United States Court of Appeals 

for the Federal Circuit ______________________ 

IN RE: CSB-SYSTEM INTERNATIONAL, INC.,

Appellant

______________________ 

2015-1832

______________________ 

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. 90/012,210.

______________________ 

Decided: August 9, 2016

______________________ 

BRUCE KOCH, Schmidt LLC, New York, NY, argued 

for appellant. Also represented by THORSTEN SCHMIDT. 

JEREMIAH HELM, Office of the Solicitor, United States 

Patent and Trademark Office, Alexandria, VA, argued for 

appellee Michelle K. Lee. Also represented by THOMAS W.

KRAUSE, AMY J. NELSON. 

______________________ 

Before NEWMAN, MOORE, and STOLL, Circuit Judges.

STOLL, Circuit Judge. 

CSB-System International, Inc. appeals the decision 

of the Patent Trial and Appeal Board upholding an examiner’s rejection of all claims of CSB’s U.S. Patent No. 

5,631,953 as unpatentable over the prior art during an ex 

parte reexamination. CSB argues that the Board construed claims applying an incorrect legal standard and
2 IN RE: CSB-SYSTEM INTERNATIONAL, INC. 

that, regardless of the standard, the Board misconstrued 

claim terms which led to rejection of all claims of the ’953 

patent. We agree with CSB that the Board should have 

applied the Phillips standard of claim construction rather 

than the broadest reasonable interpretation standard 

used by the examiner because the ’953 patent expired 

during the reexamination. We conclude, however, that 

the Board’s claim construction was correct even under the 

Phillips standard, and we affirm its rejection of all claims 

of the ’953 patent as unpatentable over the prior art.

BACKGROUND

CSB is the assignee of the ’953 patent, issued May 20, 

1997, and directed to a circuit arrangement for integrating an electronic data processing (“EDP”) system with 

telephone systems connected to an integrated services 

digital network (“ISDN”) telephone network. Figure 1 

illustrates the arrangement the patent discloses. 
IN RE: CSB-SYSTEM INTERNATIONAL, INC. 3

In this arrangement, telephone line “a” (shown using 

a dotted line) connects individual telephone units 2, 11, 13

directly with an intelligent telephone installation 3, which 

interfaces with the ISDN network 1. A local area network 

(“LAN”) 9, with a LAN server 10, aggregates personal 

computers 4, 12, 14, which each connect to the intelligent 

telephone installation 3 through an integration component 5. The integration component is a computing system 

6 running software 7 and including an ISDN connector 8. 

The ’953 patent contemplates providing data from incoming telephone calls over the LAN to personal computers. For example, when an incoming call is received from 

the ISDN network 1, the intelligent telephone installation 

3 will route the telephone call to one of the telephones 2, 

11, 13 and will send call information to the integration 

component 5. A personal computer, upon having a call 

routed to its associated telephone by the intelligent telephone installation 3, will retrieve call information from 

the integration component via the LAN 9. 

Independent claim 1 of the ’953 patent is representative and recites:

1. A circuit arrangement for integration of EDP 

systems in utilization of telephone systems connected to a public ISDN or Euro ISDN telephone 

network, the circuit arrangement comprising

a plurality of telephone extensions which are 

directly connectable to a telephone network selected from the group consisting of a public ISDN 

telephone network and Euro ISDN telephone 

network; 

a first line; 

an intelligent telephone system arranged so 

that said telephone extensions are connectable 

with said at least one telephone network through 
4 IN RE: CSB-SYSTEM INTERNATIONAL, INC. 

said first line and said intelligent telephone system; 

a plurality of personal computers; 

an integration element arranged between said 

intelligent telephone system and said personal 

computers, said integration element receiving 

signals via at least one connection element selected from the group consisting of an SDLC connection element and an ISDN connection element via 

a second line from said at least one telephone 

network via said intelligent telephone system and 

sending back signals to said at least one telephone network, said integration element also

sending a data record assigned an appropriate information via a third line, via a LAN connected to 

a LAN server by a fourth line and via a fifth line 

to said personal computers and receiving a data 

record from said personal computers again; 

a computing system; and 

a software layer arranged so that a conversion 

of the signals into a data record and vice versa is 

carried by said integration element, by said computing system, by said software layer and by said 

at least one connection element with an internal 

software.

’953 patent col. 5 l. 52 – col. 6 l. 12 (emphases added). 

A third-party requested ex parte reexamination of the 

’953 patent, which was granted. As part of the reexamination proceeding, the examiner construed several of the 

’953 patent’s claim terms. Pertinent here, the examiner 

refused to depart from the plain meaning of the term 

“personal computer” by not, as CSB had argued, inserting 
IN RE: CSB-SYSTEM INTERNATIONAL, INC. 5

a limitation which would exclude personal computers that 

emulate terminals.1 The examiner also declined to adopt 

CSB’s construction of the claim term “LAN server,” which 

sought to read in that the “LAN server” must provide 

shared services to other components on the LAN and to 

respond to requests from clients.

The primary prior art patent considered during the 

reexamination was U.S Patent No. 5,097,528 (“Gursahaney”). Gursahaney is directed to “a subsystem for 

providing a programmable interface between a host based 

application program and a telephone network to automatically transfer operands derived from caller identification 

data from the telephone network to the host application 

program.” Gursahaney col. 1 ll. 50–54. Gursahaney 

discloses a system including “a workstation coupled to a 

telephone network for receiving caller identification data 

and coupled to a host computer running a menu driven 

host application program which exchanges menu images 

with the workstation . . . .” Id. col. 1 ll. 55–58. Gursahaney explains that its workstations “can be an IBM PS/2 

model 80, for example,” id. col. 15 ll. 28–29, with a 

memory which “includes a multi-tasking operating system . . . and a terminal emulation program,” id. col. 16 

ll. 6–10. The workstations in Gursahaney are connected 

to a LAN through which they can access a host computer, 

which in turn provides the workstations with call information. Id. col. 4 ll. 37–48. Figure 4 depicts an embodiment of Gursahaney. 

 

1 A terminal is a device through which data may be 

sent, received, and displayed. E.g., J.A. 9118.
6 IN RE: CSB-SYSTEM INTERNATIONAL, INC. 

The examiner rejected claims 1–6 as anticipated by 

Gursahaney and claims 7–8 as obvious over: (1) Gursahaney in view of U.S. Patent No. 5,046,183 (“Dorst”) and 

U.S. Patent No. 4,995,073 (“Okata”); and (2) Gursahaney

in view of Dorst and U.S. Patent No. 4,652,933 (“Koshiishi”). CSB appealed to the Board, and during the pendency of that appeal, the ’953 patent expired. The Board

nonetheless decided to apply the broadest reasonable 

interpretation (“BRI”) standard when analyzing the claim 

constructions entered by the examiner, ultimately agreeing with the constructions and affirming the examiner’s 

rejection of all claims of the ’953 patent.

CSB appealed to us, and we have jurisdiction under 

28 U.S.C § 1295(a)(4)(A).

DISCUSSION

We review the Board’s ultimate claim construction in 

a reexamination de novo. Teva Pharm. USA, Inc. v. 

Sandoz, Inc., 135 S. Ct. 831, 840–41 (2015); In re Teles AG 

Informationstechnologien, 747 F.3d 1357, 1366 (Fed. Cir.

2014). We review any determinations involving extrinsic 
IN RE: CSB-SYSTEM INTERNATIONAL, INC. 7

evidence for substantial evidence, but in this case “because the intrinsic record fully determines the proper 

construction, we review the Board’s claim constructions 

de novo.” Microsoft Corp. v. Proxyconn, Inc., 789 F.3d 

1292, 1297 (Fed. Cir. 2015) (citing Teva, 135 S. Ct. at 

840–42). 

I.

Typically, claims in issued patents are construed using the framework set forth in Phillips v. AWH Corp.,

which emphasizes considering the plain meaning of the 

claim terms themselves in light of the intrinsic record. 

415 F.3d 1303, 1312–15 (Fed. Cir. 2005) (en banc). During reexamination proceedings of unexpired patents, 

however, the Board uses the “broadest reasonable interpretation consistent with the specification” standard, or 

BRI. In re NTP, Inc., 654 F.3d 1268, 1274 (Fed. Cir. 2011)

(requiring use of BRI in reexamination of unexpired 

patents); cf. Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 

2131, 2145 (2016) (acknowledging Board use of BRI 

during reexamination (citing In re Yamamoto, 740 F.2d 

1569, 1571 (Fed. Cir. 1984))). The rationale for permitting this broader standard in reexaminations is that a 

patent owner before the Patent and Trademark Office 

(“PTO”) with an unexpired patent “may amend claims to 

narrow their scope,” negating any unfairness that may 

otherwise result from adopting the BRI standard. In re 

ICON Health & Fitness, Inc., 496 F.3d 1374, 1379 (Fed. 

Cir. 2007) (citing In re Am. Acad. Of Sci. Tech Ctr., 367 

F.3d 1359, 1364 (Fed. Cir. 2004); Yamamoto, 740 F.2d at 

1571); see also Cuozzo, 136 S. Ct. at 2145–46. Further

justification comes from the fact that constructions unhinged from the patent in which they are found are erroneous even under BRI, as the BRI claim construction 

exercise must always be reasonable and must consider the 

claims “in light of the specification and teachings in the 

underlying patent.” Proxyconn, 789 F.3d at 1298 (quoting

In re Suitco Surface, Inc., 603 F.3d 1255, 1260 (Fed. Cir.
8 IN RE: CSB-SYSTEM INTERNATIONAL, INC. 

2010)). Even so, when an expired patent is subject to 

reexamination, the traditional Phillips construction 

standard attaches. In re Rambus Inc. (Rambus I), 694 

F.3d 42, 46 (Fed. Cir. 2012). 

 The ’953 patent expired on May 20, 2014, after the 

examiner issued a final rejection but before consideration 

by the Board. The Board’s decision acknowledged that 

the patent had expired, but nevertheless applied the BRI

standard. The Board contended that employing BRI was 

proper because CSB had the opportunity to amend its 

patent claims while they were pending before the examiner in the reexamination, as the patent had yet to expire. 

We disagree with the Board’s approach. When a patent expires during a reexamination proceeding, the PTO 

should thereafter apply the Phillips standard for claim 

construction. We hold as much regardless of whether this 

means that the Board applies a different standard than 

the examiner. Our decision in In re Rambus, Inc. (Rambus II), 753 F.3d 1253 (Fed. Cir. 2014) is instructive. In 

Rambus II, the patent undergoing reexamination expired 

after the examiner issued a right of appeal notice. See id. 

at 1255–56; Rambus II Joint Appendix at 64, 130. While 

the Board’s decision did not indicate whether it reviewed 

the examiner’s claim construction under the BRI standard 

or the Phillips standard, see Rambus II Joint Appendix at 

1–54, on appeal we indicated that we must use the Phillips standard because the patent had expired during the 

appeal before the Board. Rambus II, 753 F.3d at 1256; see 

also Facebook, Inc. v. Pragmatus AV, LLC, 582 F. App’x 

864, 868–69 (Fed. Cir. 2014) (non-precedential) (applying 

Phillips standard when patent expired after the Board’s 

reexamination decision pending appeal to the Federal 

Circuit). 

The PTO argues that because the Board operates as a 

tribunal of review for the examiner’s work, the Board 

must scrutinize claims consistent with the standard used 
IN RE: CSB-SYSTEM INTERNATIONAL, INC. 9

by the examiner in the first instance, even after a patent 

has expired. But, if anything, the Phillips standard 

would result in a more narrow claim scope and, consequently, we see little chance of the Board issuing new 

grounds of rejection based on a narrower claim scope. See 

Facebook, 582 F. App’x at 869 (explaining that construction of term under the BRI standard “cannot be narrower” 

than that under the Phillips standard). In many cases, 

the claim construction will be the same under the Phillips

and BRI standards. See, e.g., Proxyconn, 789 F.3d at 1302 

n.1 (noting that the claim term under review had the 

same construction under the BRI and Phillips standards); 

Facebook, 582 F. App’x at 869 (“The broadest reasonable 

interpretation of a claim term may be the same as or 

broader than the construction of a term under the Phillips

standard.”).

We are also not persuaded by the PTO’s argument 

that BRI should apply here because the patent owner 

could have amended its claims while before the examiner. 

The policy underlying our embrace of BRI in limited 

circumstances does not extend to cases where a patent 

expires during a reexamination because the patent owner’s ability to amend is substantially diminished when 

this occurs regardless of the stage of the reexamination. 

Under the PTO’s regulations, a patentee may not amend a 

claim that expires during prosecution. 37 C.F.R. 

§ 1.530(j) (“No amendment may be proposed for entry in 

an expired patent.”). Moreover, patents that expire 

during an appeal to the Board, as in this case, will not be 

issued with amended claims even if the patent owner 

amended them while before the examiner. See Institut 

Pasteur & Universite Pierre Et Marie Curie v. Focarino, 

738 F.3d 1337, 1343 (Fed. Cir. 2013) (holding that, under 

§ 1.530(j), (k), “the PTO may not issue the amended claim 

now that the patent has expired” after the Board issued a 

reexamination decision). Because it is not always clear 

how much time a Board appeal will take and at what 
10 IN RE: CSB-SYSTEM INTERNATIONAL, INC. 

point a patent owner can reopen prosecution and amend 

its claims, and we do not think an inquiry into whether or 

not a patent owner could have amended its claims, or 

speculation as to whether the patent owner could in the 

future have an opportunity to amend its claims, should 

resolve the question. 

In sum, we hold that BRI is not a monolithic standard 

that the Board can use even after a patent expires. 

Rather, consistent with our prior precedent and customary practice, we reaffirm that once a patent expires, the 

PTO should apply the Phillips standard for claim construction.

II.

While we hold that the Board erred in using the BRI 

standard, the Board’s use of BRI did not produce a different result than the one we reach using the Phillips standard. See, e.g., Proxyconn, 789 F.3d at 1302 n.1; Facebook, 

582 F. App’x at 869. Even under the Phillips standard, 

there is no basis for limiting the claims as narrowly as 

CSB argues.

First, contrary to CSB’s arguments, there is no support whatsoever for limiting the broad claim term “personal computer” in the ’953 patent to exclude personal 

computers running software to emulate terminals. In the 

context of the ’953 patent, a personal computer is defined 

by its hardware and computing capability, not by the 

software it happens to run at a point in time. Indeed, the 

specification refers only to PCs generically, with no special or unusual explanation. E.g., ’953 patent col. 2 l. 35 – 

col. 3 l. 14, col. 4 l. 33 – col. 5 l. 17. Nothing in the ’953 

patent suggests that any other understanding should 

apply. Thus, we agree with the Board’s view of “personal 

computer” and decline to import the negative limitation 

sought by CSB. Because CSB’s arguments that Gursahaney does not teach a “personal computer” hinge on its
IN RE: CSB-SYSTEM INTERNATIONAL, INC. 11

proffered construction, we reject CSB’s argument that 

Gursahaney fails to teach a personal computer. 

We are also not convinced by CSB’s argument that the 

term “LAN server” requires embellishment beyond its 

plain meaning. CSB argues that LAN server should be 

construed to expressly require purported characteristics 

of a LAN server, such as providing shared services to 

other components on the LAN and responding to requests 

from clients. At the same time, however, CSB describes 

the Board’s construction of the term as “agreed upon.” 

Appellant Br. 14. Moreover, its specific arguments relate 

to a comparison of the ’953 patent claims to the prior 

art—which is part of the anticipation analysis, reviewed 

for substantial evidence, not claim construction. Id. at 14, 

36–38. Without a “fundamental dispute regarding the 

scope” of this term, construction is not necessary. O2 

Micro Int’l Ltd. v. Beyond Innovation Tech. Co., 521 F.3d 

1351, 1362 (Fed. Cir. 2008). 

Substantial evidence supports the Board’s finding 

that Gursahaney discloses a LAN server. Gursahaney 

discloses that the “workstation components 100 [are] 

connected by a token ring local area network (LAN),” 

Gursahaney col. 4 ll. 37–38, and that these workstations 

“access[] host applications running on the host 200, to 

provide caller-specific information to the service representative,” id. col. 4 ll. 46–48. 

Because there is substantial evidence that Gursahaney discloses the “personal computer” and “LAN server” 

limitations, the Board did not err in rejecting the sole 

independent claim of the ’953 patent, claim 1, as anticipated by Gursahaney. The Board also rejected dependent 

claims 2–6 as anticipated by Gursahaney and claims 7 

and 8 as obvious over Gursahaney in view of several prior 

art references not directly at issue in this appeal. CSB 

makes no particularized argument to support patentability of these dependent claims apart from the arguments it 
12 IN RE: CSB-SYSTEM INTERNATIONAL, INC. 

makes for claim 1, so we also affirm these rejections. 

Having affirmed the Board’s rejection of all claims on 

these grounds, we need not discuss the other prior art 

grounds that the Board found rendered the claims of the

’953 patent unpatentable.

CONCLUSION

For the foregoing reasons, we affirm the Board’s decision to reject all claims of the ’953 patent in view of prior 

art presented during reexamination.

AFFIRMED