Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[patentwind]

Hi all,

The process for interpreting a means-plus-function claim:

1. Determine the claimed function.
2. Identify the corresponding structure in the written description of the patent that performs that function.
3. Identify the relevant structure in the accused device. Literal infringement of a means-plus-function claim limitation requires that the relevant structure in the accused device perform the identical function recited in the claim and be identical or equivalent to the corresponding structure in the specification.
4. The plaintiff then has the burden to show that the accused device performs the identical claimed function in substantially the same way, with substantially the same result.

My question is if, in step 3, the relevant structure in the accused device is neither identical nor equivalent to the corresponding structure in the specification, that is there is no literal infringement, what next to do? Must we still determine the infringement of doctrine of equivalent? if the answer is yes, how to determine?

Thank you, and you are appreciated to provide relevant information about this topic.

[JimIvey]

First, my understanding is that Section 112, p6 equivalents are different from DoE equivalents.  Exactly how they're different, I don't know.  My understanding is that Section 112, p6 equivalents are extremely narrow.

Second, I think DoE + 112, p6 = 2 degrees of equivalence.  Suppose the Spec teaches A as doing X (and the claim recites "means for doing X") and the accused device uses C for that and that C is not equivalent to A.  What if C is equivalent to B and B is equivalent to A?  B would infringe literally and C can therefore infringe under the DoE (doctrine of equivalence).  I don't think you can do the two-stage equivalence under the DoE alone.

Regards.

[Isaac]

First, my understanding is that Section 112, p6 equivalents are different from DoE equivalents.  Exactly how they're different, I don't know.  My understanding is that Section 112, p6 equivalents are extremely narrow.

Besides the narrowness that Jim describes, 112, p6 equivalents include only structures existing at the time of the invention.  The DoE can be applied to equivalents developed by the infringer after the patent issues.

[TataBox]

I may be wrong, but I think for literal under para 6 it is equivalent structure which performs an identical function, and under the DOE of para 6 it is equivalent structure that performs an equivalent function. Look at Chiuminatta Concrete Concepts, Inc. v. Cardinal Industries, Inc.

Regards,

[JimIvey]

My take on the whole of equivalence is that it's all just rephrasing of the term "equivalence".  The "substantially same function/way/result" is an arbitrary construct with which people populate with phrases to drive the intended result (result of the equivalence analysis).  For example, if you think one thing is an equivalent of another, you populate the substantially same function/way/results with things that support your conclusion.  Note that the "result" is nearly always that the "function" is fulfilled.

Nearly always, equivalent functions can be worded identically.

Of course, we all need to know the icons so we can touch them all in proper sequence to satisfy the powers to be, but it appears -- to me anyway -- to be much ado about nothing.  In other words, in all the phrasing and rephrasing of the various tests for equivalence, I find little, if anything, that's tangible and truly helpful. 

The same is true for obviousness, in my opinion.

Regards.