Non infringement opinion; Why is there a prior art section?

[patentpanda]

I am reading a non-infringement opinion issued by a firm of patent attorneys with respect to our firm's technology and two competitor US patents (Let's call them X and Y both with priority dates around 2001). 

One part I was curious about is that it has a section where they have done a "Prior Art Search" using a set of search terms and have presented info on a set of other patents they discovered. These are patents spanning a priority date time range from before 2001 to very recent.

I am wondering what is the relevance of this section?

How is the question of whether our extant technology infringes on US patent X or US patent Y impacted by the existence of other prior art?

Just curious to know why a non-infringement opinion about *specific* patents would search out other patents on which a non-infringement opinion has not even been sought? Is this just gratuitous background or can that info impact the specific question of infringement of Patents X and Y?

[tati]

In my field (chemistry) there is often the case that some patents claim stuff which are actually prior art, but the claim scope was not properly restricted. In this respect, a specific reaction sequence may actually be ok, because it's prior art, yet there is a patent out there which appears to be infringed. What actually happens is that the patent is not valid, at least with regard to the subject matter claimed which is prior art. Therefore, it is sometimes essential to know what is validly claimed and what is not.

Does the prior art section appear to have been done with respect to the claimed subject matter of the two competitor's patents?

[NJ Patent1]

Just to paraphrase tati; its largely about claim construction, a tedious time-consuming endeavor.  If the claims of X or Y were construed to read on your product ("technology"), would they also read on the prior art?  Prior art, if close in time to the priority dates of X and Y, can sometimes inform how the skilled artisan in the relevant art understood a particular term used in X and Y. 

[patentpanda]

This is indeed a Chemistry patent.

The prior art search seems to have been done with some of the relevant keywords. The search seems indeed good. I was merely wondering how it impacts infringement. Now I guess I can see some of the reason after reading your replies.

[patentpanda]

>>>If the claims of X or Y were construed to read on your product ("technology"), would they also read on the prior art?  <<<

So if I understand this correctly: If the claims of X/Y were interpreted in such a way as blocking my process and a similar interpretation would also block processes already known in art prior to the priority date of X/Y; then that can be taken to be supporting evidence that such an interpretation was not correct because interpreting it such a way would be akin to granting a patent that was de facto making the prior art as infringement?


But assuming my understanding of the issues is correct, shouldn't the non-infringement legal opinion be *only* interested in prior art that predates the priority dates of X/Y?  What's the point in surveying prior art between 2001 and now. How do those have any bearing on non-infringement?

[tati]

In this case, that sounds more like an FTO search. If you believe the firm had explicit instructions for non-infringement opinion, perhaps the instructions were misunderstood?

[patentpanda]

In this case, that sounds more like an FTO search. If you believe the firm had explicit instructions for non-infringement opinion, perhaps the instructions were misunderstood?

Sounds like it to me. The document seems a cross between an FTO and a specific non-infringement opinion.

I will check with the person who commissioned this what exactly was the brief given to the firm.

[NJ Patent1]

panda:  "so if I understand this correctly ..."  "That which infringes if later in time anticipates if earlier in time."  Is that what you meant?  If a claim construction of X/Y that causes the claims to read on your process would also cause them to be anticipated by (or be obvious over) the prior art, then the claims of X/Y are invalid.  Recognizing that an invalidity defense is a steep hill, that's the way I usually approach it, rather than altering my claim construction to "preserve the validity" of the claims of X/Y.  At some point, I have to man-up and construe the claims so that I can compare them to the accused product or process.

Were you billed for legal work that you did not request or that was unnecessary?  As has been pointed-out, you need to consult the engagement letter.  If all you contracted for was an opinion of noninfringement / FTO wrt X and Y only (I've handled such limited engagements), then I don't see much need to search for let alone analyze patents having a priority date later that those of X and Y.  If you were otherwise satisfied with the work and the law firm sees a possibility of further engagements, they will probably be willing to adjust the debit note. 

[patentpanda]

Were you billed for legal work that you did not request or that was unnecessary?  As has been pointed-out, you need to consult the engagement letter.  If all you contracted for was an opinion of noninfringement / FTO wrt X and Y only (I've handled such limited engagements), then I don't see much need to search for let alone analyze patents having a priority date later that those of X and Y.  If you were otherwise satisfied with the work and the law firm sees a possibility of further engagements, they will probably be willing to adjust the debit note.

Thanks! No it's not so much a billing issue. The opinion is approx. 2 years old.

More like I wanted to know why they did it  because in knowing so it clarified my understanding of the defense and the process. Which your replies did.