NOTE: This disposition is nonprecedential.

United States Court of Appeals 

for the Federal Circuit ______________________ 

HO KEUNG TSE,

Plaintiff-Appellant

v.

APPLE INC., MUSICMATCH, INC., SONY 

NETWORK ENTERTAINMENT INTERNATIONAL 

LLC,

Defendants-Appellees

______________________ 

2015-1639

______________________ 

Appeal from the United States District Court for the 

Northern District of California in No. 4:06-cv-06573-SBA, 

Judge Saundra Brown Armstrong.

______________________ 

Decided: November 5, 2015

______________________ 

HO KEUNG TSE, Hong Kong, China, pro se.

MICHAEL ALLEN JACOBS, Morrison & Foerster, LLP, 

San Francisco, CA, for defendant-appellee Apple Inc. Also 

represented by RICHARD HUNG, ESTHER KIM; BRIAN 

ROBERT MATSUI, Washington, DC. 
2 TSE v. APPLE INC. 

DOUGLAS ETHAN LUMISH, Latham & Watkins LLP, 

Menlo Park, CA, for defendant-appellee MusicMatch, Inc.

Also represented by PATRICIA YOUNG. 

JOHN FLOCK, Kenyon & Kenyon, LLP, New York, NY, 

for defendant-appellee Sony Network Entertainment 

International, LLC. Also represented by MICHELLE

CARNIAUX. 

______________________ 

Before PROST, Chief Judge, REYNA, Circuit Judge, and 

STARK, Chief District Judge.

∗

PER CURIAM. 

This appeal arises from an order of the United States 

District Court for the Northern District of California 

dismissing a patent infringement action filed by the 

plaintiff, Ho Keung Tse, against Apple Inc., MusicMatch, 

Inc., and Sony Network Entertainment International LLC 

(collectively, “Defendants”). Tse asserted claims 1-5, 13, 

16, 17, 20, and 23-26 of U.S. Patent No. 6,665,797 (“’797 

patent”) against the Defendants. The district court dismissed the action based on the doctrine of collateral 

estoppel. The district court noted that the same claims 

were previously found invalid for lack of written description, Tse v. Google, Inc., 2013 WL 6502478 (N.D. Cal Dec. 

11, 2013), and that we summarily affirmed that invalidity 

determination, Tse v. Google, Inc., 571 F. App’x 951 (Fed. 

Cir. 2014). 

Because we agree that Tse’s action is barred by the 

doctrine of collateral estoppel, we affirm the district 

court’s dismissal order.

∗ Honorable Leonard P. Stark, Chief District Judge, 

United States District Court for the District of Delaware, 

sitting by designation.

 
TSE v. APPLE INC. 3

BACKGROUND

On August 5, 2005, Tse filed an action against the Defendants in the District of Maryland alleging infringement of the ’797 patent. The case was then transferred to 

the Northern District of California. On July 24, 2007, the 

Defendants initiated an ex parte reexamination proceeding of all of the asserted claims of the ’797 patent and the 

district court stayed the case pending conclusion of the 

reexamination. While those proceedings were pending, 

Tse sued Google, Inc.; Samsung Telecommunications 

America, LLC; HTC America; and Blockbuster, LLC 

alleging infringement of the same claims of the ’797 

patent that are at issue here. On December 11, 2013, the 

district court in that case (“the Google litigation”) found 

claims 1-5, 13, 16, 17, 20, and 23-36 of the ’797 patent 

invalid for lack of written description under 35 U.S.C. 

§ 112. Tse v. Google, Inc., 2013 WL 6502478, at *6. Tse 

appealed that ruling, and, on July 16, 2014, we summarily affirmed the invalidity determination. Tse v. Google, 

Inc., 571 F. App’x 951 (Fed. Cir. 2014). Tse then petitioned for panel rehearing and rehearing en banc, both of 

which we denied. Tse also filed a petition for writ of 

certiorari from the Supreme Court, which was similarly 

denied. 

The district court in this case issued an order to show 

cause, directing the parties to demonstrate why this 

action should or should not be dismissed based on the 

outcome of the Google litigation. The district court put a 

five-page limit on the submissions. Tse submitted a brief 

pursuant to the district court’s order but did not address 

the applicability of collateral estoppel; instead, Tse primarily argued that the invalidity determination in the 

Google litigation was erroneous. The district court concluded that Tse had ample opportunity in the Google

litigation to argue against invalidity and that the Google

court issued a reasoned and detailed order granting 

summary judgment. Thus, the district court held that Tse 
4 TSE v. APPLE INC. 

was collaterally estopped from re-litigating the validity of 

the same claims from the ’797 patent and dismissed the 

action. Tse appeals from that dismissal. 

DISCUSSION

We apply the law of the regional circuit to the application of collateral estoppel. See Bayer AG v. Biovail Corp., 

279 F.3d 1340, 1345 (Fed. Cir. 2002). In the Ninth Circuit, the availability of collateral estoppel is a mixed 

question of law and fact reviewed de novo. United States 

v. Geophysical Corp. of Alaska, 732 F.2d 693, 697 (9th Cir. 

1984). Once it is determined that collateral estoppel is 

available, the Ninth Circuit reviews a district court’s 

decision to accord preclusion and apply collateral estoppel 

for an abuse of discretion. Dias v. Elique, 436 F.3d 1125, 

1128 (9th Cir. 2006). 

“The doctrine of collateral estoppel applies if (1) the 

issue sought to be precluded from relitigation is identical 

to the issue decided in the earlier proceeding; (2) the issue 

was actually litigated in the former proceeding; (3) the 

issue was necessarily decided in the former proceeding; 

and (4) the person against whom collateral estoppel is 

asserted was a party, or in privity with a party, to the 

earlier proceeding.” Enovsys LLC v. Nextel Commc’ns, 

Inc., 614 F.3d 1333, 1342-43 (Fed. Cir. 2010) (applying 

California law). However, “a judgment of invalidity will 

have no collateral estoppel effect if the patentee can show 

that it did not have a full and fair opportunity to litigate.” 

Pharmacia & Upjohn Co. v. Mylan Pharm., Inc., 170 F.3d 

1373, 1379 (Fed. Cir. 1999) (citing Blonder-Tongue Labs., 

Inc. v. Univ. of Ill. Found., 402 U.S. 313, 329-334 (1971)).

On appeal, Tse first challenges the merits of the invalidity determination in the Google litigation. That challenge fails, however, because the relevant inquiry here is 

whether the district court properly applied collateral 

estoppel, not whether the judgment of invalidity is cor-
TSE v. APPLE INC. 5

rect. Pharmacia & Upjohn, 170 F.3d at 1380 (“[O]ur role 

is limited to reviewing the district court’s application of 

collateral estoppel, not the correctness of the [underlying] 

verdict[].”). 

Tse next relies on language from Blonder-Tongue to 

argue that, because the Google court “wholly failed to 

grasp the technical subject matter,” Tse was unable to 

fully and fairly litigate the validity of the ’797 patent in 

the prior case. Blonder-Tongue, 402 U.S. at 333 (noting 

that a factor in determining whether a patentee has had a 

full and fair chance to litigate is whether “the opinions 

filed by the District Court and the reviewing court, if any, 

indicate that the prior case was one of those relatively 

rare instances where the courts wholly failed to grasp the 

technical subject matter and issues in suit”). This challenge also fails because Tse has not shown that this is 

“one of those relatively rare instances.” Id. In fact, the 

record indicates that the Google court fully grasped the 

technical subject matter and provided a well-reasoned 

order granting summary judgment, which we summarily 

affirmed on appeal. 

Finally, Tse argues that he was denied a full and fair 

opportunity to contest collateral estoppel because he was 

confined to a five-page brief in response to the district 

court’s order to show cause. Tse did not, however, seek 

additional briefing to address the issue of collateral 

estoppel, and, in fact, spent the entire five pages of his 

brief attacking the merits of the underlying judgment. 

Moreover, Tse had the opportunity on appeal to contest 

the collateral estoppel issue and again chose to primarily 

focus on the merits of the invalidity determination. Thus, 

the district court did not err in limiting the submissions 

in response to its order to show cause to five pages. 
6 TSE v. APPLE INC. 

CONCLUSION

For the reasons stated above, we affirm the district 

court’s dismissal of the action due to collateral estoppel.

AFFIRMED