United States District Court, N.D. Illinois, Eastern Division
MEMORANDUM OPINION AND ORDER
Honorable Edmond E. Chang, United States District Judge.
litigation concerns two patents on audio conferencing
technology. Shure, Inc. sued its competitor ClearOne (the
owner of the patents), seeking a declaration of invalidity
and non-infringement at first on U.S. Patent No. 9, 635,
R. 1, Compl. ¶ 1. In response, ClearOne filed a counterclaim
for infringement against Shure.R. 28, Counterclaim. After
expedited discovery, ClearOne moved for a preliminary
injunction to halt Shure's alleged infringement of the
'186 Patent. R. 81, Mot. Prelim. Inj. '186 Patent.
The Court denied ClearOne's motion. R. 278, '186
Patent Prelim. Inj. Op. During the pendency of the first
preliminary-injunction motion, ClearOne was granted another
audio conferencing patent, U.S. Patent No. 9, 813, 806, and
asserted infringement on that patent, too. R. 260, Second Am.
Compl. ClearOne later moved for a preliminary injunction to
halt Shure's alleged infringement of the '806 Patent,
also based on Shure's MXA910. R. 369, Mot. Prelim. Inj.
'806 Patent. The Court eventually granted that
preliminary injunction motion. R. 551, '806 Patent
Prelim. Inj. Order.
the parties finished fact discovery and briefed their claim
construction arguments on both the '186 and '806
Patents. See R. 508, Shure Br.; R. 520, ClearOne
Resp.; R. 535, Shure Reply. The Court heard oral argument on
claim construction on July 12, 2019. See R. 540,
Minute Entry. The Court made final claim construction
decisions on some terms from the '806 Patent in its
preliminary injunction order, including “beamforming
microphone array”'; “said beamforming
microphone array integrated into said ceiling tile as a
single unit”; “the drop space of the drop
ceiling”; and “wherein said outer surface is
coplanar with said ceiling tile.” '806 Patent
Prelim. Inj. Order. This order decides the parties'
remaining claim construction disputes on the '806 Patent,
as well as on the '186 Patent.
The '186 Patent
core contribution of the U.S. Patent No. 9, 635, 186 (the
'186 Patent) is a method of efficiently combining
beamforming (a technology that combines signals from multiple
microphones to generate a combined audio signal that picks up
sounds from a particular location) with acoustic echo
cancellation (known in the industry as AEC), a technology
that removes far-end echo from an audio-conferencing system.
'186 Patent Prelim. Inj. Op. at 3. Figuring out how to
combine beamforming and acoustic echo cancellation in a
cost-efficient way-while still preserving audio quality-has
been a longstanding challenge in the audio industry. See,
e.g., R. 158, Kellerman Decl. Exh. 2 at 281
(“[S]traightforward combinations of the two techniques
either multiply the considerable computational cost of AEC by
the number of array microphones or sacrifice algorithmic
performance if the beamforming is time-varying.”); R.
83, 8/6/17 Schonfeld Decl. ¶ 23.
illustrative claim of the '186 patent (Claim 7) discloses
an efficient method of combining a beamforming microphone
with AEC. R. 57-1, '186 Patent Col. 19:48-20:8. The
claimed method reduces AEC processing costs by providing a
beamformer capable of picking up a number of audio signals,
which are then combined into a smaller number of
“fixed” beams. Id. Col. 2:3-16. AEC is
then performed on only the smaller number of fixed beams.
Id. Col. 19:65-67. Performing AEC on fixed (as
opposed to adjustable) beams reduces the amount of work for
the acoustic echo cancellers, which would otherwise need to
constantly adjust to track the changing beams. Id.
Col. 2:3-16. After AEC is performed, a “signal
selection module” selects one or more of the
echo-cancelled signals to transmit to the far end.
Id. Col. 20:1-3 (Limitation 5). The signal selection
module also uses the far-end signal as information to inhibit
the change of the near-end signal selection while only the
far-end signal is “active.” Id. Col.
20:3-8 (Limitation 6).
The '806 Patent
'806 Patent builds on the '186 Patent and claims an
invention that combines a beamforming microphone array (BFMA)
with a ceiling tile so that the BFMA can pick up sound
throughout a conference room while remaining somewhat hidden
from view. The benefit of integrating a beamforming
microphone array with a ceiling tile is that it allows the
technology to be out-of-sight. In the context of audio
conferencing, the typical conference set-up involves multiple
speakers in one room, all communicating with speakers in
another location. R. 372, 9/24/18 Schonfeld Decl. ¶ 26.
The “conventional wisdom” was that microphones
should be as close to the attendees as possible.
Id.; R. 360, Graham Decl. ¶ 8. The development
of beamforming microphones did not immediately disrupt that
view, but in the course of product development, ClearOne
engineers realized that mounting their BFMA on the
ceiling-that is, increasing the distance between the BFMA and
the speakers in the room-reduced the quality of the sound it
produced less than the engineers thought it would.
Graham Decl. ¶ 9. Their beamforming technology made the
audio quality better than the quality that a
non-beaming microphone would achieve when mounted on
the ceiling. R. 477, Prelim. Inj. Hrg. Tr. at 76:1-9.
has identified four representative claims of the '806
Patent: Claim 1 is the independent claim, and Claims 4, 5,
and 6 depend on it. R. 326-1, ClearOne Am. Alleged Infring.
Content. at 1. The preamble to Claim 1 disclosed a BFMA
integrated with a ceiling tile as a “single unit where
the ceiling tile is used in a drop ceiling mounting
configuration.” R. 412-1, '806 Patent Col.
13:12-15. Limitation 1 of Claim 1 requires “a
beamforming microphone array that includes a plurality of
microphones that picks up audio input signals.”
Id. Col. 13:16-17. Limitations 2 and 3 disclose an
acoustically transparent outer surface to the tile through
which the BFMA picks up audio input signals. Id.
Col. 13:18-24. Limitation 4 states that the integrated
tile-BFMA is “used in a drop ceiling mounting
configuration.” Id. Col. 13:25-26. And
finally, Limitation 5 discloses that the BFMA is
“coupled to the back side of said ceiling tile and all
or part of said beamforming microphone array is in the drop
space of the drop ceiling.” Id. Col. 13:27-30.
Dependent Claims 4, 5, and 6 disclose, respectively, that the
ceiling tile “comprises acoustic or vibration damping
material” (Claim 4); that the “outer surface [of
it] comprises a grille” (Claim 5); and that “said
outer surface is coplanar with said ceiling tile”
(Claim 6). Id. Col. 13:38-43.
construction requires that the Court determine how a person
of ordinary skill in the art would understand the claim
terms. Phillips v. AWH Corp., 415 F.3d 1303, 1313
(Fed. Cir. 2005) (en banc). The claim's own language is
the starting point, but “[c]laims must be read in view
of the specification, of which they are a part.”
Markman v. Westview Instruments, Inc., 52 F.3d 967,
979 (Fed. Cir. 1995) (en banc). Prosecution history
is also “of primary significance” in determining
how a claim should be understood. Id. at 980.
Lastly, extrinsic evidence-that is, expert testimony or any
other evidence outside of the patent and prosecution
history-can also be considered, but carries less weight than
intrinsic evidence. Id. at 980-982. Extrinsic
evidence is mostly useful for helping the Court to understand
the relevant art and to explain how the invention works.
Phillips, 415 F.3d at 1318-19.
The '186 Patent
Court previously interpreted several terms in the context of
ClearOne's motion for a preliminary injunction on the
'186 Patent. See '186 Patent Prelim. Inj.
Op. at 7-16. This Opinion assumes familiarity with that
preliminary injunction decision, R. 278.
“each of the plurality of combined signals
corresponding to a ...