US 11371755

I'll search for litigation/docket information on this patent, since the patent text itself is already provided.

Summary — US Patent No. 11,371,755 ("11371755")

⚠️ Important caveat on the search: I searched for litigation and CAFC docket activity. I found no CAFC 2026 docket, no district court case, and no USPTO proceeding involving US 11,371,755. The only "CAFC 2026 docket" result returned was an unrelated appeal (Contour IP Holding LLC v. GoPro, Inc., Fed. Cir. Docket No. 2026‑2012, N.D. Cal. 3:17‑cv‑04738‑WHO) that does not concern this patent or this assignee. Likewise, a UK Companies House gazette entry and an SEC Form 10‑K record both merely reuse the digit string "11371755" and are not this patent. Treat the absence of litigation as a negative finding only.

Also note: the provided full patent text does not include the numbered claims section (the text ends mid‑description). Claim language below is reconstructed from the Summary of Invention (which tracks claim 1) and from search snippets of the application publication US20200182516A1. I flag where I am inferring rather than reading claim text directly.

Bibliographic data (per the authoritative Google Patents text and corroborating records)

Abstract (as printed)

An air‑conditioning apparatus that includes a compressor, a flow switching device, an outdoor heat exchange unit, an expansion section and an indoor heat exchanger, which are connected by pipes, in which the outdoor heat exchange unit includes a first outdoor heat exchanger, a first flow rate control device, a second outdoor heat exchanger, a second flow rate control device, a bypass pipe, the second outdoor heat exchanger, the second flow rate control device, a third flow rate control device, and a flow control device.

Plain‑language overview

The patent concerns a multi‑indoor‑unit (heat‑recovery/"cooling‑and‑heating mixed") air conditioner. It addresses a specific problem with prior art WO 2013/111176: in low‑outdoor‑temperature cooling, heat exchange was reduced by throttling a valve downstream of the outdoor heat exchanger, so refrigerant backed up in that heat exchanger and the circulating charge became insufficient (and liquid could carry over to the compressor, i.e., "liquid back").

The claimed fix splits the outdoor heat exchanger into two parallel branches (first 3a with first valve 22; second 3b with second valve 24), adds a bypass pipe 25 with a third valve 26 that bypasses both, and adds a flow rate adjustment device 2b connected between the compressor discharge side and the second outdoor heat exchanger 3b. To cut heat‑exchange capacity, the controller ties the second heat exchanger to the compressor suction and closes its valve, letting low‑pressure gaseous refrigerant accumulate there (low density → little charge loss) while the bypass valve is opened to maintain the circulation amount. A controller coordinates the valves and the outdoor fan.

Independent claim(s) — Based on the Summary of Invention, which reproduces the claim‑1 substance:

1. Claim 1 (independent): An air‑conditioning apparatus in which a compressor, a flow switching device, an outdoor heat exchange unit, an expansion section and an indoor heat exchanger are connected by pipes, wherein the outdoor heat exchange unit comprises: (a) a first outdoor heat exchanger connected to the flow switching device; (b) a first flow rate control device connected in series to the first outdoor heat exchanger; (c) a second outdoor heat exchanger connected in parallel with the first outdoor heat exchanger and the first flow rate control device; (d) a second flow rate control device connected in series to the second outdoor heat exchanger; (e) a bypass pipe configured to bypass the first outdoor heat exchanger and first flow rate control device, and the second outdoor heat exchanger and second flow rate control device; (f) a third flow rate control device provided in the bypass pipe; and (g) a flow rate adjustment device connected between a discharge side of the compressor and the second outdoor heat exchanger. The stated advantage: even when outflow from the second outdoor heat exchanger falls, the circulation amount can be made up via the bypass pipe.

Dependent claims (evidence‑based, from the US 2020/0182516 A1 snippet) — I cannot confirm their exact numbering or that no additional independent claim exists:

• A claim adding a controller with a determination unit (determines whether discharge pressure is below a discharge target value) and an outdoor flow rate control unit configured to reduce the outdoor fan/pump rotation speed when discharge pressure is below the target.
• Claim 5‑type: the determination unit also determines whether suction pressure is above a suction target value; a second flow rate control unit intermittently opens/closes the second flow rate control device at preset intervals when suction pressure is at or below the target.
• Claim 6‑type: the flow rate adjustment device switches between a state connecting the second outdoor heat exchanger to the compressor discharge side and a state connecting it to the compressor suction side.
• Claim 7‑type: in the second flow rate control device, flow resistance changes continuously.
• Claim 8‑type: the apparatus comprises an outdoor unit (compressor, flow switching device, outdoor heat exchange unit), a plurality of indoor units (with a plurality of expansion sections and indoor heat exchangers), and a relay between the outdoor unit and the indoor units that distributes refrigerant from the outdoor unit to the indoor units.

There is at least one further dependent claim (the snippet cuts off at claim 9).

Uncertainty / limitations

• No litigation found. I could not identify any 2026 CAFC docket, IPR/PGR, or district court case for US 11,371,755. This is a search negative, not proof of non‑existence.
• Full claim set not verified. The claims section was not present in the supplied patent text; claim 1's language is taken from the "Solution to Problem" mirror, and dependent‑claim content from the US 2020/0182516 A1 search snippet. Exact claim numbering, the total number of claims, and whether additional independent claims (e.g., an apparatus claim, or the US‑specific amended claim set) exist beyond claim 1 should be confirmed against the granted patent's claims page.

Sources: Google Patents US11371755B2; Google Patents US20200182516A1; EPO register publication EP2808621A1 citing US11371755B2; PatentLeaderboard inventor listings (Maruyama/Morimoto/Okano); CourtListener Fed. Cir. Docket 2026‑2012 (unrelated, Contour IP Holding LLC v. GoPro, Inc.).

I'll search for litigation involving US patent 11371755 across the sources you specified.

Let me search more specifically on litigation databases.

Search Results: Litigation Involving U.S. Patent No. 11,371,755

Summary finding: I found no litigation (district court, CAFC, ITC, or PTAB) specifically involving U.S. Patent No. 11,371,755.

What I searched

I ran targeted queries designed to surface case records tied to this specific patent number — including Unified Patents' litigation portal, CourtListener, Justia, PACER-adjacent dockets (Docket Alarm, PacerMonitor), and general web queries for "11371755" combined with patent/litigation terms, as well as the patent owner (Mitsubishi Electric). Per your instruction, I filtered for the exact number and did not substitute similar-looking numbers.

What the searches actually returned

None of the results concerned the '755 patent. Instead they were:

1. Unrelated subject matter that happens to contain the digits "11371755" — e.g., a UK Companies House gazette entry for "Squirrels Montessori Schools Limited 11371755," and a Telesat Corporation SEC filing tagged internally with the identifier "11371755." These are not the patent.

2. Mitsubishi Electric litigation and PTAB proceedings involving different patents — e.g., Ultravision Technologies v. Mitsubishi Electric (E.D. Tex. 2:18-cv-00105), M-Red Inc. v. Mitsubishi Electric (E.D. Tex. 2:21-cv-00075), Mitsubishi Electric v. Sceptre (C.D. Cal. 2:14-cv-04994), Portus Singapore v. Mitsubishi Electric US (D. Mass. 1:26-cv-12576), OnePlus/Oppo v. Mitsubishi Electric (UK FRAND actions), and IPR2023-00957 (TCL v. Mitsubishi Electric). None of these assert the '755 patent, and I could not confirm that any of them are about the air-conditioning technology of the '755 patent at all.

3. General patent-default/antitrust opinions with no connection to the '755 patent.

Confirmed bibliographic facts about the patent (relevant to whether litigation is plausible)

• Patent: U.S. 11,371,755 B2, "Air-conditioning apparatus"
• Inventor(s): Hiroki Maruyama, Osamu Morimoto, Hiroyuki Okano, Naofumi Takenaka
• Assignee: Mitsubishi Electric Corporation
• Application: US 16/640,871 — a U.S. national-stage filing of PCT/JP2017/033439
• Priority/filing date: 2017-09-15
• Grant date: 2022-06-28
• Status: Active (per Google Patents' legal-status data)

Important caveats

• I could not run exhaustive docket-level searches. I was cut off before completing additional planned queries (e.g., a dedicated CourtListener/Unified Patents case-list pull, Lex Machina/Docket Navigator, ITC EDIS, and CAFC docket searches). Litigation databases that index by patent number (Lex Machina, Docket Navigator, Unified Patents' litigation caselist) are the definitive tools for this; my web queries may not surface them.
• A negative result is not proof of no litigation. Recent filings (2025–2026), sealed cases, and foreign actions may not be indexed in the sources available to me. The patent is relatively recent (granted mid-2022) and sits in a Mitsubishi-only portfolio, which is consistent with low or no observed assertion activity to date, but I cannot assert that categorically.
• I have not verified the full text of the CAFC docket or PACER directly for this patent number.

Recommendation

To obtain a definitive answer, check the Unified Patents Litigation caselist (portal.unifiedpatents.com/litigation/caselist), Lex Machina / Docket Navigator, and the CAFC and PACER dockets filtered by the exact patent number 11,371,755. If those return nothing, the accurate statement is that no litigation involving U.S. Patent No. 11,371,755 is known as of today.

Bottom line: Based on the searches I was able to complete, no known litigation asserting or challenging U.S. Patent No. 11,371,755 exists in the sources reviewed — but I could not complete exhaustive database checks, so this should be stated as "none found," not "none exists."

I'll verify the structured data against live sources before reporting.

Let me run additional targeted checks before concluding.

One more verification pass — checking litigation/assertion and PTAB docket aggregation sources.

Proceedings overview

Total AIA trial proceedings on file for US 11,371,755: 0. The USPTO Open Data Portal structured block returns no AIA trial proceedings for this patent as of the most recent ingest, and independent web searching (2026-09-29) surfaced no IPR, PGR, CBM, or Federal Circuit appeal touching this patent number — breakdown by status is therefore nil across every category (0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied). The bottom-line defensive posture is not "the patent has survived two IPRs and is hardened" and not "the claims have been canceled" — it is that every claim of this patent is validity-untested at the PTAB, and a challenge remains procedurally available in full.

No proceedings to profile

Because the canonical proceeding list is empty, there is no {PROCEEDING_NUMBER} — {Petitioner} v. {Patent Owner} block to populate. Reporting the requested per-proceeding fields (petition grounds, institution decision, FWD verdict, settlement terms, appeal docket) would require inventing proceeding numbers, panels, and dispositions — which the operating rules prohibit. I am stating plainly that the data does not exist rather than backfilling it.

Two caveats I want to be explicit about, because absence-of-evidence claims are easy to overstate:

• Ingest lag is real. Google Patents' legal-events timeline for this patent (https://patents.google.com/patent/US11371755/en) shows only the 2020-02-21 assignment to Mitsubishi Electric, the 2020-06-11 publication of US20200182516A1, the 2022-06-28 grant, and a 2037-09-15 anticipated expiration. No PTAB event appears. A very recently filed petition (say, within the last few weeks) could in principle not yet be reflected in ODP or in an aggregator. My searches did not find one, but I would re-verify against PTAB E2E before relying on this for a filing deadline.
• My searches were noisy. Queries for "11,371,755" and for IPRs generally returned a large volume of hits on unrelated patents whose numbers end in "755" (e.g., US 9,063,755 in the Express Mobile v. Meta line of Federal Circuit cases, and the UK company number 11371755). None of those involve this patent. I flagged them rather than mis-attributing them.

Strategic summary

Claim-status ledger. Every claim of US 11,371,755 is UNTESTED. No claim is canceled; no claim has been sustained against a PTAB challenge; no claim has been narrowed by an adverse judgment or disclaimer in an AIA trial. The patent issued 2022-06-28 from a national-stage entry (US 16/640,871) of PCT/JP2017/033439, filed 2017-09-15 — so this is an AIA (first-inventor-to-file) patent, and its PGR window closed on 2023-03-28 (nine months post-grant). PGR is no longer available to anyone. CBM is not a viable route either: the claims are directed to a mechanical/refrigeration air-conditioning apparatus (CPC F25B 13/00, F25B 49/02, F24F 11/81/83) with no financial-services nexus, and the transitional CBM program sunset for new petitions on 2020-09-16. IPR under 35 U.S.C. § 311 is the only AIA trial vehicle, and no one has used it.

Estoppel landscape. Because there is no IPR that reached a final written decision, § 315(e)(2) estoppel has never attached to anyone. There is no petitioner, no privy, and no "grounds raised or reasonably could have been raised" that are foreclosed. For a defendant currently being asserted against (or expecting to be), the entire prior-art universe is on the table — § 102 and § 103, in district court and at the PTAB, without any AIA-trial estoppel shadow. The only clocks that matter are statutory: (i) § 315(b) — a petition is barred if filed more than one year after the petitioner, RPI, or privy is served with a complaint alleging infringement, so the window starts on service and is unforgiving; and (ii) § 325(d) and the Director's discretion, discussed below. Note also that under Shaw / HP v. MPHJ / Synopsys, grounds presented in a petition but not instituted escape estoppel — but that doctrine is academic here because no petition exists.

Discretionary-denial climate is a material headwind for a 2026 petitioner. This patent has been in force roughly four years, from a 2017 priority date. Under the PTAB practice reset described in the 2025 year-in-review literature — Acting Director Stewart's 2025-02-28 rescission of the 2022 Fintiv memo, the bifurcated discretion-first institution regime, the addition of a "settled expectations" factor keyed to patent age (commentators identify a ~6-year in-force threshold), and Director Squires' 2025-10-17 memorandum asserting personal control over all IPR/PGR institution decisions — the realistic institution rate has dropped sharply and denial notices are often unreasoned, which also kneecaps any request for rehearing. A petition against this patent must be built to win on compelling merits and should include a Sotera-style stipulation (which is now "highly relevant but not dispositive"), because the patent's age will draw heightened discretionary scrutiny.

Pattern signals. There is no petitioner pattern to read — nobody has filed. There is no defensive aggregator in the chain; I found no Unified Patents (or similar) filing, membership, or press release referencing this patent. Equally important for framing: the patent owner is Mitsubishi Electric Corporation, an operating company, not an NPE. M-Red Inc. (a Quest Patent Research affiliate) sued Mitsubishi in E.D. Tex. in 2021 (2:21-cv-00075), i.e., Mitsubishi was the defendant — the reverse of the "troll demand letter" posture in this task's framing. On the record I can see, Mitsubishi does not appear to be asserting US 11,371,755 against anyone, which is consistent with the absence of litigation-driven IPR activity.

Prosecution leverage that a challenger should mine now. The specification itself concedes the closest art: the Background identifies WO 2013/111176 (Patent Literature 1) as disclosing an outdoor fan + outdoor heat exchanger + series outdoor-side flow rate control device + bypass flow rate control device on a bypass pipe, with heat-exchange-amount control via fan airflow and expansion-valve throttling. That reference (and the family around it, e.g., US 9,915,454, which shares the "control heat-transfer coefficient outside / inside / heat-transfer area A" teaching) is the natural § 103 anchor, and the patentee's own adversarial characterization of it in the Background is usable. The file history in US 16/640,871 will show which limitations the examiner credited over that art — that is where the obviousness argument should be aimed. I have not verified the exact issued claim count or the full independent/dependent claim structure from the provided text, so pull the claims and the full prosecution history from PatentCenter before finalizing any ground.

Recommended next steps

1. Re-verify zero proceedings at the source before acting. Run the patent number (and application 16/640,871) through PTAB E2E at https://ptacts.uspto.gov/ptabweb/ and cross-check the Google Patents legal-events timeline at https://patents.google.com/patent/US11371755/en. If something has appeared since the ODP ingest, it changes the analysis materially — an instituted IPR would start a statutory 1-year clock to FWD from the institution date (§ 316(a)(11)) and would put § 315(e)(2) estoppel on the horizon.
2. If you are a defendant being asserted on this patent — there is no canceled claim to point to and no FWD to quote, and I will not manufacture one. Your posture is offensive, not defensive: the patent is unlitigated at the Board, so the correct play is to evaluate an IPR (or a § 282 district-court invalidity case) around WO 2013/111176 and the § 112/§ 103 weaknesses in the claimed "flow rate adjustment device connected between a discharge side of the compressor and the second outdoor heat exchanger" combination. Calendar the § 315(b) date immediately — one year from service of the complaint.
3. If the patent has not been asserted against you, the absence of PTAB activity is itself weak information: this is a manufacturer-owned component patent in a crowded refrigeration-control field, and its non-assertion says more about Mitsubishi's licensing posture than about its strength. Do not read "no IPRs" as "unassailable."
4. Sourcing discipline. No proceeding number, judge panel, FWD quote, settlement term, or CAFC docket number appears above, because none exists on the record available to me. Any future update to this section should cite the specific PTAB paper (via PTAB E2E) and the CourtListener docket for any appeal.

I'll start by gathering what's verifiable about this patent's ownership record before assembling the sections.

No litigation surfaced yet. Let me dig into the assignment records and check for assertion activity.

Let me check for assertion activity and the assignment search page directly.

Ownership & Assignment Reconstruction — US 11,371,755 B2

"Air-conditioning apparatus" · App. 16/640,871 · PCT/JP2017/033439 · Granted 2022-06-28

Inventors

All four inventors are listed with a Tokyo correspondence address and all four appear in third-party inventor roll-ups as Mitsubishi Electric Corporation inventors — Morimoto with 77 patents and Okano with 36 patents credited to Mitsubishi Electric (PatentLeaderboard, https://www.patentleaderboard.com/mitsubishi-electric/osamu-morimoto/[815663](/patent/815663)). Takenaka, Morimoto, Maruyama and Okano are also the four assignors named in the recorded assignment of 2020-02-21, which confirms the employer relationship for the whole inventive entity.

Pattern note — no departure anomaly. There is no evidence of inventors leaving the original assignee within 12 months of filing. The PCT was filed 2017-09-15 and the inventors' assignment to Mitsubishi Electric was recorded during national-stage entry in 2020-02 — the normal chronology for a Japanese-origin corporate filing, not the "inventors bail out, portfolio gets sold" pattern. The deep continuing patent output of Morimoto and Okano at Mitsubishi Electric (77 and 36 patents) indicates sustained employment rather than attrition.

Original assignee

Mitsubishi Electric Corporation — 7-3, Marunouchi 2-chome, Chiyoda-ku, Tokyo 100-8310, Japan. Assignee on the face of the patent and (per the legal-events record) still the owner.

• Primary line of business: diversified electrical and electronics manufacturer; the relevant business unit is Living Environment Systems (residential and commercial air conditioning, VRF/City Multi, heat pumps). Air conditioning is one of its largest revenue segments.
• Product embodying the claims: Yes. The patent is directed to simultaneous cooling/heating ("cooling main" / "heating main") control of a multi-split outdoor unit with two parallel outdoor heat exchangers, a bypass pipe and a four-way flow rate adjustment device — the architecture of Mitsubishi Electric's commercial VRF/City Multi line. This is a commercially shipped product family, not a paper patent.
• Current status: Operating, publicly traded (Tokyo Stock Exchange), no bankruptcy, no acquisition, no dissolution. No change-of-name or merger record appears in the chain.

Also assigned in the same family: EP 3 683 511 B1 (granted 2023-06-28), CN 111051786 A, and a JP family member (number truncated in the source I retrieved, https://data.epo.org/pise-server/rest/collections/lgpi/EP3683511B1.pdf).

Assignment timeline

Important limitation, stated up front: Google Patents' Legal Events record (reproduced in the patent text supplied to me) shows only one post-filing assignment transaction for this patent. Attempts to pull the reel/frame and correspondent fields from USPTO Assignment Center via search did not return the record for this patent number, and the legal-events feed does not publish reel/frame, execution date or correspondent. I am therefore listing the reel/frame and correspondent as not retrieved rather than reconstructing them. Verification requires a direct lookup at Assignment Center by patent number.

• Execution date not shown in the sources reached / recorded 2020-02-21 — Reel not retrieved (Assignment Center lookup required)
  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Takenaka, Naofumi; Morimoto, Osamu; Maruyama, Hiroki; Okano, Hiroyuki (all four named inventors)
  • Assignee: MITSUBISHI ELECTRIC CORPORATION, Chiyoda-ku, Tokyo, Japan
  • Correspondent: Not exposed in Google Patents Legal Events. On the face of Mitsubishi Electric US filings the attorney/agent of record is commonly a Tokyo-US prosecution firm; I have not verified this for US 11,371,755 and do not assert it as a finding. Because the chain contains only this single link, the "recurring correspondent" test cannot be run at all — a single appearance would not be probative even if confirmed.
  • Context: Standard inventor-to-employer assignment perfecting title at US national-stage entry (35 U.S.C. § 261), executed against the PCT/JP2017/033439 priority. Not a fire-sale, not a securitization, not a transfer to an asserter.

No other recorded conveyances — no assignment, security agreement, merger, change of name, license, release or correction — appear in the record for this patent. No owner other than Mitsubishi Electric Corporation is disclosed anywhere in the file.

Other dated events (not assignments, for timeline context):

• 2017-09-15 — PCT/JP2017/033439 filed (application date; filing date of the US case as a national stage)
• 2020-06-11 — US 2020/0182516 A1 published
• 2022-06-28 — US 11,371,755 B2 granted
• 2037-09-15 — anticipated expiration

Litigation check: No infringement action naming US 11,371,755 was found in the searches I ran (Google Patents, Justia, general docket/web search, Unified Patents / RPX references). Mitsubishi Electric is an active litigant in other matters, but nothing ties this patent to an assertion campaign. Absence of a suit is a negative finding, not proof no suit exists.

Timeline diagram

timeline
    title Ownership of US 11371755
    2017 : PCT application filed by Mitsubishi Electric
    2020 : Inventor assignment recorded to Mitsubishi Electric
         : US publication 20200182516
    2022 : Patent US 11371755 granted
    2037 : Anticipated expiration

NPE / troll-pattern signals

Verdict

Insufficient data — but on this record that is a clean bill of health, not a gap in the ownership story.

Justification: exactly one conveyance is recorded for US 11,371,755 — a four-inventor-to-employer assignment to MITSUBISHI ELECTRIC CORPORATION recorded 2020-02-21 against the 2017-09-15 PCT/JP2017/033439 filing (Google Patents Legal Events, https://patents.google.com/patent/US11371755/en; execution date and reel/frame not published in that feed and not retrievable from the sources I reached). Because the assignment section contains only the original assignment, the rubric lands on Insufficient data rather than Operating-company assertion, which would additionally require an affirmative suit against a competitor that I could not find. Every NPE indicator that can be tested is not present: no shell-entity successor, no known asserter, no cascading LLC chain, no bankruptcy, no privateering, and no defensive-aggregator endpoint. Mitsubishi Electric remains the owner of a patent that reads on its own commercial VRF product line.

Verify the reel/frame and correspondent directly (the only unresolved field) at:

• https://assignmentcenter.uspto.gov/ (search by patent number 11371755 or application 16/640,871)
• https://assignment.uspto.gov/patent/index.html

Caveat on completeness: I could not execute a live query against Assignment Center in this session, and Google Patents Legal Events is a secondary feed that can lag or omit records. A verified Assignment Center pull showing a post-2022 conveyance would change the analysis, particularly signals 1, 4 and 5.

I'll research the prior-art citations for US Patent No. 11,371,755. Let me start with targeted searches.

I found useful leads. Let me dig into the specific citations listed on the patent and its PCT search report.

Let me get the specific cited references from the US patent's front page and the Google Patents "Citations" list.

I've reached my search-step limit, so I'll report what I was able to verify — and be explicit about what I could not verify.

Prior-Art Analysis — U.S. Patent No. 11,371,755 B2

0. Important methodology note before the tables

• Strict identifier handling: I searched only for 11371755 / US11371755B2 / application 16/640,871. I did not substitute similar numbers.
• Source limitation (please read): I was not able to complete a direct USPTO Patent Public Search / Patent Center front-page pull for the "References Cited" box before hitting my search-step limit. The citation data below comes from (a) the patent's own specification, and (b) Google Patents' machine-compiled citation data for the US/JP/PCT family (US20200182516A1 / US11371755B2 / JPWO2019053876A1 / JP6880204B2). Google Patents' "Citations" list is a derived index, not the official USPTO front page. Where I could not confirm the official record, I say so.
• Distinction to keep in mind: "Citations" (backward = prior art cited against this patent) vs. "Cited By" (forward = later documents citing this patent). Your task is the former.
• No contradiction found with the previously generated Litigation summary section (which reported no litigation found); nothing here changes that.

1. Bibliographic anchor (confirmed)

Key §102 timing consequence: because the priority/filing date is 2017-09-15 with no earlier benefit claim, anything published before 2017-09-15 is fair game as prior art. All four references identified below comfortably predate that date.

2. The prior-art references I could identify

2A. Reference expressly cited in the specification (the "Patent Literature 1")

2B. The "Citations" list Google Patents indexes for the '755 family (JPWO2019053876A1 page)

These four documents are the indexed citations for the family; R1 appears in this list too, which corroborates it.

2C. "Family Cites Families" list indexed by Google Patents (US 20200182516A1 page, N=14; JP page, N=10)

These appear to be references cited in the prosecution of sibling family members (not necessarily the US application). Treat as indicative, not as the US front page. The entries I could read in full are:

(The remaining ~6 entries were truncated in the retrieved text and I will not guess at them.)

§102 note: these are dated 1989–2011, all pre-dating 2017-09-15, so they are eligible prior art. But they are peripheral multi-air-conditioner / expansion-valve-control art, and on the data available they map only loosely onto claim 1's distinguishing elements (parallel second outdoor heat exchanger with its own series flow-rate control device, plus the flow-rate adjustment device tied to the compressor discharge side). They read primarily as §103 background, not §102 anticipatory references.

2D. Additional same-field reference surfaced (NOT confirmed as cited against '755)

3. Direct answer to "which claim(s) does each reference potentially anticipate"

Being candid, because you asked for §102 specifically:

1. No reference I could identify is a clean §102 anticipatory reference against independent claim 1. Every candidate is missing at least one of the two elements that appear to be the '755 patent's point of novelty: (i) the second outdoor heat exchanger connected in parallel with the first outdoor heat exchanger and its first flow-rate control device, and (ii) the flow-rate adjustment device connected between the compressor discharge side and the second outdoor heat exchanger.
2. R1 (WO 2013/111176 / EP2808621A1) is the strongest candidate and is the reference the applicant itself acknowledged — it is the natural primary §103 reference, and possibly §102 for the broader bypass/flow-control concepts, pending full-text verification.
3. R2–R4 are citations I can only describe at title level. I will not fabricate a claim-by-claim §102 mapping for documents whose text I could not retrieve.
4. The §102 vs §103 framing matters here: the specification's own "Technical Problem" concedes that Patent Literature 1 (R1) already controls outdoor-heat-exchanger heat-exchange amount via fan + expansion valve and already uses a bypass flow-rate control device — i.e., the applicant treats R1 as known art and frames novelty around maintaining circulation amount / avoiding liquid back, not around the bare bypass topology. That is an admission that strengthens an obviousness attack and weakens a bare §102 attack.

4. What I could not do (explicit)

• I could not open the official USPTO front-page "References Cited" box (U.S. Patent Documents, Foreign Patent Documents, Other Publications) for 11,371,755 in this session. Therefore the possibility of U.S. patent documents among the cited references is unverified. If U.S. references exist, they are not in the material I retrieved.
• I could not verify whether EP2472202B1 is on the '755 record.
• The "Family Cites Families" entries were truncated; ~6 entries are unknown to me.

Recommended verification step: pull the official record at USPTO Patent Public Search / Patent Center for application 16/640,871 and read the front page "References Cited," then cross-check against Espacenet/Global Dossier for the PCT/JP2017/033439 ISR and the JP6880204B2 prosecution citations. That will give you the authoritative, complete citation list — which I have only partially reconstructed here.

I'll research the claims and prior art landscape for this patent before building the obviousness analysis.

Let me pull the actual claim language and identify candidate prior art references.

Now let me examine the examiner-cited references and additional analogous art.

Obviousness Analysis — U.S. Patent No. 11,371,755 ("Air-conditioning apparatus")

Assignee: Mitsubishi Electric Corporation · Priority/filing: 2017-09-15 · Granted: 2022-06-28 · Status: Active

This section builds on the earlier litigation summary (no assertion/challenge activity found for the '755 patent) and does not repeat it. The analysis below assumes the patent is presumptively valid and asks only whether the claims would have been obvious under 35 U.S.C. § 103 at the 2017-09-15 effective filing date.

1. Evidentiary basis and flagged discrepancies

⚠️ Contradiction flag (material to the analysis): The granted claim 1 and the published application's claim 1 are not the same:

• Published (2020/0182516) claim 1 ends at "…a flow rate adjustment device connected between a discharge side of the compressor and the second outdoor heat exchanger." No controller limitation.
• Granted ('755) claim 1 adds: "a controller configured to control operation of the flow rate adjustment valve, the controller is configured to switch a connection state where… the second outdoor heat exchanger is connected to an accumulator provided at a suction side of the compressor and a discharge side of the compressor is connected to a tail end of the pipes where refrigerant flow therethrough terminates, and control the second flow rate control device to close, when performing a cooling operation."

The granted claim is therefore narrower than what the earlier-generated sections may have implicitly assumed. All obviousness reasoning below is keyed to the granted claim set. I also note the terminology shift: the granted claim uses "flow switching valve" and "flow rate adjustment valve," while the specification describes "flow switching device 2a" and "flow rate adjustment device 2b." These are the same physical components; the claim-drafting change does not affect the analysis.

Additional gaps I could not close: I did not retrieve (a) the examiner's "References Cited" list from the file wrapper — a search for it returned an unrelated patent, US 11,105,539 — or (b) the full text of dependent claims 3–5 and 7–8. Only claims 1, 2, 6 and 9 were recoverable. The analysis of dependent claims is therefore partial.

2. Claim 1 — element decomposition and coverage

Conclusion: WO'2013/111176 alone does not anticipate claim 1 (it lacks the second outdoor heat exchanger and the flow rate adjustment valve). The invalidity theory must be a § 103 combination.

3. Prior art references

All four references are in the same field of endeavor (compression-type refrigeration / air-conditioning) and address the same problem (heat-exchange-amount control of an outdoor heat exchanger at part load), so they are analogous art and proper for combination.

4. Combination theories

Theory 1 (primary): WO'176 + Ref A + Ref B

Claim 1. WO'176 discloses the outdoor heat exchange unit with a series flow rate control device and a parallel bypass carrying a second flow rate control device, and expressly teaches controlling the heat exchange amount of the outdoor heat exchanger by airflow adjustment and valve adjustment. Ref A teaches that the single outdoor heat exchanger of such a unit may be split into two parallel heat exchangers, each with its own series flow rate control device — a routine capacity-scaling/part-load-modulation arrangement in multi-air-conditioner (VRF) outdoor units. Ref B teaches that an outdoor heat exchanger's effective heat exchange amount can be modulated by a valve that proportions refrigerant between the heat exchanger and a bypass, and that this valve control is coordinated with fan speed against a capacity/discharge target.

The only element not squarely met by WO'176 + Ref A + Ref B is the flow rate adjustment valve between the compressor discharge and the second outdoor heat exchanger, switchable to the accumulator (1.8–1.10). This is met by ordinary skill: four-way valves placed in the high-pressure line of an individual outdoor heat exchanger to connect it either to the discharge side or to the suction/accumulator side are a standard building block of multi-outdoor-unit and simultaneous cooling/heating systems (consistent with the patent's own classification entries, e.g., F25B2313/0252 "multiple outdoor units with bypasses" and F25B2313/02741 "one four-way valve"). The patent's own specification concedes that device 2b "may be an on-off valve… or… a flow rate adjustment valve" and is "a four-way switching valve," i.e., a conventional component.

Theory 2 (alternative): WO'176 + Ref A + Ref C

Ref C supplies elements 1.8–1.10 more directly: a flow path switching valve that re-routes a heat exchanger to a different return path plus a bypass regulating valve, with the controller selecting the state based on load (low load → bypass/alternate path; high load → main path). A PHOSITA seeking to extend the part-load range of WO'176's apparatus below the minimum achievable by fan speed would look to exactly this kind of valve-based capacity unloading, and would apply it to one of the two parallel outdoor heat exchangers of Ref A.

Theory 3 (single-reference-plus-admissions): WO'176 + the '755 specification's own admissions

The '755 specification admits that "the air-conditioning apparatus in which heat exchange amount control of the outdoor heat exchanger is performed has hitherto been known" and that avoiding "liquid back" into the compressor suction was a known problem (the accumulation/liquid-back failure mode is described as the prior-art problem being solved). When the problem itself is recognized in the art and the claimed remedy (isolate one parallel heat exchanger on the low-pressure side and make up the circulating charge through the bypass) is a known technique, the claimed subject matter is at most an "obvious to try" combination of known options with a predictable result (KSR Int'l v. Teleflex).

5. Dependent claims

6. Motivation to combine (KSR factors)

1. Same field / same problem. WO'176, Ref A, Ref B and Ref C all address part-load heat-exchange-amount control of outdoor heat exchangers in air-conditioning apparatus. No field-of-endeavor or analogous-art barrier.
2. Addressing a recognized deficiency in the primary reference. The '755 patent itself frames the invention as solving the deficiency of WO'176: at low outdoor temperature, throttling the outdoor flow rate control device makes the refrigerant outflow smaller than the compressor discharge, refrigerant accumulates in the outdoor HX, and the circulating charge becomes insufficient. Ref A's parallel-HX architecture and Ref B's proportional valve control directly address "how else can I reduce the outdoor heat exchange area/capacity?" — a predictable combination.
3. Known technique, predictable result. Reducing condenser area during cooling by deactivating one of several parallel outdoor heat exchangers (via a four-way/on-off valve to the suction side) and compensating the charge via a bypass is a well-understood refrigeration-cycle manipulation; a PHOSITA would expect success with a reasonable expectation.
4. Design incentives / market pressure. Low-ambient cooling is a standard operating condition for VRF equipment; avoiding liquid back and maintaining the minimum circulating charge are recognized reliability requirements. These provide a concrete commercial and technical impetus.
5. No teaching away. None of the identified references criticizes the parallel-HX or HX-unloading approach; WO'176 affirmatively endorses bypass-based heat-exchange-amount control.

7. Counterarguments a patent owner could raise (and an assessment)

8. Bottom line

• Claim 1 is vulnerable to a § 103 challenge over WO 2013/111176 in view of parallel-outdoor-heat-exchanger art (e.g., JP 6320567 B2) and valve-based flow-proportioning/bypass art (e.g., US 2012/0192588 A1 / EP 2 472 202 B1, or alternatively US 11,112,140 B2). WO'176 is cited on the face of the patent itself and supplies most of the outdoor-heat-exchange-unit architecture; the remaining elements are a routine duplication of the heat-exchange path and a conventional four-way/flow-rate-adjustment valve.
• Alternative theory: WO'176 + Ref A + Ref C, which supplies the load-based HX re-routing/bypass-switching structure more directly for elements 1.8–1.10.
• Dependent claims 2, 6 and 9 appear obvious for the reasons given. Claims 3–5, 7 and 8 could not be assessed because I could not retrieve their text.

9. Confidence, gaps, and recommended next steps

• High confidence that claim 1 is not anticipated by WO'176 alone (missing second outdoor HX and flow rate adjustment device).
• Medium confidence in the specific primary combination; JP 6320567 B2's publication/priority dates and its exact disclosure of the bypass pipe were not fully verified from the sources available to me, and should be confirmed, since its § 102(a)(2) status relative to 2017-09-15 depends on its filing date.
• Not verified: the examiner's actual cited-art list from the '755 file wrapper, the full claim set, and the EP 3 683 511 B1 counterpart's prosecution history (which would show what art the EPO considered — the EPO publication record confirms the family and grant).
• Recommended: (1) pull the '755/16/640,871 U.S. file wrapper for the examiner's cited references and any § 103 rejections; (2) pull the JP 6320567 B2 and WO 2014/054091 A1 texts and confirm filing dates; (3) obtain the full claim set (claims 3–5, 7–8) to complete the dependent-claim analysis; (4) run the combination against a full claim chart once the authoritative claim text is in hand.

This is a preliminary technical/legal-analysis work product, not a legal opinion. Statement of no known litigation is carried forward from the earlier section and remains "none found," not "none exists."