This document discusses the "Bow Tie of Patent Claim Construction", which refers to the different methodologies used for construing patent claims during prosecution and litigation. During prosecution, claims are given their broadest reasonable interpretation to facilitate narrowing the claims. During litigation, claims are given a contextually narrowed interpretation based on the specification and prosecution history, and can only be broadened if legally justified. These differing methodologies serve different purposes - narrow construction during prosecution and broader construction during litigation. The document provides historical context on the development of patent claims and analyzes key court cases addressing claim construction standards.

1. The Bow Tie of Patent Claim Construction
By Andrew J. Fischer and David A. Jones
R
ecent articles have argued for harmonization of claim
construction procedures performed during the prosecu-
tion of patent applications at the United States Patent
and Trademark Office (USPTO) and during the litigation of
issued U.S. patents.1
These articles overlook the purpose and
necessity of the dual claim construction methodologies embod-
ied by the “Bow Tie of patent claim construction” (Bow Tie),
which this article explores.
The Bow Tie focuses on the comparative construction of
claims during patent application prosecution and patent litigation.
During prosecution, claim construction begins with a broad inter-
pretation and is narrowed throughout the prosecution process.2
Conversely, during litigation, the claim construction framework
begins with a contextually narrowed interpretation of the claims,
which is broadened only so far as the specification and prosecu-
tion history permit.3
When one places the two claim construction
methodologies on a timeline, the result is a visual representation of
the Bow Tie (see figure 1).
To understand the purpose and application of the Bow Tie,
this article provides a brief overview of the history of the pat-
ent claim and discusses the legal application of the Bow Tie to
patent claim construction. This article also addresses practical
considerations regarding the need for the current dual claim
construction paradigm and provides recommendations for
more clearly delineating and applying the dual claim construc-
tion methodologies during the appropriate proceeding.
A Brief History of the Patent Claim
In the beginning of U.S. patent law, there was no requirement
for a patent claim. The first Patent Act4
“vested jurisdiction to
issue patents in a Board consisting of the Secretary of State [as
head of the Board], the Attorney General, and the Secretary of
War.”5
The law was changed in 1793 to make the patent system
a de facto registration system. For example, under the Act of
1793,6
patent granting became simply a clerical function, and
patents were granted to anyone who applied and fulfilled the
formal requirements, including filing the required papers and
paying the required fee. Under this registration system, the sub-
sequent enforcement of a patent was the first time validity was
assessed. Consequently, early patent decisions often focused
on issues of validity, even at the highest appellate level.
During this time, courts in litigation struggled to determine what
was “known or used before” and what was “new.”7
For example, in
addition to a novelty requirement, courts desired certainty to deter-
mine what was novel, as opposed to inference and conjecture. In
Lowell v. Lewis, Justice Story stated that the patentee:
should distinguish, what is new and what is old in his speci-
fication, so that it may clearly appear, for what the patent is
granted. . . . If, therefore, the description in the patent mixes
up the old and the new, and does not distinctly ascertain for
which, in particular, the patent is claimed, it must be void; since
if it covers the whole, it covers too much, and if not intended
to cover the whole, it is impossible for the court to say, what,
in particular, is covered as a new invention. . . . It is, however,
sufficient, if what is claimed as new appear with reasonable cer-
tainty on the face of the patent, either expressly or by necessary
implication. But it ought to appear with reasonable certainty; for
it is not to be left to minute inferences and conjectures . . . .8
Although claims were not required, many patent applicants
voluntarily summarized their invention nonetheless. As a
result, courts began to hold inventors to their “summaries.” For
example, in Moody v. Fiske, the court stated:
It is often a serious difficulty from the obscure language of
the specification, to ascertain what is the nature and extent of
the invention claimed by the patentee. Whether his patent be
valid or not, must materially depend upon the accuracy and
distinctness with which the invention is stated. But in all cases
where the patentee claims [anything] as his own invention,
in his specification, courts of law cannot reject the claim . . . .
[W]here a patentee in his specification states and sums up the
particulars of his invention, and his patent covers them, he is
confined to such summary[.]9
Because of dissatisfaction with the registration system and
the problem of defining the nature and extent of the patented
invention from the obscure nature of the specification identi-
fied in Moody, Congress enacted a new Patent Act10
on July 4,
1836, which set forth many of the fundamental principles that
still exist in patent law today.11
Unlike the de facto registration
system of before, the Act of 1836 created a Patent Office and
assigned to it the role of patent examination. Additionally,
the Act of 1836 formally embraced the use of an invention
“summary” and, for the first time, set forth a claim require-
ment stipulating that the inventor “shall particularly specify
and point out the part, improvement, or combination, which he
claims as his own invention or discovery.”12
However, patent drafters did not embrace the formal
requirement of a patent claim. Many still desired to set forth
their invention in the specification and drawings, but not the
claim. Nevertheless, to comply with the new statute, patent
drafters often used “backfiring expressions,” such as “I claim
the invention described herein,” to explicitly incorporate the
specification or drawings into the claims.13
This was for good
reason; many of these backfiring expressions helped maintain
validity in subsequent litigation14
without holding the pat-
ent owner to a more defined, limited scope of the claims and
summary. This way the patent owner could selectively point to
sections of the specification as the “claimed” invention while
technically satisfying the statutory requirement to “particularly
specify and point out the part, improvement, or combination,
which he claims as his own invention or discovery.”15
The
sufficiency of these backfiring expressions came under attack
in 1870, when the statute was amended to read: “[H]e shall
particularly point out and distinctly claim the part, improve-
ment, or combination which he claims as his invention or
Andrew J. Fischer is a graduate of the Thomas M. Cooley Law
School and received his LL.M at the Washington College of Law,
American University. David A. Jones is an associate at Maschoff
Gilmore & Israelsen PLLC and a former patent examiner at the
United States Patent and Trademark Office. The views expressed in
this article are those of the authors and are not to be attributed to
their clients or employers. The authors would like to thank Adam
Weinacker and Rachel Jacques for their editorial assistance.
Published in Landslide Volume 4, Number 3, January/February 2012. © 2012 by the American Bar Association. Reproduced with permission. All rights reserved. This information or any portion
thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.

2. discovery.”16
Nevertheless, the use of backfiring expressions
became even more widespread following the 1870 amendment.
However, within a few years the circumvention of the
statutory claim requirement by the use of backfiring expres-
sions had become so widespread that in Ex parte Holt, USPTO
Acting Commissioner Dyrenforth finally stated, “The aim, the
end, the purpose of the claim is to point out particularly and
distinctly define the invention to be secured to the individual.
The claim is the measure of the patent and the day has passed
when the courts will search through the specification for
information which it is the very office of the claim to impart.”17
Thus, historically, there has been a strong desire to eliminate
backfiring expressions, thereby requiring the claims alone to
define the invention.
In 1926, Congress adopted the United States Code, a
codification of the existing general and permanent laws of the
United States arranged in 50 titles according to subject matter
and declared to be the prima facie evidence of the law.18
In the
early 1900s, the desire to look to the specification remained in
the form of interpreting claims “in the light of specifications
as though the words ‘substantially as described’ were incorpo-
rated in each claim.”19
Since the 1952 Act, the law has required the written
description to end with at least one claim “particularly point-
ing out and distinctly claiming the subject matter which the
applicant regards as his invention.”20
And, in 2005, the Federal
Circuit, en banc, decided Phillips v. AWH Corp., in which
the court explained that “the specification is the single best
guide to the meaning of a disputed term.”21
The court further
stated, it is “entirely appropriate for a court, when conducting
claim construction, to rely heavily on the written description
for guidance as to the meaning of the claims.”22
However,
as figure 1 illustrates, the concerns of Phillips should not be
applied to the claim construction methodology during patent
application prosecution. Rather, the concerns of Phillips are
more appropriate for the claim construction methodology dur-
ing the litigation of issued patents.23
And there are fundamental
reasons for these differences.24
The distinction between the claim construction method-
ologies in litigation and prosecution is important because,
legally, the claims are the most important part of the patent.
“The claims . . . give notice of the scope of patent protection.
The claims give notice both to the examiner at the U.S. Patent
and Trademark Office during prosecution, and to the public
at large, including potential competitors, after the patent has
issued.”25
As the Federal Circuit has said, “the name of the
game is the claim,”26
and only that which is construed to be
encompassed by the claim is allowed patent protection by the
federal government.
The Bow Tie of Modern Patent Claim Construction
Although the patent claim has evolved as a necessary tool to
place the public on notice as to the metes and bounds of patent
protection,27
it is important to understand that there is a differ-
ence between the claim construction methodology performed
during prosecution and litigation.28
More specifically, claim
construction during prosecution of a U.S. patent application
begins with the broadest reasonable interpretation,29
and the
applicant is allowed to argue and amend the claims as neces-
sary to obtain allowance of the claimed invention.30
During
litigation, however, claim construction begins with a contextu-
ally narrowed interpretation,31
and the patentee is allowed to
present evidence so as to broaden the claim scope only to the
extent that the patentee is legally entitled.32
The claim construction methodology used during patent
application prosecution at the USPTO is referred to as the
“Morris Approach,” named after the landmark Federal Circuit
case In re Morris,33
and the claim construction methodology
used during patent litigation before a tribunal is referred to as
the “Context Approach.” The Morris Approach is an interac-
tive approach between the USPTO and the applicant.34
The
USPTO has a duty to give claims the broadest reasonable
interpretation.35
“This approach serves the public interest by
reducing the possibility that claims, finally allowed, will be
given broader scope than is justified.”36
The patent applicant
provides arguments, amendments, and evidence to establish
entitlement to the patent.37
And, “[a]bsent an express [lexico-
graphic] definition in their specification, the fact that appel-
lants can point to definitions or usages that conform to their
interpretation does not make the PTO’s definition unreason-
able when the PTO can point to other sources that support its
interpretation.”38
Thus, the relevant inquiry under the Morris
Approach is whether one of ordinary skill would consider
the USPTO’s source of a broad interpretation as reasonable.
During prosecution, the Context Approach is simply not used39
because the broadest reasonable interpretation is balanced by
the ability to amend the claims.40
In both instances, the public
interest is served by the relevant methodology.41
In In re Morris, the appellant essentially argued for
application of the Context Approach, contending that the
USPTO was required “in the course of prosecution to interpret
claims in the same manner as courts are required to during
infringement proceedings.”42
The Federal Circuit rejected that
argument in stating that:
The appellants urge us to consult the specification and some of
the cited prior art, including Brown, and interpret the disputed
language more narrowly in view thereof. When read in light of
this material, according to applicants, the “true” meaning of the
phrase emerges. We decline to attempt to harmonize the appli-
cants’ interpretation with the application and prior art. Such an
approach puts the burden in the wrong place. It is the applicants’
burden to precisely define the invention, not the PTO’s.43
The appellant further argued that the Federal Circuit was
required to follow the contextual methodologies set forth in
Markman v. Westview Instruments.44
The Federal Circuit again
disagreed and stated that:
[W]e reject appellants’ invitation to construe either of the cases
cited by appellants [including Markman] so as to overrule, sub
silentio, decades old case law. . . .
Had either of the cases cited by appellants intended to make the
dramatic shift in our jurisprudence suggested by appellants one
can safely assume they would have done so explicitly. We need
not, however, rely solely on assumption or inference. Both
cases are readily distinguishable from the present case. The
first, Markman, involved an infringement suit in the district
court. This is a distinction with a difference.45
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thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.

3. Instead, the Federal
Circuit reaffirmed the
broadest reasonable
interpretation standard.46
Thus, with the exceptions
of lexicographic defini-
tions47
and the invocation
of § 112, paragraph 6,
limitations48
—in which
the specification is
properly imported into the
claims—during the Morris
Approach, the claims
are given their broadest
reasonable interpretation.
In contrast, the Context
Approach employs a bal-
ancing methodology that
considers a totality of the
evidence, with weighted
importance given to the
claims and specification,
as well as consideration
of prosecution history and extrinsic evidence.49
In Phillips, the
Federal Circuit essentially reaffirmed the contextual analysis
of Markman.50
However, as explained in Phillips, “The risk of
systematic overbreadth is greatly reduced if the court instead
focuses at the outset on how the patentee used the claim term
in the claims, specification, and prosecution history, rather
than starting with a broad definition and whittling it down.”51
Phillips rejected the dictionary based approach used in
Texas Digital Systems, Inc. v. Telegenix, Inc., to ensure that
during litigation claim construction begins with a contextually
narrowed interpretation52
and the patentee is allowed to present
evidence so as to broaden the claim scope only to the extent
that the patentee is legally entitled.53
“The problem is that if
the district court starts with the broad dictionary definition in
every case and fails to fully appreciate how the specification
implicitly limits that definition, the error will systematically
cause the construction of the claim to be unduly expansive.”54
Concerns of systematic overbreadth also exist during prose-
cution, but this is, in fact, the reason for the broadest reasonable
interpretation. Adopting the Context Approach during prosecu-
tion would result in similar unduly expansive construction of
claims—the very essence of what Phillips was trying to guard
against.55
This “Bow Tie” distinction is illustrated in figure 1.
The basis for the dual claim construction methodologies
is that during prosecution the patent applicant prefers that the
USPTO take a narrow interpretation of the patent claims to
promote allowance of the claims with minimal amendments.
During litigation the patent owner (formerly patent applicant)
desires a broad interpretation to capture additional infringing
parties while enjoying the presumption of validity. In each
instance, the public’s interest is to limit the patent applicants/
owners from obtaining more patent scope than they are right-
fully entitled in exchange for the patent right.
Starting with the key premise that the claims should cover
only the subject matter invented, the court in Phillips noted
that the “main problem”
with Texas Digital and its
dictionary usage approach
is that such approach
focuses too much on “the
abstract meaning of words
rather than on the meaning
of claim terms within the
context of the patent.”56
This “heavy reliance on
the dictionary divorced
from the intrinsic evidence
risks transforming the
meaning of the claim
term to the artisan into the
meaning of the term in the
abstract.”57
And during prosecution
the same key premise is
served by the broadest rea-
sonable interpretation: to
promote the public-notice
purpose of the patent
claim and closely define what the invention is without looking
back to the specification. That is, if claims are defined broadly
during prosecution, the key problem of systemic overbreadth
is not present because the patent examiner’s interpretation of
a claim’s term or phrase is often broader than an applicant’s
preferred interpretation set forth in the context of his or her
specification. If claims are construed more broadly than
contextually supported by the specification,58
then the problem
with the Texas Digital approach, as set forth in Phillips, is
simply not present during examination.
Thus, applying the Context Approach, as set forth in
Phillips, during ex parte examination would result in the
issuance of more patent claims because claims that would
otherwise have been rejected under the “broadest reasonable
interpretation” standard would be allowed under the nar-
row Context Approach. If the prime reason for adopting the
Context Approach during litigation was to ensure that the
claims covered only the invented subject matter, the same
rationale equates to a broad interpretation during prosecu-
tion—to ensure that the claim language issued in a patent
clearly defines the invention.59
Practical Reasons for the Bow Tie
In addition to public interest concerns, several practical differ-
ences exist between patent prosecution and patent litigation.60
First, claims can be amended during prosecution and cannot be
amended during litigation.61
This ability to amend the claims
in response to the broadest reasonable interpretation provides
the very historical context that Phillips sought to achieve.62
Second, the selective invocation of the Context Approach
tends to make the Context Approach less predictable.63
In addition, the record is created during prosecution and appli-
cation of the Morris Approach, producing the context explored
later during the Context Approach. Therefore, the intrinsic evi-
dence used in the Context Approach, in the form of prosecution
Relative
Claim
Scope
Initial
Claim
Scope
Context
Approach
Morris
Approach
Ex Parte
Examination
Inter Partes
Litigation
Filing
Date
Patent
Issuance
Time (t) (a) (b) (c) (d) (e)
Figure 1 –The BowTie of Patent Claim Construction
Published in Landslide Volume 4, Number 3, January/February 2012. © 2012 by the American Bar Association. Reproduced with permission. All rights reserved. This information or any portion
thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.

4. history, is in development during the Morris Approach.
There are also monetary, efficiency, and predictability
constraints during prosecution that are less evident during
litigation. The parties involved in litigation, including district
courts, are in a superior position to spend additional resources
and time on claim interpretation. This is because:
[t]rial judges can spend hundreds of hours reading and reread-
ing all kinds of source material, receiving tutorials on technol-
ogy from leading scientists, formally questioning technical
experts and testing their understanding against that of various
experts, examining on site the operation of the principles of
the claimed invention, and deliberating over the meaning of
the claim language.64
Conversely, patent examiners and attorneys engaged in
patent prosecution generally do not enjoy such luxuries of
time and resources on claim interpretation. In fact, the average
number of hours for an examiner to understand the claimed
invention, conduct a search for prior art, and make a first
determination of patentability is about 10 hours.65
Although it has been said that amendment during prosecu-
tion is costly, averaging between $1,920 and $3,680,66
the
cost is relatively insignificant when compared to the cost of
litigation, which averages between $3 million and $5 million,
depending on whether an appeal occurs.67
Even the invalida-
tion of patents using reexamination proceedings pales in com-
parison with the costs associated with patent litigation.68
With
about 480,000 patent applications filed each year,69
as opposed
to around 2,700 patent litigations filed and 100 cases going to
trial,70
there is a clear need for efficiency and simplification
during prosecution.71
Therefore, the claim construction methodology during pros-
ecution is further served by the inherent simplification of the
broadest reasonable interpretation and the ability to amend the
claims, in contrast to extended deliberations over the context
of the claims performed during litigation.
Recommendations
In light of the Bow Tie, the following three recommendations
are suggested:
The first recommendation—directed toward creating
a clear delineation between application of the Context
Approach and the Morris Approach—is to recognize the pur-
pose behind the dual claim construction paradigm represented
by the Bow Tie. In conjunction with this recognition, statu-
tory and common law guidance should be applied only to the
extent that it conforms to this purpose. As such, cases directed
to the Context Approach should not be followed during pros-
ecution of patent applications. Likewise, with the inequitable
conduct exception discussed in Therasense,72
cases directed to
the Morris Approach should not be followed during litigation
of issued patents.
For example, in light of the historic, legal, and practical
reasons to apply the Morris Approach discussed herein, the
USPTO should discontinue its at least implicit endorsement of
the Context Approach in its administrative guidance for prose-
cution procedure.73
Much of the case law cited in the Manual of
Patent Examining Procedure (MPEP) section 2111.01 involves
interparty litigation.74
Such case law should be reviewed and
analyzed for its compliance with the Morris Approach and the
century old prohibition against the use of backfiring expres-
sions.75
Additionally, the USPTO should revert back to the
August 2005 version of MPEP section 2111.01, in which only
“CCS Fitness Factor #1” (lexicography)76
and “CCS Fitness
Factor #4” (§ 112, paragraph 6)77
were allowed.
The second recommendation involves the two major excep-
tions to the “broadest reasonable interpretation:” (1) 35 U.S.C.
§ 112, paragraph 6, and (2) lexicographic definitions.
When drafting patent specifications, patent applicants
should first carefully consider the use of “mean plus function”
language, especially for computer implemented inventions.
Even if a patent application as filed does not initially include
any claim phrases that invoke § 112, paragraph 6, patent appli-
cants should nevertheless ensure that their specification has
sufficient disclosure such that the specification clearly links
and associates corresponding structure to a desired function.
Second, patent applicants also should carefully consider and
strategically select chosen glossaries or other explicit lexico-
graphic definitions. Regardless of whether courts eventually
adopt either the Morris Approach or the Context Approach,
lexicographic claim construction is the same for both
approaches. The use of lexicographic definitions is the easiest
and most consistent way to get the claim interpretation desired
by the patent applicant.
And, as the primary enforcer of the notice function of patent
claims, the USPTO should insist that any exception to the
broadest reasonable interpretation be explicitly made on the
record. For example, while the Context Approach allows for
implicit invocation of lexicography, it should not be allowed
under the Morris Approach. If the patent applicant desires to
use a lexicographic definition from his or her specification,
the USPTO should insist that the definition be explicitly made
clear on the record instead of its current practice of allowing
implicit lexicography.78
During examination, the applicant still
has an opportunity to amend the claims to include a desired
definition of a term or phrase if needed for patentability.
Therefore, a requirement for explicit lexicography would
provide strong support for the notice function of the claims.
Finally, the third recommendation is directed to the use of
reexamination or post grant review as the preferred methods
for invalidating issued patents. This is because, as a patent
litigation defendant, the broadest reasonable interpretation of
the Morris Approach is the ideal claim construction methodol-
ogy for invalidating an issued patent as opposed to the narrow
Context Approach claim construction. In the recent case of
Microsoft v. i4i Ltd. Partnership, the defendant, Microsoft,
argued that a “heightened standard of proof dampens inno-
vation by unduly insulating ‘bad’ patents from invalidity
challenges.”79
The U.S. Supreme Court noted in response that
“Congress has amended the patent laws to account for con-
cerns about ‘bad’ patents, including by expanding the reexami-
nation process to provide for inter partes proceedings.”80
Although reexamination is not currently available for all
potential invalidity arguments,81
as noted by Microsoft,82
had
Microsoft’s invalidity evidence qualified for reexamination,
Microsoft could have easily obtained the desired preponder-
ance of the evidence standard simply by choosing the USPTO
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thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.

5. as its invalidating venue.
In addition to the lower evidentiary standard for invalidity,
the claim construction analysis during reexamination begins
with the Morris Approach,83
where claim terms are given their
broadest reasonable interpretation as opposed to a narrow
interpretation under the Context Approach in litigation. As
a result, claims are more likely to be invalid under the broad
Morris Approach than under the narrow Context Approach
in addition to the lower evidentiary standard. For example,
during reexamination, the specification is not contextually
consulted, the prosecution history (sometimes called “prosecu-
tion disclaimer”)84
is generally not considered, and the overall
context of the patent application is once again not relevant to
the patentability inquiry. And the patent owner is once again
allowed to amend the claims to obtain a reexamination certifi-
cate of a modified claim. Thus, a specific patent claim is more
likely to be found invalid when its claim terms are assigned the
broadest reasonable interpretation of reexamination as opposed
to a contextually narrowed interpretation of litigation. n
Endnotes
1. See, e.g., Dawn-Marie Bey & Christopher Anthony Cotropia,
The Unreasonableness of the Patent Office’s “Broadest Reasonable
Interpretation” Standard, 37 AIPLA Q.J. 285, 288 (2009) (arguing for
a “consistent claim interpretation methodology throughout the patent
system”); Joel Miller, Claim Construction at the PTO—The “Broadest
Reasonable Interpretation . . .,” 88 J. Pat. & Trademark Off. Soc’y 279
(2006); Michael Risch, The Failure of Public Notice in Patent Prosecution,
21 Harv. J.L. & Tech. 179 (2007).
2. See U.S. Patent & Trademark Office, Manual of Patent
Examining Procedure § 2111 (8th ed. Rev. 8, July 2010) [hereinaf-
ter MPEP]; see also In re Carr, 297 F. 542, 544 (D.C. Cir. 1924) (“[W]e
have uniformly ruled that claims will be given the broadest interpretation
of which they reasonably are susceptible. This rule is a reasonable one, and
tends not only to protect the real invention, but to prevent needless litigation
after the patent has issued.”).
3. As the Federal Circuit described the proper approach in Phillips v.
AWH Corp.:
[a]lthough the Texas Digital line of cases permit[s] the dictionary
definition to be narrowed in some circumstances even when there is not
an explicit disclaimer or redefinition in the specification, too often that
line of cases has been improperly relied upon to condone the adoption of
a dictionary definition entirely divorced from the context of the written
description. The problem is that if the district court starts with the broad
dictionary definition in every case and fails to fully appreciate how the
specification implicitly limits that definition, the error will systematically
cause the construction of the claim to be unduly expansive. The risk of
systematic overbreadth is greatly reduced if the court instead focuses
at the outset on how the patentee used the claim term in the claims,
specification, and prosecution history, rather than starting with a broad
definition and whittling it down.
415 F.3d 1303, 1321 (Fed. Cir. 2005) (criticizing cases stemming from
Texas Digital Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193 (Fed. Cir. 2002)).
4. An Act to Promote the Progress of Useful Arts, ch. 7, 1 Stat. 109
(1790).
5. P.J. Federico, Commentary on the New Patent Act, 75 J. Pat. &
Trademark Off. Soc’y 161, 164 (1993).
6. An Act to Promote the Progress of Useful Arts; and to Repeal the
Act Heretofore Made for that Purpose, ch. 11, 1 Stat. 318 (1793).
7. Id.
8. 15 F. Cas. 1018, 1020 (D. Mass. 1817); see also McFarlane v. Price,
1 Stark. 199 (“It is essential to point out what is new and what is old. A
patent ought to inform the person who consults it what is new and what is
old. A person ought to be warned by the specification against the use of a
particular invention.”); Evans v. Eaton, 16 U.S. (3 Wheat.) 454, 518 (1818)
(Marshall, C.J.) (“In all cases where [a patentee’s] claim is for an improve-
ment on a machine, it will be encumbent on him to show the extent of his
improvement, so that a person understanding the subject may comprehend
distinctly in what it consists.”).
9. 17 F. Cas. 655, 657–58 (D. Mass. 1820); see also Whitney v.
Emmett, 29 F. Cas. 1074 (E.D. Penn. 1831) (Baldwin, J.) (“[T]he summary
is equally binding.”).
10. An Act to Promote the Progress of Useful Arts, and to Repeal All
Acts and Parts of Acts Heretofore Made for that Purpose, ch. 357, 5 Stat.
117 (1836) [hereinafter Patent Act of 1836].
11. N.J. Brumbaugh & G.S. Rafter, History and Purpose of
Claims in United States Patent Law 10 (1915) (“The obvious solu-
tion of the problem was to require the inventor to formulate his invention in
a claim or claims at the end of his description. This, the act of 1836 for the
first time positively required.”).
12. Patent Act of 1836, supra note 10, § 6.
13. See 20 W.M. Wallace White, Patent and Trade Mark Review
374 (1921).
14. See Jeanne C. Fromer, Claiming Intellectual Property, 76 U. Chi. L.
Rev. 719, 734 n.71 (2009) (noting common backfiring expression “substan-
tially as described”).
15. Patent Act of 1836, supra note 10, § 6.
16. An Act to Revise, Consolidate, and Amend the Statutes Relating to
Patents and Copyrights, ch. 230, 16 Stat. 198–217, § 26 (1870) (emphasis
added).
17. See Brumbaugh & Rafter, supra note 11, at 17 (quoting Ex parte
Holt, 29 O.G. 171 (1884)) (emphasis added).
18. See 1 U.S.C. § 204(a) (2006); cf. United States Nat’l Bank v. Indep.
Ins. Agents of Am., Inc., 508 U.S. 439, 448 (1993).
19. R.M. Hollingshead Co. v. Bassick Mfg. Co., 73 F.2d 543, 546 (6th
Cir. 1934); see also 35 U.S.C. § 112 (2006); Motion Picture Patents Co. v.
Universal Film Mfg. Co., 243 U.S. 502, 510 (1917) (“The scope of every
patent is limited to the invention described in the claims contained in it, read
in the light of the specification.”).
20. An Act to Revise and Codify the Laws Relating to Patents and the
Patent Office, and to Enact into Law Title 35 of the United States Code
Entitled “Patents,” ch. 950, 66 Stat. 792 (1952) (codified at 35 U.S.C. §§ 1
et seq. (2006)).
21. 415 F.3d 1303, 1321 (Fed. Cir. 2005) (internal quotation marks
omitted).
22. Id. at 1317.
23. See infra text accompanying notes 27–59.
24. See infra text accompanying notes 60–71.
25. Johnson & Johnston Assocs. Inc. v. R.E. Serv. Co., 285 F.3d 1046,
1052 (Fed. Cir. 2002) (en banc) (per curiam) (citations omitted).
26. In re Hiniker Co., 150 F.3d 1362, 1369 (Fed. Cir. 1998).
27. See Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1347 (Fed.
Cir. 2010) (“[Claims’] principal function, therefore, is to provide notice of
the boundaries of the right to exclude and to define limits.”).
28. See In re Am. Acad. of Sci. Tech Ctr., 367 F.3d 1359, 1369 (Fed.
Cir. 2004); In re Morris, 127 F.3d 1048, 1054 (Fed. Cir. 1997); In re Zletz,
893 F.2d 319, 321–22 (Fed. Cir. 1989).
29. See MPEP, supra note 2, § 2111; In re Horton, 54 F.2d 961
(C.C.P.A. 1932) (“For this reason we have uniformly ruled that claims will
be given the broadest interpretation of which they reasonably are suscep-
tible. This rule is a reasonable one and tends not only to protect the real
invention, but to prevent needless litigation after the patent has issued.”
(internal quotation marks omitted)); In re Am. Acad. of Sci. Tech Ctr., 367
F.3d at 1364; In re Yamamoto, 740 F.2d 1569, 1571 (Fed. Cir. 1984).
30. See In re Yamamoto, 740 F.2d at 1572 (“An applicant’s ability to
amend his claims to avoid cited prior art distinguishes proceedings before
the PTO from proceedings in federal district courts on issued patents. When
an application is pending in the PTO, the applicant has the ability to correct
errors in claim language and adjust the scope of claim protection as needed.
This opportunity is not available in an infringement action in district court.
District courts may find it necessary to interpret claims to protect only that
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thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.

6. which constitutes patentable subject matter to do justice between the par-
ties.” (citing In re Prater, 415 F.2d 1393, 1404 (1969))).
31. See Phillips v. AWH Corp., 415 F.3d 1303, 1321–22, 1333 (Fed. Cir.
2005).
32. Id. at 1321.
33. 127 F.3d 1048 (Fed. Cir. 1997).
34. See In re Morris, 127 F.3d at 1054.
35. Spring Window Fashions LP v. Novo Indus., L.P., 323 F.3d 989,
994 (Fed. Cir. 2003) (“an examiner has the duty to police claim language
by giving it the broadest reasonable interpretation” (citing In re Hyatt, 211
F.3d 1367, 1372 (Fed. Cir. 2000))).
36. In re Yamamoto, 740 F.2d 1569, 1571 (Fed. Cir. 1984).
37. See id.
38. See In re Morris, 127 F.3d at 1056.
39. Id.
40. In re Am. Acad. of Sci. Tech Ctr., 367 F.3d 1359, 1364 (Fed. Cir.
2004).
41. See id.; Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1345
(Fed. Cir. 2010) (noting the need to describe one’s invention so the public
can “understand and improve upon the invention”).
42. In re Morris, 127 F.3d at 1053.
43. Id. at 1056.
44. Id. at 1053 (citing Markman v. Westview Instruments, 52 F.3d 967
(Fed. Cir. 1995)).
45. Id. at 1054.
46. See id.
47. See id. at 1055; In re ICON Health & Fitness, Inc., 496 F.3d 1374,
1379 (Fed. Cir. 2007) (“Therefore, we look to the specification to see if it
provides a definition for claim terms, but otherwise apply a broad interpre-
tation. As this court has discussed, this methodology produces claims with
only justifiable breadth.” (citing In re Yamamoto, 740 F.2d 1569, 1571
(Fed. Cir. 1984))).
48. In re Morris, 127 F.3d at 1055; see also 35 U.S.C. § 112 (2006).
49. See Phillips v. AWH Corp., 415 F.3d 1303, 1319 (Fed. Cir. 2005);
Stephany Ann Yonker, Post-Phillips Claim Construction: Questions
Unresolved, 47 IDEA 301, 324 (2007).
50. Phillips, 415 F.3d at 1312 (stating “we reaffirm . . . today” a series
of cases laying out the basic principles of claim construction, including
Markman).
51. Id. at 1321.
52. See id. (“The problem is that if the district court starts with the broad
dictionary definition in every case and fails to fully appreciate how the
specification implicitly limits that definition, the error will systematical-
ly cause the construction of the claim to be unduly expansive.” (criticizing
Texas Digital Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193 (Fed. Cir. 2002)));
id. at 1321–22 (discussing the overbreadth of claim interpretation using
broad definitions presented in dictionaries without the narrow context of the
specification and prosecution history).
53. Cf. id. at 1317–19.
54. Id. at 1321.
55. Id.
56. Id. at 1321.
57. Id.
58. Should an interpretation of a claim term or phrase under the Context
Approach actually be broader than the examiner’s initial determination—
e.g., using a dictionary—the examiner could simply shift and use the speci-
fication as an evidentiary “source” to establish a baseline or meaning under
the broadest reasonable interpretation standard. In other words, the exam-
iner is never prevented from using the specification as a source under the
broadest reasonable interpretation standard.
59. See Risch, supra note 1, at 181–82.
60. See Therasense, Inc. v. Becton, Dickinson & Co., 593 F.3d 1289,
1300–01 (Fed. Cir. 2010) (describing the difference between the applica-
tion of the overly broad duty of candor under Rule 56 during prosecution
and the more narrowly applied requirements of inequitable conduct during
litigation).
61. In re Yamamoto, 740 F.2d 1569, 1572 (Fed. Cir. 1984) (“An
applicant’s ability to amend his claims to avoid cited prior art distinguishes
proceedings before the PTO from proceedings in federal district courts on
issued patents. When an application is pending in the PTO, the applicant
has the ability to correct errors in claim language and adjust the scope of
claim protection as needed. This opportunity is not available in an infringe-
ment action in district court.”).
62. See Phillips, 415 F.3d at 1321.
63. See R. Polk Wagner & Lee Petherbridge, Did Phillips Change
Anything? Empirical Analysis of the Federal Circuit’s Claim Construction
Jurisprudence, in Intellectual Property and the Common Law (S.
Balganesh ed., forthcoming 2012).
64. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1477 (Fed. Cir.
1998) (Rader, J., dissenting); see also Phillips, 415 F.3d at 1332 (discussing
the length of Markman hearings).
65. See U.S. Patent & Trademark Office, Request for Quote
(RFQ) and Statement of Objectives (SOO): Patent Examiners
Production Expectancy Goals Re-Assessment and Adjustment;
see also Eric B. Chen, Conflicting Objectives: The Patent Office’s Quality
Review Initiative and the Examiner Count System, 10 N.C. J.L. & Tech.
28, 31–36 (2009); Memorandum from Peggy Focarino, Deputy Comm’r for
Patents, to the Patent Examining Corps (Aug. 31, 2010), available at http://
www.popa.org/pdf/agreements/counts-counts-31aug2010.pdf (explaining
that two examiner production counts is equal to a balanced disposal and the
first count generally equates to the effort set forth in issuing a first action on
the merits).
66. Bey & Cotropia, supra note 1, at 307 n.111 (citing Am.
Intellectual Prop. Law Ass’n, Report of the Economic Survey
(2007)).
67. See Richard D. Margiano, Cost and Duration of Patent Litigation,
Managing Intell. Prop. (Feb. 1, 2009), available at http://www.
managingip.com/Article/2089405/Cost-and-duration-of-patent-litigation.
html.
68. For ex parte reexamination, the median cost of attorney fees in 2008
was $10,000; for inter partes reexamination, the median cost of attor-
ney fees in 2008 through prosecution was $55,000; through appeal to the
Appeal Board was $80,000, and through appeal to the Federal Circuit
was $188,000. Am. Intellectual Prop. Law Ass’n, Report of the
Economic Survey (2009).
69. See U.S. Patent & Trademark Office Patent Technology Monitoring
Team (PTMT), U.S. Patent Statistics Chart: Calendar Years 1963–2010,
available at http://www.uspto.gov/web/offices/ac/ido/oeip/taf/us_stat.htm.
70. See Stephan Kinsella, Patent Litigation Facts (Nov. 24, 2010),
Center for Study of Innovative Freedom, http://c4sif.org/2010/11/
patent-litigation-facts/.
71. See supra note 3; Wagner & Petherbridge, supra note 63.
72. See Therasense, Inc. v. Becton, Dickinson & Co., 593 F.3d 1289,
1300–01 (Fed. Cir. 2010). It is also important for district court judges to
understand the Bow Tie for application of the Morris Approach and the
broadest reasonable interpretation when applying the “but for” test as
opposed to a standard litigation-based Context Approach.
73. See, e.g., MPEP, supra note 2, § 2111.01 (“This means that the
words of the claim must be given their plain meaning unless the plain
meaning is inconsistent with the specification.”).
74. See id. § 2111.01 (8th ed. Rev. 6, Sept. 2007) (citing Chef Am., Inc.
v. Lamb-Weston, Inc., 358 F.3d 1371, 1372 (Fed. Cir. 2004); Phillips v.
AWH Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005) (en banc); SuperGuide
Corp. v. DirecTV Enters., Inc., 358 F.3d 870, 875 (Fed. Cir. 2004); Liebel-
Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 906 (Fed. Cir. 2004); E-Pass
Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369 (Fed. Cir. 2003); SunRace
Roots Enter. Co. v. SRAM Corp., 336 F.3d 1298, 1302 (Fed. Cir. 2003);
Brookhill-Wilk 1, LLC v. Intuitive Surgical, Inc., 334 F.3d 1294, 1298
(Fed. Cir. 2003); Altiris, Inc. v. Symantec Corp., 318 F.3d 1363, 1371
(Fed. Cir. 2003); Ex parte Technofirst S.A., No. 2009-010931 (B.P.A.I.
Mar. 5, 2010) (“While Appellant points to examples of complex poly-
nomial functions in the Specification (Reply Br. 9-11), the Examiner
is correct that Appellant has not specifically defined that term therein
(Ans. 24). However, while giving claim terms their broadest reasonable
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thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.

7. interpretation is correct and proper, such interpretations need to be
made in view of the specification. See Phillips v. AWH Corp., 415 F.3d
1303, 1316 (Fed. Cir. 2005). With such a standard, we do not find the
Examiner’s alternate interpretations to be consistent with the instant
Specification.”).
75. See Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1347
(Fed. Cir. 2010) (en banc) (“As the Supreme Court stated in admonishing
this court, we ‘must be cautious before adopting changes that disrupt the
settled expectations of the inventing community.’” (quoting Festo Corp.
v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 739 (2002)));
Brumbaugh & Rafter, supra note 11 (admonishing against the use of
backfiring expressions).
76. See MPEP, supra note 2, § 2111.01 (8th ed. Rev. 3, Aug. 2005)
(“This means that the words of the claim must be given their plain meaning
unless applicant has provided a clear definition in the specification. . . . It is
only when the specification provides definitions for terms appearing in the
claims that the specification can be used in interpreting claim language.”).
77. See id. (“There is one exception, and that is when an element is
claimed using language falling under the scope of 35 U.S.C. 112, 6th para-
graph (often broadly referred to as means or step plus function language).
In that case, the specification must be consulted to determine the structure,
material, or acts corresponding to the function recited in the claim.”).
78. See id. § 2111.01(IV) (“The specification should also be relied on
for more than just explicit lexicography or clear disavowal of claim scope
to determine the meaning of a claim term when applicant acts as his or her
own lexicographer; the meaning of a particular claim term may be defined
by implication, that is, according to the usage of the term in >the< context
in the specification.”).
79. 131 S. Ct. 2238, 2251 (2011).
80. Id. at 2252 (citing Optional Inter Partes Reexamination Procedure
Act of 1999, 113 Stat. 1501A-567, codified at 35 U.S.C. §§ 311 et seq.).
81. It is limited to “writ[ten] prior art consisting of patents or printed
publications,” 35 U.S.C. § 301, and “applied under the appropriate parts
of 35 U.S.C. 102 and 103,” see MPEP, supra note 2, § 2609 (8th ed. Rev.
8, July 2010), but does not address inventorship, best mode, sufficiency of
disclosure, indefiniteness, public use or sale prior to one year, or any of the
other challenges to patentability.
82. Microsoft, 131 S. Ct. at 2251–52.
83. In re Yamamoto, 740 F.2d 1569, 1572 (Fed. Cir. 1984).
84. See Todd R. Miller, The “Doctrine of Prosecution Disclaimer”
in Construing Patent Claims, 86 J. Pat. & Trademark Off. Soc’y 931
(2004); F.O. Richey, File Wrapper Estoppel, 23 J. Pat. & Trademark
Off. Soc’y 559 (1941).
Published in Landslide Volume 4, Number 3, January/February 2012. © 2012 by the American Bar Association. Reproduced with permission. All rights reserved. This information or any portion
thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.