United States: Dispositive Motions in Patent Cases - Strategies And Considerations

Your company has been served with a complaint alleging patent infringement against your flagship product. Your lawyers have given you the sobering news that defending the case through trial likely will cost millions of dollars, and even if you win you may never recoup that expense from the plaintiff. Even more sobering, your lawyers caution you that although your case is very strong, anything can happen at trial. "Isn’t there something we can do to get rid of this thing without all that time, money and risk?" you ask.

Maybe there is. Consider an early motion for summary judgment—a motion that tells the court there is no point in presenting this case to a jury because applying the law to the clear and undisputed facts, you win. In patent cases in particular, there may be several potential grounds on which a patent may be ruled invalid, or a product may be found non-infringing, even with limited or no discovery.

A Motion for Summary Judgment Can Result in Dismissal of a Case

A motion for summary judgment, if granted, will result in a decision by the judge that resolves some or all of a case, without a trial. A successful motion may result, for example, in a finding of invalidity of a patent or of certain patent claims, in a finding of infringement (or noninfringement) as to some or all products or in the dismissal of a defense. A motion for summary judgment, or for summary adjudication of an issue,1 is brought under Federal Rule of Civil Procedure 56. Under Rule 56, a party will prevail on such a motion if it can "show that there is no genuine issue as to any material fact and that the moving party is entitled to a judgment as a matter of law." F.R.C.P. 56(c). Essentially, the party moving for summary judgment on a claim or defense must show that there are no genuinely disputed facts for a jury to decide at a trial, and that based on the undisputed facts, the party is entitled to judgment.

Although this standard is sometimes difficult to meet, summary judgment is especially well-suited to patent cases, where witnesses’ different recollections of events are less important, and relatively objective issues – such as whether an accused product includes every element of a patent claim – are determinative.

By a successful motion for summary judgment, also known as, summary adjudication, a defendant may be able to completely eliminate from the case some or all of a patentee’s claims, and a plaintiff may be able to eliminate some or all of a defendant’s defenses. Similarly, certain products or classes of products accused of infringement may be found to infringe or not infringe without necessity of a trial. Disposing of the case, or at least some of the issues, early saves time and money.

Even if it is not successful, a motion for summary judgment may reveal important strategies and positions of the opposing party, which will be forced to respond to the motion by presenting the evidence that it believes precludes the entry of summary judgment.2 Such a motion also will educate the judge in a context that allows the moving party to present its version of the case. In addition, an order denying a motion for summary judgment will usually reveal the judge’s reaction to the evidence, and may provide important information in presenting the case at trial. Moreover, if a motion for summary judgment is denied because the court finds there are disputed facts that must be decided by a jury, the party who brought that unsuccessful motion generally has not lost much. (It may still present the same evidence and arguments to the jury at trial.) Finally, because motions for summary judgment often decide the most important issues, cases are more likely to settle after court order, either granting or denying such a motion.

Of course, a party moving for summary judgment is also revealing its own strategies and positions. In addition, a motion that is not well founded will irritate the court and may reduce the party’s credibility. A weak motion may also encourage the court to grant a countermotion by the opposing party—possibly resulting in disposal of the case in the opponent’s favor.

In most cases, however, the potential advantages of motions for summary judgment outweigh the disadvantages, and thus, though not universally used in patent cases, such notions are very common. The decisions regarding when to bring such motions, and on what issues, are among the most important strategic choices in the case. This article examines some of the bases and important considerations for bringing certain motions for summary judgment in a patent case.

Motion for Summary Judgment – What Must Be Filed

To meet its burden of establishing that "there is no genuine issue as to any material fact," the moving party generally must file with its motion factual evidence to support its position. F.R.C.P. 56(e). For example, documents submitted to the court must be shown to be authentic and relevant, either by the declarations of witnesses or by stipulation. In some cases, the only relevant evidence will be the patent and its prosecution history. For other motions, substantial factual declarations from fact and/or expert witnesses may be necessary. Such evidence may include a declaration from an expert explaining why a patent fails to show one of ordinary skill in the art how to make or use a claimed invention, or how a prior art publication discloses each and every element of an asserted patent claim. The nature of the evidentiary showing will vary substantially depending on the grounds for the motion, several of which are discussed in more detail below.

A party opposing a motion for summary judgment may submit its own documents and declarations to show either that the material facts are disputed, and/or that the moving party’s proffered conclusions of law are incorrect. The opposing party also may object to evidence submitted by the moving party on the same grounds it could use at a trial (e.g., irrelevance, hearsay, privilege, etc.). See, F.R.C.P. 56(e). In addition, the opposing party may obtain, upon an appropriate showing, an order permitting it to take discovery before filing its opposition papers (F.R.C.P. 56(f)) or an order that summary judgment is premature until the court rules on issues of disputed claim construction.

It is important to remember that patents are presumed to be valid and in order to invalidate a patent; the defending party must show invalidity by clear and convincing evidence. Motions directed at the validity of a patent must take into account this higher burden of proof.

Motions Based On the Four Corners of the Patent and Its Prosecution History

To determine what early motions for summary judgment may be effective against a claim of patent infringement, the requirements of §112 of the patent statute should be considered.

The first paragraph of §112 of the patent statute imposes three distinct (although sometimes overlapping) requirements: (1) the specification must contain a written description of the invention; (2) the specification must enable any person skilled in the art to which it pertains to make and use the invention; and (3) the specification must set forth the best mode contemplated by the inventor of carrying out his invention. These three requirements are commonly referred to, respectively, as the "written description requirement," the "enablement requirement" and the "best mode requirement."

The second paragraph of §112 requires that "[t]he specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention." This requirement is known as the "definiteness" requirement.

Written Description Requirement

"The ‘written description’ requirement serves a teaching function, as a ‘quid pro quo’ in which the public is given ‘meaningful disclosure in exchange for being excluded from practicing the invention for a limited period of time.’" University of Rochester v. G.D. Searle & Co.3 The requirement means that the patent specification must "set forth enough detail to allow a person of ordinary skill in the art to understand what is claimed and to recognize that the inventor invented what is claimed."4 Compliance with the written description requirement is a question of fact.5

The Enablement Requirement

"Enablement is a legal determination of whether a patent enables one skilled in the art to make and use the claimed invention." BJ Services Co. v. Halliburton Energy Services, Inc.6 Compliance with the enablement requirement is also a question of law.7

The Best Mode Requirement

The best mode requirement "requires an inventor to disclose the best mode contemplated by him, as of the time he executes the application, of carrying out the invention." "…[T]he existence of a best mode is a purely subjective matter depending upon what the inventor actually believed at the time the application was filed." Bayer AG v. Schein Pharmaceuticals, Inc.8 Whether or not an inventor has complied with the best mode requirement is a question of fact.9

The Definiteness Requirement

"The definiteness inquiry focuses on whether those skilled in the art would understand the scope of the claim when the claim is read in light of the rest of the specification." BJ Services Co., v. Halliburton Energy Services, Inc.10 Definiteness is a question of law arising out of the court’s performance of its duty construing the claims. Nevertheless, "[l]ike enablement, definiteness, too, is amenable to resolution by the jury where the issues are factual in nature."11

Each of these statutory requirements should be carefully reviewed as a basis for a possible early attack on validity. All four concern the language and descriptions used in the patent itself. None of these theories involves whether the applicant actually invented the claimed subject matter first; whether the invention may have been on sale or disclosed in a publication more than one year prior to the applicant’s patent application; whether the applicant waited too long to file his application for patent; or whether the claimed invention is obvious. Thus, a motion to invalidate a patent under any of these §112 based theories may be filed relatively early in the case, well before the close of discovery, and usually without any third party discovery at all.

Indeed, a motion arguing that a patent fails to comply with the written description requirement or the enablement requirement may be brought without any discovery whatsoever, since only the four corners of the patent are involved. A moving party, nevertheless, may wish to present evidence (via fact witnesses and/or experts) showing that the patent fails to adequately disclose or teach the invention to one of ordinary skill in the art (written description requirement) or how to make and use it (enablement requirement).

A motion for summary judgment for failure to disclose the best mode, similarly, may require no third party discovery. However, since this inquiry concerns what the inventor knew about how best to make or practice his or her invention at the time the application was filed, a motion on this ground generally will require discovery from the inventor(s).

A motion based on indefiniteness of a claim, because it is closely related to claim construction (a question of law decided by the court), often must wait until the claim construction phase of the case. Still, in many jurisdictions, claim construction generally occurs some time before the discovery cut-off or trial, and such a motion may be brought well before trial.

Motion for Summary Judgment of Invalidity Due to Prior Art

A patent is invalid if the prior art reveals the claimed invention. In particular, a patent is invalid if the invention was known or used by others prior to the applicant’s invention, or if it was patented or described in a printed publication or in public use or on sale more than one year before the application was filed in the U.S. See, 35 U.S.C. §§102(a), (b). In patent law vernacular, §102 invalidity is called "anticipation" or "lack of novelty." In addition, a patent is invalid, even if the claimed invention is not completely disclosed in a single prior art publication, if the differences between the prior art and the claimed invention would have been obvious to one of ordinary skill in the art at the time of the applicant’s invention. See, 35 U.S.C. §103. Invalidity under §103 is called "obviousness," and is usually shown by presenting more than one prior art publication along with evidence that, at the time of the invention, one of ordinary skill in the relevant would have been motivated to combine them.

Unlike the §112 based invalidity theories discussed above, anticipation and obviousness generally depend on claim construction, and therefore a motion based on such grounds is best filed only after the court has ruled on what the claims mean. In fact, some courts discourage summary judgment motions until after claim construction, or until the close of discovery.

In any event, motions based on anticipation or obviousness usually include testimony of one or more experts to explain what one having ordinary skill in the art would understand was disclosed in the prior art. Because a party often will not want its expert to be deposed until relatively late in the case, motions on these grounds generally are not filed early.

Motions based on obviousness, as a general rule, are harder to win than motions based on anticipation. Anticipation depends primarily on the meaning of the claims in the asserted patent and the disclosures made in the prior art publication. Thus, the inquiry is by its nature relatively objective. Obviousness, on the other hand, generally requires consideration of how one of ordinary skill in the art would have been motivated to combine the teachings of more than one piece of prior art—a much more subjective inquiry, and therefore one more likely to involve disputed facts (or, at a minimum, disputed expert opinions).

Motions for Summary Judgment of Infringement (or Non-infringement)

Motions for summary judgment on other bases may be brought to minimize the time and expense of litigation. In a case where the structure and operation of an accused product is not in dispute, a motion for summary judgment of infringement (or non-infringement) may help dispose of the case early. Determining infringement is a two-step process: first, the terms of the asserted patent claims are construed (i.e., interpreted), and second, the accused product or process is analyzed to see if it contains every element of the construed claims. Markman v. Westview Instruments Inc.12 Therefore, even though a motion directed to infringement (or non-infringement) requires claim construction by the court, such a motion may resolve the case well before trial – and before much discovery – since claim construction alone may determine the infringement issues.

Claim construction is a question of law, and therefore within the authority of the judge to decide. Most courts will hold a claim construction (or Markman) hearing relatively early in the case, during which the court generally will resolve disputed facts relevant to claim construction. Although the second step of the infringement analysis (whether the accused product or process includes the elements of the claims) is a question of fact; in many cases the accused product or process is not in dispute, and (assuming the opposing party has had an adequate opportunity to obtain discovery) the matter may be resolved directly following claim construction.

Motion for Summary Judgment under "Doctrine of Equivalents"

Case law has long recognized that, in some cases, even though the accused product does not literally include every element of an asserted patent claim, the differences between the product and the claim are so insubstantial that the product still infringes. In other words, the actual words used in the patent claim effectively are broadened to include a range of "equivalent" products or processes that do not literally infringe. This tenet is called the "doctrine of equivalents," which has been the recent subject of substantial appellate attention, including by the U.S. Supreme Court. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co.13 While a detailed review of this doctrine is beyond the scope of this article, a motion for summary judgment may be effective in limiting (or broadening) the scope of "equivalent" products that infringe.

In particular, the Supreme Court has made clear that any narrowing amendments an applicant makes to his or her patent claims during the course of the prosecution of the patent application, if made to overcome prior art objections or other patentability objections by the examiner, give rise to a presumption that the patent owner is precluded from later extending the reach of the claims to products having features given up by the amendments.14 Moreover, the Federal Circuit has held that whether this doctrine, called "prosecution history estoppel," applies is a question of law. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd.15

The patent owner may try to overcome the presumption on three specified grounds: (1) the alleged equivalent was "unforeseeable" at the time the amendment was made; (2) the narrowing amendment was merely "tangential" and not directly relevant to the alleged equivalent; or (3) some other reason why the patent applicant could not reasonably be expected to have described the insubstantial substitute in question.16 The Federal Circuit has held that the latter two of these grounds should be confined to a review of the patent and its file history, and should not generally involve other evidence. In other words, the merit of these two grounds is a ripe topic for summary judgment determination.

The patent owner, therefore, probably will be able to raise a factual dispute only under the grounds of unforeseeability by seeking to show that the difference between the literal claim language and the accused product was "unforeseeable" at the time of the amendment.17 Depending on the facts of the case, summary judgment may be an appropriate way to have the court determine the applicable scope of any alleged equivalent beyond the literal patent claim language.


A motion for summary judgment, in appropriate cases, is an effective tool for disposing of all or part of a case prior to trial, saving substantial time and money. In patent cases, there are several potential grounds for which such a motion may be filed relatively early in a case, even prior to discovery. A motion for summary judgment may also provide an opportunity to educate the court about a party’s positions early in the case, and may force an opposing party to reveal its theories of the case. Such motions are especially effective in patent cases, where objectively verifiable facts often predominate over subjective recollections of witnesses. Reviewing possible grounds for summary judgment early may help create a stronger case strategy and provide a roadmap to success down the road. Whether or not and when to file a motion for summary judgment, and the grounds therefore, are among the most important strategic decisions to be made in the case.


1. A motion for summary adjudication of issues refers to a motion that will resolve some issues in the case, but not the entire case. See, F.R.C.P. 56(d).

2. A moving party may not bring the motion, of course, merely to learn the opposing party’s case; Rule 11 requires that all motions be brought in good faith and with reasonable bases. Further, a court may deny a motion for summary judgment due to a moving party’s failure, or a non-moving party’s lack of opportunity, to complete adequate discovery, or as premature until the court has ruled on claim construction.

3. 2004 U.S. App. LEXIS 2458 (Fed. Cir. 2004).

4. Id.

5. Id.

6. 338 F.3d 1368 (Fed Cir. 2003).

7. Id.

8. 301 F.3d 1306, 1314 (Fed. Cir. 2002).

9. Id. at 1312.

10. 338 F.3d 1368 (Fed Cir. 2003).

11. Id.

12. 52 F.3d 967, 976, (Fed. Cir. 1995) (en banc), aff'd, 517 U.S. 370 (1996).

13. 535 U.S. 722 (2002).

14. Id.

15. 344 F.3d 1359, 1367 (Fed. Cir. 2003).

16. Id. at 1369-70.

17. Id. at 1369.

David L. Larson Margaret M. Duncan David L. Larson, a Washington, D.C. based-partner, focuses on patent and other intellectual property litigation and counseling. Margaret M. Duncan, partner and head of the Firm's Chicago Intellectual Property practice, focuses her practice on patent, trademark and copyright litigation, protection, counseling and transactions. (continued on page 18)

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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