Other points:
Intent is not an element of infringement
Equivalents are not limited to those disclosed in the patent itself
The Court leaves it to the Federal Circuit to determine the ‘test’
3/17/03
Law 507 | Spring 2003

9. The Doctrine of Equivalents
Limits on the DOE:
Prior art limitations: Equivalents cannot encompass the prior art (Wilson Sporting Goods)
Prosecution History Estoppel (PHE) (Festo)
Public Dedication: disclosed-but-unclaimed subject matter (Johnson & Johnston)
Wilson Sporting Goods:
Suggests a ‘hypothetical claim’ analysis. (Why?) (Is this useful?)
What if the accused device is obvious in light of the prior art?
3/17/03
Law 507 | Spring 2003

10. The Doctrine of Equivalents
Prosecution History Estoppel
Basic rule of PHE: cannot assert infringement by equivalents over subject matter ‘surrendered’ during prosecution.
Why have this rule?
What is the key analytic problem?
Festo Corp. (2002)
The Federal Circuit rule: amendment = no equivalents for that element. (Why do you think the court did this? Pros?/Cons?)
The Supreme Court: ‘presumption’ that an amendment = no equivalents for that element. Exceptions:
Where the ‘equivalent’ technology was ‘unforeseeable
The rationale for the amendment is unrelated to the equivalent in question
Otherwise ‘unreasonable’ to prevent infringement
3/17/03
Law 507 | Spring 2003

11. The Doctrine of Equivalents
Public Dedication
Johnson & Johnston Assocs. (2002) (en banc)
The claimed invention was a ‘backing’ sheet of aluminum that allowed thin copper sheets to be safely handled for semiconductor manufacturing.
The specification notes that various metals other than aluminum (including steel) could be used as the backing material.
A jury found that the steel backing material was equivalent to the claimed aluminum
3/17/03
Law 507 | Spring 2003

12. The Doctrine of Equivalents
Public Dedication
Johnson & Johnston Assocs. (2002) (en banc)
Why does the court find no infringement as a matter of law?
Is it correct to say that the patentee has dedicated the disclosed-but-unclaimed material to the public? (Is this always the case?)
Doesn’t the court appear to suggest that the patentee seek examination of even equivalents to the claimed invention? Is this consistent with the reasoning behind the DOE?
In what ways can a patentee avoid the holding of Johnson & Johnston? Are these beneficial?
3/17/03
Law 507 | Spring 2003

13. The Subject Matter of Patents
Next Class
Patents VII
The Subject Matter of Patents
3/17/03
Law 507 | Spring 2003