Patent Litigation

Many patent litigation treatises or other secondary materials describe the types of discovery devices that can be used in patent cases, but few of them discuss what to seek—and why.  Attorneys who are new to patent litigation often rely on exemplars of discovery requests prepared by others but may not appreciate their purpose.  In this post, we discuss some key requests for production that defendants should propound to assess and build their defenses to a claim of patent infringement.   These are not meant to be exhaustive, and requests may be sliced and diced in a variety of ways.  However, they should be helpful to new attorneys trying to figure out what to seek in discovery.

Our focus here is on the initial round of written discovery.  Subsequent rounds of discovery will tend to be more focused and case specific because they will be informed by the patent owner’s responses to the initial round of discovery. In a subsequent post, we will focus on interrogatories.

Before serving requests for production, it is advisable to obtain all of the information you can about the topics below through publicly available information such as SEC filings, press releases, product brochures, patent office records, etc.  This information may help you better focus the requests on those areas that are most likely to be productive.  You should also talk to your client to see what it knows about these subjects.

Requests for Production Topics

1.  The file history for the patent-in-suit.  This is a critical source of intrinsic evidence for claim construction and also determines whether prosecution history estoppel may limit the scope of the doctrine of equivalents. However, you often can get it directly from the USPTO’s PAIR system, or for older file histories, from a file history service. You should also seek file histories for parent applications and child applications of the patent-in-suit.

2.  Documents corroborating the inventors’ conception and/or reduction to practice of the invention (e.g., lab notebooks, records of invention, prototypes, presentations, test results, etc.).  These are relevant to the issue of inventorship and may reveal whether the inventors developed information necessary to enable the invention that was not included in the patent application.

3.  Documents concerning the structure and operation of commercial embodiments of the patented invention made by the patent owner or its licensees (e.g., specifications, design drawings, relevant computer programs, etc.).  This information may reveal how the patent holder has read its claims in the past and to damages.  You should not assume that an alleged “commercial embodiment” is actually covered by the patent owner’s claims.  If it is not, then sales or other commercial information regarding the product may be irrelevant to damages or to secondary considerations of non-obviousness.  In addition, this information may reveal an inconsistency in the manner in which the patent holder is applying its claims to its own products and to the defendant’s accused product.

4.  Documents concerning the benefits of the invention (e.g., surveys regarding the invention, reactions of those skilled in the art to the invention, marketing documents). This information may be relevant to whether the patent claims are invalid for obviousness and to damages.

5.  Documents concerning prior art searches, and in particular, any uncovered prior art.  This information may be relevant to invalidity and inequitable conduct.

6.  File histories for foreign equivalent patent applications.  The prosecution histories of foreign counterparts to the patent-in-suit may reveal prior art that did not surface in the prosecution of the U.S. patent.  They may also reveal claim construction issues that were not fleshed out during U.S. prosecution.  Foreign office actions may stimulate your thinking as to how to assert defenses based on the written description or enablement requirements of the patent statute, or based on claim indefiniteness.  In particular, if the patent holder filed a patent cooperation treaty (PCT) application for the invention that is the subject of the patent-in-suit, the PCT search authority will have issued an International Search Report and a Written Opinion on the validity of the application’s claims.

7.  Any correspondence that the patent owner had with the defendant concerning the technology or the patent-in-suit.  This information may reveal the strength or weakness of induced infringement claims (by establishing whether the defendant knew of the patent prior to the filing of the law suit) and may have helpful admissions regarding the scope of the patent claims.  It may also be relevant to the issue of willful infringement by establishing whether the defendant was on actual notice of the patent and its alleged infringement of it.  Such correspondence may also provide a basis for a laches or equitable estoppel defense.

8.  Any correspondence that the patent owner had with third parties regarding alleged infringement of the patent-in-suit.  This information may reveal how the patent owner has applied the claims of the patent-in-suit in the past.  It may also provide you with leads to similarly situated parties who may be willing to share information that is helpful to the defense.

9.  Documents concerning offers to sell and sales of the invention (e.g., quotations, requests for quotation, purchase orders, invoices, shipping documents, sales records).  Depending on the timing, such offers to sell or sales may provide an on-sale bar invalidity defense. They may also be relevant to damages, especially lost profits damages.

10. Documents concerning public uses of the invention (e.g., trade show documents).  Depending on the timing, these documents may provide evidence a public use bar invalidity defense.

11. Documents concerning licenses to the invention (e.g., copies of the licenses, draft licenses, negotiation documents).  These may provide evidence of what a “reasonable royalty” for use of the patented invention would be.

12.  Documents concerning the patent owner’s participation in standard setting organizations (e.g., meeting minutes, letters to the organization concerning the licensing of relevant patents to organization members).  These documents can be relevant to the issue of patent enforceability.  The failure to disclose intellectual property necessary to practice a standard could render the patent unenforceable against standard practitioners.

13.  Documents concerning the marking of commercial embodiments with the patent number.  These documents are relevant to the issue of the damages period.  If the patent includes apparatus claims and commercial embodiments were not marked with the patent number, damages may be limited to the period after which the defendant was placed on actual notice of its alleged infringement.

14.  Documents concerning the patent holder’s contentions.  In addition to framing requests in terms of the underlying information being sought, you can frame them in terms of the patent owner’s contentions, e.g.:

a.  Documents concerning the patent owner’s infringement allegations.

b.  Documents concerning the patent owner’s allegations of willful infringement.

c.  Documents concerning secondary considerations of non-obviousness (e.g., documents that show “teaching away” from the claimed invention, unexpected benefits of the claimed invention, acquiescence by those in the industry, etc.).

d.  Documents concerning lost profits damages.

e. Documents concerning reasonable royalty damages.

The foregoing categories of document requests can be subdivided into numerous individual requests and may be tailored to case specifics. However, they should help start the process of formulating useful requests for production.