Court Opinion

ID: 2764495
Source: CourtListenerOpinion
Date Created: 2014-12-24 17:00:59.417506+00
Date Added: 2024-06-11T12:27:09.298451
License: Public Domain

United States Court of Appeals
      for the Federal Circuit
                ______________________

                 HOYT A. FLEMING,
                  Plaintiff-Appellant,

                           v.

    ESCORT INC. AND BELTRONICS USA, INC.,
          Defendants-Cross-Appellants.
             ______________________

                   2014-1331, -1371
                ______________________

    Appeal from the United States District Court for the
District of Idaho in No. 1:09-CV-00105-BLW, Chief Judge
B. Lynn Winmill.
                  ______________________

              Decided: December 24, 2014
               ______________________

    MICHAEL S. DOWLER, Park, Vaughan, Fleming & Dow-
ler, LLP, of Houston, Texas, argued for plaintiff-
appellant.

   GREGORY F. AHRENS, Wood, Herron & Evans, L.L.P.,
of Cincinnati, Ohio, argued for defendants-cross-
appellants. With him on the brief was BRETT A. SCHATZ.
                  ______________________
 Before TARANTO, BRYSON, and HUGHES, Circuit Judges.
2                                     FLEMING v. ESCORT INC.

TARANTO, Circuit Judge.
    The district court in this case refused to disturb a jury
verdict concerning two reissue patents. The jury found
for the patentee on infringement and validity as to most
of the asserted claims, but it invalidated five claims. The
patentee, Hoyt Fleming, appeals the five invalidity de-
terminations, arguing that (1) the testimony offered to
establish invalidity was insufficiently specific to support
the verdict; (2) there was insufficient corroboration of the
prior invention relied on for the invalidity determinations;
and (3) the prior invention, if it existed, was abandoned,
suppressed, or concealed, disqualifying it from invalidat-
ing the claims. The adjudicated infringers, Escort, Inc.,
and Beltronics USA, Inc. (collectively, Escort), cross-
appeal on the ground that all of the asserted claims are
invalid because Fleming’s reason for seeking reissue did
not meet the “error” precondition for obtaining reissue.
We affirm.
                       BACKGROUND
    Hoyt Fleming owns two reissue patents—U.S. Patent
Nos. RE39,038 (issued Mar. 28, 2006) and RE40,653
(issued Mar. 10, 2009)—issued under 35 U.S.C. § 251.
Both relate to radar detectors for detecting police signals.
They claim methods for incorporating, as well as apparat-
uses that incorporate, a Global Positioning Satellite (GPS)
unit into a radar detector. The incorporated GPS can
reduce false alarms (i.e., the signaling of a police presence
when none exists) by allowing the detector to disregard, or
“lock out,” certain signals from an identified location
known to produce such false alarms (e.g., a storefront door
opener transmitting a radar signal that can be mistaken
for a police presence).
   Claim 1 of the ’038 patent is representative of the
method claims. It reads:
FLEMING v. ESCORT INC.                                      3

    1. A method, executed by a device having a posi-
    tion, of generating an alert to an incoming radar
    signal having a frequency and a signal strength,
    the method comprising the acts of:
    (a) detecting the incoming radar signal;
    (b) determining the position of the device that de-
    tected the incoming radar signal; and
    (c) generating an alert if the position of the device
    is not within a predetermined distance of a prede-
    termined position.
’038 patent, col. 6, lines 49–58.
   Claim 18 of the ’038 patent is representative of the
apparatus claims. It reads:
    18. A radar detector for alerting an operator of a
    motor vehicle to an incoming police radar signal
    comprising:
    (a) a microprocessor;
    (b) a circuit coupled to the microprocessor for de-
    tecting the incoming police radar signal; and
    (c) a global positioning system receiver coupled to
    the microprocessor and operable to provide the
    microprocessor with data that indicates the posi-
    tion of the radar detector.
’038 patent, col. 7, lines 53–61.
    On March 10, 2009, Fleming sued Escort for in-
fringement of his two patents. At the heart of Escort’s
defenses was the contention that Steven Orr, who works
for Escort as a consultant, had invented a GPS-
incorporating radar detector before Fleming did—a prior
invention Escort invoked to support anticipation and
4                                     FLEMING v. ESCORT INC.

obviousness challenges under 35 U.S.C. §§ 102(g) and 103
(2006). 1 Fleming’s claimed priority date is April 14,
1999—the filing date of his original patent application.
Orr alleged that he conceived his invention in 1988 and
made a working embodiment that reduced it to practice in
April 1996. From 1988 to 1996, Orr was working at
Cincinnati Microwave, which owned the potential patent
rights to the alleged invention at issue. Cincinnati Mi-
crowave entered bankruptcy on February 14, 1997. With
Orr assisting in the bankruptcy process, Escort acquired
Cincinnati Microwave’s assets, including the potential
patent rights to the alleged Orr invention, during the
summer of 1997. Escort sought Orr’s assistance in the
new enterprise, and Orr began working at Escort in July
1998. He filed a patent application to claim his alleged
invention, with Escort as assignee, on June 14, 1999, two
months after Fleming filed his application.
    The jury in this case found most of Fleming’s asserted
claims to be infringed by Escort and not to be invalid. It
found invalidity, however, as to five claims of the ’038
patent—claims 1, 18, 45, 47, and 48. The jury invalidated
claim 45 as anticipated by Orr’s prior invention. It inval-
idated claim 18 as anticipated by the Orr invention and
also for obviousness in light of Orr’s invention and two
prior-art patents, Hoffberg (U.S. Patent No. 6,252,544)

    1   This case is governed by the statutory provisions
in effect before the Leahy–Smith America Invents Act
(AIA), Pub. L. No. 112-29, § 3, 125 Stat. 284, 285–93
(2011), put into effect revisions of many provisions of Title
35 of the U.S. Code, including sections 102, 103, and 251.
See AIA § 3(n)(1), 125 Stat. at 293 (relevant AIA amend-
ments apply only to applications and patents containing a
claim with an effective filing date of March 16, 2013, or
later). We hereafter omit a date in citing the statutory
provisions.
FLEMING v. ESCORT INC.                                    5

and Ross (U.S. Patent No. 5,977,884). And it invalidated
claims 1, 47, and 48 for obviousness in light of Orr’s prior
invention and two prior-art patents, Hoffberg and Valen-
tine (U.S. Patent No. 5,146,226).
    Fleming subsequently sought judgment as a matter of
law to reverse the jury’s five invalidity determinations.
He argued that the testimony regarding invalidity was
conclusory, that Orr’s testimony regarding his prior
invention was insufficiently corroborated, and that Orr’s
prior invention—even if it existed—had been abandoned,
suppressed, or concealed within the meaning of 35 U.S.C.
§ 102(g)(2), disqualifying it as a basis for invalidity.
Escort, in turn, sought judgment that Fleming’s patents
were invalid, arguing that Fleming had not identified an
“error” in his original patent (U.S. Patent No. 6,204,798),
a prerequisite to securing a reissue patent under section
251. The district court denied both sides’ motions.
   Both parties appeal the district court’s decision. We
have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).
                         DISCUSSION
     We review the denial of a motion for judgment as a
matter of law de novo, applying the same standards as did
the district court in deciding whether the jury verdict
must be reversed. See Enovsys LLC v. Nextel Commc’ns,
Inc., 614 F.3d 1333, 1341 (Fed. Cir. 2010) (applying Ninth
Circuit law). In doing so, we accept express or implied
jury factual determinations, if supported by substantial
evidence, and assess whether those facts support the
judgment under the governing legal standards, whose
interpretation we review de novo. See, e.g., Baxter
Healthcare Corp. v. Spectramed, Inc., 49 F.3d 1575, 1582
(Fed. Cir. 1995) (applying Ninth Circuit law); Pierce v.
Underwood, 487 U.S. 552, 558 (1988). “Substantial
evidence is such relevant evidence as reasonable minds
might accept as adequate to support a conclusion even if
it is possible to draw two inconsistent conclusions from
6                                     FLEMING v. ESCORT INC.

the evidence.” Landes Const. Co., Inc. v. Royal Bank of
Can., 833 F.2d 1365, 1371 (9th Cir. 1987).
                             A
                             1
     Fleming’s first contention on appeal from the five in-
validity verdicts is that Escort’s evidence in support of
invalidity was insufficiently specific to support the ver-
dict.   Fleming’s argument invokes our rulings that
“[g]eneral and conclusory testimony . . . does not suffice as
substantial evidence of invalidity.” Koito Mfg. Co. v.
Turn-Key-Tech, LLC, 381 F.3d 1142, 1152 (Fed. Cir.
2004); see CytoLogix Corp. v. Ventana Med. Sys., Inc., 424
F.3d 1168, 1176 (Fed. Cir. 2005); Motorola, Inc. v. Inter-
digital Tech. Corp., 121 F.3d 1461, 1473 (Fed. Cir. 1997).
It is not enough simply to introduce a prior-art reference
into the record, with no testimony showing where the
limitations of the claims are to be found. Koito, 381 F.3d
at 1151–52; see also Fresenius USA, Inc. v. Baxter Int’l,
Inc., 582 F.3d 1288, 1300 (Fed. Cir. 2009). In this case,
the principal prior art was not a patent or publication but
the prior invention of Orr, who testified extensively about
it.
    We conclude that there was sufficiently specific factu-
al support for the invalidity determinations. The jury’s
verdict on invalidity rested on two overlapping classes of
findings. The first concerned Orr’s prior invention, which
the jury found to anticipate claims 18 and 45—a question
of fact. TI Grp. Auto. Sys. (N. Am.), Inc. v. VDO N. Am.,
LLC, 375 F.3d 1126, 1133 (Fed. Cir. 2004). The second
concerned the teachings of the asserted combinations of
Orr’s prior invention and Hoffberg, Ross, and/or Valen-
tine. The content of those teachings and the motivation to
combine are fact questions, see Kinetic Concepts, Inc. v.
Smith & Nephew, Inc., 688 F.3d 1342, 1360, 1367 (Fed.
Cir. 2012), which we assume the jury answered in Escort’s
favor in finding claims 1, 18, 47, and 48 invalid for obvi-
FLEMING v. ESCORT INC.                                       7

ousness. Sufficiently specific evidence supported the
jury’s findings.
    The invalidated claims do not contain a large number
of limitations, so extensive testimony was not required.
Nevertheless, Orr and Escort’s expert, Dr. Grindon,
together provided testimony that explained how the prior
art taught the limitations of each invalidated claim.
     For example, claim 45 recites two limitations: (1) “a
circuit operable to detect an incoming radar signal” and
(2) “a microprocessor operable to disable an alert to the
incoming radar signal based at least in part upon the
position of the radar detector.” ’038 patent, col. 10, lines
24–30. As to the first limitation, Orr explained that part
of his invention consisted of a radar detector that received
frequency information, allowing the detection of radar
signals. J.A. 6198. As to the second limitation, Orr
explained that the radar detector was connected to a GPS
navigational card and a laptop, allowing the muting of
certain signals “when [he] hit the spacebar” based on
position information expressed in cylindrical coordinates.
J.A. 6198. As to both limitations, Dr. Grindon evaluated
evidence of Orr’s prior invention, including files that
showed “routes that [Orr] took driving around under
different conditions to collect . . . position and velocity
information from a GPS device in his car,” J.A. 6324, and
explained that Orr’s invention “definitely shows and
discloses . . . the combination for a radar detector with a
GPS system . . . combined with a processor, in this case a
laptop computer . . . [to] suppress[] . . . false alerts . . .
based upon location . . . [and] the speed of the car . . . [by]
press[ing] the space bar on the laptop,” J.A. 6325.
    With regard to the other invalidated claims, Dr. Grin-
don testified in some detail to the aspects of Hoffberg,
Ross, and Valentine—as well as the motivation to com-
bine—that would have made the claimed subject matter
obvious at the relevant time. E.g., J.A. 6328–29 (describ-
8                                       FLEMING v. ESCORT INC.

ing how Hoffberg “teach[es] . . . radar detection . . . in . . .
various frequency bands” and “stor[ing] information . . . to
discriminate against false alarms”); J.A. 6330–31 (describ-
ing how Ross “integrat[es] a system with a radar detector
and a GPS, and then a processor . . . [to] address[] the
same problem of false alarms and false alerts” through a
comparison of “[t]he speed of the vehicle, which is derived
from the GPS unit, . . . with [a] preset maximum”); J.A.
6332–33 (describing how Valentine “address[es] the
problem of false alerts in a very similar, but slightly
different, way [from Hoffberg],” by “discriminat[ing] the
signals based on frequency . . . in the same way [as Orr’s
prior invention]”).
    In light of this and other testimony, we cannot say
that the invalidity challenge was supported by only
conclusory testimony and unexplained prior-art docu-
ments. There was specific evidence sufficient to support
the verdict.
                               2
      Fleming also challenges the proof of Orr’s prior inven-
tion by invoking the principle that “oral testimony by an
alleged inventor asserting priority over a patentee’s rights
. . . must be supported by some type of corroborating
evidence.” Woodland Trust v. Flowertree Nursery, Inc.,
148 F.3d 1368, 1371 (Fed. Cir. 1998) (citation and internal
quotation marks omitted). Such evidence is evaluated
under “the rule of reason,” whereby “all pertinent evi-
dence is examined in order to determine whether the
inventor’s story is credible.” Sandt Tech., Ltd. v. Resco
Metal & Plastics Corp., 264 F.3d 1344, 1350 (Fed. Cir.
2001) (citations and internal quotation marks omitted);
see also Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157,
1171 (Fed Cir. 2006) (“corroboration is fundamentally
about ‘credibility’ ”). Importantly, “[t]he law does not
impose an impossible standard of independence on cor-
roborative evidence by requiring that every point of a
FLEMING v. ESCORT INC.                                        9

reduction to practice be corroborated by evidence having a
source totally independent of the inventor; indeed, such a
standard is the antithesis of the rule of reason.” Cooper v.
Goldfarb, 154 F.3d 1321, 1331 (Fed. Cir. 1998) (citation
and internal quotation marks omitted). We have treated
the sufficiency of corroboration as a question of fact, with
the district court’s determination subject to review for
clear error. Medichem, 437 F.3d at 1171–72.
    Here, Orr’s testimony of prior invention was suffi-
ciently corroborated by the documentary evidence. The
record contains 1992 data from GPS experiments that Orr
ran at the time, e.g., J.A. 7757 (frequency plot entitled
“Ka band in False Region Record”), and 1996 notes and
correspondence from Orr pertaining to GPS and, more
specifically, to “realizing product features identified in . . .
[a] brainstorming meeting . . . [by] integrat[ing] a radar
detector into . . . automotive navigation systems,” J.A.
7352–53. Most tellingly, perhaps, the record contains a
1996 letter from Greg Blair, Vice President of Cincinnati
Microwave, addressed to Orr and other employees, which
refers to “entering the ETAK [a type of automotive navi-
gation system] business . . . to get speed and position to
silence a detector” and to “patent[ing] the concept of . . .
vehicle position muting and then working with the ETAK
folks for a data link to our detectors,” J.A. 7354.
    This evidence makes credible Orr’s general account: in
1988, when he had his specific conception, various indus-
try participants were thinking generally about equipping
radar detectors with GPS to reduce false alarms; Cincin-
nati Microwave, in particular, was interested in the idea;
by 1992, Orr was collecting data and working toward
reducing the conception to practice; and in 1996, spurred
by great interest in his project, Orr reduced his invention
to practice. The evidence, in referring to frequencies and
to using a GPS-given location to mute a detector alarm,
also provides substantial corroboration of the more specif-
10                                    FLEMING v. ESCORT INC.

ic claim limitations concerning lockout frequencies and
distances that Fleming has highlighted in his argument.
    Fleming is correct that none of the corroborating evi-
dence constitutes definitive proof of Orr’s account or
discloses each claim limitation as written. But the cor-
roboration requirement has never been so demanding.
See Cooper, 154 F.3d at 1331. It is a flexible, rule-of-
reason demand for independent evidence that, as a whole,
makes credible the testimony of the purported prior
inventor with regard to conception and reduction to
practice of the invention as claimed. Sandt, 264 F.3d at
1350–51. The evidence presented here sufficiently does
that.
                             3
    Fleming’s final challenge is that, even if Orr had pri-
ority of invention by virtue of his activities through 1996,
he lost priority under 35 U.S.C. § 102(g)(2)’s disqualifica-
tion of prior inventions that have been “abandoned,
suppressed, or concealed.” Although we accept the facts
as found by the jury where (as here) they are supported
by substantial evidence, we have said that “[s]uppression
or concealment is a question of law which we review de
novo.” Fujikawa v. Wattanasin, 93 F.3d 1559, 1567 (Fed.
Cir. 1996). We reject Fleming’s challenge.
    Abandonment, suppression, or concealment may be
shown by proof of the prior inventor’s active efforts to do
so or “may be inferred based upon the prior inventor’s
unreasonable delay in making the invention publicly
known.” Dow Chem. Co. v. Astro–Valcour, Inc., 267 F.3d
1334, 1342 (Fed. Cir. 2001); see also Fox Grp., Inc. v. Cree,
Inc., 700 F.3d 1300, 1305–06 (Fed. Cir. 2012). Whether a
delay is sufficiently reasonable to avoid the inference “has
consistently been based on equitable principles and public
policy as applied to the facts of each case.” Checkpoint
Sys., Inc. v. U.S. Int’l Trade Comm’n, 54 F.3d 756, 761
(Fed. Cir. 1995) (citation and internal quotation marks
FLEMING v. ESCORT INC.                                    11

omitted). For example, “delay between the first reduction
to practice and public disclosure” is excused “if the inven-
tor continued to refine, perfect, or improve the invention.”
Eolas Techs. Inc. v. Microsoft Corp., 399 F.3d 1325, 1333
(Fed. Cir. 2005). Moreover, even “a long period of inactiv-
ity need not be a fatal forfeiture, if the first inventor
resumes work on the invention before the second inventor
enters the field.” Paulik v. Rizkalla, 760 F.2d 1270, 1272
(Fed. Cir. 1985).
     In this case, there is no evidence of any active efforts
to suppress or conceal. And we find the timing of Orr’s
activities leading to his June 1999 patent application not
to warrant an inference of abandonment, suppression, or
concealment. The evidence is sufficient to establish the
following facts, covering three periods starting from the
April 1996 reduction to practice.
    In the first period, before the February 1997 date of
Cincinnati Microwave’s bankruptcy, Cincinnati Micro-
wave had great interest in the project, J.A. 6094, and Orr
studied, refined, and improved his invention: he studied
“selective availability,” i.e., signal interference by the
military that impaired the use of his invention, J.A. 6095,
and conducted field testing and wrote additional code to
perfect his invention, J.A. 6104–22. In the third period,
after Orr started working at Escort in the summer of
1998, he was immediately put to work on his invention,
and he continued this work at least until he filed for his
own patent in June 1999. E.g., J.A. 6293 (Escort’s Kuhn
testifying that Escort was motivated to hire Orr because
of Orr’s expertise in radar/GPS, and that Kuhn told Orr to
work on his invention once he joined Escort), J.A. 7494–
546 (Orr’s timesheets at Escort from July 1998 to July
1999, mentioning work on radar/GPS work, including “Ka
falsing improvements”).
   What happened in the middle period—between Febru-
ary 1997 and summer 1998—is this: For a period of
12                                    FLEMING v. ESCORT INC.

“approximately 13 months after the bankruptcy,” Orr
joined another firm to work with “a group of engineers
that were designing a cordless telephone.” J.A. 6123. The
patent rights to Orr’s radar/GPS prior invention, created
at Cincinnati Microwave, were acquired by Escort in the
bankruptcy, and Escort set priorities to get its new busi-
ness going but, even so, was interested in developing this
invention. Orr testified that, from the middle of 1997 to
the middle of 1998, while working elsewhere, he was
giving Escort information about his invention, J.A. 6182,
and that Escort was pursuing Orr’s invention and confer-
ring with Orr about it during that period, J.A. 6184.
Escort’s Kuhn testified that, from the start, Escort was
motivated to hire Orr because of Orr’s expertise in ra-
dar/GPS, was seeking to hire him during its startup
period, and finally did hire Orr, in July 1998, to adapt his
invention to “a new detection scheme” to resolve perfor-
mance issues. J.A. 6287–93.
    In these circumstances, we do not infer suppression,
concealment, or abandonment for two reasons. First: In
making his argument in this court and in the district
court, Fleming’s position has been that his priority date is
April 14, 1999, when he filed his patent application. That
date is later than the dates of Orr’s conception (1988) and
reduction to practice (1996)—not in dispute for purposes
of the present issue. It also is later than the latest possi-
ble date—summer 1998—that the evidence establishes
Orr resumed work on his prior invention when joining
Escort. Even if the focus were solely on Orr (thus disre-
garding Escort, the patent-rights owner), and even if Orr
had abandoned his invention before summer 1998, the
defense of abandonment is properly rejected on the
ground that Orr resumed his active work before Fleming’s
April 1999 priority date. See Paulik, 760 F.2d at 1272.
    Second: Although Fleming has not made an argument
based on a pre-1999 priority date, the conclusion would
not change even if we assumed a May 1998 conception
FLEMING v. ESCORT INC.                                   13

date for Fleming (for which there is evidence). On that
assumption, the crucial period for the abandonment
analysis would be the time between Cincinnati Micro-
wave’s February 1997 bankruptcy and Orr’s July 1998
employment at Escort. But what occurred during that
period does not warrant an inference of suppression,
concealment, or abandonment. At most, there was a
reasonable pause in active work: the rights to the inven-
tion were transferred from one owner to a new owner
during a period of bankruptcy; the new owner concentrat-
ed its initial efforts on products ready for immediate sale;
and even during that period, the new owner maintained
communication with Orr and made efforts to bring him to
the firm precisely to resume the work needed to perfect
the prior invention. The delay of active work in these
circumstances was not unreasonable and was consistent
with a continuing commitment to pursuing the project to
the full extent conditions allowed. In brief, the concepts
of abandonment, suppression, and concealment do not fit
the facts as reasonably found by the jury.
                             B
    Escort, in its cross-appeal, argues that Fleming’s reis-
sue patents are invalid because there was no “error” in
the original patent, a prerequisite to obtaining a reissue
patent. “Determining whether an applicant has met the
statutory requirements of 35 U.S.C. § 251 is a question of
law, which we review de novo.” In re Clement, 131 F.3d
1464, 1468 (Fed. Cir. 1997). We reject Escort’s conten-
tion.
   The version of section 251 applicable here reads:
   Whenever any patent is, through error without
   any deceptive intention, deemed wholly or partly
   inoperative or invalid, by reason of a defective
   specification or drawing, or by reason of the pa-
   tentee claiming more or less than he had a right
   to claim in the patent, the Director shall, on the
14                                    FLEMING v. ESCORT INC.

     surrender of such patent and the payment of the
     fee required by law, reissue the patent for the in-
     vention disclosed in the original patent, and in ac-
     cordance with a new and amended application, for
     the unexpired part of the term of the original pa-
     tent.
35 U.S.C. § 251 (2006).
    Escort invokes the requirement that there have been
an “error” in the original patent. Errors are not limited to
slips of the pen but encompass—and most often are—
deliberate drafting choices. See In re Dinsmore, 757 F.3d
1343, 1347–48 (Fed. Cir. 2014). Not all choices qualify,
though: “it is important whether deficient understand-
ings, by the applicants or their agents, gave rise to the
patenting choice that reissue is being invoked to correct.”
Id. at 1348. A drafting choice that rested on “no cogniza-
ble false or deficient understanding of fact or law,” but
that was, say, an eyes-open choice made to secure the
patent, “is not ‘error’ as required by section 251.” Id. at
1347. That kind of choice is nothing but a “now-regretted
choice,” which is not error. Id. But this case does not fall
into that category.
    The asserted error here is that, when drafting his
original patent, Fleming failed to appreciate the full scope
of his invention and the inadequacy of the original claims
for properly capturing the full scope. This is a classic
reason that qualifies as error. Id. at 1348. It identifies a
deficient understanding of some combination of fact and
law bearing on the meaning of claim language, the inven-
tions disclosed in the written description, and how partic-
ular language does or does not map onto products or
processes that could be claimed under section 251 con-
sistent with the written description.
    Escort suggests otherwise by noting Fleming’s expla-
nation that he wrote his original patent from the perspec-
tive of a “programmer.” J.A. 5947, 5980. That fact,
FLEMING v. ESCORT INC.                                  15

however, in no way undermines the premise of a mistaken
understanding of the scope of the written description
and/or claims—it actually helps explain the origin of the
error. Likewise, the fact that it was marketplace devel-
opments that prompted Fleming to reassess his issued
claims and to see their deficiencies, J.A. 5926–27, 5945,
does not alter the qualifying character of the reason for
reissue. Erroneous understandings of the written de-
scription or claims are just that, regardless of what trig-
gered the recognition of error in those understandings.
    Any reissue patent, of course, must meet all of section
251’s requirements. But the only challenge presented by
Escort is the lack of “error.” That challenge is meritless.
                         CONCLUSION
    For the foregoing reasons, we affirm the district
court’s judgment upholding the jury’s verdict.
                         AFFIRMED