Case: 20-1775 Document: 50 Page: 1 Filed: 06/29/2021
NOTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
CORUS REALTY HOLDINGS, INC.,
Plaintiff-Appellant
v.
ZILLOW GROUP, INC., ZILLOW, INC., TRULIA,
LLC,
Defendants-Appellees
______________________
2020-1775
______________________
Appeal from the United States District Court for the
Western District of Washington in No. 2:18-cv-00847-JLR,
Senior Judge James L. Robart.
______________________
Decided: June 29, 2021
______________________
JOSHUA HAMILTON LEE, Kilpatrick Townsend & Stock-
ton LLP, Atlanta, GA, argued for plaintiff-appellant. Also
represented by VAIBHAV P. KADABA, MITCHELL G.
STOCKWELL; KASEY KOBALLA, Raleigh, NC; DARIO
ALEXANDER MACHLEIDT, Seattle, WA.
RAMSEY M. AL-SALAM, Perkins Coie, LLP, Seattle, WA,
argued for defendants-appellees. Also represented by
CHRISTOPHER MARTH, CHRISTINA JORDAN MCCULLOUGH.
Case: 20-1775 Document: 50 Page: 2 Filed: 06/29/2021
2 CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC.
______________________
Before PROST ∗, SCHALL, and REYNA, Circuit Judges.
REYNA, Circuit Judge.
Appellant appeals a decision of the United States Dis-
trict Court for the Western District of Washington granting
Zillow Group, Inc.’s motion for summary judgment that Zil-
low did not infringe Appellant’s patent. Corus claims that
the district court erred in granting summary judgment of
noninfringement based on incorrect claim constructions
and that the court erred in striking portions of its expert
witness report. We affirm.
BACKGROUND
U.S. Patent No. 6,636,803 (the “’803 patent”), 1 entitled
“Real-Estate Information Search and Retrieval System,”
generally describes “a system and method which uses digi-
tal technology to acquire and then present, in integrated
form, information relating to one or more properties in a
real estate market.” ’803 patent col. 4 ll. 4–6. The system
generates a map on a digital device, such as a cell phone or
computer, of an area of the user’s interest and displays
property icons and real estate information from sources
such as a multiple listing service (“MLS”) to inform real-
estate agents and property buyers of offers for sale, lease,
or rent. See J.A. 5 (citing ’803 patent col. 4 ll. 7–12). Ac-
cording to the patent, this map can be generated on a “data
∗
Circuit Judge Sharon Prost vacated the position of
Chief Judge on May 22, 2021.
1 Some of the ’803 patent claims were amended in
reexamination on January 21, 2015. Due to the amend-
ments, the patent is divided into two sections, referred to
as B1 and C1. Section C1 contains the amended claims
that are at issue in this litigation. The court cites B1 for
the specification and C1 for the claims.
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CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC. 3
terminal,” comprising a map generation unit, a storage
unit, a processor, and a display and may be used as a tool
by real-estate agents and property buyers. See ’803 patent
col. 4 ll. 12–25; col. 8 ll. 45–59. The map generation unit
generates a map in an area of interest; the storage unit
stores into its own database property information derived
from an MLS database.
Id. at col. 2 ll. 42–50. “The proces-
sor implements management software which integrates
the property information with the digital map,” which “in-
cludes the display of icons which correspond to properties
available in the map,” which may be “selectable by the
user,” and which provides real estate information about
that property from the MLS or other sources.
Id. at col. 2
ll. 50–55. In other words, when an icon is selected, “prop-
erty information obtained from the storage unit is dis-
played in association with the map.”
Id. at col. 2 ll. 55–57.
The ’803 patent discloses two preferred embodiments.
In the first embodiment, user input determines the map
and the data terminal is a stand-alone device.
Id. at col. 4
ll. 31–35. In the second embodiment, location data deter-
mines the map, which means this embodiment is “not a
stand-alone system but rather is a mobile terminal con-
nected to a location-positioning system via a communica-
tions link.”
Id. at col. 8 ll. 45–50. More specifically, the
second embodiment, in addition to the map generation
unit, storage unit, processor, and display, also has a loca-
tion data receiver that can specify the current position of
the terminal in the digital map.
Id. at col. 8 ll. 45–59. The
mobile terminal of the second embodiment is also capable
of connecting to a “remote storage device” such as “a remote
server connected to a network such as the Internet, or a
database.”
Id. at col. 10 ll. 1–6. This particular feature
allows the mobile terminal to gather updated property in-
formation from sources like MLS.
Id. at col. 10 ll. 1–16.
During prosecution of the ’803 patent, the United
States Patent and Trademark Office (“PTO”) rejected Co-
rus’s patent application over the prior art reference Weise,
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4 CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC.
among others. J.A. 9. Corus distinguished its invention as
an innovative way to store real estate information on a lo-
cal database. In doing so, Corus argued that under Weise,
a user must access a remote system using the Internet to
obtain property information, whereas “in the present in-
vention, the property information is obtained from a data
base stored on the mobile computing device.” J.A. 10. The
PTO allowed the patent upon this disclaimer.
In 2013, Corus Realty Holdings, Inc. (“Corus”) accused
Zillow Group, Inc., Zillow, Inc., Trulia, LLC (collectively,
“Zillow”) of infringing its ’803 patent. Zillow denied in-
fringement stating that its property database is main-
tained on a remote server and not on the mobile device, as
required by the ’803 claims. J.A. 786 ¶ 4. Zillow also told
Corus that the ’803 patent was invalid in light of U.S. Pa-
tent No. 6,871,140 (“Florance”).
Corus sought reexamination of the ’803 patent in view
of Florance. The Florance reference is directed to “a system
for creating a unified commercial real estate database”
that, in relevant part, uses global satellite positioning
(“GPS”) and the Internet “to coordinate remote field re-
search vehicles equipped with GPS transponders, laptop
computers, cellular communications, and laser measure-
ment devices to provide precise and timely inventory of
available buildings.” J.A. 10.
In light of Florance, Corus sought to amend its claims
to require “cellular-based location data” as opposed to the
original specification and claim which describe use of sev-
eral different positioning systems. See, e.g., ’803 patent
col. 3 ll. 12–18 (“[T]he terminal is equipped with a receiver
for acquiring location data from an external positioning
system, which may be satellite-based, cellular-based, or
any other type capable of tracking the position of an object
in an area of interest. Preferably, the receiver is a GPS
receiver linked to the data terminal processor.”). The PTO
ultimately rejected Corus’s proposed amendments in light
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CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC. 5
of Florance and two other references not as issue in this
appeal. J.A. 11.
Corus then sought to narrow its claims further by
amending “capable of” to “configured to” in the limitation
“data-enabled mobile phone configured to obtain cellular-
based location data,” and adding the new limitation “ob-
taining said area of interest from the cellular-based loca-
tion data.”
Id. Corus successfully argued to the PTO that
these changes distinguished the ’803 patent from Florance.
In June 2018, Corus brought an infringement suit
against Zillow alleging that various of its mobile applica-
tions, i.e., Zillow Real Estate, Trulia Real Estate, Zillow
Rentals, Trulia Rentals, and HotPads (collectively, the “Zil-
low Apps”) infringe claims 1–6, 8–10, 14–18, 20–23, 25–27,
30–31, and 33–38 of the ’803 patent. All parties agree that
the Zillow Apps request location data by “calling” to an op-
erating system, either Apple’s iOS or Google’s Android.
J.A. 13. Furthermore, the parties agree that the Zillow
Apps request property information from Zillow’s remote
database, which requires an internet connection, that the
retrieved results are stored in a device’s working memory,
and that the Zillow Apps can display a map with icons
showing the property information received from the remote
database. J.A. 13 (citing Zillow’s Mot. for Summ. Judg-
ment at 20–21; Corus’s Resp. to Zillow’s Mot. at 19–20).
Corus and Zillow dispute how Apple and Google’s location
services utilize “cellular-based location data,” but, because
no discovery was taken from either company, the evidence
in the record is “limited to the deposition testimony of Zil-
low witnesses, screenshots of Google and Apple web pages,
and tests conducted by Corus’s infringement expert, Dr.
David Martin.” J.A. 13–14.
During claim construction, the parties agreed that “da-
tabase” should be construed as “a collection of data ar-
ranged for search and retrieval.” J.A. 14. Following a
Markman hearing, the court construed the disputed term
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6 CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC.
“cellular-based location data” to mean “location data from
a cellular-based positioning system capable of tracking the
position of a device in an area of interest.” J.A. 14–15,
1059.
On October 30, 2019, Zillow moved to exclude several
of Corus’s infringement theories and portions of Dr. Mar-
tin’s expert report that were untimely disclosed. ECF No.
58 at 1. The court granted the motion on January 30, 2020.
ECF No. 114 at 24.
On February 18, 2020, the district court issued an or-
der granting in part Zillow’s motion for summary judgment
of noninfringement. J.A. 1–49, ECF No. 138. The district
court agreed with Zillow that “search,” as stated within the
construction of the “database” limitation, required that the
user be capable of obtaining “new” property information
and that for such “new” searches in Zillow’s apps, “all
searches in the apps rely on remote databases on the Inter-
net.” J.A. 2185; see also J.A. 21–22 (the district court opin-
ing that “the alleged functionality of the Zillow Apps does
not meet the database limitations.”). It was undisputed
that using the Zillow Mobile Apps, property information is
(i) obtained from Zillow’s remote servers, (ii) placed in
memory on the mobile device, and (iii) retrieved from
memory and displayed to the user when a user clicks a
property icon. J.A. 22. The district court found it relevant,
however, that “a user cannot obtain additional property in-
formation without connecting back through the Internet to
the remote database.”
Id. (emphasis added). Under this
view, the district court found that “the ‘retrieval’ of prop-
erty information from working memory [on the mobile de-
vice], where the application is not designed to obtain any
new information except through internet access to a remote
database does not mean that the working memory is a ‘da-
tabase’” for purposes of meeting the claim limitation. J.A.
23.
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CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC. 7
Corus appeals. We have jurisdiction pursuant to
28
U.S.C. § 1295(a)(1).
DISCUSSION
On appeal, Corus argues that the district court improp-
erly granted Zillow’s motion for summary judgment of non-
infringement. This Court reviews a district court’s decision
to grant summary judgment under the law of the applica-
ble regional circuit, here, the Ninth Circuit. Ultimate-
Pointer, L.L.C. v. Nintendo Co.,
816 F.3d 816, 824 (Fed. Cir.
2016). In the Ninth Circuit, a grant of summary judgment
is reviewed de novo.
Id. Infringement is a question of fact
that this court reviews without deference on appeal from a
decision granting summary judgment. See Epos Techs.
Ltd. v. Pegasus Techs. Ltd.,
766 F.3d 1338, 1341–42 (Fed.
Cir. 2014). This Court also reviews claim construction de
novo.
Id. at 1341.
I
A
Corus asserts that the district court erred in granting
summary judgment because of certain claim construction
irregularities as to two limitations: (1) “database,” and (2)
“cellular-based location data.” Zillow first counters that
the district court did not err in granting Zillow’s motion for
summary judgment because the Zillow Apps do not meet
the “database” limitation.
As mentioned above, during claim construction the par-
ties agreed that “database” should be construed as “a col-
lection of data arranged for search and retrieval.” J.A. 14,
252 (emphasis added). During prosecution of the ’803 pa-
tent, the claims were rejected, in part, based on a prior art
patent to Wiese. J.A. 2332–35. In response to that rejec-
tion, Corus narrowed the independent claims by requiring
that property information be “obtained from a data base
stored on the mobile computing device.” J.A. 2350. Corus
argued to the patent examiner that this amendment
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8 CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC.
distinguished the claimed invention from Wiese. The dis-
trict court found the following disclaimer from the prosecu-
tion file history to be persuasive:
. . . Wiese teaches accessing a remote system to
gather the sales information needed to display sym-
bols at the property locations on the map. . . . As
shown in Fig. 1, a remote user using CPU 72 would
have to go through ISP 44, Internet 32 and Server
30 to access value database 54. In the present in-
vention, the property information is obtained from
a data base stored on the mobile computing device.
J.A. 1079 (emphasis added).
In addition, Corus’s own expert, Mr. Sturza, distin-
guished a prior art reference used in the reexamination to
say that “retrieval” from a “cache” is not a “search.” J.A. 24
(quoting Sturza deposition testimony).
The parties do not dispute the method by which the Zil-
low Apps retrieve property information. J.A. 22. The Zil-
low Apps do not infringe because all searches in the Apps
rely on remote databases on the Internet which are down-
loaded to the local memory on the device and viewed by the
user.
Id. In order for a user to conduct another search (i.e.,
apply new filters or change the search region), a Zillow App
user must connect back through the Internet to the remote
database, an action which Corus disclaimed in prosecution,
as correctly recognized by the district court. J.A. 10, 22.
Therefore, Zillow’s working memory of the devices is not
arranged for “search and retrieval” as required to consti-
tute a database. J.A. 22. For the Zillow Apps, results are
downloaded and displayed from a remote server. Although
the user may click on the property icon to see additional
information, the results are not “searched.” In other words,
the Apps allow a view of already downloaded results. If a
search of any kind needs to be conducted, it must be con-
ducted in a remote database.
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CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC. 9
Corus contends that there is no requirement that fur-
ther searching be done in response to new user input nor
that the database needs additional information. Alterna-
tively, Corus argues that the ’803 patent describes further
searching can be performed because a user can select an
icon on the map which searches for and retrieves, within
the storage unit’s database, certain property information
“in response to displayed icon selection[].” See, e.g., ’803 pa-
tent col. 5 ll. 46–47.
We are not persuaded. Even if the Zillow Apps can re-
trieve property information from the local memory on the
mobile device if, for example, access to Zillow’s remote serv-
ers is severed, as confirmed by a number of the parties’ ex-
perts, J.A. 4861–62 (Oubraham); 4901 (Perrin); 1638 ¶ 60
(Martin), this does not mean that the Zillow Apps are per-
forming a search as contemplated by the agreed upon con-
struction of the database limitation. Instead, the record
shows that all Zillow App “searches” are performed in a re-
mote database. Accordingly, we affirm the district court’s
determination of noninfringement based on the “database”
limitation.
B
The district court also held that the term “cellular-
based location data” requires “that the location data must
be obtained directly from requests to a cellular network,”
thereby precluding any claim coverage over a mixture of
cellular and other location data. J.A. 27–29 citing J.A.
1094–95. The district court found that Corus had made
several amendments disclaiming “fused” sources of loca-
tion information and that such amendments created an
“unambiguous disclaimer that the area of interest must be
obtained from a cellular-based positioning system, and not
merely incorporate cellular data in an unspecified man-
ner.” J.A. 30–31. The Court primarily focused on the fol-
lowing amendments made by Corus: (1) limiting the claims
to “cellular-based location data,” rather than “location
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10 CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC.
data,” J.A. 30 (emphasis added), (2) narrowing “obtaining
said area of interest, wherein said area of interest is user-
designated or corresponds to the cellular-based location
data,” to “obtaining said area of interest from the cellular-
based location data,” J.A. 30 (emphasis in original), and
(3) “capable of obtaining cellular-based location data” to
“configured to obtain cellular-based location data,” J.A. 31
(emphasis in original).
During claim construction, the court construed the
term “cellular-based location data” as “location data from a
cellular-based positioning system capable of tracking the
position of a device in an area of interest.” See J.A. 1059.
The district court held Zillow was entitled to summary
judgment because “the mere presence of cellular hardware,
‘fused’ location data, or the location of cell towers based on
GPS data” did not suffice for purposes of finding infringe-
ment “because they do not constitute obtaining ‘location in-
formation from a cellular-based positioning system capable
of tracking.’” J.A. 28.
Corus argues that the district court, sua sponte, found
that Corus disclaimed “crowd-sourced” “fused” sources of
location information and that the claimed “area of interest”
must be obtained “directly from requests to a cellular net-
work” and “not merely incorporate cellular data in an un-
specified manner.” Corus asserts that the file history for
the ’803 patent demonstrates that none of the amendments
or remarks made by Corus demonstrate a disclaimer of any
and all “crowd-sourced” and “fused” sources of location in-
formation—i.e., “where some cellular data is combined
with GPS, WiFi, and/or other forms of location data.” Ap-
pellant’s Br. 20; J.A. 29–30. Instead, Corus contends that
any perceived disclaimer with respect to Florance was only
meant to disclaim the use of GPS alone. Appellant’s Reply
Br. 13.
Corus amended “capable of obtaining cellular-based lo-
cation data” to “configured to obtain cellular-based location
data.” In Ball Aerosol & Specialty Container, Inc. v.
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CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC. 11
Limited Brands, Inc.,
555 F.3d 984, 994–95 (Fed. Cir.
2009), this Court held that an accused product “reasonably
capable of being put into the claimed configuration [was]
insufficient for a finding of infringement,” where the claim
“specifie[d] a particular configuration.” See also J.A. 30–
31. We are not persuaded by Corus’s argument that the
amendments were not made to distinguish the invention
from “crowd-sourced” or “fused” system, but rather to over-
come the specific citation to the prior art that taught the
use of GPS alone. The language of the amended claims ap-
pears to make the disclaimers found by the district court.
In addition, an amendment is typically made to overcome
an examiner’s rejection. Corus unpersuasively argues it
made its claim amendment at the examiner’s suggestion
rather than to overcome the obviousness rejection.
We therefore agree with the district court that Corus
lacked evidence of the “cellular-based location data” limi-
tation because the Zillow Apps do not themselves deter-
mine a user’s location. Rather, they request location
information from the operating system (Apple iOS or
Google Android). J.A. 13, Appellee’s Br. 43. And as the
district court explained, even if the expert testimony cited
by Corus regarding Apple and Google’s location functional-
ity (which the district court excluded) “was based on per-
sonal knowledge, it is not evidence that the Zillow Apps”
meet the claim limitation because at most the testimony
suggests that the Zillow Apps might utilize “fused” or
“crowd-sourced” location data. J.A. 37–38. Accordingly, we
affirm the district court’s determination of noninfringe-
ment based on the “cellular-based location data” limitation.
II
This Court “review[s] evidentiary determinations un-
der the law of the regional circuit.” Pozen Inc. v. Par
Pharm., Inc.,
696 F.3d 1151, 1161 n.6 (Fed. Cir. 2012) (ci-
tation omitted). The Ninth Circuit reviews such
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12 CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC.
evidentiary rulings for abuse of discretion. See United
States v. Childs,
5 F.3d 1328, 1332 (9th Cir. 1993).
Corus did not include citations to Zillow’s source code
in its infringement contentions, but rather only identified
the functionality within the accused apps that correspond
to the “database” limitation. Corus states that Zillow cre-
ated many obstacles to Corus’s inspection of Zillow’s source
code. Notwithstanding those obstacles, the district court
held that the Local Patent Rules required Corus to specifi-
cally identify in its infringement contentions all of Zillow’s
source code that supported its infringement theories. See
J.A. 63–66. The district court stated “[i]n cases involving
software allegations, the party asserting infringement has
an obligation to ‘promptly and appropriately’ amend its
contentions to identify pinpoint citations to source code af-
ter it has had an opportunity to review the code.” J.A. 62.
Corus argues that the district court erred in rejecting
parts of its expert’s witness report. We disagree. First, the
district court found that Dr. Martin’s expert report in-
cluded some source code, but because the report was sub-
mitted late, it prejudiced Zillow because it was served on
Zillow after the district court’s claim construction, during
which the parties agreed to the construction of “database.”
J.A. 72–73.
Second, even if Mr. Martin’s expert report would have
shed some light on the alleged “database” for the Zillow
Apps, the report was late, and the contentions were not
supplemented to reflect Corus’s new theory based on source
code. 2 We conclude that the district court did not abuse its
2 Corus’s infringement expert, Dr. Martin, presented
evidence that search results could be downloaded to the mo-
bile device and that a user, without Internet access, could
still click on a property icon to retrieve that data (but could
not conduct a new search). This “required database” theory
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CORUS REALTY HOLDINGS, INC. v. ZILLOW GROUP, INC. 13
discretion in excluding Mr. Martin’s testimony. Although
Corus argues that the exclusion was an attack on the
weight and credibility of the testimony, it was in fact a
wholesale exclusion based on untimeliness. See J.A 15, 20–
21. The local rule mandates supplementation of infringe-
ment contentions and solely submitting an untimely expert
report containing such contentions cannot be sufficient.
Accordingly, we conclude that the district court did not
abuse its discretion in striking Dr. Martin’s expert report.
CONCLUSION
The Court has considered the parties remaining argu-
ments but does not address them in light of its decision.
Accordingly, the Court concludes that the district court did
not err in granting Zillow’s motion for summary judgment,
nor did it abuse its discretion in striking portions of Dr.
Martin’s expert report.
AFFIRMED
only suggests that the underlying data is arranged for “re-
trieval,” not for “search” as it would be if it were in a “da-
tabase.” Zillow argues that on this basis, the retrieval of
icon-related information is not based on a search of the da-
tabase. Appellee’s Br. 36.
