Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-cand-5_06-cv-01839/USCOURTS-cand-5_06-cv-01839-17/pdf.json

Nature of Suit Code: 840
Nature of Suit: Trademark
Cause of Action: 35:271 Patent Infringement

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United States District Court

For the Northern District of California

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United States District Court

For the Northern District of California

IN THE UNITED STATES DISTRICT COURT

FOR THE NORTHERN DISTRICT OF CALIFORNIA

ELANTECH DEVICES CORP., a

corporation existing under the laws of

Taiwan, R.O.C.,

Plaintiff,

 v.

SYNAPTICS, INC., a Delaware corporation;

and AVERATEC, INC., a California

corporation,

Defendants. /

No. C 06-01839 CRB

MEMORANDUM AND ORDER RE:

SUMMARY JUDGMENT MOTIONS

[REDACTED VERSION]

Elantech Devices Corp. (“Elantech”) filed suit against Synaptics, Inc. (“Synaptics”)

for infringement of U.S. Patent No. 5,825,352 (“the ’352 patent”). Synaptics counterclaimed

for infringement of U.S. Patents No. 5,880,411 (“the ’411 patent”), No. 5,943,052 (“the ’052

patent”), No. 5,543,592 (“the ’592 patent”), and No. 6,380,931 (“the ’931 patent”). The

court issued a Claim Construction Order on April 6, 2007. 

Now pending before the Court is Synaptics’ motion for summary judgment of

noninfringement of the ’352 patent. Also before the Court is Elantech’s cross motion for

summary judgment of infringement of the ’352 patent. The patent discloses a method for

recognizing the presence of multiple fingers on a computer touchpad and emulating various

mouse functions. 

//

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Elantech amended its complaint on July 20, 2006, naming Averatec, Inc. (“Averatec”)

and Prostar Computer, Inc. (“Prostar”) as additional defendants. Elantech and Prostar

subsequently settled. See Stipulated Consent Judgment, filed on November 1, 2006. Averatec

has joined in Synaptics’ instant motion and opposition.

2

I. BACKGROUND

A. Procedural History

The Court construed eight terms from the asserted patents as selected by the parties,

including one term from Synaptics’ ’411 patent, three terms from Synaptics’ ’931 patent, and

four terms from Elantech’s ’352 patent. See generally Claim Construction Order. Elantech

properly filed its Final Infringement Contentions 30 days after the Claim Construction Order

pursuant to Northern District Patent Local Rules 3-6(a). See Declaration of Sean P.

DeBruine (“DeBruine Decl.”), filed May 11, 2007, Ex. E (Elantech’s Final Infringement

Contentions) (“Final Infringement Contentions”). Fourteen days after the Claim

Construction Order issued, Synaptics moved for summary judgment of noninfringement of

the ’352 patent.1

 Elantech subsequently cross-moved for summary judgment of

infringement. The Court heard oral argument from both parties in support of their motions

for summary judgment on October 5, 2007. 

B. The ’352 Patent

The ’352 patent, entitled “Multiple Fingers Contact Sensing Method for Emulating

Mouse Buttons and Mouse Operation on a Touch Sensor Pad,” discloses a method for

recognizing the presence of multiple fingers on a touchpad and emulating various mouse

functions. The patent also discloses a touchpad with such capabilities. The patent was

issued October 20, 1998, and by assignment, Elantech is the owner of the entire right, title,

and interest of the ’352 patent. 

The ’352 patent has two independent claims: 1 and 18. Claim 1 discloses a method to

detect multiple fingers in contact with a touch sensor. Claim 18 discloses a touch sensor that

carries out the method of claim 1. Both claims require “scanning the touch sensor to (a)

identify a first maxima in a signal corresponding to a first finger, (b) identify a minima

following the first maxima, (c) identify a second maxima in a signal corresponding to a

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second finger following said minima” and “providing an indication of the simultaneous

presence of two finger in response to identification of said first and second maxima.” 

In the Claim Construction Order, the Court construed “scanning the touch sensor” to

mean “measuring the values generated by a touch sensor to detect operative coupling and

determining the corresponding positions at which measurements are made.” Claim

Construction Order at 12:22-24. The Court construed the sub-limitations (a)-(c) to mean (a)

“identify a first peak value in a finger profile obtained from scanning the touch sensor,” (b)

“identify the lowest value in the finger profile that occurs after the first peak value, and

before another peak value is identified,” and (c) “after identifying the lowest value in the

finger profile, identify a second peak value in the finger profile.” Id. at 15:1-7.

Elantech alleges that Synaptics and its customer Averatec infringe claims 1 and 18 of

the ’352 patent. Specifically, Elantech alleges infringement by Synaptics’ TM41 series of

touchpad devices, and by Averatec products that incorporate those devices (collectively,

“Accused Touchpads”). See generally Final Infringement Contentions.

II. LEGAL OVERVIEW

A. Summary Judgment

Summary judgment is appropriate when there is no genuine issue as to any material

fact and the moving party is entitled to judgment as a matter of law. Summary judgment is

improper “if the evidence is such that a reasonable jury could return a verdict for the

nonmoving party.” Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 248 (1986); Vanmoor v.

Wal-Mart Stores, Inc., 201 F.3d 1363, 1365 (Fed. Cir. 2000). An issue is “genuine” only if

there is sufficient evidence for a reasonable fact finder to find for the non-moving party. See

Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 248-49 (1986). A fact is “material” if the

fact may affect the outcome of the case. See id. at 248. “On summary judgment, the

evidence must be viewed in the light most favorable to the party opposing the motion, with

doubts resolved in favor of the nonmovant.” Crown Operations Int'l, Ltd. v. Solutia Inc., 289

F.3d 1367, 1375 (Fed. Cir. 2002) (citations omitted).

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B. Literal Infringement 

To determine infringement, the asserted claim must be compared to the allegedly

infringing method or device. Markman v. Westview Instruments, Inc., 52 F.3d 967, 976

(Fed. Cir. 1995). To establish literal infringement, every claim limitation, or claim element,

must be found in the accused subject matter. Warner-Jenkinson Co. v. Hilton Davis

Chemical Co., 520 U.S. 17, 29, 40 (1997). Thus, establishing that the accused method or

device does not satisfy one claim limitation would support a finding of noninfringement. Id.

The patentee must prove infringement by a preponderance of the evidence. Bayer AG v.

Elan Pharm. Research Corp., 212 F.3d 1241, 1247 (Fed. Cir. 2000).

C. Doctrine of Equivalents

Under the doctrine of equivalents, a product that does not literally infringe a patent

claim may still infringe if each and every limitation of the claim is literally or equivalently

present in the accused device. See Warner-Jenkinson, 520 U.S. at 40 (“In our view, the

particular linguistic framework used is less important than whether the test is probative of the

essential inquiry: Does the accused product or process contain elements identical or

equivalent to each claimed element of the patented invention?”). 

Whether an element of an accused product infringes under the doctrine of equivalents

depends in part on whether that component performs substantially the same function as the

claimed limitation in substantially the same way to achieve substantially the same result. See

 Ethicon Endo-Surgery, Inc. v. United States Surgical Corp., 149 F.3d 1309, 1315 (Fed. Cir.

1998); Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934-35 (Fed. Cir. 1987) (en

banc) (“Under the doctrine of equivalents, infringement may be found (but not necessarily) if

an accused device performs substantially the same overall function or work, in substantially

the same way, to obtain substantially the same overall result as the claimed invention.”). If

the differences between a claim and an accused device are “insubstantial” to one with

ordinary skill in the art, the product may infringe under the doctrine of equivalents. See

Ethicon, 149 F.3d at 1315; Sage Prods., Inc. v. Devon Indus., Inc., 126 F.3d 1420, 1423 (Fed.

Cir. 1997). The doctrine prevents an accused infringer from avoiding infringement by

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changing minor details of a claimed invention while retaining its essential functionality. See

Sage, 126 F.3d at 1424. 

III. DISPUTED CLAIM TERMS

Elantech and Synaptics dispute the meaning of certain claim terms in their respective

motions for summary judgment. Because the meaning of these terms are material to the

pending motions, the Court first considers these terms.

A. “peak value” and “lowest value”

In the Claim Construction Order, the Court construed sub-limitations (a)-(c) of claims

1 and 18 according to the construction proposed by the patent holder Elantech. See Claim

Construction Order at 13-15. In relevant part, the Court construed “identify a...maxima” to

mean “identify a...peak value” and “identify a minima” to mean “identify the lowest value.”

See id. Elantech argues that the construed sub-limitations (a)-(c) are met by identification of

the traces with the peak (maximum) and lowest (minimum) values. Synaptics counters that

the construed claims require identification of “specific” or “particular” measured capacitance

values. Accordingly, methodology that does not somehow identify “particular measured

values” cannot infringe. 

At oral argument on October 5, 2007, Synaptics supported its reading of the terms by

noting that the example method described in the ’352 patent specification explicitly records

the maxima and minimum measure capacitance values in a number of variables. See ’352

patent at p. 22, col. 8 l. 52 - p. 23, col. 9 l. 14. However, standing alone, an embodiment

disclosed in the specification does not limit the claims. Liebel-Flarsheim Co. v. Medrad,

Inc., 358 F.3d 898, 906 (Fed. Cir. 2004). Even when the specification describes only a single

embodiment, the claims of the patent are not to be construed as restricted to that embodiment

unless the patentee demonstrates a clear intention to limit the claim scope using “words or

expressions of manifest exclusion or restriction.” Teleflex, Inc. v. Ficosa N. Am. Corp., 299

F.3d 1313, 1327 (Fed. Cir. 2002). Absent clear statements of scope, courts must follow the

language of the claims and not that of the written description provided by the specification. 

Id. at 1328. 

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The ’352 patent specification states that the example embodiment is not meant to limit

the invention. See ’352 patent, p. 26, col. 16 ll. 6-12. Therefore, the example itself does not

support Synaptics’ view that the claim scope is limited to only cover methods that explicitly

identify particular measured values corresponding to maxima and minima. See Teleflex, 299

F.3d at 1327. 

In addition, Synaptics’ reading of the construed claims would inappropriately limit

their scope. The plain language of the claims reads on identifying maxima and minima. The

claims neither mention nor require any sort of operation to be performed on capacitance

values. Taken literally, Synaptics reading of the claims would allow a party to escape literal

infringement by transforming the measured capacitance values (e.g. trivially multiplying the

finger profile values by two) before identifying minima and maxima, because the

identification steps would not use the literally measured capacitance values. There is no

support for such a limited reading of the claims in the patent specification or intrinsic

evidence. 

The construed claims require identification of peak and lowest values, corresponding

to maxima and minima, respectively. This step is satisfied by methodology that scans the

finger profile to identify traces that contain the peak and lowest values. 

B. “providing an indication”

Claims 1 and 18 of the ’352 patent also require “providing an indication of the

simultaneous presence of two fingers in response to identification of said first and second

maxima.” This limitation was amended during prosecution to distinguish prior art that

inherently produced a finger profile with two maxima separated by a minimum when two

fingers were placed on the touchpad. Applicants explained the amendment stating that “[t]he

present invention uniquely utilizes the detection of two maxima to determine if two fingers

are present on the touchpad. Nowhere does [the prior art] suggest analyzing profile

information to obtain this result, or to use the result to provide an indication of two fingers.” 

Declaration of Karl J. Kramer in Support of Synaptics’ Motion for Summary Judgment of

Noninfringement of the Asserted Claims of the ’352 patent (“Kramer SJ Decl.”), Ex. 5, April

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6, 1998 Amendment at 4. The Court did not construe the meaning of the “providing an

indication” limitation in the Claim Construction Order. 

Synaptics alleges that the parties agreed that “providing an indication” is “[t]he

function of detecting the simultaneous presence of two fingers and reporting that presence to

the host.” Synaptics’ MSJ Brief at 11:18-20 (emphasis supplied). Elantech disputes that the

claim requires an indication of multiple fingers returned to the host; instead, Elantech argues

that any form of indication is sufficient to satisfy the claim limitation. For example, Elantech

argues that the “providing an indication” step is met by Synaptics’ [ redacted ]

code module. This module processes the finger profile to determine the location of the user’s

primary finger on the touchpad. [ redacted ] creates a temporary data structure

which implicitly identifies multiple fingers in contact with the touchpad, although the code

never attempts to “provide” such indication outside of the code module itself. Elantech

alleges creating this data structure alone is sufficient to meet the “providing an indication”

limitation. 

Neither party’s argument is persuasive. Nothing in the claim language or prosecution

history supports Synaptics’ argument that an indication of multiple fingers must be returned

to the host in order to infringe. On the other hand, Elantech’s position reads the limitation

out of the claims. Elantech argues that implicit identification of multiple fingers is all that is

required to meet the claim limitation. But simply recognizing a finger profile with two

maxima separated by a minima also implicitly identifies the presence of multiple fingers, and

the “providing an indication” limitation was added to the claims of the ’352 patent during

prosecution for the express purpose of overcoming prior art that produced such a finger

profile. See Kramer SJ Decl., Ex. 5, April 6, 1998 Amendment at 4. Thus, Elantech’s

argument that implicit identification of multiple fingers is all that the claim requires

eviscerates the claim limitation and cannot stand. 

The “providing an indication” limitation does not require that the “indication” of two

fingers be returned to the host. However, the limitation does require that infringing

methodology perform some affirmative step to provide an indication of multiple fingers. 

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IV. SUMMARY JUDGMENT OF NONINFRINGEMENT

Synaptics now moves for summary judgment of noninfringement of the ’352 patent,

or, in the alternative, partial summary judgment of noninfringement. Synaptics is entitled to

summary judgment of noninfringement only if the facts and inferences, when viewed in the

light most favorable to Elantech, could not persuade a reasonable jury to return a verdict in

favor of Elantech, the non-moving party. See Anderson, 477 U.S. at 255.

The Accused Touchpads use one of two software algorithms with multiple-finger

detection capabilities. The first, “Type 1 Code,” uses a threshold method to determine the

position of fingers contacting the touchpad. See, e.g., Declaration of Dr. Andrew Wolfe in

Support of Synaptics’ Motion for Summary Judgment on Non-Infringement of the Asserted

Claims of the ’352 patent (“Wolfe SJ Decl.”), ¶ 21. The second, “Type 2 Code,” uses a “bit

vector,” or “bit pattern,” algorithm to identify peaks in the finger profile. See id., ¶ 25. 

Because the Accused Touchpads implement either Type 1 or Type 2 Code, but not both, the

two algorithms and devices using them must be considered separately to determine whether

summary judgment is appropriate. 

A. Partial summary judgment of noninfringement for touchpads that do not 

enable multiple-finger detection functions

Synaptics moves for partial summary judgment of noninfringement as to accused

touchpads that do not enable multiple-finger detection functions. 

Synaptics argues that “many implementations of the Accused Touchpad devices

[have] no multiple-finger detection function enabled” and therefore these devices are

incapable of “providing an indication of the simultaneous presence of two fingers in response

to identification of said first and second maxima,” as required by asserted claims 1 and 18. 

Synaptics’ Notice of Motion and Motion for Summary Judgment of Noninfringement of 

the Asserted Claims of the ’352 patent (“Synaptics’ MSJ Brief”), filed April 20, 2007. 

Specifically, Synaptics argues that its “‘current’ version of code does not use a finger

counting algorithm and or provide any indication of the presence of multiple fingers on the

touch sensor.” Synaptics’ Reply Brief in Support of Motion for Summary Judgment of

Noninfringement of the Asserted Claims of the ’352 patent (“Synaptics’ Reply Brief”) at

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4:20-21. To support its argument, Synaptics’ expert Dr. Wolfe testifies that the “current”

code is specifically designed so that the firmware and driver software cannot be set to enable

finger-counting functions. See Wolfe SJ Decl., ¶ 19-20. Because Synaptics’ “current” code

uses the Type 2 Code algorithm, Synaptics requests that the Court enter partial summary

judgment of non-infringement as to devices implementing the “current” version of Type 2

Code. 

The Federal Circuit has held that “an accused device may be found to infringe if it is

reasonably capable of satisfying the claim limitations, even though it may also be capable of

non-infringing modes of operation.” Hilgraeve Corp. v. Symantec Corp., 265 F.3d 1336,

1343 (Fed. Cir. 2001). Nevertheless, “a device does not infringe simply because it is

possible to alter it in a way that would satisfy all the limitations of a patent claim.” High

Tech Med. Instrumentation, Inc. v. New Image Indus., Inc., 49 F.3d 1551, 1555 (Fed. Cir.

1995). To determine infringement, the Court must consider whether the accused party

“intended or anticipated” the device being modified for use in an infringing manner. High

Tech Med., 49 F.3d at 1555. “If a device is designed to be altered or assembled before

operation, the manufacturer may be held liable for infringement if the device, as altered or

assembled, infringes a valid patent.” Id. at 1556.

The Accused Products contain driver and firmware software. Software programs

directly infringe a patent if they present users with options to enable infringing functionality,

regardless of whether the users ever activate or utilize those functions. Fantasy Sports

Properties, Inc. v. Sportsline.com, Inc., 287 F.3d 1108, 1118 (Fed. Cir. 2002). But programs

built from source code containing infringing functions do not infringe if users cannot access

the accused functionality. Southwest Software, Inc. v. Harlequin Inc., 226 F.3d 1280, 1291

(Fed. Cir. 2000) (affirming a jury verdict of noninfringement where the accused software

program contained source code to carry out infringing functions but the functions made

unavailable to the end user); Telemac Cellular Corp. v. Topp Telecom, Inc., 247 F.3d 1316,

1330 (Fed. Cir. 2001) (affirming summary judgment of noninfringement when the source

code for a device contained code to carry out infringing functions, but the source code also

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contained code that prevented users of the device from accessing those functions). 

Accordingly, one way for the Accused Touchpads to carry out the “providing an

indication” step is to provide purchasers (e.g. computer manufacturers) with options that can

enable finger counting functions, regardless of whether the purchasers are shown to have

used those functions. See Fantasy Sports, 287 F.3d at 1118. But the Accused Products do

not infringe if they are incapable of practicing the “providing an indication” step, even if

their driver and firmware software are built from source code containing modules that could

carry out that step. See Southwest Software, 226 F.3d at 1291; Telemac, 247 F.3d at 1330. 

Elantech presents convincing evidence that some Accused Touchpad devices

containing Type 2 Code are “reasonably capable” of “providing an indication of the

simultaneous presence of two fingers,” that users are able to access this functionality, and

that Synaptics “intended or anticipated” such usage. Type 2 Code can generate a data packet

labeled “W” that provides the host computer with an indication of the presence of multiplefingers. See Wolfe SJ Decl., ¶¶ 17, 30. Synaptics’ own customer guide, the Synaptics’

Touchpad Interfacing Guide, instructs computer vendors how to interface with Synaptics

touchpads, including instructions for enabling the “W” multiple-finger detection option. See,

e.g., Wolfe SJ Decl., Ex. 4, Synaptics’ Touchpad Interfacing Guide (“Synaptics’ Guide”)

§ 2.3.4. Thus, Synaptics “intended or anticipated” multiple-finger detection for at least some

touchpads containing Type 2 Code. See High Tech Med., 49 F.3d at 1555. By following the

instructions provided in the Synaptics’ Guide, Elantech engineers were able to direct

computers purchased at retail which contain Synaptics’ touchpads and driver software to

report “W” values. See Declaration of Jeng-Yin Wu in Support of Elantech’s Reply Brief in

Support of Motion for Summary Judgment of Infringement (“Wu Decl.”), ¶¶ 3-5. The values

returned when one, two or three fingers were held down corresponded to those reported in

the Synaptics’ Guide. Id., ¶ 5. Like the software product found to infringe in Fantasy Sports,

Elantech was able to enable the multiple-finger detection functions without modifying the

underlying code. See 287 F.3d at 1118. These Accused Touchpads meet the “providing an

indication” limitation of claims 1 and 18 as a matter of law. 

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In addition, Elantech has presented evidence that [redacted] is included in all Synaptics

products containing Type 2 Code, and that it is either executed in those products or can be

enabled. Declaration of Ian Scott MacKenzie, Ph.D. in Support of Elantech’s Motion for

Summary Judgment of Claim 18 of the ’352 Patent (“MacKenzie Decl.”), ¶ 22.

11

However, Synaptics moves for partial summary judgment of noninfringement for

Accused Touchpads using the “current” version of the Type 2 Code. Synaptics contends that

the computers Elantech purchased and enabled to set the “W” multiple-finger detection

option do not contain this “current” code version. Synaptics’ expert Dr. Wolfe testifies that

the “current” Type 2 Code cannot be set by the customers to enable finger counting

functionality. Wolfe SJ Decl. ¶¶ 19-20. He states that the [ redacted ] flag must

be set for the multiple finger detection code to be executed in the firmware software, but that

in the “current” version of Type 2 Code this flag is disabled by default, and the Synaptics’

driver software never sends a message to enable multiple-finger detection. Id. Dr. Wolfe

explains that when [ redacted ] is not set, the “W” value that would return

multiple finger count to the host does not report finger count values. Id. ¶ 30.

But Dr. Wolfe also testifies that the [redacted] routine in the Type 2 Code firmware

counts fingers. Id. at ¶ 27. Because this routine is capable of providing an indication of the

simultaneous presence of two fingers, its execution satisfies the “providing an indication”

claim limitation. As explained above, the limitation is met whether or not the indication is

provided to the host, for example, via the “W” flag. Although Synaptics contends that

[redacted] is not enabled or activated in the “current” version of Type 2 Code (see, e.g.,

Synaptics’ Brief in Opposition to Elantech’s Motion for Summary Judgment of Infringement

(“Synaptics’ Opp. Brief”) at 12:17-18, 12:23-26), Dr. Wolfe’s testimony never states that

[redacted] is not executed in the “current” Type 2 Code. See id. at ¶¶ 18-20. Rather, he

testifies that the “W” value never indicates finger count if [ redacted ] is not set.

Id. at ¶ 30. Because Synaptics has not presented evidence that the [redacted] routine is not

executed in the “current” version of Type 2 Code, it has failed to meet its burden of showing

that the code does not practice the “providing an indication” limitation of claims 1 and 18.2

 

Accordingly, the Court denies Synaptics’ motion for partial summary judgment of

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noninfringement as to Accused Touchpads that do not enable multiple-finger detection

functions. Synaptics has not proved that any of the Accused Touchpads do not enable

multiple-finger detection. 

B. Partial summary judgment of noninfringement for touchpads containing 

Type 1 Code

Next, Synaptics moves for partial summary judgment of noninfringement as to

accused touchpads containing Synaptics’ Type 1 Code. 

Type 1 Code uses a threshold method to detect the number of fingers in contact with

the touchpad. See Wolfe SJ Decl., ¶ 21-24. The code creates a data array by assigning 1's or

0's for each trace value depending on whether the trace value is above or below a certain

threshold. A group of contiguous 1's in the data array indicates the presence of a finger. If

two fingers are present, the data array will contain two contiguous groups of 1's separated by

a group of 0's. For example, the data array might consist of the following bits when two

fingers are present, wherein each group of 1's represents a finger: 001110001110000. See

id., Figure at ¶ 22 (“Type 1 Code Figure”). 

1. Literal infringement

Synaptics first argues that Type 1 Code does not literally infringe claims 1 and 18

because it does not detect the presence of multiple fingers by looking for a ‘minima’ between

two ‘maxima’ and thus does not perform the steps required by sub-limitations (a)-(c). 

Synaptics notes that Type 1 Code never identifies particular maximum or minimum scan

lines, but only determines whether or not the capacitance value at each scan line exceeds the

threshold value. 

Elantech counters that Type 1 Code does carry out sub-limitations (a)-(c) because a

pattern such as “001110001110000” identifies a plateau maximum (the first group of 1's),

followed by a minimum (the group of 0's between the group of 1's), followed by a second

maximum (the second group of 1's). 

Elantech’s arguments fail to demonstrate that sub-limitations (a)-(c) are met by the

Type 1 Code algorithm. The Court adopted the construction of the sub-limitations proposed

by Elantech, which requires identification of two peak values and an intervening lowest

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value. See Claim Construction Order at 13:1-15:7. However, Type 1 Code never identifies

peak and lowest values, or the scan lines containing those values, but only determines

whether each scan line capacitance value exceeds the threshold value. Elantech’s assertion

that Type 1 Code identifies plateau maxima (groups of 1's) and plateau minima (groups of

0's) does not rescue their infringement argument. In the Claim Construction Order, the Court

noted that a plateau maximum occurs where “the maximum capacitance value appears over a

range of X axis values and/or Y axis values.” Id. at 14:20-23. Type 1 Code does not identify

plateau maxima or minima, as alleged by Elantech, because nothing in the algorithm

identifies a range of maximum or minimum capacitance values. 

Because Type 1 Code does not literally carry out sub-limitations (a)-(c) of claims 1

and 18 of the ’352 patent, Type 1 Code does not literally infringe those claims. See WarnerJenkinson, 520 U.S. at 29, 40. 

2. Doctrine of equivalents

Elantech asserts that even if Type 1 Code does not literally infringe the ’352 patent, it

nevertheless infringes under the doctrine of equivalents. 

Elantech’s expert Dr. MacKenzie opines that the Type 1 Code algorithm presents “at

most only an insubstantial variation” from sub-limitations (a)-(c) of claims 1 and 18 because

the two methods perform substantially the same function (“determine the presence of a . . .

finger”), in substantially the same way (“examining the values on each trace”), to achieve

substantially the same result (“identification of a value that accurately represents the

presence of a finger”). MacKenzie Decl., ¶ 28. However, the ’352 patent’s claimed “way”

to determine whether multiple fingers are in contact with the touchpad is not merely by

“examining the values on each trace;” rather, claims 1 and 18 determine the presence of two

fingers by identifying two peak values (maxima) separated by a lowest value (minimum). 

Indeed, identification of the two maxima corresponding to two fingers lies at the heart of

Elantech’s claimed invention. Therefore, the claims cannot be stretched under the doctrine

of equivalents to cover methods that do not identify maxima and minima. And Type 1 Code

does not identify maxima and minima in the finger profile, but only determines whether each

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trace value exceeds a given threshold. Thus, Dr. MacKenzie’s brief recitation of a function,

way, result analysis is insufficient to support infringement under the doctrine of equivalents. 

Accordingly, the Court grants Synaptics’ motion for partial summary judgment of

noninfringement as to accused touchpads that implement Type 1 Code. 

C. Partial summary judgment of noninfringement for touchpads containing 

Type 2 Code

Finally, Synaptics seeks partial summary judgment of noninfringement as to accused

touchpads containing Synaptics’ Type 2 Code. 

Type 2 Code uses a “bitpattern” or “bit vector” algorithm to identify maxima in the

finger profile. The algorithm first creates a vector containing a 0 or 1 corresponding to each

scan line, depending on whether the capacitance value of the next scan line is higher or

lower, respectively. See MacKenzie Decl., Figure at ¶ 30 (“Type 2 Code Figure”). As a

result, a “01” pattern in this vector identifies the presence of a maximum and a “10” pattern

identifies the presence of a minimum. See id., line A. After further processing steps, the

code produces a bit vector containing all 0's except that 1's are found for each scan line

identified as containing a maximum, or peak value. See id., line D. If multiple-finger

counting code is enabled, the 1's in the bit array are counted to determine the number of

fingers in contact with the touchpad, and the count is available to the host computer. See

Wolfe SJ Decl., ¶¶ 27, 30. 

Synaptics first argues that the Type 2 Code does not infringe because it never

identifies the lowest value in the finger profile that appears after the first peak value. But it

admits that a “10” pattern in the first step of the algorithm “would ‘indicate’ a ‘minima’ if

analyzed.” See Synaptics’ Reply Brief at 7:23-8:4. However, the asserted claims do not

require an “analysis” or “indication” of the minima or lowest value; the claims only require

that the minima or lowest value is “identified,” and Type 2 Code identifies a minimum or

lowest value at the “10” transitions. See line A, Type 2 Code Figure. Synaptics attempts to

bolster its argument by noting that the bit pattern in line A is “immediately deleted” and

information about the minimum or lowest value is unavailable by the time the finger count is

calculated. Such immediate deletion is irrelevant, however, because the claims do not rule

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out intermediate processing steps between the steps of identifying maxima and minima and

providing an indication of finger count. Moreover, the “providing an indication” step only

requires that the finger count is provided in response to detection of the maxima or peak

values. Thus, Synaptics’ contention that Type 2 Code does not identify a minimum or lowest

value does not support a ruling of summary judgment of noninfringement. 

Synaptics further argues that Type 2 Code does not infringe because the code does not

identify particular capacitance values as maximum or peak values. It argues that any finger

count provided to the host “is based only upon a ‘1’ bit defining a scan line with a ‘peak’ and

not a finger-profile capacitance value.” Id. at 9:5-7. This argument is unpersuasive,

however, because as is explained supra, the Type 2 Code identifies maxima or peak values

by a “01” pattern in the first step of the algorithm. See line A, Type 2 Code Figure. Thus,

these contentions also fail to support summary judgment of noninfringement. 

Accordingly, the Court denies Synaptics’ motion for partial summary judgment of

noninfringement as to accused touchpads that implement Type 2 Code 

V. SUMMARY JUDGMENT OF INFRINGEMENT

The Court now turns to Elantech’s cross motion for summary judgment of

infringement. Elantech requests that the Court enter judgment that all of the Accused

Touchpads literally infringe claim 18 of the ’352 patent. 

For the reasoning set forth above, the Court denies Elantech’s motion for summary

judgment of infringement for all Accused Touchpads. In particular, Accused Touchpads

implementing Type 1 Code do not infringe claim 18. The Court would grant summary

judgment of infringement for Accused Touchpads implementing Type 2 Code and having

enabled finger counting functionality, but Elantech did not move for partial summary

judgment; instead, its motion seeks judgment on all Accused Touchpads without distinction. 

VI. CONCLUSION

Synaptics’ motion for partial summary judgment of noninfringement for those devices

implementing Type 1 Code is GRANTED. A reasonable trier of fact could not find that

these devices infringe claims 1 or 18 of the ’352 patent. Synaptics’ motion for partial

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summary judgment of noninfringement on the ground that the “current” Type 2 Code does

not enable multiple finger detection capabilities is DENIED. Synaptics has not proved as a

matter of law that Accused Touchpads using the “current” version of Type 2 Code do not

carry out the “providing an indication” limitation. Synaptics’ motion for partial summary

judgment of noninfringement for those devices implementing Type 2 Code on the grounds

that the code does not identify peak and/or lowest values is also DENIED. Elantech’s

motion for summary judgment of infringement is DENIED. 

The parties are directed to appear for a further case management conference on

December 7, 2007 at 8:30 a.m. 

IT IS SO ORDERED.

Dated: October 26, 2007 

CHARLES R. BREYER

UNITED STATES DISTRICT JUDGE

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