Markem v . Zipher, Ltd. CV-07-06-PB 08/28/08
UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF NEW HAMPSHIRE
Markem Corp.
v. Case N o . 07-cv-0006-PB
Opinion N o . 2008 DNH 161
Zipher Ltd. and Videojet
Technologies, Inc.
MEMORANDUM AND ORDER
Markem Corporation (“Markem”), a manufacturer of thermal
transfer printers, seeks a declaratory judgment that neither
Markem nor its printers have infringed a patent held by Zipher
Ltd. (“Zipher”). In this Memorandum and Order, I construe the
relevant patent terms.
I. BACKGROUND
A. Overview of Thermal Transfer Printers
This dispute involves the tape drive systems used in
industrial thermal transfer printers. Product manufacturers use
these printers to rapidly print unique information onto
individual labels or packaging material. For example, a potato
chip manufacturer might use a thermal transfer printer to stamp
expiration dates onto a roll of flat potato chip packages before
separating the roll into individual bags and filling the bags
with potato chips.
The act of thermal transfer printing consists of pressing a
print head against an inked tape that contacts the printing
medium (the potato chip bag) and then using the print head to
selectively heat the tape, thereby transferring the desired ink
pattern to the printing medium (e.g., “BEST IF USED BY
08.29.2008”). The basic principle is similar to that of a
typewriter or dot matrix printer, except that the print head uses
heat rather than the force of the impact to transfer the ink from
the ribbon to the printing medium.
The printer may be required to operate in intermittent mode
or continuous mode, depending on how the production line is set
up in a particular factory. In intermittent mode, the printing
medium is advanced into position and remains stationary during
the printing process. In continuous mode, the printing medium
advances through the printer at a constant rate throughout the
printing process; as the printing medium moves forward, the
printing head moves with i t . Once the current sheet has been
printed, the printing head then rapidly returns to its home
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position and the printing ribbon briefly rewinds so that the
printing head is lined up with the boundary between the used and
unused sections of ribbon.
As with any industrial application, reliability is extremely
important in a thermal transfer printer. Some of the failures
that can interrupt the operation of such a printer include
excessive tape tension (which can cause the tape to break,
forcing the operator to halt the production line to respool the
tape), insufficient tape tension (which can interfere with the
printer’s ability to position the tape properly), wastage of
unused tape (which forces the operator to replace the tape spools
more frequently), and mechanical failures caused by wear and tear
on the tape drive system. Accordingly, tape drives must be
designed to maintain tape tension within an appropriate range.
For two reasons, simply rotating each spool the same number
of degrees for each printing cycle will not produce consistent
tape tension. First, even in perfect conditions, rotating a
given spool by a given number of degrees will result in a
different length of ribbon advance depending on the diameter of
ribbon on the spool. For example, a one-degree rotation of a
spool 100 mm in diameter will result in about 0.9 mm of ribbon
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advance, whereas a one-degree rotation of a spool 50 mm in
diameter will result in only about 0.4 mm of ribbon advance.
Thus, the rotation of each spool must be adjusted according to
the amount of ribbon remaining on the spool. Second, real-world
conditions can interfere with the ideal mathematical relationship
between spool diameter, spool rotation, and ribbon advance. For
example, ribbon may stretch unevenly over time, causing
unpredicted slack to develop. Additionally, if the ribbon
breaks, operators may take actions (such as taping two sections
of ribbon together or tying off the ribbon) that make it even
more difficult to measure how much ribbon remains on each spool.
B. Prior Art
The most common form of prior art relies upon a single motor
to drive the take-up spool (the spool onto which used ribbon is
taken u p ) , with tension control provided by some form of
“slipping clutch” arrangement on the supply spool (the spool from
which fresh ribbon is drawn). As the take-up motor pulls more
ribbon from the supply spool, the slipping clutch provides a
resistive force that maintains an appropriate level of tension in
the ribbon. The slipping clutch becomes less reliable, however,
as it wears out over time. Additionally, a slipping clutch
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system’s reliance on friction for tension control limits the
acceleration, deceleration, and maximum speed capability of the
ribbon transport system.
Other prior art uses two motors, with one motor driving the
ribbon in a tape-transport direction and the other functioning
solely for tension control, not ribbon advance. For example,
U.S. Patent N o . 5,366,303 (filed May 1 1 , 1993) (“Barrus”)
discloses a printer that employs a take-up motor and a supply
motor. Barrus, however, is a “pull-drag” device in that only the
take-up motor provides rotational torque in the direction of
ribbon transport; the supply motor merely provides a variable
drag on the other motor.
C. The ‘572 Patent
The patent at issue in this case, U.S. Patent N o . 7,150,572
(filed Dec. 1 9 , 2006) (“the ‘572 Patent”), discloses a tape drive
intended for use in a thermal transfer printer.
The exemplary embodiment described in the specification
consists of two stepper motors1 operating in push-pull mode. The
1
The parties agree that a “stepper motor” is an electric
motor that achieves step advance of a motor shaft.
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exemplary embodiment energizes2 both motors to drive the spools
in a tape transport direction, drives the spools to add or
subtract appropriate lengths of ribbon for tension control
purposes, uses the operation of the motors to measure tape
tension without making physical contact with the tape, and
switches easily between continuous and intermittent operation.
At issue in this case is Claim 1 , which reads as follows:
A tape drive comprising:
two motors, at least one of which is a
stepper motor;
two tape spool supports on which spools of
tape are mounted, each spool being driveable
by a respective one of said motors;
a controller adapted to control energization
of said two motors such that tape is
transported in at least one direction between
spools of tape mounted on the spool supports;
wherein the controller energizes both said motors
to drive the spools in a tape transport direction,
and
said controller calculates a length of tape to be
added to or subtracted from tape extending between
said spools in order to maintain tension in said
tape between predetermined limit values and
2
The parties agree that “energization” is the application
of electrical power to the motors, and that to “energize” means
to cause electrical power to be applied to the motors.
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controls said motors to drive the spools to add or
subtract the calculated length of tape to or from
the tape extending between said spools.
The claim chart in Appendix A identifies the terms construed
in this order and the definitions proposed by each of the
parties.3
II. CLAIM CONSTRUCTION
The words of a patent claim “are generally given their
ordinary and customary meaning.” Vitronics Corp. v .
Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996). “[T]he
ordinary and customary meaning of a claim term is the meaning
that the term would have to a person of ordinary skill in the art
in question at the time of the invention, i.e., as of the
effective filing date of the patent application.” Phillips v .
AWH Corp.,
415 F.3d 1303, 1313 (Fed. Cir. 2005).
3
The parties have proposed differing constructions of
certain other terms in the claim. Because it appears unlikely
that the differences between their respective constructions will
affect the infringement analysis, I decline to construe them at
this time. See O2 Micro Int’l Ltd. v . Beyond Innovation Tech.
Co., 521 F.3d 1351, 1362 (Fed. Cir. 2008) (“[D]istrict courts are
not (and should not be) required to construe every limitation
present in a patent’s asserted claims.”).
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To ascertain this meaning, I examine the so-called intrinsic
evidence, including the claim language, the patent specification,
and the prosecution history. Id. The claim language is a useful
starting point.
Id. “[T]he context in which a term is used in
the asserted claim can be highly instructive.” Id. at 1314.
“Differences among claims can also be a useful guide in
understanding the meaning of particular claim terms.” Id. In
addition, “claims ‘must be read in view of the specification, of
which they are a part.’” Id. at 1315 (quoting Markman v .
Westview Instruments, Inc.,
52 F.3d 9 6 7 , 979 (Fed. Cir. 1995),
aff’d,
517 U.S. 370 (1996)). In fact, the specification is
usually “‘the single best guide to the meaning of a disputed
term.’”
Id. (quoting Markman, 52 F.3d at 9 7 9 ) . Finally, the
prosecution history should also be consulted to clarify “how the
inventor understood the invention and whether the inventor
limited the invention in the course of prosecution, making the
claim scope narrower than it would otherwise be.” Id. at 1317.
Extrinsic evidence such as dictionaries, treatises, and expert
testimony may also be useful if “considered in the context of the
intrinsic evidence.” Id. at 1319.
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Although there is “no magic formula or catechism for
conducting claim construction,” id. at 1324, the Federal Circuit
has made clear that “‘[t]he construction that stays true to the
claim language and most naturally aligns with the patent’s
description of the invention will b e , in the end, the correct
construction.’” Id. at 1316 (quoting Renishaw PLC v . Marposs
Societa’ per Azioni, 158 F.3d 1243, 1250 (Fed. Cir. 1998)).
III. ANALYSIS
A. Construction of “Drive” and “Driveable”
The first claim terms that the parties have asked me to
construe are the terms “drive” and “driveable.” Markem urges me
to adopt a narrow construction of both terms in which the motor
“drives” the spool only when the motor is energized to rotate the
spool -- that i s , when the motor applies torque to the spool that
causes it to rotate. Zipher urges me to adopt a much broader
construction in which the motor “drives” the spool whenever the
motor controls the movement of the spool, regardless of whether
the motor exercises that control by applying rotational torque or
by applying a holding torque that prevents the spool from
turning. The parties base their arguments on both intrinsic and
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extrinsic evidence. Because the intrinsic evidence (consisting
of the claim itself, usage of “drive” and “driveable” within the
specification, and patent prosecution history) clearly
establishes the meaning of the disputed terms, I need not
consider the extrinsic evidence, which in any event does not
contradict my reading of the intrinsic evidence.4 See
Helmsderfer v . Bobrick Washroom Equip., Inc., 527 F.3d 1379, 1382
(Fed. Cir. 2008) (“A court may look to extrinsic evidence so long
as the extrinsic evidence does not contradict the meaning
otherwise apparent from the intrinsic record”).
1. Usage in the Claim
I first consider the claim language itself, for as a general
rule, “a claim term should be construed consistently with its
4
Zipher relies on the McGraw-Hill Dictionary of Scientific
and Technical Terms, which defines “drive” as the “means by which
a machine is given motion or power . . . or by which power is
transferred from one part of a machine to another . . .” McGraw-Hill Dictionary of Scientific and Technical Terms 616 (Sybil P.
Parker ed., 5th ed. 1994). At best, this dictionary definition
establishes that the word “drive” may carry a range of different
meanings depending on the context in which it is used. As
discussed below, however, the specification and prosecution
history show that Claim 1 of the ‘572 Patent uses the word
“drive” in a single, relatively narrow context that constrains
its meaning. Accordingly, the dictionary definition has no
effect on my analysis.
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appearance in other places in the same claim or in other claims
of the same patent.” Rexnord Corp. v . Laitram Corp., 274 F.3d
1336, 1342 (Fed. Cir. 2001); see also PODS, Inc. v . Porta Stor,
Inc.,
484 F.3d 1359, 1366 (Fed. Cir. 2007), cert. denied, 128 S .
C t . 618 (U.S. 2007). The terms “drive” and “driveable” are used
in three elements of the claim. I address each in turn.
(a) First Usage
“[T]wo tape spool supports on which spools of tape are
mounted, each spool being driveable by a respective one
of said motors . . .” (‘572 Patent, col. 2 8 , l l . 36-
38)
This usage sheds no light on the meaning of “drive,” because
it could equally support either the broad or the narrow
construction.
(b) Second Usage
“[T]he controller energizes both said motors to drive
the spools in a tape transport direction . . .” (‘572
Patent, col. 2 8 , l l . 43-44)
This usage more strongly supports Markem’s narrower
construction. When the motors “drive the spools in a tape
transport direction,” this can only mean that the motors are
actively causing the spools to rotate. It would be nonsensical,
for example, to say that the controller may energize the motors
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to hold the spools stationary “in a tape transport direction,”
because a spool cannot simultaneously rotate yet also remain
motionless. For this reason, Zipher correctly concedes that, at
least in the context of this particular usage, energizing the
motors “to drive the spools in a tape transport direction” means
to energize the motors “such that each motor turns its respective
spool in a tape transport direction.” (Opening B r . of Zipher and
Videojet on Claim Construction 26.)
Adopting this common-sense construction creates a problem
for Zipher, however, because it threatens to create an
inconsistency between various instances of “drive” within the
claim. See Wilson Sporting Goods C o . v . Hillerich & Bradsby Co.,
442 F.3d 1322, 1328 (Fed. Cir. 2006) (holding that when the same
term appears in different portions of a patent’s claims, each
instance should be given the same meaning as the others unless
the specification and prosecution history make it clear that the
term has different meanings at different portions of the claims);
Rexnord,
274 F.3d at 1342 (stating the general rule that “a claim
term should be construed consistently with its appearance in
other places in the same claim or in other claims of the same
patent”). During oral argument, Zipher argued that its
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construction of the second usage is nevertheless consistent
because the term “control” is vague enough, depending on the
circumstances, to encompass every controlled state of the spools,
whether rotating or stationary. That i s , “drive” sometimes means
control that results in rotation and sometimes means control that
prevents rotation. In support of this vague definition, Zipher
analogizes the patent’s use of “drive” to driving a car. The
phrase “driving a car toward Boston,” for example, may encompass
not only controlled forward and reverse movement, but also
controlled stops. It is accurate, for example, to describe me as
“driving” my car both when I am accelerating onto a highway
onramp and when I am idling in neutral at a stoplight.
Zipher’s analogy fails, however, because it conflates the
the motor’s relationship to the spools with the controller’s
relationship to them. When I “drive” my car, I am not directly
applying torque to the wheels. Rather, I am using the gas pedal
to send control signals to the engine. In response to these
control signals, the engine applies torque to the car tires,
causing them to accelerate or decelerate as desired. My role in
“driving” the car is thus not analogous to a motor’s role in
“driving” the spools of a thermal printer. Rather, my role as a
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car driver is most akin to that of the controller to the print
system as a whole (sending control signals to the printer motors,
but not directly applying torque to the spools), and the
relationship of the engine to the car tires is most closely akin
to the relationship of the printer motors to the spools (directly
applying torque to the spools). Zipher’s analogy works only if I
assume that the motor-spools relationship is more like the
driver-car relationship than the engine-wheels relationship. It
is not.5 Zipher’s analogy therefore offers no assistance in
construing “drive” and “driveable” as those words are used in
Claim 1 of the ‘572 Patent.
Without the aid of this flawed analogy, Zipher’s
construction would require me to give inconsistent constructions
of “drive” in different sections of the claim. Such a result
would be undesirable and should be avoided unless it is clear
from the prosecution history and specification that “drive”
should have different meanings in different parts of the claim.
5
For example, when I am idling my car in neutral at a
stoplight, I am still “driving” the car, but the engine is not
“driving” the wheels. The word “drive” has distinct meanings
when applied to my relationship to the car and when applied to
the engine’s relationship to the wheels.
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See Wilson, 442 F.3d at 1328; Rexnord,
274 F.3d at 1342. That is
not the case here. The second usage therefore supports Markem’s
construction, which introduces no such inconsistencies.
(c) Third Usage
“[S]aid controller . . . controls said motors to drive
the spools to add or subtract the calculated length of
tape to or from the tape extending between said
spools.” (‘572 Patent, col. 2 8 , l l . 45-51)
The third usage even more strongly supports the narrower
interpretation of “drive.” It is easy to understand this
sentence under Markem’s narrow construction: that i s , the
controller controls the motors to rotate the spools to add or
subtract certain lengths of tape. Replacing “drive” with
Zipher’s broad construction, however, results in the following:
the “controller . . . controls said motors to drive control the
spools to add or subtract the calculated length of tape.” If the
drafters of the ‘572 Patent had intended to give this meaning to
the claim, then one would expect them to have simply repeated the
word “control” multiple times rather than inserting “drive” as a
synonym for “control.” See Innova/Pure Water, Inc. v . Safari
Water Filtration Sys., Inc., 381 F.3d 1111, 1119 (Fed. Cir. 2004)
(“[W]hen an applicant uses different terms in a claim it is
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permissible to infer that he intended his choice of different
terms to reflect a differentiation in the meaning of those
terms.”). But they did not. Indeed, as discussed below, during
prosecution, Zipher implied that the words “drive” and “control”
each had distinct meanings. It is therefore proper to infer that
Zipher intended to differentiate the terms “drive” and “control.”
See id. This inference cuts in favor of Markem’s construction.
Thus, because two of the three instances of “drive” in the
claim better support Markem’s narrower construction, and the
remaining instance could support either construction, it is most
appropriate to adopt Markem’s narrow construction for all three
instances. See Wilson, 442 F.3d at 1328; Rexnord,
274 F.3d at
1342.
2. Usage in the Specification
The usage of “drive” and “driveable” in the specification
also supports Markem’s narrower construction. When describing
the invention and preferred embodiment, the specification uses
the terms “drive” and “driveable” in three different contexts:
driving the spools, driving the motors, and driving the ribbon.
I discuss each in turn.
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(a) Driving the Spools
Most of the references to driving the spools in the
specification could accommodate either proposed construction.
See, e.g., ‘572 Patent, col. 4 , l l . 27-30 (“[A]n exemplary
embodiment relies upon both motors which drive the two tape
spools to drive the tape during tape transport.”); ‘572 Patent,
col. 1 8 , l l . 35-38 (“[T]he exemplary embodiment relies upon . . .
the accurate control of the drive applied to the stepper motors
14 and 15 (FIG. 1 ) which drive the ribbon spools.”).
The remainder, however, support the narrow construction
rather than the broad construction. In one instance, the
specification states, “Generally the known arrangements drive
only the spool onto which ribbon is taken up (the take-up spool)
and rely upon some form of “slipping clutch” arrangement on the
spool from which ribbon is drawn (the supply spool) . . .” ‘572
Patent, col. 1 , l l . 36-40. In a slipping clutch arrangement, the
device controls the supply spool by applying a drag torque.
Thus, stating that such an arrangement “drive[s] only the spool
onto which ribbon is taken up” is nonsensical unless to “drive”
the spools requires that the motors apply rotational torque, not
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drag torque, to the spools. In another instance, the
specification states, “[I]f motor 92 is pulling, the drive
circuit 108 for that motor is enabled and therefore the rotation
angle for the spool being driven (94) is known. The drive
circuit for the motor being pulled (93) is disabled (line 104
low). Thus motor 93 acts as a generator and a back-emf is
generated across each of the motor windings . . .” ‘572 Patent,
col. 2 3 , l l . 35-40. In other words, the specification describes
a circumstance in which the take-up motor is energized to rotate
and the supply motor is de-energized. In this context, the fact
that only the take-up spool is described as being “driven”
suggests that driving a spool means actively rotating i t , not
passively or indirectly controlling its motion.
(b) Driving the Motors
When referring to driving the motors, the specification
mostly uses the term “drive” in ways that imply motion but that
do not clearly support Markem’s narrower construction. For
example, the specification states at one point, “[I]f the tape is
traveling in one direction between the spools both stepper motors
are driven in that direction, and conversely when the ribbon is
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being driven in the opposite direction both stepper motors are
driven in that opposite direction.” ‘572 Patent, col. 1 8 , l l .
39-43. The specification also states, “[W]hen the magnitude of
the difference in current falls outside an acceptable tolerance
band, the previously assumed ratio of the spool outside diameters
is adjusted, resulting in a small change in the speed at which
the two motors are driven.” ‘572 Patent, col. 2 5 , l l . 35-39.
In one instance, however, the specification states that the
motors are “driven” to apply a decelerating torque to the spools:
“[T]he supply spool motor is driven by pulses to cause
deceleration. The application of deceleration pulses to the
supply spool motor in synchronism with motor rotation is achieved
by monitoring the back-emf generated in one winding of that
motor, and then energizing that winding at an appropriate time to
apply a decelerating torque.” ‘572 Patent, col. 2 0 , l l . 1-7.
This usage is inconsistent with Markem’s construction of “drive,”
which requires that the torque be used to rotate the spools
rather than impede their rotation.
(c) Driving the Ribbon
The specification repeatedly refers to “driving” the ribbon.
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Each usage requires some kind of motion, which is consistent with
defining “drive” as “rotate.”6 For example, the specification
states, “If the clutch force is too great the ribbon transport
system may have inadequate power to drive the ribbon throughout
the range of spool diameters from a new supply roll to an empty
supply roll.” ‘572 Patent, col. 1 , l l . 61-64. It also states,
“The tape drive may be incorporated in a printing apparatus
comprising a housing, a print head mounted on a print head
support assembly which is displaceable relative to the housing in
a direction parallel to a print ribbon path along which a ribbon
is driven by the tape drive . . .” ‘572 Patent, col. 7 , l l . 35-
39.
(d) Reconciling the Usages in the Specification
Within the specification, “drive” is used in three ways:
driving the spools, driving the motors, and driving the ribbon.
6
Zipher argues that the idea of “driving the print ribbon”
is inconsistent with construing “drive” as “rotate,” because
rotating the ribbon would twist it rather than advance i t . This
argument has no merit. When the spools cause the ribbon to
advance, they do so by unwinding the ribbon from the supply spool
and winding it onto the take-up spool. It is entirely accurate
to describe these acts of winding and unwinding as “rotating” the
ribbon, because the ribbon is in fact rotating on axes
perpendicular to the direction of ribbon advance.
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The only usages directly relevant to the claim’s usage of “drive”
or “driveable,” however, are those in which the specification
describes driving the spools. And when the specification uses
“drive” to refer to the spools, it supports Markem’s narrower
construction of rotating the spools rather than merely
controlling them.
Although “drive” can sometimes mean something other than
“rotate” when applied to subjects other than the spools, I give
this fact less weight because of the difference in subject. As
explained above, just as “driving” a car is different from
“driving” the wheels of a car, “driving” the spools may differ
from “driving” the motors or the ribbon. Accordingly, I find
that the specification weighs in favor of adopting Markem’s
construction of “drive” and “driveable.”
3. Prosecution History
During prosecution, application claim 68 is the claim that
eventually became patent claim 1 . Markem and Zipher disagree,
however, on the significance of various amendments to application
claim 68 and the relevance of the Examiner’s decision to reject
certain other claims on which application claim 68 originally
depended. For that reason, I discuss the amendments in some
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detail below.
When first submitted to the Examiner on December 1 3 , 2005,
application claim 68 read:
A tape drive as in claim 64 or 65 wherein:
said controller calculates a length of tape to be added
to or subtracted from tape extending between said
spools in order to maintain tension in said tape
between upper and lower limit values and then controls
said motors to add or subtract the calculated length of
tape to the tape extending between said spools.
(M012552-53.7)
On April 1 7 , 2006, the Examiner rejected eleven of the
application claims, including claims 64 and 6 5 , as anticipated by
Barrus, a prior art ribbon motor controller that employed a dual
motor pull-drag system. (M011659); see U.S. Patent N o . 5,366,303
(filed Nov. 2 2 , 1994) (“Barrus”). The Examiner noted, however,
that application claim 68 would be allowable “if rewritten in
independent form including all of the limitations of the base
claim and any intervening claims.” (M011663.)
On July 6, 2006, Zipher significantly altered the scope of
application claim 68 by amending it as follows:
7
Because both of the parties use the Bates-numbered pages
of Exhibit 4 to Markem’s Opening Claim Construction Brief when
referring to the prosecution history, I do so as well.
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A tape drive as in claims 64 or 65 wherein comprising:
two motors, at least one of which is a stepper
motor;
two tape spool supports on which spools of tape
may be mounted, each spool being drivable by a
respective one of said motors;
a controller adapted to control energization of
said two motors such that tape is transported in at
least one direction between spools of tape mounted on
the spool supports;
wherein the controller energizes both said motors
to drive the spools in a tape transport direction, and
said controller calculates a length of tape to be
added to or subtracted from tape extending between said
spools in order to maintain tension in said tape
between upper and lower predetermined limit values and
then controls said motors to add or subtract the
calculated length of tape to or from the tape extending
between said spools. (M011644-45.)
The newly-added language largely tracked the wording of the
rejected claims 64 and 6 5 , except that the fourth element
(“wherein the controller energizes both said motors to drive the
spools in a tape transport direction”) omitted the phrase “push-
pull.”8
Concurrent with this amendment to application claim 6 8 ,
Zipher traversed the Examiner’s rejection of the other related
claims. (M011650.) Zipher argued that these claims were
8
Claims 64 and 65 specified that the controller energized
the motors “so as to push-pull drive the spools in a tape
transport direction . . .” (M012552.)
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distinguishable from Barrus because “the claims require that the
controller is operative to energize both motors to drive the
spools of tape in the direction of tape transport,” whereas
Barrus teaches “that only one of the motors is energized to drive
a spool of tape in the direction of tape transport [with] the
other being controlled to provide drag.” (M011650-51.)
In September 2006, Zipher and the Examiner continued to
discuss whether the patent was sufficiently distinct from Barrus.
The Examiner’s interview summary from the September 6, 2006,
interview states:
Discussed the differences between the instant invention
and the applied prior art. Especially the feature
regarding “the controller is operative to energize both
motors to drive the spools of tape in the direction of
tape transport”. [sic] Further consideration and/or
search will be made regarding the amended claim 6 8 .
(M011638.)
The Examiner’s interview summary from the September 7 , 2006,
interview states:
Discussion regarding the status of claim 68 and
additional languages have been disscused [sic] between
the Examiner and M r . Nelson to more clearly defines
[sic] the scope of claim 6 8 . The amended languages
have been agreed to and M r . Nelson has authorized the
Examiner to do the Examiner’s Amendment. (M011623.)
Zipher’s interview summary, encompassing both interviews, offers
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a somewhat different characterization of what concerns the
Examiner expressed and the purpose of his amendments. Although
the Examiner’s interview summaries name no specific claims other
than claim 68 and do not draw distinctions between the Examiner’s
concerns regarding claim 68 and his concerns regarding the other
claims, Zipher’s interview summary states that the discussions
focused on “the patentability of the claims (primarily
independent claim 4 ) with respect to the Barrus Patent” and
“minor changes to claim 68 to improve the style of the claim.”
(M011629-30.)
Ultimately, the Examiner amended the application with
Zipher’s consent to cancel several claims (including claim 4 ) and
amend claim 68 as follows:
A tape drive comprising:
two motors, at least one of which is a stepper
motor;
two tape spool supports on which spools of tape
may be mounted, each spool being drivable by a
respective one of said motors;
a controller adapted to control energization of
said two motors such that tape is transported in at
least one direction between spools of tape mounted on
the spool supports;
wherein the controller energizes both said motors
to drive the spools in a tape transport direction, and
said controller calculates a length of tape to be
added to or subtracted from tape extending between said
spools in order to maintain tension in said tape
-25-
between predetermined limit values and controls said
motors to drive the spools to add or subtract the
calculated length of tape to or from the tape extending
between said spools. (See M011621.)
As his reason for allowance, the Examiner stated:
Claims 68 and 72 have been indicated for allowance
because the prior art fails to teach the combination of
a tape drive including a controller calculates a length
of tape to be added to or subtracted from tape
extending between the spools in order to maintain
tension in the tape between predetermined limit values
and controls the motors to drive the spools to add or
subtract the calculated length of tape to the tape
extending between the spools. (M011621.)
Zipher claims that this prosecution history shows that only
the other application claims, not claim 6 8 , were rejected in
favor of Barrus. Zipher further argues that any amendments to
application claim 68 were purely for stylistic purposes rather
than to escape rejection, and that the prosecution history
therefore provides no assistance in construing the claim. I find
this interpretation of the prosecution history unpersuasive,
because the only support for it comes from Zipher’s own self-
serving interview summaries. Nothing in the Examiner’s own
summaries or the other communications contained in the
prosecution history suggests that the amendments in question were
purely stylistic in nature or that the Examiner’s discussions of
-26-
Barrus were irrelevant to application claim 6 8 . Faced with the
choice between relying upon Zipher’s self-serving summary or
relying upon the Examiner’s summaries, I choose the latter. See
Moleculon Research Corp. v . CBS, Inc., 793 F.2d 1261, 1270 (Fed.
Cir. 1986) (holding that documents submitted by the patentee
during prosecution may be considered for claim interpretation
purposes, but “might very well contain merely self-serving
statements which likely would be accorded no more weight than
testimony of an interested witness or argument of counsel.
Issues of evidentiary weight are resolved on the circumstances of
each case.”).
Markem argues that the prosecution history shows that the
final amendment to claim 68 was made to avoid Barrus. Markem’s
argument proceeds in two steps: first, that the arguments Zipher
made to distinguish the rejected claims from Barrus rely upon a
narrower definition of “drive” than the one Zipher now adopts;9
9
Markem is not asserting prosecution disclaimer, see Omega
Eng’g, Inc. v . Raytek Corp., 334 F.3d 1314, 1324 (Fed. Cir. 2003)
(“[W]here the patentee has unequivocally disavowed a certain
meaning to obtain his patent, the doctrine of prosecution
disclaimer attaches and narrows the ordinary meaning of the claim
congruent with the scope of the surrender.”), but rather arguing
that the amendment should be construed in light of Zipher’s
arguments to distinguish Barrus.
-27-
and second, that the similarities between claim 68 and the
rejected claims adequately support the inference that the
Examiner’s amended claim 68 to avoid Barrus.
When Zipher was applying for the patent, it sought to
distinguish Barrus by claiming that its invention energizes “both
motors to drive the spools of tape in the direction of tape
transport,” whereas Barrus energizes only one motor “to drive a
spool of tape in the direction of tape transport [with] the other
being controlled to provide drag.” (M011650-51) (emphasis
added). As Markem points out, this argument contrasts the term
“drive” with the term “control” to signify the key difference
between the ‘572 Patent and Barrus: rather than using both motors
to actively rotate the spools together for a combination of tape
advance and tension control, Barrus uses one motor to actively
rotate the spools and the other only to apply a resistive torque
for tension control purposes.10 Zipher’s use of this linguistic
10
Barrus discloses a pull-drag device in which the take-up
motor provides a pulling torque in the direction of tape
transport and the supply motor provides a variable drag torque
purely for tension control purposes. Barrus, col. 3 , l l . 32-37.
This drag torque is supplied by a de-energized supply motor in
which the controller adjusts the drag torque by use of either
resistor combinations or a variable impedance amplifier. Id.,
col. 4 , l l . 5-15.
-28-
contrast to distinguish Barrus is inconsistent with the idea that
“drive” could include the use of a holding torque as well as
active rotational torque.11
The more difficult question, however, is whether this
inconsistency guided the Examiner’s decision to add the phrase
“drive the spools to” in claim 6 8 . Markem argues that it did.
The Examiner’s September 6 interview summary states that they
discussed distinguishing the prior art from “the instant
invention,” and specifically references language from claim 4
that is extremely similar to the language of claim 6 8 . The
summary also states that the Examiner will give further
consideration to claim 6 8 . Nothing about this suggests that he
considered the issues raised by claim 68 to be distinct from
those raised by the analogous language in claim 4 . Similarly,
the Examiner’s September 7 interview summary states that the
11
During oral arguments, Zipher argued that the prior art
was distinguished based on the difference between controlling the
tape for tape advance purposes (“drive”) and controlling the tape
for tension control purposes (“control”). This attempted gloss
on the prosecution history is unconvincing, however, because it
would make the use of the term “drive” misleading or wrong in the
context of the patented device, which uses motorized advance in
the direction of tape transport for both tape advance and tension
control purposes.
-29-
interview dealt with “[d]iscussion regarding the status of claim
68 and additional languages,” which suggests that the Examiner’s
concerns related to all of the claims then extant, including
claim 6 8 . Nevertheless, the Examiner’s interview summary is
hardly a model of clarity; he never specifies the precise reasons
for the amendment to claim 6 8 . Accordingly, the most that can be
said about the history of amendments to the other claims is that
it leaves unchanged my construction of “drive” and “driveable” in
patent claim 1 as derived from the other intrinsic evidence. See
N . Telecom Ltd. v . Samsung Elecs. Co., 215 F.3d 1281, 1295 (Fed.
Cir. 2000) (“The plain and ordinary meaning of claim language
controls, unless that meaning renders the claim unclear or is
overcome by a special definition that appears in the intrinsic
record with reasonable clarity and precision.”).
4. Reconciling the Claim Language, Specification
Language, and Prosecution History
Based on the foregoing, the claim language supports Markem’s
interpretation, as does the most relevant language from the
specification. Additionally, the prosecution history, though
informing my discussion of the claim language, does not cut
strongly in either direction. Accordingly, I adopt Markem’s
-30-
construction and construe “drive” and “driveable” to mean,
respectively, “rotates” and “rotateable.”
C. Whether the Patent Requires Touchless Tension Measurement
Markem argues that the phrase “said controller calculates a
length of tape to be added to or subtracted from tape extending
between said spools in order to maintain tension in said tape
between predetermined limit values” should be construed to
require that the device measure tension in the tape, and that it
do so without contacting the tape. (Markem Corp.’s Opening Claim
Construction B r . 27.) Zipher argues that it would be improper to
add such limitations because this would be an improper
importation of limitations from the preferred embodiment into the
claims.
As a general rule, it is improper to read in limitations
from the specification that do not appear in the claim.
SuperGuide Corp. v . DirecTV Enters., Inc., 358 F.3d 8 7 0 , 875
(Fed. Cir. 2004) (“Though understanding the claim language may be
aided by the explanations contained in the written description,
it is important not to import into a claim limitations that are
not a part of the claim.”). As the Federal Circuit succinctly
put it over twenty years ago, “Specifications teach. Claims
-31-
claim.” SRI Int’l v . Matsushita Elec. Corp. of Am., 775 F.2d
1107, 1121 n.14 (Fed. Cir. 1985). Markem argues, however, that
the measurement of tension is a necessary and inherent predicate
for maintaining the tape tension within predetermined limits
because the controller cannot calculate an appropriate length of
tape to add or subtract for tension correction purposes without
first knowing the existing tension in the tape. Markem further
argues that using a contactless means of tension measurement that
occurs during the rotation of both motors is a necessary and
inherent aspect of such measurement because the specification
does not describe any other method of such measurement.
Markem cites Honeywell International, Inc. v . Universal
Avionics Systems Corp., 488 F.3d 982 (Fed. Cir. 2007), and
Network Commerce, Inc. v . Microsoft Corp.,
422 F.3d 1353 (Fed.
Cir. 2005), to support its two related arguments. In Honeywell,
the Federal Circuit construed a patent directed at terrain
warning systems that help airplane pilots avoid collisions with
mountains and hillsides.
488 F.3d at 989. In particular, the
court relied upon the specification to determine that the term
“look ahead distance” in the claim included both speed and time
components, even though the claim included no limitations
-32-
regarding the time component. Id. at 990. Reading this time
component into the definition was appropriate, the court held,
because the entire concept of a look ahead distance requires that
both speed and time and be taken into account.
Id. In
Microsoft, the Federal Circuit construed a patent directed at the
purchasing of software and audio files over a computer network.
422 F.3d at 1355. The court relied on the specification to
construe the term “download component” in the claim, which was
not a term of art and was not defined anywhere in the claim.
Id.
at 1360-61. The specification made it “clear that the download
component must include a boot program, and that the boot program
interacts directly with the operating system of the computer . .
. .”
Id. Consequently, the court held, it was appropriate to
read these attributes into the definition of “download
component.”
Id. at 1361.
As to the measurement of tension, I find that some method of
deriving a tension measurement, whether directly or indirectly,
is a necessary predicate to maintaining tension “between
predetermined limit values.” ‘572 Patent, col. 2 8 , l l . 47-48.
Without having a reasonable estimate of the current tape tension,
it is not possible to identify whether the tension is approaching
-33-
or exceeding the limit values. I do not find, however, that the
patent claims any particular means of measuring or estimating the
tape tension. The mere fact that the preferred embodiment uses a
touchless method of tension measurement does not require that I
read that method into the claim. See SuperGuide, 358 F.3d at 875
(“[A] particular embodiment appearing in the written description
may not be read into a claim when the claim language is broader
than the embodiment.”). This is particularly true when, as here,
nothing in the claim itself suggests any particular method of
tension measurement. See Storage Tech. Corp. v . Cisco Sys.,
Inc., 329 F.3d 823, 831 (Fed. Cir. 2003) (“[T]here is sometimes a
fine line between reading a claim in light of the written
description and relevant prosecution history, and reading a new
limitation into the claim. However, interpreting what is meant
by a word in a claim is not to be confused with adding an
extraneous limitation . . . , which is improper.” (internal cites
and quotations omitted)).
D. Whether the Patent Claims Only a Dual-Spool Correction Step
Markem argues that the phrase “said controller . . .
controls said motors to drive the spools to add or subtract the
calculated length of tape to or from the tape extending between
-34-
said spools” should be construed to require that both spools
rotate together during tension correction. In support of this
construction, Markem points to language in the specification
describing the preferred embodiment. The claim language itself,
however, is ambiguous enough to encompass either one motor
driving a single spool or both motors driving the spools
together. I decline to import this limitation from the preferred
embodiment into the claim. See SuperGuide, 358 F.3d at 875.
Accordingly, I find that the claim does not require that both
spools rotate together during the correction step.
IV. CONCLUSION
For the foregoing reasons, I construe “drive” and
“driveable” to mean, respectively, “rotate” and “rotateable.” I
further construe the phrase “said controller calculates a length
of tape to be added to or subtracted from tape extending between
said spools in order to maintain tension in said tape between
predetermined limit values” to require the derivation of a
tension measurement or estimate, but without claiming any
particular means of doing s o . Finally, I construe the phrase
“said controller . . . controls said motors to drive the spools
-35-
to add or subtract the calculated length of tape to or from the
tape extending between said spools” to require that at least one
spool rotate during the correction step, but not necessarily both
spools.
SO ORDERED.
/s/Paul Barbadoro
Paul Barbadoro
United States District Judge
August 2 8 , 2008
cc: Christopher H.M. Carter, Esq.
Kurt L . Glitzenstein, Esq.
Matthew J. Leary, Esq.
Peter Kirk, Esq.
Daniel Milville Deschenes, Esq.
Barbara L . Dittmar, Esq.
Gordon P. Klancnik, Esq.
J. Michael Jakes, Esq.
James T . Hosmer, Esq.
Jeffrey Nelson, Esq.
Joyce Craig, Esq.
Kara Stoll, Esq.
Larry S . Nixon, Esq.
Molly R. Silfen, Esq.
Sheri Lea Gordon, Esq.
Brian Gould, Esq.
Daniel Bourque, Esq.
Phillip Braley, Esq.
-36-
APPENDIX A
Claim Term or Phrase Markem Proposed Zipher Proposed
Construction Construction
“control the tape spools”
“drive” “rotate”
“driveable” “rotateable” “capable of being controlled”
“said controller calculates a “while both motors are rotating “the controller derives by a
length of tape to be added to or to move the tape in the tape process an amount of tape to be
subtracted from tape extending transport direction, the control added to or removed from the
between said spools in order to of the motors is used to measure tape extending between the
maintain tension in said tape tape tension without contacting spools so that tension in the
between predetermined limit the tape, and the controller uses tape is maintained within
values” the measured tension value to acceptable limits”
calculate a length of tape to
either be added to or subtracted
from the total length of tape
extending from the take-up
spool to the supply spool, such
that the tension in the tape is
kept between a predetermined
low limit value and a
predetermined high limit value
during tape transport”
“said controller . . . controls “the controller controls both the “the controller controls the
said motors to drive the spools motor that rotates the takeup motors to drive the spools so as
to add or subtract the calculated spool support and the motor that to add or remove the determined
length of tape to or from the rotates the supply spool support, amount of tape to or from the
tape extending between said so that both spools of tape tape extending between the tape
spools.” rotate to either add or subtract spools”
the length of tape calculated by
the controller”
-37-
