Flex-Rest, LLC appeals from a final judgment following a jury verdict finding U.S. Patent No. 5,709,489 (’489 patent) invalid for anticipation and obviousness and from a grant of summary judgment finding that Steelcase, Inc. did not infringe U.S. Patent No. 5,961,231 (’231 patent). Flex-Rest, LLC v. Steelcase, Inc., No. 1:02-CV-537 (W.D.Mich. Nov. 10, 2003); Flex-Rest, LLC v. Steelcase, Inc., No. 1:02-CV-537 (W.D.Mich. Mar. 11, 2004). Steelcase cross-appeals the district court’s order denying Steelcase’s motion for a determination of inequitable conduct in procuring the ’489 patent. Flex-Rest, LLC v. Steelcase, Inc., No. 1:02-CV-537 (W.D.Mich. Mar. 23, 2005) (“Inequitable Conduct Decision”). Because we discern no error in these decisions, we affirm.
I. BACKGROUND
Flex-Rest owns the ’489 and ’231 patents, which relate to computer keyboard positioning systems. The ’489 patent involves a clamping system that allows adjustment of the keyboard to a negative tilt position, with the palm rest adjusted above the plane of the keys. The ’231 patent involves a tray system that positions the keyboard in a similar negative tilt position. A view of this system is shown in Figure 7 of the ’489 patent, reproduced below:
*1355 [[Image here]]
On April 17, 2002, Flex-Rest filed suit against Steelcase, Office Details, Inc., and Office Concepts, Inc. asserting infringement of both patents. Steelcase stipulated that it was liable for Office Details, and the case was bifurcated against Office Concepts. The claims against Office Details and Office Concepts were therefore dismissed, and the case proceeded against Steelcase alone.
The claim terms at issue in this appeal were construed in a Memorandum Opinion and Order of November 10, 2003 following a hearing on claim construction. At issue in the ’489 patent was a limitation related to keyboard position as highlighted in claim 1 below:
1. A device for mounting a keyboard to a base and for positioning the keyboard in a backward tilted position ..., the device comprises:
(b) a clamp engaged with said bracket said clamp being engagable with a keyboard such that the keyboard may be oriented in a backward tilted position defined by the rear end of the keyboard being disposed below the front end of the keyboard, to prevent the keyboard from falling off when the keyboard is orientated in said backward tilted position;
’489 patent, col. 4, 11. 41-54. The district court construed this language to mean that “the support device permits the bottom of a keyboard to be tilted backward (ie., at any angle of less than 0 degrees).” At issue in the ’231 patent was the “sidewall” limitation highlighted in claim 1 below:
1. A device for mounting a keyboard to a base and for positioning the keyboard in a backward tilted position ..., the device comprising:
(c) a support tray comprising:
a support surface and
a keyboard stop member comprising a stop wall, said support surface comprising a front portion, a rear portion, a first sidewall, and a second sidewall, such that said stop wall extends from said first side wall to said second side wall and wherein said stop wall is disposed in said rear portion of said support surface,
’231 patent, col. 9, 11. 38-54. The district court construed “sidewall” to mean “a structure projecting or extending upward, i.e., above the plane of the support surface, from either side of the support tray.” Finding that Steelcase’s products did not possess sidewalls that projected or extended upward, the district court granted Steelcase’s motion for partial summary judgment of non-infringement of the ’231 patent.
After a hearing on various pretrial motions, the district court granted Steelcase’s *1356 motion in limine to exclude certain portions of testimony by Dr. John C. Rose-crance, Flex-Rest’s designated expert. Specifically, Dr. Rosecrance was allowed to testify to his field of expertise, ergonomics, but was precluded from testifying as an expert regarding designs of keyboard support systems and the prior art at the time of the invention.
As trial began on the ’489 patent, Steel-case stipulated that its accused devices infringed. In turn, Flex-Rest stipulated that Steelcase’s KBS device was conceived and reduced to practice before Flex-Rest’s invention was conceived in November 1990, and that the KBS device taught each limitation of the asserted claims. Thus, the primary issue for trial was whether the KBS device anticipated the ’489 patent under 35 U.S.C. § 102(g) or qualified as prior art for obviousness purposes.
With respect to the KBS device, Flex-Rest requested that the jury be instructed that in order to constitute prior art under section 102(g), the prior inventor could not have suppressed or concealed the invention. The district court found that there was not sufficient evidence to support such an instruction and denied Flex-Rest’s request.
During deliberations, the jury requested clarification regarding what is considered “public” and “prior art.” The district court defined “public” as “information not restricted by confidentiality.” As to “prior art,” the court responded:
In answer to your question, anything made or built in the United States by another person before the date of the claimed invention can be prior art for purposes of ‘obviousness’ even if it is not publically [sic] available before the date of the claimed invention.... Keep in mind that you should consider what I have just written, together with all the other instructions that I gave you earlier. All the instructions are important, and you should consider them as a whole.
The jury returned a verdict for Steelcase, finding the ’489 patent invalid under both 35 U.S.C. § 102(g) and 35 U.S.C. § 103. Flex-Rest did not make a motion for judgment as a matter of law (JMOL) or move for a new trial.
After entering judgment for Steelcase, the district court considered Steelcase’s motion for a determination of inequitable conduct in procuring the ’489 patent. Steelcase argued that Flex-Rest received — but failed to disclose to the U.S. Patent and Trademark Office (the Patent Office) — a letter and photographs from a competitor that constituted prior art material to patentability. Steelcase also argued that Flex-Rest failed to disclose the KBS device to the Patent Office, and that Flex-Rest’s patent counsel made a false declaration in his petition to make special because he did not investigate the photographs or the KBS device in his search of the prior art. The court concluded that Steelcase failed to show clear and convincing evidence of an intent to deceive and therefore denied the motion.
On appeal, Flex-Rest challenges the district court’s jury instructions, the court’s ruling limiting Dr. Rosecrance’s expert testimony, and the court’s claim construction of disputed terms in the ’489 and ’231 patents. On cross-appeal, Steelcase challenges the district court’s finding that clear and convincing evidence did not demonstrate inequitable conduct in procuring the ’489 patent. We have jurisdiction under 28 U.S.C. § 1295(a)(1).
II. DISCUSSION
A. Standard of Review
“Notwithstanding the absence of a motion for JMOL, a party may still challenge a jury verdict by establishing
*1357
that the judge committed legal error” in instructing the jury.
Advanced Display Sys. v. Kent State Univ.,
A district court’s decision to preclude expert testimony is an evidentiary issue that is reviewed for an abuse of discretion.
Gen. Elec. Co. v. Joiner,
This court reviews the district court’s grant of summary judgment of non-infringement
de novo. Hilgraeve Corp. v. McAfee
Assocs.,
Inc.,
Inequitable conduct is an equitable issue committed to the discretion of the trial court and reviewed by this court under an abuse of discretion standard.
Kingsdown Med. Consultants, Ltd. v. Hollister, Inc.,
B. Analysis
1. Jury Instructions
The district court found that Flex-Rest had failed to establish “a sufficient eviden-tiary basis for a reasonable jury to find ... that there was suppression or abandonment by Steelcase in connection with *1358 the KBS [device]” under 35 U.S.C. § 102(g).
Relying on
Lutzker v. Piet,
Steelcase responds that
Checkpoint Systems, Inc. v. United States International Trade Commission,
We must first determine if there is disputed evidence of record supporting an instruction on suppression or concealment of the KBS device. We conclude that there is none and agree with the district court and Steelcase that Flex-Rest did not make out a prima facie case of suppression.
Patent law provides that: “[a] person shall be entitled to a patent unless— ... before such person’s invention thereof, the invention was made in this country by another inventor who had not abandoned, suppressed, or concealed it.” 35 U.S.C. § 102(g)(2) (2004);
Dow Chemical, 267
F.3d at 1339. If prior invention has been established, the burden shifts to the patentee to produce sufficient evidence to create a genuine issue of material fact as to whether the prior inventor abandoned, suppressed, or concealed the invention.
Dow Chemical,
Flex-Rest first argues that the KBS device was intentionally suppressed or concealed. Intentional suppression occurs when an inventor “designedly, and with the view of applying it indefinitely and exclusively for his own profit, withholds his invention from the public.”
Paulik v. Rizkalla,
Flex-Rest next argues that the delay in filing a patent application for the KBS device supports an inference of suppression or concealment. “The failure to file a patent application, to describe the invention in a published document, or to use the invention publicly, within a reasonable time after first making the invention may constitute abandonment, suppression, or concealment.”
Dow Chemical,
Our case law provides guidance on what constitutes a reasonable delay when an invention is disclosed to the public by commercializing the invention. In
Dow Chemical,
we held that a delay of two and one-half years between reduction to practice and the commercialization of an invention did not constitute a
prima facie
case of suppression or concealment where the first inventor made “reasonable efforts to bring the invention to market.”
In this case, Flex-Rest offered no evidence to indicate that Steelease’s delay of six and one-half months between reduction to practice and commercialization of the KBS device was not the result of reasonable steps to bring the invention to market. After reduction to practice, Steelcase resolved design issues and spent $775,000 on tooling for the parts to the KBS device. The lead times for creating the tooling varied from four weeks to approximately six months. Therefore, it does not appear that Steelcase could have brought the KBS device to market much sooner than the trade show unveiling in June 1991.
*1360 At the same time, Steelcase’s patent counsel began drafting a patent application for the KBS device, submitting a first draft to Steelcase in March 1991. The draft was reviewed by the four named inventors and filed in May 1991. No evidence indicated that this amount of time was unreasonably long. 1
Because Flex-Rest offered no evidence to demonstrate that Steelcase failed to take reasonable steps toward market, and because Flex-Rest offered no evidence that a delay of six and one-half months from reduction to practice to filing an application was unreasonable, we conclude that there is not sufficient evidence to support a jury instruction regarding an inference of suppression or concealment.
We disagree with Flex-Rest’s contention that
Lutzker
and
Young
command a different result. First, both
Lutzker
and
Young
address disclosing a prior invention only by filing a patent application; they do not address — -as is the case here — disclosure through commercialization. In an interference context, we have held that delayed filing due to commercialization efforts or improvements not reflected in the patent application are inexcusable.
Lutzker,
Flex-Rest had the burden to produce sufficient evidence to create a genuine issue of material fact as to whether the KBS device was suppressed or concealed. We conclude that no evidence of record supports such an instruction. We also conclude that the district court fairly stated the legal principles in answering the jury’s questions on “public” and “prior art” and did not commit prejudicial error.
2. Expert Testimony
The district court found that one skilled in the art of the invention was a keyboard designer. Accordingly, the court excluded testimony by Dr. Rosecrance on the issues of anticipation and obviousness, finding that his area of expertise was in ergonomics rather than keyboard design support systems. Flex-Rest argues that the invention applies ergonomic principles to keyboard design, and that Dr. Rosecrance is qualified in the ergonomics field.
The district court held a hearing to fully investigate Dr. Rosecrance’s qualifications to testify about designs of keyboard systems and prior art. The court considered Dr. Rosecrance’s expertise in ergonomics, but concluded that he was not one of ordinary skill in the art at the time of the invention. There is no indication that the district court abused its discretion in arriving at this conclusion.
*1361 Because the district court did not err in instructing the jury or abuse its discretion in precluding Dr. Rosecrance’s testimony, we affirm the jury verdict finding the ’489 patent invalid.
3. Summary Judgment of N on-Infringement
Flex-Rest challenges the district court’s construction of the “backward tilted position” language in claim 1 of the ’489 patent and the term “sidewall” in claim 1 of the ’231 patent. Flex-Rest, however, stipulated that the KBS device taught each limitation of the ’489 patent and disputed only whether the KBS device met the requirements of 35 U.S.C. § 102(g). Because that stipulation was not limited to a specific construction, and because we have affirmed the jury’s invalidity finding, there is no need to address the court’s construction of the ’489 patent. Our claim construction inquiry is therefore limited to the term “sidewall” in the ’231 patent.
The district court construed the “sidewall” limitation to mean “a structure projecting or extending upward, i.e., above the plane of the support surface, from either side of the support tray.”
Flex-Rest argues that “sidewall” does not include a directional limitation and can therefore be met by a projection extending downwards. Flex-Rest characterizes the sidewall term as “minor,” “inconsequential,” and “unimportant,” and asserts that there is no basis in the intrinsic record for importing a directional limitation. Steel-case counters that the specification and prosecution history make clear that “sidewall” is part of the “support surface” and can only serve its function if it extends upward from the “support surface.”
In determining the meaning of the disputed claim limitation, we look principally to the intrinsic evidence of record, examining the claim language itself, the written description, and the prosecution history, if in evidence.
See Phillips,
Because there is no dispute that the accused devices do not meet the “sidewall” limitation under this construction, summary judgment of non-infringement of the ’231 patent was appropriate.
4. Inequitable Conduct
Steelcase challenges the district court’s inequitable conduct ruling based on two of the three grounds argued below. First, Steelcase argues that Steven Fox, Flex-Rest’s patent counsel, withheld prior art by not disclosing to the Patent Office a letter from a competitor which included photographs of a keyboard support system (the Ergo photographs). Steelcase argues that the Ergo photographs were highly material to patentability, were not cumulative of information already disclosed, and that Flex-Rest’s intent to deceive the Patent Office can be inferred from the surrounding circumstances. Second, Steelcase argues that Fox made a false representation to the Patent Office when he filed a declaration accompanying a petition to make special, which stated he had “conducted a careful and thorough search of the prior art.” Steelcase argues that this statement was false based on Fox’s failure to investigate the Ergo photographs.
The district court found that the Ergo photographs were “of uncertain import and reliability,” that Fox was justified in concluding they were cumulative of a patent already disclosed to the Patent Office, and that the facts triggering a duty to investigate in
Bmsseler, U.S.A. I, L.P. v. Stryker Sales Corp.,
Steelcase argues that the district court erred in finding that the Ergo photographs were of uncertain import and reliability, that Fox concluded the photographs were cumulative, and that Bmsseler is distinguishable. Steelcase also argues that the district court erred in finding that Fox’s declaration was not false because the photographs were not cumulative and Fox was therefore not excused from investigating them further.
Flex-Rest counters that the district court was correct in its findings because the Ergo photographs were received more than five years from the priority date for the ’231 patent and were not dated; the photographs were described in the letter as an embodiment of U.S. Patent No. 5,041,770 (the Seiler patent), which Fox disclosed in an Information Disclosure Statement (IDS); and Fox believed the photographs were not “prior art” subject to investigation.
Failing to disclose material information, or submitting false material information or statements, coupled with an intent to mislead or deceive the Patent Office, constitutes inequitable conduct.
Purdue Pharma L.P. v. Endo Pharms.
*1363
Inc.,
The district court did not abuse its discretion in denying Steelcase’s motion. The Ergo photographs are undated and identified in the letter as showing equipment that embodied the Seiler patent. The letter containing the Ergo photographs is dated May 14,1996; Fox submitted an IDS that disclosed the Seiler patent on October 21, 1996. In deposition, Fox stated that “the Seiler patent teaches anything and everything that may or may purportedly have been contained in those photographs.” To be sure, some of the photographs plainly depict a keyboard with a negative tilt, and thus Fox’s statement in his deposition seems at odds with his statement to the Patent Office during prosecution of the ’489 patent that the Seiler patent contains “no teaching of positioning the keyboard in a negative tilt position. ... It does not disclose or teach that the wrist rest may be moved to a position above a substantial portion of the keys of the keyboard.” However, the main thrust of Fox’s deposition explanation for not disclosing or conducting a further investigation of the photographs was that in the context in which the photographs were presented to him, he did not regard them as constituting credible evidence of prior art that was in existence as of the priority date of the ’489 patent.
Steelcase was required to prove by clear and convincing evidence that Fox possessed an intent to deceive or mislead the Patent Office. On this record, we do not have a definite and firm conviction that the court was mistaken in finding the photographs were “of uncertain import and reliability” and that Fox believed them to be, “in the main, cumulative.” We are further not persuaded that the court was mistaken in finding — in light of Fox’s testimony that the photographs were not credible and largely cumulative- — that the facts were distinguishable from those in
Brasseler.
The patent attorneys in
Brasseler
had knowledge of a potential on-sale bar by their client, had no rational basis to support their contention of when the sale had occurred, and offered no credible evidence or explanation for their failure to inquire about the sale before or after an application was filed.
As to Fox’s declaration, Fox stated in deposition that he considered the Ergo photographs not credible and cumulative of the Seiler patent he later disclosed in the submitted IDS. We therefore do not believe that the district court clearly erred in finding that Fox’s declaration was not false and not made with intent to mislead the Patent Office.
When materiality of information is close — as it appears to be here with the Ergo photographs — a patent applicant should err on the side of disclosure.
See Critikon,
III. CONCLUSION
Because we find that the district court properly instructed the jury and did not abuse its discretion in limiting Dr. Rose-crance’s testimony, we affirm that the ’489 patent is invalid. Because there is no genuine issue of material fact that the accused devices do not possess the “sidewall” limitation as properly construed, we affirm the district court’s grant of summary judgment that the ’231 patent was not infringed. Because the district court did not abuse its discretion, its order denying Steelcase’s motion for a determination of inequitable conduct is affirmed.
AFFIRMED.
Notes
. Flex-Rest's argument that
Shindelar
identifies a reasonable amount of time for drafting when the court stated that "a period of approximately three months could possibly be excused” takes that quote out of context. In reviewing the outcome of an interference proceeding, the Court of Customs and Patent Appeals stated that the evidence submitted to support a twenty-nine month delay in filing only supported, at most, three months of the delay.
Shindelar,
