Cite As: Daniel J. Melman, Note, Post Markman: Claim Construction Trends, 7 RICH. J.L. & TECH. 34 (Spring 2001), at http://www.richmond.edu/jolt/v7i4/note2.html.
A. Pitney Bowes, Inc. v. Hewlett-Packard Co.
B. Elkay Mfg. Co. v. Ebco Mfg. Co.
C. Micro Chemical, Inc. v. Great Plains Chemical Co.
{1}The strength of a patent as a legal instrument to protect
an invention rests primarily on the drafting quality of its claims.
The claims of a patent recite the invention "that is deemed
by [the] applicant to be operable and patentable."[1] Furthermore, the claims define the
legal metes and bounds of an invention so that a patent owner
can prevent others from making, using, and selling[2] a patented
product in the United States for a period of twenty years from
the filing of the patent application.[3] The Supreme
Court has long held that a patent's claim, more so than any other
aspect of the patent, bears the distinction of being the sole
measure of the grant of the patent.[4]
{2}In a typical suit claiming infringement of a patent, the trial
court undertakes a two-step analysis. First, the patent
claims at issue must be properly construed, and second, the claims
must be compared to the allegedly infringing device.[5] Since a particular claim construction
is often outcome determinative in an action for infringement,
the stakes for the claim construction are very high for both the
patent owner and the accused infringer. Patent claims, however,
are made up of simple words, and the nature of language can render
words and corresponding patent claims ambiguous and open to competing
interpretations. Often attorneys for the patent owner will
try to convince the court that their interpretation of the claims
at issue is correct, while another team of attorneys for the accused
infringer will attempt to impress a contrary construction upon
the court.
{3}Prior to Markman v. Westview Instruments, Inc.,[6] Federal Circuit opinions were incongruous
as to whether claim interpretation was a factual, legal, or mixed
question of fact and law.[7] In Markman v. Westview Instruments,
Inc.,[8] the Supreme Court laid to rest the issue of whether
claim interpretation is a question of fact to be decided by the
jury or a question of law for the court. Prior to the Supreme
Court's decision, a divided Court of Appeals for the Federal Circuit
held, en banc, that claim construction is a question of
law to be decided by a judge.[9] To support
its reasoning, the Federal Circuit stated that it is a fundamental
principle of American law that "the construction of a written
evidence is exclusively with the court."[10]
Furthermore, the Federal Circuit reasoned that since a patent
is essentially a government grant of legal rights to the patentee,
the judge must define those legal rights on behalf of the government.[11] Public policy considerations also motivated
the Federal Circuit's decision. The court reasoned that judges,
rather than lay jurors, are superior appraisers in determining
the scope of patent rights because of the serious consequences
resulting from infringement.[12] In addition,
consistency motivated the Federal Circuit to support a rule that
makes claim construction the province of the judge.[13]
{4}The Supreme Court affirmed the Federal Circuit's decision,
unanimously holding that patent claim construction is a question
of law for the court to resolve and not subject to the Seventh
Amendment right to a jury trial.[14] The Court acknowledged that claim
construction "falls somewhere between a pristine legal standard
and a simple historical fact."[15] Therefore,
the Court turned to functional considerations and concluded that
"judges, not juries, are the better suited to find the acquired
meaning of patent terms."[16] Additionally,
the Court observed that requiring judges to construe patent claims
would result in greater consistency and "uniformity in the
treatment of a given patent."[17] Notably, the Supreme Court did
not address the question of the proper standard of review to be
applied by an appellate court considering the issue of claim construction.
{5}Two years later, the Federal Circuit directly addressed the
proper standard of review for claim construction. In Cybor
Corp. v. FAS Technologies, Inc., the Federal Circuit reaffirmed
earlier holdings that claim construction is entirely a matter
of law and is subject to de novo review on appeal.[18]
De novo review means that "[o]n appeal the Federal
Circuit is required to construe the claim . . . without deference
to the trial court."[19] Therefore, on appeal, a successful party
must undertake the arduous task of re-litigating the proper construction
of the patent claims.
{6}Since Markman I, the Federal Circuit has attempted to
delineate the proper analysis to be employed to interpret patent
claims.[20] In Vitronics Corp. v. Conceptronic,[21] the Federal Circuit limited references to extrinsic
evidence (such as technical treatises, prior art, dictionaries,
and expert testimony), to occasions when the claims remain ambiguous
after all intrinsic evidence (such as the claim language, the
specification,[22] and the patent's prosecution history)[23],
has been considered.[24]
{7}While it is clear that intrinsic evidence should be primarily
used in construing patent claims, district courts have been left
to resolve the vexing question of precisely how to analyze and
apply intrinsic evidence in the claim construction process, and
the equally troublesome issue of when reference to extrinsic evidence
is permissible. Virtually every Federal Circuit decision
since Markman I presents the opportunity for practitioners
and trial courts to learn how that court resolves complex claim
construction issues.
A. Pitney Bowes, Inc. v. Hewlett-Packard Co.
{8}The Federal Circuit finds the preambles of patent claims
to be highly persuasive, details the proper weight to be given
to parts of the intrinsic record, and sends a modified directive
to the district courts regarding the use of extrinsic evidence.
{9}In Pitney Bowes, Inc. v. Hewlett-Packard Co.,[25] the
Federal Circuit vacated and remanded the district court's summary
judgment of noninfringement in favor of the defendant based on
improper claim construction.[26] Pitney Bowes
("Pitney") is the assignee of United States patent 4,386,272
("'272"), entitled "Apparatus and Method for Generating
Images by Producing Light Spots of Different Sizes," which
is directed towards the technology of laser printing.[27] Laser printers operate by directing
laser light onto a photoreceptor, which is essentially the surface
of a drum covered with an electrical charge.[28]
During printing, a beam of light strikes the surface of the drum
and dissipates a small area of charge.[29] This discharged area then attracts
charged toner, which is transferred from the drum to the paper.
Hence, every image is made up of thousands of small dots of toner
particles.[30] Because of the use of similarly
sized toner dots, the edges of certain characters can have an
uneven appearance.[31] The '272 patent is meant to solve the
computer printing problem of "jaggies"–the uneven
appearance of the edges of certain printing characters–by
disclosing a method to vary the size of the toner dots.[32]
{10}The '272 patent involves attaching an intensity modulator
to the light source.[33] The intensity of the light in turn affects
the number of electrons displaced on the photoreceptor.[34] Depending on the number of electrons
displaced, the size of the exposed area generated on the photoreceptor
will vary and, thus, the size of the toner dot ultimately produced
will also vary.[35]
{11}Hewlett Packard ("HP") manufactures printers, which
use essentially the same light scanning system as the Pitney printers.
HP's printers, however, do not adjust the intensity of the light
beam, but rather, modify the pulse-width of the light beam, the
length of time that the light beam is in contact with the surface
of the photoreceptor.[36] By varying the length of time that the
beam of light remains in contact with the photoreceptor, HP's
method, likewise, varies the size of the exposed area generated
on the photoreceptor, also varying the size of the toner dot ultimately
produced. In 1995, Pitney sued HP, charging that HP's laser
printers infringed claims 1, 2, and 3 of its '272 patent.[37]
The dispute centered on the meaning of the claim limitation "spots
of different sizes."[38] HP contended that "spots" meant
spots of light generated on the photoreceptor, while Pitney argued
that "spots" meant spots of discharged area on the photoreceptor
that result from contact with the light beam.[39]
Upon examining the specification and the prosecution history,
the district court adopted HP's argument and granted HP's motion
for summary judgment of non-infringement.[40]
{12}The first three claims of the '272 patent were the only claims
at issue on appeal. Claim 1 of the '272 patent recited:
A method of producing on a photoreceptor an image of generated shapes made up of spots, comprising: directing a plurality of beams towards a photoreceptor, each beam of light generating a spot on the photoreceptor and controlling a parameter of the light beams to produce spots of different sizes whereby the appearance of smoothed edges are given to the generated shapes.[41]
{13}Claim 2 recited in part: "The method of claim 1 wherein
the parameter controlled is . . . intensity."[42]
Claim 3 recited in part: "Apparatus for producing on a photoreceptor
an image of generated shapes made up of spots, comprising: ...
generating spots of different sizes whereby the appearance of
smoothed edges are given to the generated shapes."[43]
In construing the claims de novo, the Federal Circuit analyzed
the claim language, the specification, and the prosecution history.
Starting, as it always does, with the claim language, the court
looked to the language of the preambles of Claims 1 and 3.[44] Noting that Claims 1 and 3 contain a preamble
stating claims of either a method or apparatus for "producing
on a photoreceptor an image of generated shapes made up of spots,"
the court concluded that the disputed term "spots" must
be the constituent parts that comprise the image of the desired
character on the photoreceptor.[45] The court
reasoned that the spots of light generated by the light beam could
not be the "spots" referred to in the preamble because
spots of light are transient and do not by themselves form an
image of the desired character.[46] Rather, as
the court observed, the spots of discharged area created by the
light beam, "last long enough to combine to form images of
characters and they produce those images 'on the photoreceptor.'"[47] Thus, the court found the language of
the preamble compelling and that the interpretation of the claim
phrase "spots of different sizes" referred to the spots
of discharged area on the photoreceptor as Pitney had contended,
and not the light spots generated by the light beam as HP had
argued.[48]
{14}Perhaps sensing that it might be criticized for basing its
construction on the preamble language of the claims, the Federal
Circuit defended its reliance on the preambles:
If the claim preamble, when read in the context of the entire claim, recites limitations of the claim, or, if the claim preamble is "necessary to give life, meaning, and vitality" to the claim, then the claim preamble should be construed as if in the balance of the claim.[49]
{15}The court declared that when the body of the claim fully
delineates the complete invention and its limitations, and the
preamble does not define any of the limitations, "but rather
merely states ... the purpose or intended use of the invention,
then the preamble is of no significance to claim construction."[50]
{16}Here, according to the court, the preamble states more than
the mere intended use or field of the invention. Rather,
the preamble "statement is intimately meshed with the ensuing
... claim."[51] The court observed that both independent
Claims 1 and 3 conclude with the clause "whereby the appearance
of smoothed edges are given to the generated shapes."[52] Due to the fact that this is the first
occurrence in the claim language of the phrase "generated
shapes," the court reasoned that the phrase could only "be
understood in the context of the preamble."[53]
Undoubtedly, the court also realized that, without reference to
the preamble statement, no antecedent basis would exist for the
phrase "the generated shapes" in the concluding clauses
of the body of the claims.[54] In addition, the court noted that
the term "spots" is initially recited in the preamble
to refer to the constituent parts of the image of generated shapes
produced on the photoreceptor.[55] Moreover,
"that the claim term 'spots' refers to the components that
together make up the images of generated shapes on the photoreceptor
is only discernible from the claim preamble."[56]
In instructive language to trial courts, the Federal Circuit stated
that "[i]n such a case, it is essential that the court charged
with claim construction construe the preamble and the remainder
of the claim ... as one unified and internally consistent recitation
of the claimed invention."[57] The court
then construed the remainder of the claim text in a manner consistent
with the preamble, and concluded that the "spots of different
sizes" (in the body of the claim) make up "the generated
shapes."[58] Again, the court reasoned that the transient
spots of light created by the light beam do not constitute "the
generated shapes" but, rather, the spots of light cause the
dissipation of charge on the photoreceptor creating "spots"
of discharged area, which make up "the generated shapes."[59]
{17}The Federal Circuit also addressed the district court's heavy
reliance on the written description of the '272 patent.
The court faulted the district court for placing undue reliance
on the fact that the written description used the term "spot"
forty-four times, forty-two of which referred to spots of light
generated by the light beam, not to spots of discharged area on
the photoreceptor.[60] Since inventors are instructed to use
words in the claims in the same way as in the specification, the
district court reasoned that, in view of the description, the
term "spot" in the claims also means a spot of light.[61] The Federal Circuit agreed with the district
court's "logic," noting that "the same word appearing
in the same claim should be interpreted consistently."[62] The court, however, noted that its precedent
also recognizes that a patent's written description may disclose
more than one definition of a claim term.[63]
Analyzing the written description, the court found that the description
uses the term "spot" in noticeably different ways.[64] The court observed that the portion of
the written description which uses the term "spot" to
refer to a spot of discharged area on the photoreceptor occurs
towards the end of the description, while the earlier parts of
the description use the term "spot" to refer to a spot
in the sense of a moving spot.[65] The court
reasoned that since a spot of discharged area on the photoreceptor
cannot be a moving spot, the earlier usage of the term "spot"
refers to a spot of light.[66] And since
the usage of the term "spot" in the latter portion of
the description is in the context of the "spot size"
used "to avoid roughed edges," this different usage
of the term "spot size" refers to the spots that make
up the printed characters.
{18}Proclaiming a significant rule, the court stated that "where
the language of the written description is sufficient to put a
reader on notice of different uses of a term ... it is appropriate
to depart from the normal rule of construing seemingly identical
terms in the same manner." [67] Accordingly,
the court held that the meaning of the term "spot size"
as used in the latter part of the description refers to the spot
of discharged area on the photoreceptor. [68]
{19}The district court was also persuaded by the Examiner's
addition of the modifier "light" to the patent title
during prosecution. The Federal Circuit faulted the district
court for attaching too much weight to the patent title and its
amendment. [69] The court acknowledged that Section
606.01 of the Manual of Patent Examining Procedure provides that
an Examiner may require a change in the patent title if the Examiner
determines that the title is not sufficiently descriptive of the
invention. [70] The court, however, noted that "the
purpose of the patent title is not to demarcate the precise boundaries
of the claimed invention but rather to provide a useful reference
... for future classification purposes." [71]
The court noted the scarcity of case law in which the patent title
was used to aid in claim construction and reiterated the irrelevancy
of the patent title to issues of claim construction. [72]
"Consequently, an amendment of the patent title during prosecution
should not be regarded as having the same or similar effect as
an amendment of the claims themselves by the applicant."[73] Therefore, the court stated that it was
error for the district court to place heavy reliance on the amendment
of the title.[74]
{20}Lastly, on appeal, Pitney argued that the district court erroneously
relied on extrinsic evidence to contradict the clear meaning of
the term "spots" that was apparent from the intrinsic
evidence.[75] In a very significant part of its discussion,
the Federal Circuit seemingly went out of its way to address the
propriety of the district court's use of expert testimony for
purposes of its claim interpretation analysis. The court took
this opportunity to clarify its prior Vitronics[76] decision.[77] "Vitronics does not prohibit
courts from examining extrinsic evidence, even when the patent
document is itself clear. Moreover, Vitronics does
not set forth any rules regarding the admissibility of expert
testimony into evidence."[78] Rather, the
court held that Vitronics "merely warned courts not
to rely on extrinsic evidence in claim construction to contradict
the meaning of claims discernible from ... the intrinsic evidence."
[79]
{21}The Federal Circuit noted that the use of expert testimony
could be helpful in explaining an invention.[80]
Drawing a distinction between expert testimony and extrinsic evidence
used solely to assist a court to understand the underlying technology,
and other extrinsic evidence on the proper construction of a disputed
claim term, the court stated that the latter "may only be
relied upon if the patent documents … are insufficient to
enable the [trial] court to construe disputed claim terms."[81] The court acknowledged that in addition
to interpreting the strictly legal aspects of the patent document,
a task the court stated that judges are well equipped to do, the
judge must also interpret the technical aspects of the patent
from the perspective of "one skilled in the art."[82] Accordingly, the court observed that,
while the patent file is most often sufficient to allow a judge
to decipher the underlying technical aspects of the patent, the
judge may nonetheless appropriately consult extrinsic evidence
"to ensure that [the judge's] understanding of the technical
aspects of the patent is not entirely at variance with the understanding
of one skilled in the art."[83] Here, the Federal Circuit was satisfied
that the extrinsic evidence of the "common convention"[84] was not relied upon by the district court to
contradict the meaning of the claims apparent from the intrinsic
evidence.[85]
{22}Judge Rader joined by Judge Plager offered additional views
on this issue of expert testimony in claim construction.
"Vitronics offers good counsel when it urges trial
judges to focus on the patent document ... to ascertain the scope
of patent coverage. This court, however, should refrain
from dictating a claim interpretation that excludes reliable expert
testimony."[86] Judge Rader noted that the use of expert
testimony will often benefit claim interpretation at the trial
level because it can: (1) provide a proper technical context for
the judge to understand the claims; (2) explain the import of
claim terms as understood by one skilled in the art; and (3) help
the trial judge understand the patent prosecution process, which
is not familiar to most trial courts.[87]
B. Elkay Mfg. Co. v. Ebco
Mfg. Co.
{23}The Federal Circuit held that the article "a"
can mean more than one, and that the prosecution history of an
earlier related patent applies to the construction of a subsequent
patent.
{24}In Elkay Manuf. Co. v. Ebco Manuf. Co.,[88] the
Federal Circuit was called upon to analyze intrinsic evidence
and prosecution history to interpret a disputed claim. Once
again, the Federal Circuit held that improper claim construction
led the district court to err in finding infringement.[89]
{25}Elkay Manufacturing Company ("Elkay") owns United
States patent 5,222,531 ("'531") and United States patent
5,289,855 ("'855") on "no-spill" adapters
for bottled water coolers. The adapters facilitate the insertion
of water jugs into coolers with their caps still attached, thereby
eliminating possible contamination or spilling when the bottle
is inserted into the cooler.[90] Ebco Manufacturing
Company ("Ebco") manufactures the competing WaterGuard
no spill adapter. The Ebco device comprises two concentric
tubes designed such that water flows down from the jug into the
cooler and air flows up into the bottle through the annular between
the two tubes.[91] Elkay sued Ebco, asserting that the Ebco
device infringed claims 1 and 7 of the '531 patent and claim 1
of the '855 patent.[92] The district court concluded that the
Ebco device embodied the patent limitations in both the '531 and
'855 patents through its use of concentric feed tubes and, therefore,
infringed both literally and under the doctrine of equivalents.
On appeal, the Federal Circuit reversed the district court's judgment
of infringement based on an improper claim construction.[93]
{26}Commencing its analysis with the actual words of the claim,
[94] the Federal Circuit first noted that claim 1
of the '531 patent includes the limitation: "an upstanding
feed tube ... to provide a hygienic flow path for delivering liquid
from ... and for admitting air ... into said container."[95] In addition, claim 7 of the '531 patent
includes the limitation: "an elongated feed tube ...
for admitting air into and dispensing drinking water ... from
within said ... container."[96] Lastly, claim 1 of the '855 patent
includes the limitation "an upstanding feed probe
... to provide a hygienic flow path for delivering liquid from
... and for admitting air ... into said container."[97]
The Federal Circuit initially focused on the limitation in claim
1 of the '531 patent.[98] Interpreting the limitation in claim 1
of the '531 patent, the district court concluded that, although
the claim language used the article "an," the claim
did not preclude a separation of the water and air flows as in
the Ebco device.[99] The district court also found that Elkay's
claim language did not require the intermixing of air and water
within one feed tube.[100] Based on this interpretation, the district
court concluded that Ebco's WaterGuard adapters embodied Elkay's
claim limitations.
{27}On appeal, Ebco challenged the district court's claim construction.
Ebco argued that the normal and accepted meaning of the articles
"a" and "an" in the claim limitations must
result in a construction describing one single feed tube corresponding
to a single flow path for both water and air. The Federal
Circuit rejected Ebco's argument. "While the article
'a' or 'an' may suggest 'one,' our cases emphasize that 'a' or
'an' can mean 'one' or 'more than one,' depending on the context
in which the article is used."[101] The court
agreed that, when the articles "a" and "an"
are used in connection with "feed tube" and "flow
path," the language suggests one single flow tube corresponding
to one single flow path for both liquid and air.[102]
The court, however, observed that the asserted claims use the
open term "comprising" in their transition phrases.
Accordingly, the court summarily concluded that the disputed limitation
in claim 1 was not limited to a single feed tube and a single
flow path for both air and water. Notably, unlike it has
done in similar cases, the court did not look to the specification
for guidance as to whether the patentee intended the article "a"
to have other than its ordinary accepted singular meaning.[103] Moreover, by the court's own
concession,[104] the written description militates strongly
against a finding that Elkay sought to have the article "a"
carry other than its ordinary singular meaning. The Federal
Circuits' holding in this regard, suggests that so long as the
transitional term "comprising" appears anywhere in the
claim language, a competitor cannot safely assume that the article
"a" or "an" describes a single item or element.
{28}Ebco also maintained that the written description of the '531
patent shows that the feed tube in the '531 patent must have a
single flow path for air and water. The Federal Circuit
acknowledged that the description makes numerous references to
"a feed tube" and "the feed tube."[105]
Furthermore, the court observed that the figures in the description
showed a single feed tube with a single flow path, and that the
description does not disclose a no-spill adapter incorporating
separate flow paths.[106] The court noted, however, that the written
description states that it describes a preferred embodiment of
the invention. Rejecting Ebco's argument, the court stated
that "[t]he general rule, of course, is that the claims of
a patent are not limited to the preferred embodiment, unless
by their own language."[107] Since the
language of claims 1 and 7 did not explicitly state that they
were so limited, the court refused to hold that the claims were
limited solely to the preferred embodiment disclosed in the written
description.[108]
{29}Next, the Federal Circuit focused its attention on the prosecution
history. Reiterating the importance of analyzing the prosecution
history when a court undertakes to interpret patent claims, the
court stated that "[t]he prosecution history gives insight
into what the applicant originally claimed as the invention, and
often what the applicant gave up in order to meet the Examiner's
objections."[109] The court noted an earlier Patent Office
action, where the Examiner rejected earlier versions of claims
1 and 7 of the '531 patent for obviousness.[110]
In that action, the Examiner rejected the claims based on the
Krug patent in view of the Savage patent.[111] In
a response to the Examiner's rejection, Elkay distinguished Krug:
Krug has no reservoir open at its upper end as recited in the preamble of [the claims] and, more importantly therefore, cannot possibly teach or suggest ... a flow path or "fluid passage means" for delivering liquid from said ... container into said reservoir ... and for admitting air from said reservoir ... into said container as recited in the body of each of applicants' ... claims ..." [112]
{30}The Federal Circuit reasoned that because the Krug patent
teaches the utilization of a liquid tube and a separate air tube,
Elkay's response to the Examiner's rejection gave up a construction
of its claim language that would encompass the employment of separate
tubes.[113] During the appeal, Elkay argued that
its response to the Examiner's rejection did not amend the claim
language regarding the feed tube structure and, in any event,
its response was focused on the lack of a reservoir in the Krug
patent and Savage patent.[114] Notably, Elkay's response to
the Examiner's rejection did not mention Krug's preferred embodiment
in which the air feed tube is contained within the liquid feed
tube. The absence of Krug's separate feed tubes embodiment
from Elkay's response detracts from the conclusiveness of the
Federal Circuit's finding that Elkay disavowed an interpretation
of separate feed tubes in its claim limitation of "a
flow path ..." Nonetheless, the court rejected Elkay's
argument and stated that "[a]rguments made during the prosecution
of a patent application are given the same weight as claim amendments
…[115] [I]t is the totality of the prosecution
history that must be assessed, not the individual segments of
the presentation made to the [Patent Office]."[116]
Therefore, the court concluded that it is irrelevant whether Elkay
gave up a potential claim interpretation encompassing separate
paths in an amendment or in an argument to overcome an objection
by the Examiner based on the prior art reference.[117]
{31}As to Elkay's argument that its statement distinguishing Krug
was insignificant, the Federal Circuit looked to the Examiner's
response to Elkay's statement.[118] In the
Examiner's Statement of Reasons for Allowance, the Examiner stated
that claim 7 of the '531 patent was being allowed because the
claim described a single feed tube with a single flow path for
both air and liquid:
In regard to [claim 7], the prior art of record does not teach a container support with a removable mounting means and feed tube as claimed wherein the feed tube has a passage means which both dispenses liquid from the container into the reservoir and admits air from the reservoir into the container. . . . [Liquid] feed tube 13 [in the Krug patent] does not provide a means for admitting air. Note that Krug provides a separate conduit for exterior air 27/34 in order to relieve the vacuum in [the Krug] container..."[119]
{32}In contrast to Elkay's statement distinguishing Krug, the
Examiner's response, allowing the claim, focused on Krug's use
of separate flow paths as the distinguishing feature. As
the court observed, however, Elkay did not respond to the Examiner's
allowance.[120] The court did not elaborate on how Elkay's
silence affected its analysis. Presumably, the court reasoned
that Elkay's silence evinced Elkay's acquiescence with the Examiner's
remarks and, thus, Elkay's acknowledgment that the critical distinguishing
feature overcoming a rejection based on obviousness was Krug's
use of separate flow paths and Elkay's use of a single flow path.
{33}The court, therefore, concluded that during the prosecution
history "Elkay disavowed a potential interpretation of the
feed tube limitations in claims 1 and 7 of the '531 patent that
would include separate feed tubes or flow paths for liquid and
air." [121] Accordingly, the Federal Circuit narrowly
interpreted the "feed tube" limitation in claims 1 and
7 to refer to a "single feed tube with a single flow path
for both liquid and air."[122]
{34}The court then turned its attention to the '855 patent.
The court noted that the relevant portion of the disputed limitation
in claim 1 of the '855 patent is identical to the disputed limitation
in claim 1 of the '531 patent with the sole exception that the
"feed tube" in the '531 patent is described as a "feed
probe" in the '855 patent.[123] The court,
however, dismissed this distinction.[124] Earlier in its
opinion, the court outlined the application history of the '531
patent and the '855 patent.[125] The '531
and '855 patents stemmed from the same genus.[126]
The '531 patent issued from application number 898,570, which
was filed as a continuation application of an earlier application,
number 684,642.[127] The '855 patent issued from application
number 58,639, which had been filed as a separate continuation
application of the 684,642 application after the '531 patent issued.[128] The court stated that "[w]hen
multiple patents derive from the same initial application, the
prosecution history regarding a claim limitation in any patent
that has issued applies with equal force to subsequently issued
patents that contain the same claim limitation."[129]
The court noted that application of this rule in the present case
was especially compelling because Elkay affirmatively linked the
meaning of claim 1 in the '855 patent as patterned on claims 1,
3 and 5 of the '531 patent.[130] The court
concluded that Elkay's statement during its prosecution of the
'855 patent "put competitors on clear notice of that linkage
and because the '531 and '855 patents stem from the same genus,
it is proper to consider the prosecution history of claim 1 of
the '855 patent to be an amalgam of the prosecution histories
of both patents."[131] Applying this expansive intrinsic record,
the court reached the same conclusion regarding the "feed
probe" limitation in the '855 patent as it did with respect
to the "feed tube" limitation in the '531 patent.[132]
C. Micro Chemical, Inc. v.
Great Plains Chemical Co.
{35}The Federal Circuit holds that means-plus-function claims
were wrongly narrowed by the preferred embodiment and prosecution
history.
{36}In a recent decision, the Federal Circuit was presented with
the issue of interpreting means-plus-function claims[133]
under the framework of § 112 of the Patent Code concerning
patent specifications.[134] In Micro Chemical, Inc. v. Great Plains
Chemical Co.,[135] the Federal Circuit held that the district
court improperly limited means-plus-function claims for dispensing
additives into livestock feed to the method described in the patent's
preferred embodiment, which is disclosed in the specification.
{37}Micro Chemical Inc. ("Micro Chemical") owns United
States patent 4,733,971 ("'971") relating to devices
and methods for dispensing the proper amount of additives into
livestock feed.[136] The '971 patent discloses machines and
methods for weighing, dispensing and delivering microingredients
such as vitamins and medicine into livestock feed. The '971
patent's preferred embodiment employs the "cumulative weigh"
method which uses a compartmented hopper to weigh the additives
before dispensing them into a liquid to be delivered to the livestock.[137] In the preferred embodiment, a first
storage bin is used to dispense an additive into a hopper compartment.
Then, each storage bin, in turn, pours its additive into a separate
hopper compartment. A load cell measures the cumulative
weight of the hopper and its contents. In turn, a central
processing unit uses the cumulative weight measurements from the
load cell to regulate the amount of each microingredient added.
This process continues until each chamber of the hopper contains
the precise amount of different additive.[138]
{38}Lextron, Inc. ("Lextron" and formerly Great Plains
Chemical Co.) also makes and sells microingredient feed additive
systems.[139] Originally, Lextron manufactured machines,
which used a cumulative weigh method similar to the preferred
embodiment in the '971 patent.[140] After issuance
of the '971 patent, Lextron adapted its machines to employ the
"weigh dump" method.[141] The weigh
dump method calls for dumping each additive one at a time directly
into the liquid.[142] In 1995, Micro Chemical sued Lextron
for direct infringement.[143] Following
an appeal by Micro Chemical to the Federal Circuit and a remand
back to the district for trial, the district court concluded that
Micro Chemical disavowed any coverage of the "weigh dump"
method and, therefore, Lextron did not infringe Micro Chemical's
'971 patent.[144]
{39}On appeal, the major dispute centered on the trial court's
claim construction. Two disputed limitations consisted of
the "weighing means" element in apparatus claim 74,
and a similar limitation element in apparatus claim 91.[145]
Apparatus claim 74 recites in part "weighing means for
determining the weights of selected additives dispensed by said
dispensing means from said storage means."[146]
Apparatus claim 91 recites in part "weighing means on said
support frame means for weighing predetermined weights
of said different additive concentrates dispensed into said multiple
hopper container means by said dispensing means."[147]
Initially, the Federal Circuit set out to determine whether apparatus
claims 74 and 91 contained limitations invoking application of
35 U.S.C. §112, ¶6. The court instructed that
"[i]f the word 'means' appears in a claim element in association
with a function, this court presumes that 35 U.S.C. §112,
¶6 applies."[148] "[I]f the claim itself[, however,]
recites sufficient structure, material, or acts to perform the
claimed function," this presumption collapses.[149]
The court noted that the disputed "weighing means" claim
elements in both claim 74 and claim 91 use means-plus-function
terminology and, therefore, concluded that 35 U.S.C. §112,
¶6 applies.[150] The court also reasoned that since neither
claim recites structure adequate to perform the recited function,
the presumption was unrebutted.[151]
{40}After determining that §112, ¶6 treatment applies,
the court set out to identify the structure in the specification
that performs the recited function.[152] The court, however, admonished
that "[t]he statute does not permit limitation of a means-plus-function
claim by adopting a function different from that explicitly
recited in the claim. Nor does the statute permit incorporation
of structure from the written description beyond that necessary
to perform the claimed function."[153] Setting out to determine the
function, the court reiterated that the function of a means-plus-function
element is signaled by the preposition "for."[154]
Apparatus claims 74 and 91 each recite a "weighing means
... for" performing a function.[155] Accordingly,
the court looked to the language immediately following the preposition
"for" in claims 74[156] and 91[157] and concluded
that the properly identified functions are "determining the
weights of selected additives," and "weighing predetermined
weights of said different additive concentrates" respectively.[158] Upon concluding that the claim language
specifies the function as "simply weighing the microingredient,"[159] the Federal Circuit criticized the district
court for narrowing that function to "sequential and cumulative
weighing."[160] The court noted that because the district
court adopted a narrow function for the "weighing means"
it incorrectly confined its search for the corresponding structure
in the specification.[161] In cautionary language to trial
courts, the Federal Circuit warned that "[a]n error in identification
of the function can improperly alter the identification of structure
in the specification corresponding to that function."[162]
{41}Applying step two of the analysis, the court looked to the
written description to identify the structure corresponding to
the claimed function. Noting that the specification describes
several structures corresponding to the claimed function, the
court held that "[w]hen multiple embodiments in the specification
correspond to the claimed function, proper application of §112,
¶6 ... reads the claim element to embrace each of those embodiments."[163] The court looked to the patent's summary
of the invention[164] and found a more general structure consisting
of a "weight scale means supporting the weigh hopper or supporting
the storage means."[165] The court
stated that "[t]his more general structure [sufficiently]
performs the recited function of 'determining the weights' and
'weighing predetermined weights' of [additives]."[166] Accordingly, the court held that
"weighing means" literally embraces this more general
structure.[167]
{42}Micro Chemical also alleged that Lextron had infringed method
claims 63, 93 and 94 of the '971 patent. The Federal Circuit
held that these claims were infringed whether or not interpreted
under the rubric of §112, ¶6.[168]
"Claim 63 is illustrative of the method claims," and
recites: " '[a] method of dispensing and delivering microingredient
... comprising the steps: ... dispensing predetermined weights
of selected said additive concentrates into a liquid carrier with
no substantial intermixing of the additive concentrates before
they enter the liquid carrier.'"[169] "Claim
94, however, contains a different disputed limitation: 'weighing
predetermined amounts of selected said additives, with no substantial
intermixing of the selected additives during the weighing process.'"[170] The Federal Circuit faulted the district
court for limiting the scope of these method claims to the cumulative
weigh method of the preferred embodiment.[171]
First, the Federal Circuit assumed that the disputed method claim
fell within the ambit of §112, ¶6 and stated that
under that statute "this court looks to the specification
for acts corresponding to the step-plus-function element which
are necessary to perform the recited function."[172]
Noting that the function of claim 63 followed the signal "comprising
the steps," the court looked for "all acts described
in the specification for dispensing microingredient quantities
measured by weight."[173] The court noted that the cumulative
weigh method of the preferred embodiment and another method in
an alternative embodiment, as well as the "weigh dump"
method of the prior art were all described in the specification
as sufficient methods or acts to accomplish the desired function.[174]
{43}The Federal Circuit also held that even if §112, ¶6
did not apply, the claims were nonetheless literally infringed.[175] The court stated that "[c]laim treatment
outside of the requirements of §112, ¶6 generally gives
the claims a broader scope."[176] Since §112,
¶6 did not apply, the court reasoned that the meaning of
the method claim elements is not limited to specific acts described
in the specification. The court, therefore, proceeded to
construe the claim elements in a manner to be given "their
ordinarily understood meanings in the art."[177] The court determined that the
"weigh dump" method, used by the accused Lextron device,
satisfied the ordinarily understood meaning of the limitation
elements of claim 63, 93 and 94.[178]
{44}Lastly, the Federal Circuit noted that, in narrowing the scope
of the apparatus and method claims to encompass only the cumulative
weigh system of the preferred embodiment, the district court relied
on the patentee's statements about the Brewster device
in the background section[179] and prosecution
history of the patent, as a "disavowal of the weigh dump
method."[180] The background section noted that the
Brewster system, which employed the "weigh dump" method,
was less effective than the preferred embodiment in performing
the claimed function.[181] In addition, the prosecution history
described the Brewster system in order to facilitate a comparison
by the examiner.[182] The Federal Circuit criticized the district
court for placing heavy reliance on these statements as a disavowal
of the "weigh dump" method. "[A]lthough the
applicant noted certain inefficiencies in the Brewster system,
the patent never clearly disavows the weigh dump method
as being incapable of performing the claimed functions."[183] The court observed that the applicant
of the '971 patent did not attribute the failure of the Brewster
system to the "weigh dump" method used by Brewster,
but, rather to the particular Brewster design.[184]
In so holding, the Federal Circuit cautioned trial courts to carefully
distinguish statements directed to a particular prior art device
from statements directed to a general method employed by that
device, in a patent's background section or prosecution history.
{45}Having assumed direct control over claim construction, the
Federal Circuit has, since Markman II,[185] struggled to refine the rules that
trial courts must apply in the process of claim construction.
The decisions illustrated in this Note are necessarily tailored
to the vagaries of the specific claims in dispute. Despite
the different nature of the cases, a pattern emerges in the Federal
Circuit's claim construction jurisprudence.
{46}The court has somewhat relaxed the prohibition on the use
of extrinsic evidence. It remains to be seen whether a trial
court, concededly at a disadvantage in understanding complex technical
terms, will be capable of receiving evidence to help it understand
the underlying technology and concomitantly not allow the same
extrinsic evidence to influence its interpretation of the claims.
Despite the Federal Circuit's clarification regarding the use
of extrinsic evidence, the cases illustrated in this Note demonstrate
that the court remains firm in the view that claim construction
begins with the language of the claim and with reference to the
specification and prosecution history whenever practicable.
The court also reminded the district courts and the intellectual
property bar to analyze carefully the specification, while cautioning
that the specification will not limit the express language of
the claims if that language does not call for such limitation.
{47}In addition, the Federal Circuit may be broadening the scope
of the prosecution history of a given patent. Accordingly,
patent prosecutors and litigators must not only cautiously draft
their statements to the Patent Office, but also must carefully
scrutinize correspondence from the Patent Office. Moreover,
patent prosecutors and litigators must determine whether the prosecution
history of earlier related patents might attach to subsequent
patents. The past year also revealed increasing attention
by the Federal Circuit to means-plus-function form, and the court
set strict rules for courts to determine when a claim falls within
the special construction rules of mean-plus-function claims.
{48}Patent infringement suits often turn on the particular construction
given to the claims. Therefore, as the Federal Circuit continues
to clarify and refine the law of claim construction, patent owners
and those seeking to evaluate the scope of a patent must be vigilant
in keeping apprised of post-Markman Federal Circuit case
law.
[*] J.D. Candidate, St. John's
University School of Law, 2001; B.S. Mechanical Engineering, cum
laude, Polytechnic University, 1995. The author would
like to thank his parents for their continual support; and to
thank his wife, Linda, and daughter, Lauren, for their ceaseless
love and patience.
[1] RONALD
B. HILDRETH, PATENT
LAW: A PRACTITIONER'S
GUIDE 171 (2d ed. 1993).
[2] Id.
[3] See 35 U.S.C. § 154(a)(2) (1994 &
Supp. IV 1998) (regarding the contents and term of a patent).
[4] See Aro Mfg. Co. v. Convertible Top Replacement
Co., 365 U.S. 336, 339 n.4, 340 (1961) (citing Mercoid Corp. v.
Mid-Continent Co., 320 U.S. 661, 667 (1944)).
[5] See Gen. Mills, Inc. v. Hunt-Wesson, Inc.,
103 F.3d 978, 981 (Fed. Cir. 1997) (citing Markman v. Westview
Instruments, Inc. 52 F.3d 967, 976 (Fed. Cir. 1995), aff'd
116 S.Ct. 1384 (1996)).
[6] 52 F.3d 967 (Fed. Cir. 1995) (en banc) [hereinafter
Markman I], aff'd, 517 U.S. 370 (1996).
[7] See, e.g., SSIH Equip. S.A. v.
United States Int'l Trade Comm'n, 718 F.2d 365, 371-72 (Fed. Cir.
1983) (claim construction is an issue of law); McGill Inc. v.
John Zink Co., 736 F.2d 666, 671-72 (Fed. Cir. 1984) (claim construction
encompasses inherent factual inquiries that must be decided by
a jury).
[8] 517 U.S. 370, 372 (1996) [hereinafter Markman
II], aff'g 52 F.3d 967 (Fed. Cir. 1995).
[9] See Markman I, 52 F.3d at 970-71.
[10] Id. at 978 (citing Levy v. Gadsby, 7
U.S. 180, 186 (1805)).
[11] Id.
[12] Id. at 979.
[13] Id. (stating that a patentee's competitors
should be able to ascertain the scope of the disputed claims with
a reasonable degree of certainty).
[14] See Markman II, 517 U.S. 370, 372 (1996).
[15] Id. at 388 (quoting Miller v. Fenton,
474 U.S. 104, 114 (1985)).
[16] Id. The Court stated that construing
written documents is a task for which judges are trained and often
perform. Id.
[17] Id. at 390.
[18] 138 F.3d 1448, 1451 (Fed. Cir. 1998) (en banc)
(concluding that based on "the Supreme Court's unanimous
affirmance" of the Federal Circuit's en banc judgment in
Markman II, "claim construction, as a purely legal
issue, is subject to de novo review on appeal." Markman
I, 52 F.3d 967, 979 (Fed. Cir. 1995) (en banc)).
[19] See Pall Corp. v. Hermasure, Inc., 181
F.3d 1305, 1308 (Fed. Cir. 1999) (citing Cybor Corp. v. Fas Technologies,
Inc., 138 F.3d 1448 (Fed. Cir. 1998) (en banc)).
[20] See e.g., Pall Corp. v. Hermasure, Inc.,
181 F.3d 1305 (Fed. Cir. 1999); Cybor Corp., 138 F.3d 1448
(Fed. Cir. 1998) (en banc).
[21] 90 F.3d 1576 (Fed. Cir. 1996).
[22] The specification "provides a complete
description of the operable invention and forms the basis for
the claims." Hildreth, supra note 1, at 16.
In addition, the specification is often referred to as the "description."
Id.
[23] The prosecution history records the dialogue
between the applicant and Patent Office representative, such as
correspondences, affidavits, prior art, amendments, summaries
of examiner interviews, and other documents leading to the finalized
allowance of the claims by the Patent Office. See John
R. Thomas, On Preparatory Texts and Proprietary Technologies:
The Place of Prosecution Histories in Patent Claim Interpretation,
47 UCLA L. REV. 183, 185 (1999).
[24] Vitronics Corp., 90 F.3d at 1583.
[25] 182 F.3d 1298 (Fed. Cir. 1999).
[26] Id. at 1300.
[27] Id. at 1301.
[28] Id.
[29] Id.
[30] Pitney Bowes, Inc., 182 F.3d at 1301.
[31] Id.
[32] Id.
[33] Id. at 1302.
[34] Id.
[35] Pitney Bowes, Inc., 182 F.3d at
1302.
[36] Id. at 1303.
[37] Id.
[38] Id. at 1303-04.
[39] Id. at 1303.
[40] Pitney Bowes, Inc., 182 F.3d at 1303.
The district court construed the claim phrase "spots
of different sizes" as referring to the different sized spots
of light generated by the light beam rather than to the different
sized spots of the of discharged area on the photoreceptor.
Id. at 1303-04.
[41] Id. at 1302. The language prior
to the transitionary term "comprising" constitutes the
preamble of claim 1.
[42] Id.
[43] Id. The language prior to the transitionary
term "comprising" constitutes the preamble of claim
3.
[44] Id. at 1305.
[45] Pitney Bowes, Inc., 182 F.3d at 1305.
[46] Id.
[47] Id.
[48] Id.
[49] Id.
[50] Pitney Bowes, Inc., 182 F.3d at 1305.
[51] Id. at 1306.
[52] Id. (emphasis added).
[53] Id. The preambles of claims 1 and
3 both recite: "producing on a photoreceptor an image of
generated shapes made up of spots." Id.
[54] The court's opinion did not mention the lack
of an antecedent basis.
[55] Pitney Bowes, Inc., 182 F.3d at 1306.
[56] Id. (emphasis added).
[57] Id.
[58] Id.
[59] Id.
[60] Pitney Bowes, Inc., 182 F.3d at 1310.
[61] Id.
[62] Id. (internal quotations and citations
omitted).
[63] Id. (citing Genentech, Inc. v. Wellcome
Foundation, Ltd., 29 F.3d 1555 (Fed. Cir. 1994)).
[64] Id. at 1311.
[65] Pitney Bowes, Inc., 182 F.3d at
1310-11.
[66] Id. at 1311.
[67] Id.
[68] Id.
[69] Id. at 1312.
[70] Pitney Bowes, Inc., 182 F.3d at 1312.
[71] Id.
[72] Id. The court could only find one
case where the patent title was briefly mentioned in connection
with the construction of the claims. See Exxon Chem.
Patent, Inc. v. Lubrizol Corp., 64 F.3d 1553 (Fed. Cir.
1995).
[73] Id.
[74] Id. at 1313. Because the district
court's summary judgment of non-infringement turned on its erroneous
interpretation of the claim term "spots," the Federal
Circuit vacated that judgement and remanded the case for further
proceedings in accordance with its correct interpretation of the
claims. Id. at 1314.
[75] The extrinsic evidence at issue was evidence
proffered by HP of the existence of a "common convention"
in the "digital printing field" that defines spot size
as the area of light where the light intensity exceeds a set threshold.
Pitney Bowes, Inc., 182 F.3d at 1307. The district
court adopted this extrinsic evidence in a footnote in order to
address a collateral argument made by Pitney. Id. at
1309.
[76] Vitronics Corp., 90 F.3d 1576 (Fed. Cir.
1996).
[77] Pitney Bowes, Inc. 182 F.3d at 1308.
Notably, both the Vitronics Corp. and Pitney Bowes,
Inc. decisions were authored by Judge Michel.
[78] Pitney Bowes, Inc., 182 F.3d at 1308.
[79] Id.
[80] Id.
[81] Id. at 1308-09.
[82] Id. at 1309.
[83] Pitney Bowes, Inc., 182 F.3d at 1309.
[84] See supra note 75.
[85] Pitney Bowes, Inc., 182 F.3d at 1309.
The Federal Circuit found that the district court relied upon
the intrinsic record to reach its claim interpretation, albeit
an erroneous interpretation, and adopted the extrinsic evidence
merely to address, in a footnote, a collateral argument made by
Pitney. Id.
[86] Id. at 1314.
[87] Id.
[88] Elkay Mfg. Co. v Ebco Mfg. Co., 192 F.3d 973
(Fed. Cir. 1999).
[89] Id.
[90] Id. at 975.
[91] Id.
[92] Id. at 976. See Elkay Mfg.
Co. v. Ebco Mfg. Co., No. 93-C-S106, 1998 U.S. Dist. LEXIS 10697
(N.D. Ill. July 10, 1998).
[93] Elkay Mfg. Co., 192 F.3d at 976.
[94] Id. at 977.
[95] Id. at 975-76. (emphasis added).
[96] Id. at 976. (emphasis added).
[97] Id.
[98] Elkay Mfg. Co., 192 F.3d.at 977.
The court observed that since the language of claim 1 and claim
7 was similar, its analysis would be identical.
[99] Id. at 976.
[100] Id. at 977.
[101] Id.
[102] Id.
[103] Compare North Am. Vaccine, Inc. v. Am.
Cyanamid Co., 7 F.3d 1571, 1576-77 (Fed. Cir. 1993) (looking to
the written description for guidance regarding the interpretation
of the article "a," and finding no support in the description
that the inventors intended "a" to have other than its
normal singular meaning).
[104] See infra notes 104-05 and accompanying
text (detailing the court's analysis of the written description).
[105] Elkay Mfg. Co., 192 F.3d.973,
977-78 (Fed. Cir. 1999).
[106] Id. at 977.
[107] Id. at 978 (emphasis added) (citing
Karlin Tech., Inc. v. Surgical Dynamics, Inc., 177 F.3d 968, 973
(Fed. Cir. 1999)).
[108] Id.
[109] Id. (citing Lemelson v. Gen. Mills,
Inc., 968 F.2d 1202, 1206 (Fed. Cir. 1992)).
[110] See 35 U.S.C. § 103 (1994 &
Supp. IV 1998) (outlining conditions for patentability and non-obvious
subject matter). "Even if an invention is new and useful,
to be patentable it must also be unobvious over the prior art
to a person skilled in the field of the invention." HILDRETH, supra note 1, at 91.
[111] Elkay Mfg. Co., 192 F.3d at 978.
The Krug patent teaches the use of separate liquid and air
feed tubes. Notably, the feed tube arrangement in the Ebco
devices was similar to the preferred embodiment in the Krug patent.
Savage describes an apparatus that facilitates the connection
of a liquid feed tube to a collapsible bag so that air is not
introduced into the bag when the connection is made.
[112] Id. at 978-79 (emphasis added).
[113] Id. at 979.
[114] Id.
[115] Id. (citing Standard Oil Co. v. Am.
Cyanamid Co., 774 F.2d 448, 452 (Fed. Cir. 1985).
[116] Elkay Mfg. Co., 192 F.3d at 979.
[117] Id.
[118] Id. Notably, here, the court referred
to Elkay's response to the Examiner as a "statement distinguishing
Krug on the basis of Krug's use of separate feed tubes."
Elkay's statement, however, does not mention Krug's use of separate
feed tubes. See supra note 111. The court's
opinion does not explain why it recasts the prosecution history
regarding Elkay's response to the Examiner as focused on Krug's
use of separate feed tubes.
[119] Id. (emphasis added) (quoting the Examiner's
statement of Reasons for Allowance, Mar. 30, 1993).
[120] Id.
[121] Elkay Mfg. Co., 192 F.3d at 979.
[122] Id.
[123] Id.
[124] Id. at 980. The court also noted
that the written description of the '855 patent is fundamentally
identical as the written description in the '531 patent.
Id.
[125] Id. at 975.
[126] Elkay Mfg. Co., 192 F.3d at 975.
[127] Id.
[128] Id.
[129] Id. at 980 (citing Jonsson v. The Stanley
Works, 903 F.2d 812, 817-18 (Fed. Cir. 1990). The Jonsson
court held that "prosecution history of a claim limitation
in the first patent to issue was properly applied to the same
claim limitation in the second patent to issue. Id.).
[130] Id. During the prosecution of
the 58,639 application, Elkay added a new claim, which issued
as claim 1 of the '855 patent. During that prosecution Elkay
stated that this new claim "is patterned after a combination
of claims 1, 3 and 5 of the [531 patent] with the 'feed tube'
changed to - feed probe -. . . ." Id.
[131] Elkay Mfg. Co., 192 F.3d at 980.
[132] Id. The Federal Circuit concluded
that both the feed tube limitation in claim 1 and 7 of the '531
patent and the feed probe limitation in claim 1 of the '855 patent
encompassed a single feed tube (probe) with a single a single
flow path for both liquid and air. Thus, since Ebco's WaterGuard
devices use separate feed tubes for air and water, the Federal
Circuit reversed and vacated the district court's decision and
held that Ebco's devices do not infringe the asserted claims of
Elkay's patents either literally or under the doctrine of equivalents.
See id. at 981.
[133] Generally, means-plus function claims recite
a means for carrying out a specific function, and are useful in
securing broader protection. The basis for a means clause
is established in 35 U.S.C. § 112, ¶ 6 (1994).
See HILDRETH, supra note
1, at 179.
[134] See 35 U.S.C. § 112, ¶6.
[135] 194 F.3d 1250, 1253 (Fed. Cir. 1999).
[136] Micro Chem., Inc., 194 F.3d at 1253.
[137] Id.
[138] Id.
[139] Id.
[140] Id.
[141] Micro Chem., Inc., 194 F.3d
at 1254.
[142] Id.
[143] Id. Initially, the
district court held that the '971 claims were invalid and that
the '971 "isolation" claims were uninfringed.
On appeal, the Federal Circuit reversed the district court's finding
of invalidity, upheld the finding of noninfringement and remanded
the case back to the district court for a ruling on the remaining
claims. See Micro Chem., Inc. v. Great Plains Chem.
Co., Inc., 103 F.3d 1538, 1540 (Fed. Cir. 1997).
[144] Micro Chem., Inc., 194 F.3d at 1255.
See Micro Chem., Inc., v. Great Plains Chem. Co., No. 88-z-499,
1997 U.S. Dist. LEXIS 23654, at *3-4 (D. Colo. Dec. 8, 1997).
[145] Micro Chem., Inc., 194 F.3d at 1258.
The parties had stipulated that the weighing means elements in
both claims had the same meaning.
[146] Id. at 1254. (emphasis added).
[147] Id. at 1255. (emphasis supplied).
See 35 U.S.C. §112 (1994).
[148] Id. at 1257.
[149] Id.
[150] Micro Chem., Inc., 194 F.3d at
1257.
[151] Id.
[152] See id. at 1258 ("§112, ¶6
requires both identification of the claimed function and identification
of the structure in the written description necessary to perform
that function.") Id.
[153] Id. (emphasis added).
[154] Id. at 1258.
[155] Micro Chem., Inc., 194 F.3d at 1258.
[156] Id. at 1254.
[157] Id.
[158] Id. at 1258.
[159] Id.
[160] Micro Chem., Inc., 194 F.3d at 1258.
Since it narrowed the claimed function to cumulative weighing
as stated in the preferred embodiment, the district court determined
that the function accomplished by the Lextron machine was not
identical to the function recited in the '971 patent. See
id. at 1255.
[161] Id. at 1258.
[162] Id.
[163] Id. (citing Serrano v. Telular Corp.,
111 F.3d 1578, 1583 (Fed. Cir. 1997)). Since the district
court incorrectly limited the function to "sequential and
cumulative weighing,," it had improperly restricted "weighing
means" to specific structures of the preferred embodiment
that accomplish "cumulative weighing" and erroneously
overlooked alternative embodiments of the invention. Thus,
the district court erred both by incorporating unrecited functional
limitations and by incorporating unnecessary structure beyond
that necessary to achieve the claimed function.
[164] The summary of the invention is a brief summary
of the invention and often includes the invention's nature and
substance. See HILDRETH, supra
note 1, at 159.
[165]Micro Chem., Inc., 194 F.3d at 1258 (quoting
a patent's summary of the invention).
[166] Id.
[167] Id. at 1259. The court then looked
to the accused Lextron device and found it to use a structure
encompassed within a literal interpretation of the '971 patent.
Thus, the Federal Circuit reversed the district court's decision
and held that Lextron's machines literally infringe claim 74.
With respect to claim 91, however, the court found additional
limitations. Since the accused device did not employ a structure
within the meaning of the claim language corresponding to those
additional limitations, the Federal Circuit affirmed the district
court's finding of noninfringement of claim 91. Id.
[168] See id.
[169] Micro Chem., Inc. 194 F.3d at 1256.
[170] Id. The district court concluded
that these claims were not in proper step-plus-function form.
See id. at 1256, 1259. And just as it did with apparatus
claims 74 and 91, the district court construed the method claims
as covering only the cumulative weigh method of the preferred
embodiment. See id. at 1256.
[171] Micro
Chem., Inc., 194 F.3d at
1260.
[172] Id.
at 1259.
[173] Id.
at 1259. (emphasis
added).
[174] See
id. at 1259 - 60. Accordingly,
the court concluded that the claims "encompass the weigh
dump method used by the accused device" and, therefore, were
literally infringed. Id. at 1260.
[175] Id.
at 1260.
[176] Micro
Chem., Inc., 194 F.3d at 1260.
[177] Id.
[178] Id.
at 1260. The court
observed that the "weigh dump method weighs predetermined
amounts of the microingredients and dispenses them into the liquid
carrier with no substantial intermixing of microingredients during
the weighing process." Accordingly, the Federal Circuit reversed
the district court's holding of noninfringement. Id.
[179] The
background section is composed of a brief statement concerning
the field of the invention and a description of any related and
material prior art. See Hildreth, supra note 1,
at 159.
[180] Id.
at 1260.
[181] Micro
Chem., Inc., 194 F.3d at 1260.
The background section stated that the Brewster machine "was
unsuccessful because it was too slow and too inaccurate for handling
additive concentrates in a feedlot environment." Id.
[182] Id.
[183] Id.
(emphasis added).
[184] Id.
[185] Markman
II, 517 U.S. 370 (1996).
(1) http://www.patentlawlinks.com
Provides links to statutes, regulations, case law, patent forms,
litigation resources.
(2) http://www.bitlaw.com
BitLaw is a comprehensive Internet resource focused on technology
law, containing over 1,800 pages on patent, copyright, trademark,
and Internet legal issues. BitLaw was created by Daniel A. Tysver,
a partner with the intellectual property law firm of Beck &
Tysver.
(3) http://www.patents.com
Oppedahl & Larson, LLP is a law firm offering patent, copyright,
trademark, trade secret, and other intellectual property services.
This Web server is intended to provide information about intellectual
property and about the firm.
(4) http://www.uspto.gov/web/offices/pac/doc/general/
The U.S. Patent and Trademark Office provides general information
concerning patents.
(5) http://www.abanet.org/intelprop/comm106/106general.html
ABA patent overview contains the same or similar information as
U.S. Patent and Trademark Office.
(6) http://www.law.cornell.edu/topics/patent.html
Provides an overview of materials, federal statutes, case law,
international material.
(7) http://www.richmond.edu/~jolt/v3i1/mota.html
Previous Richmond Journal of Law and Technology article. Sue Ann
Mota, Markman v. Westview Instruments, Inc: Patent Construction
Is Within The Exclusive Province Of The Court Under The Seventh
Amendment, 3 RICH. J.L. TECH.
3 (1997).
(8) http://www.escm.com/new/art/MARKMAN.html
Eckert Seamans Cherin & Mellott, LLC. Markman: Where Are We
Now?
An Update on Developments and Trends in Claim Construction. Speech
before: American Bar Association Section of Intellectual Property
Law 1999 IPL Summer Conference. June 23-27, 1999. San Francisco,
California.
(9) http://www.venable.com/tools/ip/patentclaim.html
Venable, Baetjer and Howard, LLP. George F. Pappas, "Patent
Claim Construction After Markman" summary of Markman and
subsequent developments from 1999.
(10) http://www.awd.com/library.asp?index=156
Howrey Simon Arnold & White website. Claim Interpretation
(Chapter 1); Reprinted from Patent Law Handbook 2000-2001 (West
Group), Glenn Rhodes, Editor, Howrey Simon Arnold & White,
LLP.
(11) http://www.oblon.com/Pub/seeker.php3?lipman-110.html
Steven E. Lipman & Elaine Wu, "The Pliability of the
Nose of Wax in the Post-Markman Era." This article explores
the impact of the Markman decision. In addition, the article includes
a table of significant court decisions after Markman through January
31, 1997.
(12) http://www.jurytrials.com/main.htm
Gary M. Hoffman & John A. Wasleff, "What They Really
Meant: The Aftermath of Markman and Hilton-Davis." This article
explains the decision in Markman and related cases. Further, the
article explores the Hilton-Davis decision and its impact on the
doctrine of equivalents.
(13) http://supct.law.cornell.edu/supct/html/95-26.ZO.html
This is a direct link to the decision in Markman et al. v. Westview
Instruments, Inc. et al. 517 U.S. 370 (1996).
(14) http://www.ljx.com/patents/evidence.html
Law Journal Extra! Claim Construction (& Markman). This site
has short summaries of the developments in patent construction
post-Markman in the Federal Circuit.
(15) http://www.fr.com/publis/claimmark.html
Fish & Richardson, P.C., Claim Construction in Markman Hearings:
Recent Trends and Evidentiary Considerations. This site outlines
the Markman decisions and their implications on the use of extrinsic
evidence in patent claim construction cases.
(16) http://www.finnegan.com/letters/april98.htm
FEDERAL CIRCUIT NEWS: John Albright summarizes the de novo review
of claim construction.
(17) http://www.finnegan.com/pubs/iplit/markmanclaim.htm
Markman, Claim Construction, and Webster's New World Dictionary
- Barry Webster and John Albright discuss how Markman has impacted
about several significant changes to patent litigation procedure.
(18) http://www.pgfm.com/publications/patentinfringement.html
PRESENTING THE WITNESSES UNIQUE TO A
PATENT INFRINGEMENT
ACTION - Blackstock, McMurtry, and Ragland
address the stages at which the courts may rely upon witness testimony
in a patent infringement action, the cast of witnesses that may
be called upon to present the testimony, the proper scope of the
testimony, and how to prepare a witness to present his or her
testimony most effectively.
(19) http://www.law.mercer.edu/lawreview/Articles/48209.htm
Markman v. Westview Instruments, Inc.: The Supreme Court Narrows
the Jury's Role in Patent Litigation - Criticizes how effect of
Markman is to jettison the jury from patent infringement litigation
altogether.
(20) http://www.oppenheimer.com/intprop/news/litigating_patent_defenses.pdf
Tactical Considerations and Strategies for Success in Litigating
Patent Issues - Experienced federal judges, leading litigators,
and expert patent litigation consultants offer their insights,
tips, and techniques on building a winning patent case.