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Lighting Ballast v. Philips Electronics: What Is the Proper Claim Construction Standard for CAFC Review?

By Eugene T. Perez and Utsav Gupta


In construing claims for purposes of assessing patentability, the USPTO patent examiner or the Patent Trial and Appeal Board (“Board”) will apply the “broadest reasonable interpretation” (“BRI”) standard.  The AIA proceedings of IPR and PGR will also apply BRI. In contrast, a district court will assess validity and use a higher claim construction standard, thus tending to construe claims more narrowly to preserve validity due to the clear and convincing standard per 35 U.S.C. § 282.

In Lighting Ballast v. Philips Electronics, the Federal Circuit held that claim construction is a matter of law.1Therefore, claim construction is reviewed without deference to the lower court’s construction.  However, the Federal Circuit has agreed to rehear en banc the issue of the amount of deference that should be given to the lower court’s claim construction, and vacated its earlier decision.2


The Federal Circuit confirmed in Cybor Corp. v. FAS Technologies, Inc. that claim construction is a purely legal issue and is subject to de novo review.3  In 2004, the court again considered the issue in Phillips v. AWH Corp.4  However, it chose “not to address” the issue.

Judge Mayer strongly dissented in Phillips, arguing that the court should consider the underlying facts to claim construction:

“Claim construction is, or should be, made in context: a claim should be interpreted both from the perspective of one of ordinary skill in the art and in view of the state of the art at the time of invention. See Multiform Desiccants, Inc. v. Medzam, Ltd.,133 F.3d 1473, 1477 (Fed. Cir. 1998) (‘It is the person of ordinary skill in the field of the invention through whose eyes the claims are construed.’). These questions, which are critical to the correct interpretation of a claim, are inherently factual. They are hotly contested by the parties, not by resort to case law as one would expect for legal issues, but based on testimony and documentary evidence.”6

The court most recently considered the appropriate standard of review in Amgen Inc. v. Hoechst Marion Roussel, Inc.7  One opinion from the case indicated a willingness on behalf of three judges to reassess the standard in “an appropriate case”.8  Lighting Ballast may be that case. Interestingly, the CAFC has invited the USPTO to file an amicus brief as well.

The Federal Circuit has also wondered if claim construction is purely a question of law when reviewing the USPTO’ claim construction (whether from ex parte prosecution or an inter partes matter such as inter partes reexamination).  The recent Flo Healthcare v. Kappos decision9 involved a 3-panel judge said it is unclear as to what is the right standard of review for the CAFC in reviewing a USPTO/PTAB claim construction (deferential, or de novo).

Lighting Ballast

The issue in this case is whether the term “voltage source means” is a means-plus-function limitation under 35 U.S.C § 112, ¶ 6.  The district court initially held the claims invalid for indefiniteness.10  However, on a motion for reconsideration, the court found that its initial construction against the patentee “exalted form over substance and disregarded the knowledge of a person of ordinary skill in the art.”11  The court entered final judgment of infringement and validity.

On appeal, the Federal Circuit noted that means-plus-function claiming is a “matter of claim construction” and is “reviewed without deference.”12  It reversed the district court decision and found the patent to invoke means-plus-function claiming.13  The claims were held invalid for indefiniteness.14

However, the Federal Circuit decided the appeal warrants en banc consideration and has posed the following questions:

“a. Should this court overrule Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448 (Fed. Cir. 1998)?

b. Should this court afford deference to any aspect of a district court’s claim construction?

c. If so, which aspects should be afforded deference?”15


A decision to overturn Cybor will have great implications for patent litigation.   While judges will continue to decide claim construction,16 some deference to factual concerns may be given to lower courts.

Additionally, the outcome of this case may serve to the help clarify the standard of review granted to the Patent Trial and Appeal Board (PTAB) by the Federal Circuit.   Currently, the Federal Circuit has two “contradictory lines of authority”: a “no-deference ‘pure’ law type review” and a deferential review.17  The PTO, however, uses the “broadest reasonable interpretation” standard, which “raises the potential of parallel appeals over a Board decision and a district court decision applying different standards of review to the same claim construction question.”18

Both Judge Plager and Judge Newman have voiced the need for a uniform standard of review.19  Should the Federal Circuit in Lighting Ballast hold that claim construction is a question not only of law, but also of fact, ora mixed question of law and fact, the Federal Circuit will likely hold similarly for a more deferential standard of review for PTAB decisions.

The Federal Circuit will hear oral arguments on September 13, 2013.20

  1. Lighting Ballast Control LLC v. Philips Elecs. N. Am. Corp., 2013 U.S. App. LEXIS 6, 9, 2013 WL 11874 (Fed. Cir. Jan. 2, 2013); vacated on March 15, 2013.
  2. 2013 U.S. App. LEXIS 5185 (Fed. Cir., Mar. 15, 2013).
  3. Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 46 USPQ2d 1169 (Fed. Cir. 1998) (en banc).
  4. Phillips v. AWH Corp., 376 F.3d 1382, 71 USPQ2d 1765 (Fed. Cir. 2004) (en banc order).
  5. Phillips v. AWH Corp., 415 F.3d at 1328.
  6. Phillips v. AWH Corp., 415 F.3d at 1332.
  7. Amgen Inc. v. Hoechst Marion Roussel, Inc., 469 F.3d 1039 (Fed. Cir. 2006), cert. denied, 127 S. Ct. 2270 (2007).
  8. 5A-18 Chisum on Patents § 18.06.
  9. Flo Healthcare Solutions LLC v. Kappos, 697 F.3d 1367, 104 U.S.P.Q.2d 1834 (Fed. Cir. 2012).
  10. Lighting Ballast Control, LLC v. Philips Elecs. North Am. Corp., 2010 U.S. Dist. LEXIS 85570, 31 (N.D. Tex. Aug. 19, 2010).
  11. Lighting Ballast Control, LLC v. Philips Elecs. N. Am. Corp., 2010 U.S. Dist. LEXIS 127409, 37 (N.D. Tex. Dec. 2, 2010).
  12. Lighting Ballast Control LLC v. Philips Elecs. N. Am. Corp., 498 Fed. Appx. 986, 989 (Fed. Cir. 2013).
  13. Id. at 992.
  14. Id.
  15. Lighting Ballast Control LLC v. Philips Elecs. N. Am. Corp., 2013 U.S. App. LEXIS 5185, 2, 2013 WL 1035092 (Fed. Cir. Mar. 15, 2013).
  16. See Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996) (holding that judges, not juries, should decide claim construction as a matter of policy).
  17. Flo Healthcare Solutions, LLC v. Kappos, 697 F.3d at 1378.
  18. Id.
  19. See Id. at 1378, 1381.
  20. United States Court of Appeals for the Federal Circuit, Upcoming Oral Arguments, available at, http://www.cafc.uscourts.gov/argument/upcoming-oral-arguments.html (last visited May 14, 2013).