United States Court of Appeals 

for the Federal Circuit 

__________________________ 

INVENTIO AG, 

Plaintiff-Appellant, 

v. 

THYSSENKRUPP ELEVATOR AMERICAS 

CORPORATION, THYSSENKRUPP ELEVATOR 

CORPORATION, AND THYSSENKRUPP ELEVATOR 

MANUFACTURING INCORPORATED, 

Defendants-Appellees. 

__________________________ 

2010-1525 

__________________________ 

Appeal from the United States District Court for the 

District of Delaware in Case No. 08-CV-0874, Judge 

Eduardo C. Robreno. 

____________________________ 

Decided: June 15, 2011 

____________________________ 

PIERRE R. YANNEY, Stroock & Stroock & Lavan LLP, 

of New York, New York, argued for plaintiff-appellant. 

DAVID E. SCHMIT, Frost Brown Todd LLC, of Cincinnati, Ohio, argued for defendants-appellees. 

__________________________ 

Before LOURIE, PROST, and MOORE, Circuit Judges. 
INVENTIO AG v. THYSSENKRUPP 2

LOURIE, Circuit Judge. 

Inventio AG (“Inventio”) appeals from the final judgment of the United States District Court for the District of 

Delaware in favor of ThyssenKrupp Elevator Americas 

Corporation, ThyssenKrupp Elevator Corporation, and 

ThyssenKrupp Elevator Manufacturing Incorporated 

(collectively, “ThyssenKrupp”). See Inventio AG v. 

ThyssenKrupp Elevator Americas Corp., No. 1:08-CV-874, 

Judgment (ECF No. 164) (D. Del. Aug. 4, 2010) (“Final 

Judgment”). The judgment follows the district court’s 

granting of ThyssenKrupp’s motion for summary judgment that the asserted claims of U.S. Patents 6,892,861 

(“the ’861 patent”) and 6,935,465 (“the ’465 patent”) are 

invalid for failure to meet the definiteness requirement of 

35 U.S.C. § 112, ¶ 2. See Inventio AG v. ThyssenKrupp 

Elevator Americas Corp., No. 1:08-CV-874, Order (ECF 

No. 163) (D. Del. Aug. 4, 2010) (“SJ Order”). The district 

court entered summary judgment after concluding that 

the claimed “modernizing device” and “computing unit” 

limitations were means-plus-function limitations subject 

to 35 U.S.C. § 112, ¶ 6 and that the written descriptions 

failed to disclose any corresponding structure. See Inventio AG v. ThyssenKrupp Elevator Americas Corp., No. 

1:08-CV-874, Order (ECF No. 162) (D. Del. Aug. 4, 2010) 

(“Order on Motion for Reargument”); Inventio AG v. 

ThyssenKrupp Elevator Americas Corp., 718 F. Supp. 2d 

529, 542–556, 558–561 (D. Del. 2010) (“Claim Construction Opinion”). Because the district court erred when it 

concluded that the “modernizing device” and “computing 

unit” terms were means-plus-function limitations subject 

to § 112, ¶ 6, we reverse and remand for further proceedings.
3 INVENTIO AG v. THYSSENKRUPP

ORDER ON MOTION TO STRIKE

Before we discuss the merits of Inventio’s appeal, we 

address ThyssenKrupp’s motion to strike. After the 

parties submitted their briefs, ThyssenKrupp filed a 

motion to strike portions of Inventio’s reply brief, arguing 

that it contained new and seriously misleading arguments 

about the disclosure of the ’861 and ’465 patents, mischaracterized legal precedent, misrepresented ThyssenKrupp’s responsive brief, and misrepresented the record in 

this case. 

ThyssenKrupp’s motion lacks merit. It reargues the 

merits of the case. ThyssenKrupp simply disagrees with 

Inventio’s legal arguments, and its motion seems to us to 

be an improper attempt to obtain the final word in the 

appeal, a practice that we strongly discourage. See

Aventis Pharma S.A. v. Hospira, Inc., 637 F.3d 1341, 

1343–44 (Fed. Cir. 2011). Its nasty tone is exemplified by 

use of the word “blatantly” or “blatant” at least four times. 

Thus, ThyssenKrupp’s filing of this motion borders on the 

type of frivolous and wasteful litigation tactics that we 

have previously frowned upon. See Otocom Sys., Inc. v. 

Houston Computer Servs., Inc., 918 F.2d 937, 943–44 

(Fed. Cir. 1990). We accordingly deny ThyssenKrupp’s 

motion and turn to the merits of Inventio’s appeal. 

BACKGROUND

This patent case relates to elevator systems. In general terms, the asserted patents involve “modernizing” a 

conventional elevator system. ’861 patent col.1 ll.6–7.1 In 

a conventional elevator system, a passenger, at the boarding floor, presses the “up/down” buttons on a floor call 

 1 Because the ’861 and ’465 patents contain a common disclosure for the issues presented in this appeal, we 

will cite the ’861 patent for simplicity. 
INVENTIO AG v. THYSSENKRUPP 4

transmitter, which causes a signal, referred to as a “call 

report,” to be sent to the elevator control. Id. col.4 ll.64–

67. The elevator control is the hardware that drives the 

elevator system to transport elevator cars between floors. 

Id. col.4 ll.16–37. The call report, which is generally an 

analog voltage signal, indicates to the elevator control the 

passenger’s boarding floor and may also indicate in which 

direction the passenger desires to travel (up or down). Id.

col.4 ll.64–67, col.5 ll.37–40. After receiving this signal, 

the elevator control dispatches an elevator car to the 

passenger’s floor. Id. col.5 ll.43–49. Once inside the 

elevator car, the passenger selects a floor, which sends a 

second call report to the elevator control and causes the 

elevator system to transport the passenger to the destination floor. Id. col.5 ll.51–58. 

The asserted patents disclose a modernized elevator 

system and a process for modernization. The modernized 

elevator system allows a passenger, at the boarding floor, 

to enter the passenger’s desired destination. Id. col.2 ll.4–

18. As part of the modernization process, new floor terminals replace the original floor call transmitters (i.e., the 

“up/down” buttons), and the new floor terminals allow a 

passenger, at the boarding floor, to input a desired destination floor when requesting an elevator. Id. col.6 ll.3–19. 

The patents also disclose the back-end technology that 

interfaces with the new floor terminals and the conventional elevator control to operate the modernized elevator 

system, and this appeal focuses on those aspects of the 

modernized elevator system. In particular, the patents 

disclose a “modernizing device” and a “computing unit” 

that interface with the new floor terminals and the elevator control to operate the elevator system. Id. col.2 ll.28–

53. Claim 1 of the ’465 patent, reproduced below, is 

representative of the claims on appeal and claims the 
5 INVENTIO AG v. THYSSENKRUPP

method of installing these components to modernize a 

conventional elevator system: 

1. A method of modernizing an elevator installation having at least one elevator controlled by 

at least one elevator control by way of at least 

one call report, comprising: 

a. installing at least one floor terminal at each 

floor served by an elevator controlled by an 

elevator control for at least one of the input of 

destination call reports and for recognition of 

identification codes of users; 

b. installing at least one computing unit and connecting the at least one computing unit to said 

floor terminals for at least one of evaluating 

the destination call reports and association of 

destination floors with recognized ones of the 

identification codes, and for the output of at 

least one destination signal; and 

c. installing at least one modernizing device and 

connecting the at least one modernizing device

to said floor terminals and said at least one 

computing unit for reading the destination 

signal, for converting the destination signal 

into at least one call report and for controlling 

the elevator control by way of the call report. 

’465 patent, col.11 ll.6–25 (emphases added). The written 

descriptions of both patents also show how the “computing unit” and the internal components of the “modernizing 

device” are connected to each other and the elevator 

control: 
INVENTIO AG v. THYSSENKRUPP 6

As shown in the above figure, the modernizing device 

may communicate with both the computing unit and the 

elevator control. The modernizing device may receive 

digital transmissions from the computing unit and convert them into call reports issued to the elevator control. 

Id. col.7 ll.49–60. In addition to converting the digital 

signal into a call report, the modernizing device is also 

capable of receiving call reports and converting them into 

a digital form for processing, either by the modernizing 

device or the computing unit. Id. col.8, ll.54–65, col.9, 

ll.34–67. 

The written descriptions explain how the modernized 

elevator system functions during operation. First, a 

passenger at the boarding floor inputs a destination floor 

to the new floor terminals by manually entering information or providing an identification code to a recognition 

device. Id. col.8 ll.8–14. The computing unit, which is 

connected to the terminals, receives the boarding floor 

and destination floor information and executes a “com-
7 INVENTIO AG v. THYSSENKRUPP

puter program product” to determine, based on that 

information and other data, the optimal use of the elevator cars to transport the passenger to the desired floor. 

Id. col.6 l.27–col.7 l.25, col.8 ll.15–23. The computer 

program product performs the calculation by executing a 

“destination dispatch algorithm.” Id. col.6 l.27–col.7 l.25. 

The computing unit then generates a control signal, 

which includes a series of destination signals, as a result 

of the optimization calculation. Id. col.8 ll.21–24. The 

modernizing device receives the first destination signal, 

converts this digital signal into an analog call report, and 

transmits the call report to the elevator control. Id. col.8 

ll.21–40. The elevator control subsequently processes the 

call report and controls the elevator machinery to move 

the elevator car to the boarding floor. Id. col.8 ll.37–40. 

After the passenger has boarded the elevator car, the 

modernizing device receives a second destination signal 

from the computing unit. Id. col.8 ll.41–45. The modernizing device, after receiving this signal, converts the 

signal into an analog call report, and transmits the call 

report to the elevator control. Id. col.8 ll.42–51. In accordance with the second call report, the elevator control 

causes the elevator car to move from the boarding floor to 

the destination floor. Id. 

In 2008, Inventio sued ThyssenKrupp in the District 

of Delaware, alleging infringement of various claims of 

the ’465 and ’681 patents. After holding a Markman

hearing, the district court construed numerous claim 

terms. During the claim construction process, the district 

court concluded that the terms “modernizing device” and 

“computing unit” were indefinite. 

In reaching this conclusion, the district court first 

concluded that both terms lacked sufficiently definite 

structure to avoid § 112, ¶ 6. With regard to the “modern-
INVENTIO AG v. THYSSENKRUPP 8

izing device,” the court concluded that while the term was 

presumptively not a means-plus-function limitation, the 

claim language failed to recite corresponding structure to 

perform the “modernizing” function. Claim Construction 

Opinion, 718 F. Supp. 2d at 542–43. For the “computing 

unit” terms, the court similarly concluded that the claim 

language, although presumptively not a means-plusfunction limitation, failed to provide corresponding structure to perform the functions of the “computing unit.” Id.

at 559–60. After concluding that the terms were meansplus-function limitations, the district court concluded that 

both terms were indefinite because the written descriptions also failed to disclose corresponding structure to 

perform the recited functions. Id. at 544–46, 559–61. 

The district court subsequently denied Inventio’s motion for reargument, Order on Motion for Reargument, at 

1, and granted ThyssenKrupp’s motion for summary 

judgment that the asserted claims were invalid for failure 

to meet the definiteness requirement under § 112, ¶ 2. SJ 

Order, at 1–2. The district court then entered final judgment for ThyssenKrupp. Final Judgment, at 1. 

Inventio timely appealed. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1). 

DISCUSSION

Central to this appeal is whether the terms “modernizing device” and “computing unit” are means-plusfunction limitations that fall within the ambit of 

§ 112, ¶ 6. Because we conclude that the claimed “modernizing device” and “computing unit” are not means-plusfunction limitations, we do not address whether the 

written descriptions disclose corresponding structure. We 

also decline to provide constructions for these claim 

terms, as the claim-scope dispute in this case focused on 

whether these claim terms are subject to § 112, ¶ 6, and 
9 INVENTIO AG v. THYSSENKRUPP

the parties did not develop how these terms should be 

construed should § 112, ¶ 6 not apply. 

I. Applicable Law 

Section 112, ¶ 6 allows a patentee to express a claim 

limitation as “a means or step for performing a specified 

function without the recital of structure, material, or acts 

in support thereof,” and the section provides that claim 

limitations expressed in this manner “shall be construed 

to cover the corresponding structure, material, or acts 

described in the specification and equivalents thereof.” 

That provision applies “only to purely functional limitations that do not provide the structure that performs the 

recited function.” Phillips v. AWH Corp., 415 F.3d 1303, 

1311 (Fed. Cir. 2005) (en banc). Whether certain claim 

language invokes § 112, ¶ 6 is an exercise in claim construction and is therefore a question of law, subject to de

novo review. Personalized Media Commc’ns, LLC v. ITC, 

161 F.3d 696, 702 (Fed. Cir. 1998). 

The framework under which we determine if a claim 

limitation invokes § 112, ¶ 6 is straightforward. The use 

of the term “means” triggers a rebuttable presumption 

that § 112, ¶ 6 governs the construction of the claim term. 

TriMed, Inc. v. Stryker Corp., 514 F.3d 1256, 1259 (Fed. 

Cir. 2008). Conversely, where, as here, the claim language does not recite the term “means,” we presume that 

the limitation does not invoke § 112, ¶ 6. Personalized 

Media, 161 F.3d at 703–04. When a claim term lacks the 

word “means,” the presumption can be overcome if the 

challenger demonstrates that “the claim term fails to 

‘recite sufficiently definite structure’ or else recites ‘function without reciting sufficient structure for performing 

that function.’” CCS Fitness v. Brunswick Corp., 288 F.3d 

1359, 1369 (Fed. Cir. 2002) (quoting Watts v. XL Sys., 

Inc., 232 F.3d 877, 880 (Fed. Cir. 2000)). 
INVENTIO AG v. THYSSENKRUPP 10

As the above standard shows, the use of the word 

“means” is central to the analysis, as the terms “means” 

and “means for” have become closely associated with 

means-plus-function claiming. See Lighting World, Inc. v. 

Birchwood Lighting, Inc., 382 F.3d 1354, 1358 (Fed. Cir. 

2004). Thus, the presumption flowing from the absence of 

the term “means” is a strong one that is not readily overcome. Id. 

At the outset, the parties dispute whether the “sufficiently definite structure” analysis focuses on the claim 

language in isolation or allows the court to view the claim 

language in light of the written description to determine if 

ThyssenKrupp has rebutted the presumption that the 

claims recite sufficiently definite structure. Quoting 

TriMed, ThyssenKrupp argues that the “sufficiently 

definite structure” analysis hinges on whether the claim 

language “specifies the exact structure that performs the 

functions in question without need to resort to other 

portions of the specification or extrinsic evidence for an 

adequate understanding of the structure.” 514 F.3d at 

1259–60. Relying primarily on Personalized Media, 

Inventio argues that, to determine if a claim term that 

lacks the word “means” is subject to § 112, ¶ 6, the court 

should consider the intrinsic record. 

We agree with Inventio. Claims are interpreted in 

light of the written description supporting them, and that 

is true whether or not the claim construction involves 

interpreting a “means” clause. The presumption that a 

claim lacking the term “means” recites sufficiently definite structure can be rebutted “if the evidence intrinsic to 

the patent and any relevant extrinsic evidence so warrant[s].” Personalized Media, 161 F.3d at 704. In deciding whether a challenger has rebutted the presumption, 

“the focus remains on whether the claim as properly 

construed recites sufficiently definite structure to avoid 
11 INVENTIO AG v. THYSSENKRUPP

the ambit of § 112, ¶ 6.” Id. To determine the proper 

construction of a claim term, we look to the words of the 

claims themselves, the written description, the prosecution history, and any relevant extrinsic evidence. Phillips, 415 F.3d at 1315–17. In addition, we allow an 

inventor to provide, in the written description, express 

definitions for terms that appear in the claims, and those 

definitions govern the construction of the claims. Id. at 

1316. 

In cases where the claims do not recite the term 

“means,” considering intrinsic and extrinsic evidence is 

usually helpful, as the litigated issue often reduces to 

whether skilled artisans, after reading the patent, would 

conclude that a claim limitation is so devoid of structure 

that the drafter constructively engaged in means-plusfunction claiming. See MIT v. Abacus Software, 462 F.3d 

1344, 1354 (Fed. Cir. 2006). Indeed, in prior cases, we 

have reviewed the intrinsic record, as well as extrinsic 

evidence such as technical dictionaries, to determine if the 

challenger successfully rebutted the presumption that a 

claim that lacks the term “means” is not subject to 

§ 112, ¶ 6. E.g., Phillips, 415 F.3d at 1311 (concluding 

that term “steel baffles” was not a means-plus-function 

limitation where “[t]he claims and the specification unmistakably establish that the ‘steel baffles’ refer to particular physical apparatus”); Personalized Media, 161 

F.3d at 704 (declining to construe “digital detector” as a 

means-plus-function limitation where “neither intrinsic 

nor extrinsic evidence” rebutted the presumption that a 

“detector” connoted structure to those of skill in the art); 

Lighting World, 382 F.3d at 1360–63 (reviewing the 

written description, technical dictionaries, and expert 

testimony to conclude that the defendant failed to rebut 

the presumption that the claimed “connector assembly” 

connoted sufficiently definite structure). 
INVENTIO AG v. THYSSENKRUPP 12

In light of this caselaw, ThyssenKrupp’s reading of 

TriMed misses the mark. While it is true that the claim 

language, in order to avoid the application of § 112, ¶ 6 

when a claim recites the term “means,” must “specif[y] 

the exact structure that performs the functions in question,” TriMed, 514 F.3d at 1259–60, TriMed does not 

preclude consideration of the written description, prosecution history, and extrinsic evidence to determine if a 

challenger has rebutted the presumption that a claim 

limitation that lacks the term “means” connotes sufficiently definite structure to those of skill in the art. 

Moreover, where the claims recite the term “means,” we 

have considered the written description to inform the 

analysis of whether the claim recites sufficiently definite 

structure to overcome the presumption that § 112, ¶ 6 

governs the construction of the claim. See e.g., TI Grp. 

Automotive Sys. (N. Am.), Inc. v. VDO N. Am., L.L.C., 375 

F.3d 1126, 1135 (Fed. Cir. 2004) (concluding that 

§ 112, ¶ 6 did not apply to recited “pumping means” where 

“[t]he written description informs and fully supports the 

structure recited in the claims”). Accordingly, it is proper 

to consult the intrinsic record, including the written 

description, when determining if a challenger has rebutted the presumption that a claim lacking the term 

“means” recites sufficiently definite structure. 

II. Modernizing Device 

Inventio argues that the district court erred when it 

concluded that the claimed “modernizing device” is a 

means-plus-function limitation. Inventio argues that the 

claims recite structural detail about the modernizing 

device and how it is connected to other components of the 

patented system. In addition, Inventio argues that the 

written descriptions identify the modernizing device as a 

structural component, as they provide a block diagram of 
13 INVENTIO AG v. THYSSENKRUPP

the modernizing device and also describe the structure 

and operation of the modernizing device. 

ThyssenKrupp argues that the claimed “modernizing 

device” is defined only in terms of the functions that the 

device performs, not its structure. ThyssenKrupp also 

argues that the claims provide no physical structure for 

the modernizing device, that there is no evidence that the 

term “modernizing device” had a well understood meaning 

in the art, and that there is no evidence that technical 

dictionaries recognize a “modernizing device” as denoting 

structure. Finally, citing MIT and Personalized Media, 

ThyssenKrupp argues that the term “device” is a generic 

term like “means” and that the modifier “modernizing” 

does not add structure. 

We agree with Inventio. The term “modernizing device” presumptively connotes sufficiently definite structure to those of skill in the art, Personalized Media, 161 

F.3d at 703–04, and that presumption is a strong one that 

is not readily overcome, Lighting World, 382 F.3d at 1358. 

In this case, ThyssenKrupp has not overcome the presumption that the claimed “modernizing device” connotes 

sufficiently definite structure. 

In past cases, we have concluded that a claimed “circuit,” coupled with a description of the circuit’s operation 

in the claims, connoted sufficiently definite structure to 

skilled artisans to avoid the application of § 112, ¶ 6. 

MIT, 462 F.3d at 1355–56; Linear Tech. Corp. v. Impala 

Linear Corp., 379 F.3d 1311, 1320–21 (Fed. Cir. 2004); 

Apex Inc. v. Raritan Comp., Inc., 325 F.3d 1364, 1374 

(Fed. Cir. 2003). As we explained in Linear, the term 

“circuit” itself connotes structure and the contextual 

language that describes the objective and operation of the 

claimed “circuit” conveys the structural arrangement of 

the circuit’s components and provides additional limiting 
INVENTIO AG v. THYSSENKRUPP 14

structure. 379 F.3d at 1320–21. Thus, we concluded in 

Linear that a claimed “circuit” for “monitoring a signal 

from the output terminal to generate a first feedback 

signal” was not subject to § 112, ¶ 6 because the term 

connoted structure and the contextual language described 

the objective of the “circuit”—“monitoring a signal from 

the output terminal”—as well as the desired output of the 

“circuit”—“generat[ing] a first feedback signal.” Id. 

In this case, the claims indicate that the “modernizing 

device” functions as an electrical circuit that receives 

signals, processes signals, and outputs signals to other 

components in the patented system. For example, claim 1 

of the ’861 patent recites that the “modernizing device” is 

connected to an elevator control and a computing unit, 

where the computing unit transmits a destination signal 

to the modernizing device. ’861 patent, col.11 ll.6–21. 

The modernizing device then converts that destination 

signal into a call report and transmits the call report to 

the elevator control. Id. In addition, dependent claims 

describe the input, output, and signal receiver aspects of 

the modernizing device, id. col.11 l.22–36, 44–55, and 

describe the comparison of a target value or indication 

signal with a plurality of travel time profiles that the 

modernizing device performs, id. col.11 ll.37–43, col.12 

ll.1–8. Similarly, claim 1 of the ’465 patent claims a 

“modernizing device” that is connected to floor terminals 

and a computing unit, where the modernizing device 

reads a destination signal, converts the destination signal 

into a call report, and controls the elevator control by way 

of the call report. ’465 patent, col.11 ll.6–25. 

The written descriptions support the conclusion that 

the claimed “modernizing device” is not a purely functional limitation. As detailed above, the written descriptions depict the modernizing device and its internal 

components, namely, the processor, signal generator, 
15 INVENTIO AG v. THYSSENKRUPP

converter, memory, and signal receiver elements. ’861 

patent, Fig. 3. The written descriptions also show how 

the elements are connected together and to the elevator 

control and computing unit components of the elevator 

system. Id. They also describe how the modernizing 

device, employing these components, receives a destination signal from the computing unit, converts it into a call 

report, and issues the call report to the elevator control. 

Id. col.7 l.49–col.8 l.4. In addition, they describe that the 

modernizing device has an input and signal receiver that 

detects a signal from the elevator control, such as a target 

value, and processes the signal with a time travel profile 

to control the elevator system. Id. col.8 l.54–col.9 l.67. 

In sum, the claims and written descriptions show that 

ThyssenKrupp has failed to overcome the presumption 

that the claimed “modernizing device” is not a meansplus-function limitation. In light of this disclosure, 

ThyssenKrupp’s reliance on dicta in the Personalized 

Media and MIT cases is unavailing. In those cases, we 

stated that the term “device” was a generic structural 

term that “typically do[es] not connote sufficiently definite 

structure.” MIT, 462 F.3d at 1354. In this case, however, 

the claims recite a “modernizing device,” delineate the 

components that the modernizing device is connected to, 

describe how the modernizing device interacts with those 

components, and describe the processing that the modernizing device performs. The written descriptions additionally show that the modernizing device conveys structure 

to skilled artisans. Thus, this is not a case where a claim 

nakedly recites a “device” and the written description fails 

to place clear structural limitations on the “device.” 

III. Computing Unit 

Inventio also challenges the district court’s conclusion 

that the claim term “computing unit” is a means-plus-
INVENTIO AG v. THYSSENKRUPP 16

function limitation. Inventio argues that a “computing 

unit” connotes structure to those of skill in the art, specifically a computer or other data processing device. 

Inventio also argues that the written descriptions explicitly define the “computing unit” as “a commercially available personal computer or a workstation,” which includes 

“at least one processor and at least one data memory.” 

ThyssenKrupp argues that the claimed “computing 

unit” lacks sufficiently definite structure to avoid the 

application of § 112, ¶ 6 because the claims fail to provide 

any physical structure, the term “computing unit” lacks a 

well understood meaning in the art, and the term “unit” is 

the legal equivalent of “means.” ThyssenKrupp also 

argues, quoting Brown v. Baylor Healthcare System, that 

even if a “computing unit” is read to mean a computer, 

simply disclosing “a general processor without more” is 

not enough “to perform the claimed function” and avoid 

the application of § 112, ¶ 6. 381 Fed. Appx. 981, 983–84 

(Fed. Cir. 2010) (nonprecedential decision).

We agree with Inventio that the “computing unit” 

here connotes sufficiently definite structure. Similar to 

the term “modernizing device,” the claimed “computing 

unit” presumptively connotes sufficiently definite structure to those of skill in the art. Personalized Media, 161 

F.3d at 703–04. The claims indicate that the presumption 

is not overcome in this case. The claims recite that the 

computing unit is connected to the modernizing device 

and generates a destination signal for transmission to the 

modernizing device. ’861 patent, col.11 ll.6–21. The 

claims elaborate that the computing unit is connected to 

the floor terminals of the elevator system, and evaluates 

incoming call reports, destination floors, and identification codes to generate the destination signal for processing by the modernizing device. Id. col.12 ll.9–52; ’465 

patent, col.12 ll.7–59. 
17 INVENTIO AG v. THYSSENKRUPP

The written descriptions also indicate that the “computing unit” connotes structure to skilled artisans. As the 

claim term implies, the written descriptions refer to the 

computing unit as a computer, where one of its functions 

is to store and execute a computer program product. ’861 

patent, col.6 ll.21–24 (stating that the “computing unit” is 

“a commercially available personal computer or workstation” and that the “computing unit” includes “at least 

one processor and at least one data memory”); id. col.9 

ll.61–64 (stating that “it is entirely possible to perform the 

computer program product on any computer, for example 

on the computing unit of the system or on a remote 

server”) (internal reference number omitted). The written 

descriptions also explain the steps that the computer 

program product performs, see id. col.6 l.3–col.7 l.25, as 

well as the interaction between the computing unit and 

modernizing device, id. col.7 ll.26–48, and the computing 

unit and the floor terminals, id. col.8 ll.6–22. 

In total, this disclosure shows that ThyssenKrupp has 

not rebutted the presumption that the claimed “computing unit” connotes sufficiently definite structure to those 

of skill in the art. In response to this evidence, 

ThyssenKrupp relies on dictum from our nonprecedential 

decision in Brown to argue that a computer, when 

claimed, is not sufficient structure to perform the claimed 

functions as a matter of law. ThyssenKrupp’s reading of 

that case, however, is overly broad. 

In Brown, the patentee had the burden to show that 

the “portable processing means” claim limitation recited 

sufficiently definite structure to perform the recited 

“processing” function, and we concluded on the record in 

that case that the patentee had failed to meet that burden. 381 Fed. Appx. at 983–84. We rejected the patentee’s argument that one would equate the “portable 

processing means” with a “general purpose processor” 
INVENTIO AG v. THYSSENKRUPP 18

because the argument ignored that the patentee “chose to 

claim the element at issue in functional terms.” Id. We 

also noted that even if the patentee’s argument were 

correct, “a general purpose processor without more would 

not be enough to perform the claimed function.” Id. at 

984. 

Contrary to ThyssenKrupp’s arguments, Brown did 

not hold, as a matter of law, that a claimed “computer” is 

not sufficiently definite structure to avoid the application 

of § 112, ¶ 6. Indeed, we have held that a claimed “control 

unit” that comprised a “CPU” and a “portioned memory 

system” recited sufficiently definite structure to perform 

the recited “controlling the communication unit” function. 

LG Elecs., Inc. v. Bizcom Elecs., Inc., 453 F.3d 1364, 1372 

(Fed. Cir. 2006), rev’d on other grounds, Quanta Computer, Inc. v. LG Elecs., Inc., 553 U.S. 617 (2008). Ultimately, whether claim language invokes § 112, ¶ 6 

depends on how those skilled in the art would understand 

the structural significance of that claim language, assessed against the presumptions that flow from a drafter’s 

choice to employ or not employ the term “means.” See

Personalized Media, 161 F.3d at 704. 

In this case, the inventor did not draft the claims in 

“means for” format, and his decision to avoid the term 

“means” raises a strong presumption that the claimed 

“computing unit” connotes sufficiently definite structure 

to those skilled in the art. Lighting World, 382 F.3d at 

1358. ThyssenKrupp had the burden to show that the 

“computing unit” terms are so structurally devoid that we 

should rewrite them in means-plus-function format. The 

claims and the written descriptions, however, indicate 

that those of skill in the art would understand a computing unit to connote sufficiently definite structure. Thus, 

on this record, ThyssenKrupp has failed to meet its burden. 
19 INVENTIO AG v. THYSSENKRUPP

CONCLUSION

For the foregoing reasons, the judgment of the district 

court is reversed and the case is remanded to the district 

court for further proceedings. 

REVERSED AND REMANDED