CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

United States Court of Appeals

for the Federal Circuit

______________________

CORE OPTICAL TECHNOLOGIES, LLC,

Plaintiff-Appellant

NOKIA CORPORATION, NOKIA OF AMERICA

CORPORATION,

Defendants-Appellees

______________________

2023-1001

______________________

Appeal from the United States District Court for the

Central District of California in No. 8:19-cv-02190-JAK-

RAO, Judge John A. Kronstadt.

-------------------------------------------------

CORE OPTICAL TECHNOLOGIES, LLC,

Plaintiff-Appellant

ADVA OPTICAL NETWORKING SE, ADVA

OPTICAL NETWORKING NORTH AMERICA, INC.,

Defendants-Appellees

______________________

2023-1002

______________________

Case: 23-1001 Document: 62 Page: 1 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

Appeal from the United States District Court for the

Central District of California in No. 8:20-cv-01463-JAK-

RAO, Judge John A. Kronstadt.

-------------------------------------------------

CORE OPTICAL TECHNOLOGIES, LLC,

Plaintiff-Appellant

CISCO SYSTEMS, INC.,

Defendants-Appellees

______________________

2023-1003

______________________

Appeal from the United States District Court for the

Central District of California in No. 8:20-cv-01468-JAK-

AGR, Judge John A. Kronstadt.

______________________

Decided: May 21, 2024

______________________

LAWRENCE MILTON HADLEY, Glaser Weil Fink Howard

Avchen & Shapiro LLP, Los Angeles, CA, argued for plain-

tiff-appellant. Also represented by STEPHEN UNDERWOOD;

JASON DANIEL EISENBERG, WILLIAM MILLIKEN, JOHN

CHRISTOPHER ROZENDAAL, Sterne Kessler Goldstein & Fox

PLLC, Washington, DC; LAWRENCE LAPORTE, Lewis Bris-

bois Bisgaard & Smith LLP, Washington, DC.

LINDA T. COBERLY, Winston & Strawn LLP, Chicago,

IL, argued for all defendants-appellees. Defendants-appel-

lees ADVA Optical Networking SE, ADVA Optical Net-

working North America, Inc., Cisco Systems, Inc. also

Case: 23-1001 Document: 62 Page: 2 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

represented by DAVID P. ENZMINGER, Los Angeles, CA;

LAUREN GAILEY, Washington, DC; KRISHNAN

PADMANABHAN, New York, NY; EIMERIC REIG-PLESSIS, San

Francisco, CA.

JOHN D. HAYNES, Alston & Bird LLP, Atlanta, GA, for

defendants-appellees Nokia Corporation, Nokia of America

Corporation. Also represented by LINDSAY C. CHURCH,

SLOANE SUEANNE KYRAZIS; JAMES ABE, Los Angeles, CA;

KIRK T. BRADLEY, NICHOLAS CHRISTOPHER MARAIS, Char-

lotte, NC; THOMAS WILLIAM DAVISON, Washington, DC.

______________________

Before DYK, MAYER, and TARANTO, Circuit Judges.

Opinion for the court filed by Circuit Judge TARANTO.

Dissenting opinion filed by Circuit Judge MAYER.

TARANTO, Circuit Judge.

Between November 2019 and August 2020, Core Opti-

cal Technologies, LLC filed complaints in the U.S. District

Court for the Central District of California alleging in-

fringement of U.S. Patent No. 6,782,211 by three groups of

defendants led by Nokia Corp., ADVA Optical Networking

SE, and Cisco Systems, Inc. (collectively, Nokia). In Au-

gust 2021, Nokia moved for summary judgment, arguing

that Core Optical lacked standing to assert the ’211 patent

even though the inventor, Dr. Mark Core, had assigned the

patent to Core Optical in 2011. Nokia’s argument was that

the 2011 assignment was ineffective because Dr. Core had

already assigned the patent rights to TRW Inc., his em-

ployer at the time of invention, through an August 1990

employment-associated agreement with TRW. The district

court agreed with Nokia and therefore granted Nokia sum-

mary judgment. Core Optical Technologies, LLC v. Nokia

Corp., No. 19-cv-02190, 2022 WL 4596547 (C.D. Cal. Aug.

4, 2022) (Decision). Core Optical appeals. We have

Case: 23-1001 Document: 62 Page: 3 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

jurisdiction under 28 U.S.C. § 1295(a)(1). We vacate the

district court’s judgment and remand for further proceed-

ings.

Dr. Core’s employment at TRW began in August 1990,

at which time Dr. Core signed a “TRW Invention Agree-

ment.” J.A. 3515–16, 6760–61. In the agreement, Dr. Core

agreed to disclose to TRW and automatically assign to

TRW all of his inventions that “relate to the business or

activities of TRW” and were “conceived, developed, or re-

duced to practice” during his employment with TRW. J.A.

3515. But the agreement included an important exception:

9. Non-TRW Inventions. I understand that

this Agreement does not require me to assign to

TRW my rights to an INVENTION for which no

equipment, supplies, facility, or trade secret infor-

mation of TRW was used and which was developed

entirely on my own time, and (a) which does not re-

late (1) to the business of TRW or (2) to TRW’s ac-

tual or demonstrably anticipated research or

development, or (b) which does not result from any

work performed by me for TRW. Nevertheless, I

shall disclose to TRW those INVENTIONS referred

to in this paragraph 9 to enable TRW to determine

if it has an interest therein.

J.A. 3515 (italicized emphasis added).

In 1993, Dr. Core was accepted into the University of

California, Irvine’s PhD program and, soon after, was ac-

cepted into TRW’s fellowship program based on the PhD

program enrollment. J.A. 6774–75, 6814. Several features

of the TRW fellowship have been central in this appeal.

While he was a fellow, Dr. Core continued to work as a sal-

aried employee at TRW but with a reduction in the number

of hours he would; and did work, like a non-fellow

Case: 23-1001 Document: 62 Page: 4 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

employee, on specific TRW-assigned commercial tasks; and

TRW paid him wages to match the reduced number of such

hours. J.A. 6770–71. TRW also paid Dr. Core, while he

was a fellow, a monthly stipend and full employee benefits

such as medical insurance, sick pay, and pension accrual.

J.A. 6771, 6774–75. Still further, TRW paid Dr. Core’s tu-

ition and fees and generally reimbursed him for the costs

of books and supplies for the PhD program. J.A. 6770,

6774. As a condition of receiving all those fellowship ben-

efits, Dr. Core was required to pursue a degree sufficiently

related to his job responsibilities; meet regularly with a

TRW sponsor to discuss degree progress; and return to

TRW for at least one year of full-time employment after

completing his degree (or instead pay back to TRW certain

degree-related costs, like the tuition and stipend). J.A.

3872, 6767–74, 9379–82.

The summary-judgment record indicates that, in the

course of his PhD research, Dr. Core conceived of and re-

duced to practice the invention claimed in the ’211 patent;

indeed, Dr. Core admitted that his PhD dissertation is “es-

sentially identical” to the provisional patent application

that turned into the ’211 patent. J.A. 6787–88. That re-

search (and the ’211 patent) concerned certain techniques

for improving optical signaling. The resulting patent de-

scribed, and claimed in various ways, using “a receiving de-

vice including a cross polarization interference canceler

(XPIC)” where “the XPIC optimizes bandwidth efficiency of

an optical link by enabling the reconstruction of two optical

signals transmitted with generally orthogonal polarization

states and routed over a single fiber optic transmission me-

dium in the same frequency band.” ’211 patent, col. 3, lines

10–18. The asserted advance was to effectively increase

the amount of information that can be communicated in a

particular optically transmitted signal (composed of or-

thogonal “vertical” and “horizontal” components) by trans-

mitting and receiving two independent but superimposed

signals, one on each orthogonal component, and using an

Case: 23-1001 Document: 62 Page: 5 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

XPIC to reduce or eliminate interference between the two

orthogonal components upon receipt of the signal. See J.A.

5219–20 ¶¶ 21–22; see also Core Optical Opening Br. at 7–

8; Nokia Response Br. at 7–9.

The provisional patent application that issued as the

’211 patent was filed on November 5, 1998. J.A. 110. Dr.

Core’s dissertation was approved and archived on Decem-

ber 21, 1998, and Dr. Core obtained his PhD on March 19,

1999. J.A. 6819. Dr. Core’s employment with TRW came

to an end in August 2000. J.A. 6760. In August 2011, Dr.

Core executed an assignment of the ’211 patent from him-

self to Core Optical (his company) and recorded that as-

signment with the U.S. Patent & Trademark Office. J.A.

6540–43.

In some respects, Core Optical and Nokia produced

competing evidence related to Dr. Core’s PhD research ac-

tivities and to various potential ownership interests in the

’211 patent. Core Optical presented evidence that Dr. Core

was careful not to work on his PhD research while “on the

clock”

at TRW and not to use TRW equipment, facilities,

or supplies when working on his PhD research. See J.A.

6819; see also J.A. 5225–26 ¶¶ 42–44; J.A. 5238–39 ¶ 87;

J.A. 5240–41 ¶¶ 93–96; J.A. 6528–31 ¶¶ 6–13. Nokia,

while disputing the significance of that evidence, does not

point us to contrary evidence on those points. See, e.g.,

Nokia Response Br. at 20, 24–25. The record also suggests

that TRW and its successor Northop Grumman (which ac-

quired TRW in 2002) did not assert ownership of the ’211

patent for a very considerable period. Core Optical identi-

fied evidence that TRW itself did not assert such an

We use this phrase, or its opposite “off the clock,”

in the sense Core Optical uses them: The phrase “on the

clock” means time spent working on TRW’s business pro-

jects, tracked in TRW’s timekeeping system, using TRW’s

job numbers. See Core Optical Opening Br. at 26–27.

Case: 23-1001 Document: 62 Page: 6 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

ownership interest, whether in communications with Dr.

Core or otherwise, and that Dr. Core’s former project man-

ager at TRW disclaimed any such TRW ownership interest

directly to Dr. Core. J.A. 5242 ¶ 101; see also J.A. 6530

¶ 11–12. There is also evidence that Northrop Grumman,

for its part, despite knowledge of Core Optical’s assertion

of the ’211 patent in unrelated litigation at least as of 2014,

J.A. 5242–43 ¶¶ 102–03, did not assert an ownership inter-

est in the patent at least until, around March 2016, Core

Optical’s attorneys communicated with Northrop Grum-

man’s corporate counsel. J.A. 9572–73.

This litigation began when, between November 2019

and August 2020, Core Optical filed complaints in the Cen-

tral District of California alleging infringement of the ’211

patent by the defendants we call “Nokia” collectively. J.A.

37–40 (Nokia Corp. et al.); J.A. 64–67 (ADVA Optical Net-

working SE et al.); J.A. 89–90 (Cisco Systems, Inc.). In Au-

gust 2021, Nokia moved for summary judgment, asserting

that Core Optical lacked standing to sue for patent in-

fringement because Northrop Grumman, not Core Optical,

owns the ’211 patent as the successor to TRW. The as-

serted basis for TRW’s ownership was that the patent was

automatically assigned to TRW under the August 1990 in-

vention agreement between it and Dr. Core. J.A. 3444–70.

The district court agreed and granted Nokia summary

judgment. Decision, at *22. The determinative issue was

whether the exception stated in the above-quoted para-

graph 9—to the otherwise-applicable assignment provision

of the invention agreement—applied to the ’211 patent’s in-

vention. The district court understood that three require-

ments had to be met for an invention to come within

paragraph 9 and thus constitute a “Non-TRW Invention”:

“1) [N]o equipment, supplies, facility, or trade secret infor-

mation of TRW were used in the invention process; 2) the

invention was developed entirely on the employee’s own

Case: 23-1001 Document: 62 Page: 7 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

time; and 3) (a) the invention does not relate to the busi-

ness of TRW or to TRW’s actual or demonstrably antici-

pated research or development, or (b) does not result from

any work performed by the employee for TRW.” Id. at *10.

The court concluded that, for requirements (1) and (3), Core

Optical presented evidence that they were met or could, in

a factual adjudication, be found to be met. Id. at *10–19.

The decisive question for summary judgment, then, was

whether Core Optical could establish that it met require-

ment (2).

The district court concluded, as a matter of law, that on

the evidence of record requirement (2) was not met, war-

ranting summary judgment of non-ownership by Core Op-

tical. Id. at *19–21. The court determined that the time

Dr. Core spent on his PhD research—during which he de-

veloped the claimed invention—was at least in part “TRW

[t]ime” and not “entirely” Dr. Core’s “own time.” Id. The

court found particularly critical that (1) Dr. Core actively

sought out TRW funding, through the fellowship program,

to support his PhD research, (2) Dr. Core received such

funding from TRW, including a monthly stipend, tuition,

fees, and full-time employee benefits, and (3) TRW benefit-

ted from Dr. Core’s participation in his PhD program. Id.

at *20–21. On that basis, the district court concluded that

the invention agreement’s paragraph 9 was unambiguous

in not reaching the ’211 patent, which, therefore, Dr. Core

had automatically assigned to TRW, depriving Core Opti-

cal of standing to bring the present action. Id. at *21 (in-

voking the automatic-assignment principle of Filmtec

Corp. v. Allied-Signal Inc., 939 F.2d 1568, 1570–72 (Fed.

Cir. 1991)).

The district court entered final judgments on Septem-

ber 14, 2022. J.A. 32, 34, 36. Core Optical filed timely no-

tices of appeal on September 28, 2022, J.A. 10001–02,

16763, 16848–51, 20281–82, within the thirty days allowed

by 28 U.S.C. § 2107(a). We have jurisdiction to decide

these appeals under 28 U.S.C. § 1295(a)(1).

Case: 23-1001 Document: 62 Page: 8 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

We review the district court’s grant of summary judg-

ment de novo, following Ninth Circuit law and asking if

there is no genuine dispute of material fact, so that the mo-

vant is entitled to judgment as a matter of law when the

evidence is viewed in the light most favorable to the non-

movant. Treehouse Avatar LLC v. Valve Corp., 54 F.4th

709, 714 (Fed. Cir. 2022) (citing Fed. R. Civ. P. 56(a); San

Diego Police Officers’ Association v. San Diego City Employ-

ees’ Retirement System, 568 F.3d 725, 733 (9th Cir. 2009);

Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255, 257

(1986)).

“[I]n a patent infringement action, ‘the plaintiff must

demonstrate that it held enforceable title to the patent at

the inception of the lawsuit’ to assert standing.” Abraxis

Bioscience, Inc. v. Navinta LLC, 625 F.3d 1359, 1364 (Fed.

Cir. 2010) (quoting Paradise Creations, Inc. v. UV Sales,

Inc., 315 F.3d 1304, 1309–10 (Fed. Cir. 2003)). “Applica-

tions for patent, patents, or any interest therein, shall be

assignable in law by an instrument in writing.” 35 U.S.C.

§ 261. For a patent-assignment agreement, “state law gov-

erns the interpretation of contracts generally,” though

“whether a patent assignment clause creates an automatic

assignment or merely an obligation to assign is intimately

bound up with the question of standing in patent cases”

and is therefore a “matter of federal law.” DDB Technolo-

gies, L.L.C. v. MLB Advanced Media, L.P., 517 F.3d 1284,

1290 (Fed. Cir. 2008).

The 1990 invention agreement does not specify which

State’s law governs its interpretation. J.A. 3515. But the

district court applied California contract law, noting that

both parties had cited California case law as the relevant

authority in their summary-judgment briefs. See Decision,

at *10 n.6. On appeal, no party has challenged the choice

of California contract law, so we follow the district court in

that respect.

Case: 23-1001 Document: 62 Page: 9 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

Under California law, “[t]he fundamental goal of con-

tractual interpretation is to give effect to the mutual inten-

tion of the parties.” City of Atascadero v. Merrill Lynch,

Pierce, Fenner & Smith, Inc., 68 Cal. App. 4th 445, 473–74

(1998) (collecting authorities), as modified on denial of

reh’g (Jan. 6, 1999). “When a contract is reduced to writing,

the intention of the parties is to be ascertained from the

writing alone, if possible.” California Civil Code § 1639.

But if the language of the written agreement does not un-

ambiguously establish how the agreement applies on the

point in dispute, courts may consider other “objective man-

ifestations” of mutual intent, including “extrinsic evidence

of such objective matters as the surrounding circumstances

under which the parties negotiated or entered into the con-

tract; the object, nature and subject matter of the contract;

and the subsequent acts and conduct of the parties.” City

of Atascadero, 68 Cal. App. 4th at 474 (collecting authori-

ties).

“When a dispute arises over the meaning of contract

language, the court must decide whether the language is

‘reasonably susceptible’ to the interpretations urged by the

parties.” Badie v. Bank of America, 67 Cal. App. 4th 779,

798 (1998) (quoting Oceanside 84, Ltd. v. Fidelity Federal

Bank, 56 Cal. App. 4th 1441, 1448 (1997)). “Whether the

contract is reasonably susceptible to a party’s interpreta-

tion can be determined from the language of the contract

itself or from extrinsic evidence of the parties’ intent.” Id.

(cleaned up) (quoting Oceanside 84, 56 Cal. App. 4th at

1448). “If the contract is capable of more than one reason-

able interpretation, it is ambiguous, and it is the court’s

task to determine the ultimate construction to be placed on

the ambiguous language by applying the standard rules of

interpretation in order to give effect to the mutual inten-

tion of the parties.” Id. (citations omitted).

The Ninth Circuit reviews “de novo the determinations

of whether contract language is ambiguous and ‘whether

the written contract is reasonably susceptible of a proffered

Case: 23-1001 Document: 62 Page: 10 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

meaning.’” U.S. Cellular Investment Co. v. GTE Mobilnet,

Inc., 281 F.3d 929, 934 (9th Cir. 2002) (cleaned up) (first

citing Tyler v. Cuomo, 236 F.3d 1124, 1134 (9th Cir. 2000);

and then quoting Brinderson Newberg Joint Venture v. Pa-

cific Erectors, 971 F.2d 272, 277 (9th Cir. 1992)).

III

The district court, concluding that there was no genu-

ine issue of material fact, held on summary judgment that

the 1990 invention agreement’s phrase “developed entirely

on my own time” does not encompass Dr. Core’s PhD re-

search, which undisputedly led to the invention claimed in

the ’211 patent. It based that determination on the TRW

fellowship program that supported Dr. Core to enable him

to undertake and complete his PhD studies. We conclude

that the entirely-own-time phrase does not unambiguously

express a mutual intent to designate either all the time Dr.

Core spent performing his PhD research as his own time

(as Core Optical contends) or some of it as partly TRW’s

time (as the district court, in agreement with Nokia, held).

Further inquiry into pertinent facts to resolve the ambigu-

ity is needed. We therefore vacate the district court’s judg-

ment and remand for further proceedings.

Besides raising the issue discussed in text, Core

Optical asks us to hold that the invention agreement, pre-

dating the invention at issue, did not effect a lawful assign-

ment of the resulting patent, which, Core Optical urges,

would require a post-invention act of assignment by Dr.

Core. Core Optical recognizes that, to adopt this position,

we would have to overrule Filmtec, 939 F.2d 1568. It suf-

fices here to say, without suggesting doubt about Filmtec,

that “[a]s a panel, we are bound by Filmtec; we cannot over-

rule that holding without en banc action.” Shukh v.

Case: 23-1001 Document: 62 Page: 11 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

The record before the district court established certain

facts that are not genuinely disputed for purposes of decid-

ing the motion for summary judgment. Dr. Core sought

funding for his PhD studies through TRW’s fellowship pro-

gram; TRW provided that funding, the PhD studies being

sufficiently connected to TRW’s business; and TRW ex-

pected to benefit from Dr. Core’s participation in TRW’s fel-

lowship program at least through Dr. Core’s return to full-

time employment for one year after the completion of his

PhD. See Decision, at *20–21. TRW’s fellowship program

required Dr. Core’s PhD research to “be in an engineering

or scientific field of study related to [his] current or antici-

pated job responsibilities” and also required Dr. Core to

have an internal TRW “sponsor . . . with whom [he] met

regularly to discuss [his] educational or research progress.”

J.A. 6814–15, 9330; Decision, at *5. In at least those ways,

TRW conditioned the receipt of a substantial benefit (Dr.

Core’s monthly stipend, PhD tuition, and fees), in part, on

Dr. Core’s performance of his PhD research, itself of benefit

to TRW. J.A. 6770–71, 6774–75.

Core Optical and Nokia offer competing views as to

what it means for an invention to be “developed entirely on

[Dr. Core’s] own time.” J.A. 3515. In Core Optical’s view,

TRW’s time is any time Dr. Core spent working “on the

clock” on commercial projects at TRW’s specific direction,

and Dr. Core’s “own time” is everything else (including his

PhD research). See Core Optical Opening Br. at 21. Nokia,

by contrast, asserts that TRW’s time also includes any time

Dr. Core spent participating in the TRW fellowship pro-

gram, with its substantial support conditional on pursuing

Seagate Technology, LLC, 803 F.3d 659, 663 (Fed. Cir.

2015).

Case: 23-1001 Document: 62 Page: 12 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

the PhD work, reporting on the work, and returning to

TRW for a period. Nokia Response Br. at 26.

We conclude that the entirely-own-time phrase does

not itself decisively compel either interpretation. More

specifically and narrowly, it does not resolve, as a matter

of law, the contract dispute about applicability of the

phrase on the just-noted facts.

The phrase at the root of the entirely-own-time phrase

is the somewhat colloquial phrase “on one’s own time”—

which paragraph 9 uses with “my” instead of “one’s” (be-

cause it is written in the first person from the employee-

signatory’s perspective) and then narrows by adding “en-

tirely.” The invention agreement does not define the

phrase, but “on one’s own time,” in its most general ordi-

nary meaning, refers to “in one’s free time,” see On One’s

Own Time, The Free Dictionary, https://idioms.thefreedic-

tionary.com/on+one%27s+own+time—carrying an implicit

reference to some other person and indicating freedom

from having to account in some way to that other person

for what the “one” does during the time at issue. In a

schoolroom, this might be time when a student is free not

to do teacher-assigned work or to attend to the teacher’s

instruction. In the employment context that is relevant

here, it refers to an employee’s not being accountable to the

employer—through conditions on payment—for what the

employee does during the time at issue (e.g., when on

break, after hours), whether pay is an hourly wage or a sal-

ary. See Time: On One’s Own Time, The New Oxford Amer-

ican Dictionary 1775 (2001) (“outside working hours;

without being paid”); Time: On One’s Own Time, Webster’s

Third New International Dictionary 2395 (2002) (“without

being paid (has done extra work on his own time)”); On

One’s Own Time, The Free Dictionary, https://idioms.the-

freedictionary.com/on+one%27s+own+time.

Case: 23-1001 Document: 62 Page: 13 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

In the present case, Dr. Core urges that the relevant

notion of accountability is limited to on-the-clock company-

assigned work for the hourly pay—so all other time was

entirely his own. The theory is that his own time was time

when he was not subject to the type of direction and control

that characterizes an employment relationship (this direc-

tion and control not existing when he was working on his

thesis). Nokia, by contrast, invokes a broader notion of ac-

countability through employer pay, covering payments

from TRW conditioned on what Dr. Core did during the

time at issue—the many hours (perhaps thousands of

hours from 1993 to 1999) he spent during his PhD studies

developing the ’211 patent’s invention. The language alone

does not clearly indicate which accountability notion is the

appropriate one for this setting.

In particular, the contract phrase does not compel one

choice or another between two different perspectives on Dr.

Core’s PhD studies during the years in question—perspec-

tives that provide different answers to the question of cov-

erage on the facts here. Putting aside the on-the-clock

hours (see supra note 1), Dr. Core was generally free of ac-

countability to TRW for how he used any particular hour

or even day: Except perhaps for things like attending class

at university-specified hours where required to stay in the

PhD program, he could use particular hours or days any

way he wished, with no accountability to TRW. But Dr.

Core was not free to use the entirety of his off-the-clock

hours any way he wished without accountability to TRW.

His participation in the fellowship program, with its sub-

stantial funding, e.g., tuition and a stipend, was dependent

on his actual pursuit of his PhD research, so he had to

spend a large chunk of his off-the-clock time in ways for

which he was accountable, financially, to TRW. The con-

tract language, “entirely on [his] own time,” allows either

perspective, though the first would support Core Optical

and the second would support Nokia.

Case: 23-1001 Document: 62 Page: 14 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

That ambiguity was not resolved by other documents

governing TRW’s relationship with Dr. Core. TRW’s fel-

lowship-related paperwork generally states that the inven-

tion agreement “will remain in force during the entire

fellowship.” J.A. 6773, 9382. TRW thus contemplated the

fellowship program and the invention agreement in con-

junction with each other. But it did nothing to clarify what

the relationship was for paragraph 9 (“Non-TRW Inven-

tions”) generally or the entirely-own-time phrase specifi-

cally: All it said was that the agreement remains in force

during the fellowship, without saying how it applies to on-

the-clock or off-the-clock inventions.

No case law cited to us provides a resolution of the un-

certainty. We may limit our discussion to the two state-

court decisions on which the district court principally re-

lied; if, as we conclude, those decisions do not resolve the

issue, neither do other decisions cited by the parties. Nei-

ther offers an interpretation of a contract provision con-

taining this language or provides sufficient support, even

indirectly, to resolve the uncertainty here.

The district court relied on Cubic Corp. v. Marty, 185

Cal. App. 3d 438 (1986). There, an employee (Marty) had

presented to his employer (Cubic) a manuscript laying out

a technological idea that he developed while an employee

and that he asserted to be the invention in the dispute that

ensued, and after the manuscript was provided to Cubic,

circuitry needed to make the idea work “was developed

with the aid of a Cubic employee on Cubic time under a

Cubic funded program.” Id. at 452–53; see id. at 444–45.

Without telling Cubic, Marty sought and obtained a patent

on the idea; then, he promptly sought to license it to Cubic,

which responded by asserting that it owned the patent un-

der an invention-assignment agreement Marty had signed

when he became an employee. Id. at 444–45. Marty and

Cubic soon parted ways, and Cubic sued Marty for breach

Case: 23-1001 Document: 62 Page: 15 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

of the invention agreement. After the trial court ruled for

Cubic, the court of appeals affirmed. Id. at 446, 457.

Unlike the 1990 invention agreement at issue in the

present case, the invention agreement in Cubic did not in-

volve entirely-own-time language, id. at 444 (quoting

agreement), so the decision in Cubic does not pronounce on

the meaning of that language in a contract. Rather, the

Cubic case involved a dispute about whether the agree-

ment there, as applied to the particular facts, was contrary

to California Labor Code § 2870—a statutory protection for

employees that, as the parties here agree, contains lan-

guage similar to that of paragraph 9 of the 1990 TRW in-

vention agreement, specifically, entirely-own-time

language.

California Labor Code § 2870 currently reads (with

emphasis added):

(a) Any provision in an employment agreement

which provides that an employee shall assign, or

offer to assign, any of his or her rights in an inven-

tion to his or her employer shall not apply to an in-

vention that the employee developed entirely on his

or her own time without using the employer’s

equipment, supplies, facilities, or trade secret in-

formation except for those inventions that either:

(1) Relate at the time of conception or re-

duction to practice of the invention to the

employer’s business, or actual or demon-

strably anticipated research or develop-

ment of the employer; or

(2) Result from any work performed by the

employee for the employer.

Case: 23-1001 Document: 62 Page: 16 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

The disputed issues of compliance with § 2870 actually

decided by the court of appeals in Cubic, however, were not

about the entirely-own-time language. Rather, they were

about enumerated requirement (1), concerning the relation

to Cubic’s business—a requirement that is not at issue in

the appeal before us. Cubic, 185 Cal. App. 3d at 451–53.

Specifically, the state court of appeals noted that the trial

court had found the entirely-own-time requirement not to

be met (by Marty’s manuscript), but the court of appeals

decided only that “[e]ven if” it were met, requirement (1) of

the statute was not met. Id. at 453.

The court of appeals then spoke of the entirely-own-

time provision while noting that it “need not decide the is-

sues” raised by that provision. Id. It said that it saw “sub-

stantial evidence to support the trial court’s conclusion

Marty did not develop the invention entirely on his own

time since he used Cubic personnel and funding to add cir-

cuitry which was necessary to make his invention work.”

Id. And it added:

[W]e do not think the Labor Code provisions

were intended to award an invention to an em-

ployee who presents an invention to an employer,

represents the invention is for the employer’s ben-

efit, actively seeks and obtains company funding to

refine his invention, uses company time and fund-

ing to develop his invention while all the time se-

cretly intending to take out a patent on the

invention for himself.

Id.

See Whitewater West Industries, Ltd. v. Alleshouse, 981

F.3d 1045, 1047 (Fed. Cir. 2020) (quoting § 2870(a)); Core

Optical Opening Br. at 21 (noting resemblance); Nokia Re-

sponse Br. at 11 (same). Though the wording has changed,

§ 2870(a) was materially the same at the time of Cubic.

Case: 23-1001 Document: 62 Page: 17 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

Thus, Cubic did not involve the meaning of a contract

provision containing the here-disputed language or a fel-

lowship program like the one at issue here. It involved a

statute that, we have noted, provides protection only for

employees, not a contract containing both employee and

employer protections. See Applera Corp.—Applied Biosys-

tems Group v. Illumina, Inc., 375 F. App’x 12, 17 (Fed. Cir.

2010) (nonprecedential) (quoted in Decision, at *11). And

the Cubic court ruled for the employer on facts materially

stronger for the employer than those present here. In these

circumstances, we see no basis for finding in Cubic a reso-

lution of the present contract dispute that supports sum-

mary judgment.

The district court also relied on Dimmig v. Workmen’s

Compensation Appeals Board, 495 P.2d 433 (Cal. 1972),

but that decision also supplies no sufficient basis to resolve

the present matter at summary judgment. William Dim-

mig was killed in an automobile accident while returning

home from night classes he was taking to obtain a bache-

lor’s degree, and his survivors sought workers’ compensa-

tion benefits. The California Supreme Court “annulled”

the state agency’s denial of the benefits and remanded for

further proceedings. Id. at 439.

The governing standard—whether the employee was

injured in the course of employment—was a statutory one

that, the court heavily stressed, is subject by legislative di-

rective to a “‘liberal construction’” in favor of employees.

Id. at 436–37 (quoting Pacific Indemnity Co. v. Industrial

Accident Commission, 159 P.2d 625, 628 (Cal. 1945)). In

explaining the resulting broad standard, the court noted an

earlier decision finding the standard to be met for “an in-

jury suffered by a camp counselor while horseback riding

on her own time” where “‘recreational horseback riding was

considered by both employer and employee as part of the

compensation’” and “‘such consideration was the practice of

the employer.’” Id. at 436 (quoting Reinert v. Industrial

Case: 23-1001 Document: 62 Page: 18 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

Accident Commission, 294 P.2d 713, 716 (Cal. 1956)). Sur-

veying cases on certain relevant doctrines, the court stated:

The rule which emerges from these cases is

that when the employee engages in a special activ-

ity which is within the course of his employment,

and which is reasonably undertaken at the request

or invitation of the employer, an injury suffered

while traveling to and from the place of such activ-

ity is also within the course of employment and is

compensable.

Id. at 439.

The court “concluded that the elements of this test are

met in the instant case.” Id. The court pointed to the em-

ployer’s policy of “encouraging its employees to attend col-

lege and, upon successful completion of a particular course,

. . . reimburs[ing] the entire cost of tuition and books for

courses directly related to the employee’s job and 50 per-

cent of such costs for courses not directly related to the job

but required for the degree being sought.” Id. at 434. It

noted the uncontradicted “substantial testimony that Dim-

mig believed a bachelor’s degree was required for his con-

tinued employment.” Id. at 435.

The Dimmig case involved education benefits but not

an invention agreement or even a statutory provision di-

rected to invention ownership, let alone one containing the

entirely-own-time language at issue. It involved a notably

different statutory context—workers’ compensation—with

a specific pro-employee construction principle. What the

California Supreme Court said and decided in Dimmig

does not carry over to resolve the textual uncertainty pre-

sent here for summary-judgment purposes.

We conclude that the 1990 invention agreement “is ca-

pable of more than one reasonable interpretation,” so in-

quiry beyond the language of the contract is needed to

Case: 23-1001 Document: 62 Page: 19 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

“determine the ultimate construction to be placed on the

ambiguous language,” “applying the standard rules of in-

terpretation in order to give effect to the mutual intention

of the parties.” Badie, 67 Cal. App. 4th at 798; see Brown

v. Goldstein, 34 Cal. App. 5th 418, 432, 438–39 (2019).

Both Core Optical’s and Nokia’s views of how the years-

long, TRW-funded research was intended to be treated un-

der the 1990 invention agreement are plausible on the un-

disputed facts we have recited, but which is ultimately the

better view has not been determined with a recognition

that the contract language lacks an unambiguous meaning

as applied to the facts. The determination of mutual inten-

tion appears to call for findings of fact inappropriate for

summary judgment. Cf. Decision, at *9 n.4 (noting some

factual disputes). But we leave that procedural point to be

decided as an initial matter on remand, where the analysis

will now proceed on the premise that the contract language

does not itself resolve the matter.

We do not undertake to identify all facts that, under

California contract law, might be material. We note the

evidence that, despite a recorded assignment from Dr. Core

to Core Optical at the Patent Office, J.A. 6540–43, TRW

and its successor Northrop Grumman did not assert own-

ership for a very long time. See J.A. 6835 ¶ 201 (citing J.A.

5242 ¶ 103) (Core Optical asserting that “[n]either

Northrop nor TRW has ever claimed to Core Optical or to

any other entity that it owns the ’211 patent”). Nokia has

suggested an explanation for the silence (that the value of

ownership was not worth the costs of establishing it), see

Oral Arg. at 27:50–29:50, but how to account for the silence

raises a factual issue that has not been fully explored or

resolved on the record before us.

We note, as well, Core Optical’s evidence that Dr.

Core’s former project manager at TRW affirmatively repre-

sented to Dr. Core that Dr. Core owned the ’211 patent and

that TRW maintained no ownership interest in it. J.A.

6793 ¶ 70; J.A. 5242 ¶ 101; see also J.A. 6530 ¶ 11 (Dr.

Case: 23-1001 Document: 62 Page: 20 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

Core’s immediate supervisor at TRW expressing a similar

understanding of the 1990 invention agreement in a 2015

declaration). Such a representation appears relevant to

applying the contract language we have concluded is am-

biguous on the point in dispute. See DDB, 517 F.3d at 1292

(“Here, evidence that the parties during performance

agreed that [the employee-inventor’s] work leading to the

patents in suit was not covered by the agreement would be

highly relevant, if not dispositive.”). Core Optical’s asser-

tion about the TRW employee’s representation raises a fac-

tual issue not fully explored or resolved on the record before

us.

In addition, evidence of custom, usage, and practice in

a field is sometimes relevant to determining mutual intent

when commonly used language is on its face uncertain in

meaning. Southern Pacific Transportation Co. v. Santa Fe

Pacific Pipelines, Inc., 74 Cal. App. 4th 1232, 1244 (1999)

(“[T]his extrinsic evidence was relevant and admissible to

prove usage or custom of the industry. . . . Parties are pre-

sumed to contract pursuant to a fixed and established us-

age and custom of the trade or industry. Contract terms

must be interpreted according to any special meaning

given to them by usage, and technical terms are inter-

preted as generally understood in the industry.” (citations

omitted)); see also California Civil Code § 1645 (“Technical

words are to be interpreted as usually understood by per-

sons in the profession or business to which they relate, un-

less clearly used in a different sense.”); Brown, 34 Cal. App.

5th at 438–39; Varni Bros. Corp. v. Wine World, Inc., 35

Cal. App. 4th 880, 889 (1995); Midwest Television, Inc. v.

Scott, Lancaster, Mills & Atha, Inc., 205 Cal. App. 3d 442,

451 (1988). At least in the abstract, evidence falling within

this category would seem significant in the present setting

if similar enough employer-funded education programs are

common. This is a subject worth exploring on remand.

Case: 23-1001 Document: 62 Page: 21 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

An additional principle (contra proferentem) may bear

on the ultimate interpretation of the 1990 invention agree-

ment. The California Supreme Court has explained:

[A]mbiguities in written agreements are to be

construed against their drafters. ([California Civil

Code] § 1654; [Restatement (Second) of] Contracts,

§ 206 [(American Law Institute 1981)].) As the Re-

statement explains, “Where one party chooses the

terms of a contract, he is likely to provide more

carefully for the protection of his own interests

than for those of the other party. He is also more

likely than the other party to have reason to know

of uncertainties of meaning. Indeed, he may leave

meaning deliberately obscure, intending to decide

at a later date what meaning to assert. In cases of

doubt, therefore, so long as other factors are not de-

cisive, there is substantial reason for preferring the

meaning of the other party.” ([Restatement (Sec-

ond) of] Contracts, § 206 cmt. a).

Thus, where . . . the written agreement has

been prepared entirely by the employer, it is a “well

established rule of construction” that any ambigui-

ties must be construed against the drafting em-

ployer and in favor of the nondrafting employee.

Moreover, “[t]he rule requiring the resolution of

ambiguities against the drafting party ‘applies

with peculiar force in the case of a contract of ad-

hesion. Here the party of superior bargaining

power not only prescribes the words of the instru-

ment but the party who subscribes to it lacks the

economic strength to change such language.’”

Sandquist v. Lebo Automotive, Inc., 376 P.3d 506, 514 (Cal.

2016) (last alteration in original) (most citations omitted).

The United States Supreme Court, in applying the Federal

Arbitration Act, 9 U.S.C. §§ 1–16, has described contra

proferentem as a default rule to be applied when mutual

Case: 23-1001 Document: 62 Page: 22 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

intention cannot be discerned. See Lamps Plus, Inc. v.

Varela, 587 U.S. 176, 186–87 (2019). The district court in

this case should consider the applicability of that principle.

One final note. Because the ownership question is a

threshold “jurisdictional issue of standing” separate from

the merits of Core Optical’s patent-infringement suit, the

district court has the authority to act as the finder of fact

“to resolve the jurisdictional issues.” See DDB, 517 F.3d at

1290–92. In this matter, shifting from summary judgment

to fact-finding does not involve a shift from judge to jury.

For the foregoing reasons, we vacate the district court’s

judgment and remand for further proceedings consistent

with this opinion.

The parties shall bear their own costs.

VACATED AND REMANDED

Case: 23-1001 Document: 62 Page: 23 Filed: 05/21/2024

United States Court of Appeals

for the Federal Circuit

__________________

CORE OPTICAL TECHNOLOGIES, LLC,

Plaintiff-Appellant

NOKIA CORPORATION, NOKIA OF AMERICA

CORPORATION,

Defendants-Appellees

______________________

2023-1001

______________________

Appeal from the United States District Court for the

Central District of California in No. 8:19-cv-02190-JAK-

RAO, Judge John A. Kronstadt.

-------------------------------------------------

CORE OPTICAL TECHNOLOGIES, LLC,

Plaintiff-Appellant

ADVA OPTICAL NETWORKING SE, ADVA

OPTICAL NETWORKING NORTH AMERICA, INC.,

Defendants-Appellees

______________________

2023-1002

______________________

Case: 23-1001 Document: 62 Page: 24 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

Appeal from the United States District Court for the

Central District of California in No. 8:20-cv-01463-JAK-

RAO, Judge John A. Kronstadt.

-------------------------------------------------

CORE OPTICAL TECHNOLOGIES, LLC,

Plaintiff-Appellant

CISCO SYSTEMS, INC.,

Defendants-Appellees

______________________

2023-1003

______________________

Appeal from the United States District Court for the

Central District of California in No. 8:20-cv-01468-JAK-

AGR, Judge John A. Kronstadt.

______________________

MAYER, Circuit Judge, dissenting.

It is undisputed that TRW Inc. paid for Mark Core to

get a Ph.D. while he was working for TRW, J.A. 6774–75,

and that Core received a prorated salary and a stipend

from TRW, as well as full-time benefits and full-time pen-

sion accrual, while he completed his Ph.D. program, J.A.

6771, 6775. There is likewise no dispute that Core’s Ph.D.

thesis related to TRW’s business, J.A. 3782, and that Core

took the technology he developed for this thesis and pa-

tented it, J.A. 6787–88. Indeed, Core acknowledges that

his Ph.D. dissertation was “essentially identical” to the pro-

visional patent application that turned into U.S. Patent

No. 6,782,211. J.A. 6787 (citation and internal quotation

marks omitted). Accordingly, I believe the district court

Case: 23-1001 Document: 62 Page: 25 Filed: 05/21/2024

CORE OPTICAL TECHNOLOGIES, LLC v. NOKIA CORPORATION

correctly granted TRW’s motion for summary judgment af-

ter determining that, as a matter of California law, Core

did not develop the patented invention “entirely on [his]

own time.” Core Optical Techs., LLC v. Nokia Corp., No.

19-cv-02190, 2022 WL 4596547, at *20 (C.D. Cal. Aug. 4,

2022) (citation and internal quotation marks omitted).

Case: 23-1001 Document: 62 Page: 26 Filed: 05/21/2024