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[Lost&Confused]

Can Prosecution History Estoppel be used without an allegation of infringement based on the doctrine of equivalents?  Put another way, can Prosecution History Estoppel be used when a device literally infringes a claim?

I ask this because I am looking at a claim that reads:

A device which comprises:
a keyboard;
where said keyboard has a button.

But in prosecuting the patent the patentee repeatedly distinguishes its invention over the prior art by saying that the invention has more than 4 buttons.  However, the issued patent contains no such limitation.  It seems that the patent examiner erred and that if challenged the patent would likely be held invalid for less than 4 buttons.  However, can I also assert Prosecution History Estoppel during the claim interpretation stage?

[bleedingpen]

However, can I also assert Prosecution History Estoppel during the claim interpretation stage?

When else would you assert it?

[Lost&Confused]

When else would you assert it?

You're right, that is a poorly worded question.  Let me try to phrase it better.

Can I assert Prosecution History Estoppel when there is literal infringement or am I limited to narrowing the claims through a claim of invalidity?

[bleedingpen]

When else would you assert it?

You're right, that is a poorly worded question.  Let me try to phrase it better.

Can I assert Prosecution History Estoppel when there is literal infringement or am I limited to narrowing the claims through a claim of invalidity?

You apply the estoppel first to determine claim scope, and then you conduct the test for infringement.  There are two main types of estoppel- prosecution estoppel where statements on the record may change the normal meaning of claim terms, and Festo estoppel which applies to limited amendments and the doctrine of equivalents. 

Still not sure I get your question, but estoppel can change the literal claim scope. 

[Lost&Confused]

Still not sure I get your question, but estoppel can change the literal claim scope. 

Well in my example above the patentee argues to the Patent Office that the device is patentable over the prior art because it has more than 4 buttons.  However, this limitation of "4 buttons or more" is not found in the claims of the issued patent.  Instead, the base claim reads that a device only requires "a button."  The accused infringing device has 2 buttons.  Can I argue that the limitation of "4 or more" should be read into the claim as a further limitation on the term "a button" as a prosecution history estoppel argument during claim construction?  Or am I limited to arguing that the claim is invalid through an invalidity defense?

[bleedingpen]

Still not sure I get your question, but estoppel can change the literal claim scope. 

Can I argue that the limitation of "4 or more" should be read into the claim as a further limitation on the term "a button" as a prosecution history estoppel argument during claim construction? 

Maybe.  It is just a hard call because I know that you have genericized the claim and I can't get my head around why anyone would argue that the prior art teaches three or less buttons when my claim reads one button. 

It seems like your better argument is for invalidity. 

[Isaac]

Maybe.  It is just a hard call because I know that you have genericized the claim and I can't get my head around why anyone would argue that the prior art teaches three or less buttons when my claim reads one button. 

I had the same impression.  I have even more difficulty believing an examiner would buy the argument and allow the patent to issue without requiring that the claims be amended.  Perhaps the applicant backed out of this argument because the examiner was not convinced.  Pehaps the applicant actually amended the claims during prosecution to remove multi-button limitations.

Or perhaps the OP's example does not reflect the issues involved with the real claims.

[Lost&Confused]

I can't get my head around why anyone would argue that the prior art teaches three or less buttons when my claim reads one button. 

It seems like your better argument is for invalidity. 

I agree the position is strange.  It appears to be a case where the patentee wore down the examiner.  The prosecution was conducted over a 5 year period with multiple abandonments and CIPs.  The limitation of "4 or more buttons" was present in prior versions of the claims.  However, during the last CIP the claim was submitted to read "a button" without further limitation.  Even in this final CIP the patentee continued to argue that the invention was patentable over the prior art because it utilized more than 4 buttons.  It appears that the examiner simply failed to realize that the claim had been broadened.

I also agree the better argument is for invalidity, it is just a more costly endeavor.

[bleedingpen]

I can't get my head around why anyone would argue that the prior art teaches three or less buttons when my claim reads one button. 

It seems like your better argument is for invalidity. 

I also agree the better argument is for invalidity, it is just a more costly endeavor.

Kick only the last patent into re exam.***  That is probably cheaper than arguing infringement. 


*** There are of course many risks with re exam, which I won't bother to restate. 

[DogDayPM 9er9er9er]

To the OP, another consideration that may not apply to your case is whether there is more than 1 independent claim, especially if there is another indep containing the 4-button limitation, whereas the 1-button claim contains any other limitation differing from the indep having the 4-button limitation.  This would give them more room to try to argue that their prior statements re the 3-button art were intended toward that other claim.** 

Otherwise, subject to limited understanding of a fictionalized/simplified case, I would probably use PHE as a non-infringement prong of the analysis (despite what "looks like" literal infringement, and understanding your concern about using it outside of DOE), but I would also complete the invalidity prong for the scenario where the claim might be construed to require fewer than 4 buttons.

I've seen Markman rulings where a limitation such as "having a sine wave cycle" which appeared to be directly infringed by a product having one sine wave cycle was not infringed because, after a PHE analysis the phrase "having a sine wave cycle" was held to be "having at least 2 sine wave cycles".  The PHE was based on statements in the spec and arguments in prosecution. 

** The other reason I asked about additional indeps is, I've had to analyze similar sounding file wrappers that ended up with a granted claim clearly contradictory to the applicant's argumentation, but in those cases the contradictory claim was usually claim 63 following independent claims 1, 19, 35, and 42 not being contradictory.  In one really egregious case, the applicant deleted the relevant term from the claims, and after the next rejection put it back into all of the indeps except one of them, while telling the examiner that the term had been reinserted "into the claims" (did not say "into all the claims").

[JimIvey]

Sorry for coming late to the party, but I thought I'd toss out one of my grossly over-simplified answers, just because....

Prosecution history is always relevant in claim construction.  It's only called "estoppel" when it estops the patent holder from asserting infringement under the doctrine of equivalents.

So, yes, prosecution history always serves as a limitation on what the claims can cover and is always relevant and useful.

Regards.

[khazzah]

Prosecution history is always relevant in claim construction.  It's only called "estoppel" when it estops the patent holder from asserting infringement under the doctrine of equivalents.

To follow up on this, some folks call it "prosecution disclaimer" in the non-DOE context. And some further divide prosecution history estoppel into argument-based and amendment-based estoppel. See, e.g, http://www.iptoday.com/articles/2008-9-marshall.asp

[Lost&Confused]

See, e.g, http://www.iptoday.com/articles/2008-9-marshall.asp

Thank you, that is a great article on the subject and has been very helpful.