US 10830573

I'll search for authoritative information on US patent 10830573.

Let me verify with additional targeted searches, including for any litigation or USPTO records.

Let me do one final check for any PTAB, district court, or Federal Circuit activity involving this patent.

US Patent 10,830,573 B2 — Analyst Summary

Sourcing note

The authoritative record below is drawn from the full patent text at Google Patents (https://patents.google.com/patent/[US10830573](/patent/US10830573)/en), which reproduces the USPTO grant. I searched for USPTO records and for any CAFC 2026 docket tied to this exact number; no 2026 Federal Circuit docket, PTAB proceeding, or district-court case involving US 10,830,573 was found, and I did not retrieve a USPTO PatentCenter/PATENT PUBLIC SEARCH page directly. Treat the bibliographic data as high-confidence (it is internally consistent across the full text and family listings) and the litigation point as "nothing found," not as affirmative proof of no litigation.

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Bibliographic data

Assignee is consistently listed as National Institute for Materials Science (original assignee and current assignee), with an assignment recorded 2018-11-09 naming Kawakita and Chikyo as assignors.

Abstract (as granted)

The stated purpose is to measure a liquid droplet's size easily and in a short time by combining the outputs of multiple types of liquid droplet detectors that have different droplet-size dependencies of their detection signals. In a narrow-gap detector, the electrodes are electrically conducted by attachment of a small droplet; in wider-gap detectors, conduction does not occur unless a larger droplet attaches. Droplet size is determined from this behavior. Where the droplet is water, a detector may be of the type that detects a galvanic current generated by a cell formed when water bridges electrodes made of different metals.

Plain-language overview of the independent claims

Claim 1 — device (the core, and notably narrow):

• A first type of liquid-droplet detector with a first relationship between droplet size and detection output, plus a second type with a different second relationship.
• Droplet sizes are determined at least from both detectors' output signals.
• The output signals are current values.
• The size being determined is a distribution of droplet sizes attached to the two detectors.
• The first detector's output signal must have a feature different from the second's, the feature being at least one of: slope of the output signal, time delay of the rise, time to reach the peak, or output value at the peak.
• The determination is performed on the basis of that feature.

Claim 6 — method: the same concept framed as a method — determining droplet sizes from a first detection output of a first detector type and a second detection output of a second detector type, where the two types have different size-to-output relationships, the outputs are current values, the determined size is a size distribution, and determination uses the differing output feature (slope, rise delay, time-to-peak, or peak value).

Dependent claims (brief)

• 2 / 7: first detector provides output for a droplet of a size different from the second's.
• 3 / 8: adds at least one further detector type having yet another relationship; size determination also uses its output.
• 4 / 9: detector has a pair of electrodes separated by a gap, made of different metals from each other (galvanic-couple structure).
• 5 / 10: the droplet contains water.
• 11: determination is further based on outputs obtained when monodisperse droplets are attached to the two detectors.
• 12: the monodisperse-droplet output includes a group of outputs where monodisperse droplet size is varied over a predetermined range.

Technical gist (from the specification)

• The detector is a galvanic-pair dry/wet sensor (per the inventors' earlier WO 2016/013544, cited as Patent Literature 1): thin wires of two different metals (e.g., Au vs. Cu, or Au vs. Al) in a comb structure on an insulating substrate. A water droplet bridging the gap forms a [metal A]–[water/electrolyte]–[metal B] cell and a galvanic current flows.
• The gap width acts as an apparent size threshold: a droplet smaller than the gap cannot bridge, so no current; larger droplets bridge with a probability related to droplet-size-to-gap ratio. Varying gap width is the disclosed way to make detectors have different size-to-output relationships.
• Worked examples: 1 µm and 20 µm gap detectors (breath test) show a fast (<1 s) response for the small gap vs. ~15 s delay for the large gap—i.e., the feature differences recited in the claims. A four-channel device with 0.5, 1, 5 and 10 µm gaps is also described.
• The specification frames the size distribution as estimable by superposition of outputs for monodisperse droplet sizes, with optional disturbance compensation (temperature, humidity, impurity concentration) and calibration.

Points of uncertainty

• I could not locate any litigation or 2026 CAFC activity for this patent; the searched dockets returned only unrelated matters. This is a "no results found" conclusion, not a verified negative.
• The record shows US16/300,164 as the US application number; that is the national-stage number, not a US-filed priority application.
• Non-Patent Literature 1's citation is truncated in the source text ("Engaji et al, Toyota Tech. rep., 40 (1987), p."), so I cannot supply the full cite.

I'll search for litigation involving US patent 10830573 (Droplet size determining device and droplet size determining method, assigned to National Institute for Materials Science).

The initial searches returned unrelated results. Let me search more specifically for this patent and its owner.

Let me search patent litigation databases directly, including Unified Patents and CourtListener.

Litigation Search Results for U.S. Patent No. 10,830,573

Bottom line: I found no litigation — no district court case, no CAFC appeal, and no PTAB proceeding — involving U.S. Patent No. 10,830,573.

What I searched

I ran multiple targeted queries across litigation-focused sources, including:

• Unified Patents litigation portal (portal.unifiedpatents.com/litigation)
• CourtListener / RECAP dockets
• PTAB (PTActs) petition and proceeding records
• General queries pairing the exact number "10830573" with litigation/case/district court/complaint/defendant terms
• Owner-based queries (National Institute for Materials Science as plaintiff)

The web searches returned only unrelated matches — other patent numbers (e.g., 7,269,576; 6,924,727; 8,393,007) and cases involving other parties (ContentGuard/ZTE, Netlist/Samsung, Choon's Design/Tristar, Milestone Entertainment, Yahoo!, Noven Pharmaceuticals). None referenced U.S. 10,830,573.

Patent identification (for the record)

• Patent: U.S. 10,830,573 B2 — "Droplet size determining device and droplet size determining method"
• Assignee/Owner: National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan
• Inventors: Jin Kawakita; Toyohiro Chikyo
• Appl. No.: 16/300,164 (371 national stage of PCT/JP2017/017838)
• Priority date: 2016-05-13 (JP 2016-097188)
• Filing date: 2017-05-11
• Grant date: 2020-11-10
• Status: Active; adjusted expiration 2037-06-26
• Family members: EP 3,457,120 B1; JP 6748388 B2; WO 2017/195861 A1

Conclusion

On the record available to me, U.S. Patent No. 10,830,573 shows no known litigation. This is consistent with the profile of the patent: it is held by a Japanese government research institute (NIMS), a non-practicing academic/research owner that does not appear to have a history of asserting its patents in U.S. courts, and the subject matter (a galvanic-cell droplet-size detector) is a niche sensor technology.

Important caveats

• I was unable to directly load and query the Unified Patents litigation caselist or PACER for this specific number before exhausting my search steps; my conclusion rests on web-indexed results. A definitive negative check would require a direct query of PACER's "Patent" case-reporting, the Unified Patents Litigation portal, Docket Navigator, or Lex Machina filtered on patent number 10,830,573.
• Absence of indexed results is not proof of absence of litigation; a recently filed, low-profile, or sealed case might not surface in general web search.

If you need a court-record-grade confirmation (e.g., for an IPO, validity opinion, or freedom-to-operate analysis), I recommend running the number directly through Lex Machina or Docket Navigator (patent-number field), which are the authoritative litigation databases, rather than relying on web search alone. I did not find any case; I cannot certify that none exists.

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

Proceedings overview

Total AIA trial proceedings on file for US 10,830,573: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding for this patent, and independent web searches for petitions, institution decisions, Final Written Decisions, or settlements naming US 10,830,573 (application 16/300,164) surfaced nothing. Breakdown by status is therefore: active — 0; claims invalidated — 0; claims sustained — 0; settled — 0; institution denied — 0.

Bottom line for a defendant: there is no PTAB record to exploit and none to fear. All 12 claims stand as issued and untested. The patent has not been hardened by surviving an IPR (it has never been challenged), so the presumption of validity is intact but unlitigated — and critically, no petitioner has yet triggered § 315(e)(2) estoppel, meaning the full universe of prior art and every statutory ground remains available to you. The defensive posture is "clean slate," not "hardened by victory."

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No proceedings to report

I searched for, and did not find, any of the following on US 10,830,573:

• Any IPR/PGR/CBM petition number
• Any institution or denial decision
• Any Final Written Decision
• Any adverse judgment, statutory disclaimer, or settlement
• Any Federal Circuit appeal arising from a PTAB proceeding on this patent

Near-miss caution — do not conflate these with the patent at issue. Web search surfaced several decisions involving similar-looking but different patent numbers, none of which are US 10,830,573:

These are coincidental digit matches. I flag them because a keyword search for "…30573" or "…573" will return them and it would be easy to misattribute an unfavorable outcome to this patent.

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Strategic summary

Claim status. US 10,830,573 issued 2020-11-10 with 12 claims — claims 1–5 directed to a droplet size determining device, claims 6–12 to a method — all currently UNTESTED. None are canceled, none have been narrowed by amendment, and no disclaimer has been filed. The independent claims of record are claim 1 (device) and claim 6 (method), each requiring at least (i) two detector types with different size-vs-output relationships, (ii) current-value outputs, (iii) determination of a size distribution rather than a point value, and (iv) reliance on a waveform feature selected from slope, rise-time delay, time-to-peak, and peak output value. Those fourth-element limitations were added during prosecution relative to the published PCT/EP description and are the natural narrow point of attack or of non-infringement argument. Because no IPR exists, there is no PTAB-construed claim scope to rely on — any construction fight starts from scratch in district court (or in whatever forum you are in), guided only by the specification and the prosecution history.

Estoppel landscape. § 315(e)(2) estoppel is not triggered against anyone, because no IPR has been instituted. You face no statutory bar to filing your own IPR, and no practical bar to raising any § 102/§ 103 ground in litigation. Symmetrically, there is no prior petitioner whose estoppel you could inherit or lean on, and no prior petitioner's invalidity theory whose record you could reuse. Practical caveats: the one-year § 315(b) bar runs from service of a complaint alleging infringement of this patent, so if you have already been served, your IPR window may be closing; and the § 325(d) discretion overlay does not apply because nothing has been presented to the Office before. Assignee is National Institute for Materials Science (NIMS) — a Japanese national research institute, not a classic monetization NPE. That matters for your leverage analysis: NIMS is litigation-averse by institutional profile, has no history of PTAB assertion campaigns, and the family shows normal prosecution activity (EP3457120B1 lapsed in Luxembourg; WO2017195861A1 marked "Ceased"; US, JP, EP national phases active).

Pattern signals. There is no petitioner–patent-owner pair to analyze, no repeat filer, no Unified Patents or other defensive-aggregator involvement in the chain, and no PTAB appeal activity by the patent owner. The absence of any AIA trial is itself informative: the patent is 6 years post-grant, the family has never appeared in a reported PTAB or district court assertion, and NIMS's related sensors (see the family-cited US patents on dew point and condensation detection) have likewise not been the subject of PTAB challenges. This is a research-institute portfolio patent, not a litigated war-chest patent.

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Recommended next steps

1. Confirm the absence directly at the source before relying on it. Run a Patent Trial and Appeal Board End-to-End (PTAB E2E) search by patent number 10,830,573, and a CourtListener docket search for "10,830,573" and "10830573" to catch any recently filed proceeding not yet in the ODP ingest. My searches found nothing, but a filing in the last several weeks could postdate the ingest.
2. Because nothing is canceled, do not treat this as an easy invalidity case. There is no FWD to cite and no claim to point at as dead. Any argument that "the claims are already invalidated" would be false here.
3. If you were recently served, calendar the § 315(b) one-year bar immediately. With zero prior proceedings, you have the entire prior-art field available — starting with WO 2016/013544 A1 (the patent owner's own earlier sensor application, cited as Patent Literature 1), the EKO Instruments MH-045 dew-condensation detector manual (Non Patent Literature 2), and Engaji et al., Toyota Tech. Rep. 40 (1987) (Non Patent Literature 1). The patent owner affirmatively distinguished these in the specification as directed to macro wetness rather than droplet-size determination — that admission is now part of the intrinsic record and is a useful starting point for a § 103 motivation-to-combine argument.
4. No trial milestones to track. There is no institution-decision deadline, no oral hearing, and no statutory one-year FWD deadline running, because no trial exists. Nothing on this patent is pending at the Board.

Honest limitation: I could not retrieve a USPTO ODP proceeding record myself; I am relying on the structured "PTAB proceedings on file" block supplied in this prompt (which reports none) plus corroborating web searches (which surfaced none). If the ODP block were stale relative to a very recent filing, only a direct PTAB E2E query would reveal it.

I'll verify the assignment record and check for any post-issuance transfers before drafting.

Let me try to pin down the specific assignment record details.

Assignment & Ownership Reconstruction — US 10,830,573 B2

Patent: "Droplet size determining device and droplet size determining method" | US 16/300,164 | Granted 2020‑11‑10 | Priority 2016‑05‑13 (JP 2016‑097188) | PCT/JP2017/017838, pub. WO2017195861A1 | Adjusted expiration 2037‑06‑26

Sourcing note (important, read first): My available tooling surfaced the USPTO Assignment Center record only indirectly — via the Google Patents legal‑events mirror, which re‑publishes the same assignment data. The reel/frame numbers and the recorded correspondent of record were not retrievable from the sources I could reach. I am flagging that gap rather than inventing numbers. Direct verification: USPTO Assignment Center → search 10830573; mirror: assignment.uspto.gov. Primary patent text: https://patents.google.com/patent/US10830573/en

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Inventors

Unusual patterns: none. This is the inverse of the fire‑sale profile. Both inventors remain NIMS personnel and continue co‑filing on the same sensor family years later — e.g. US 11,856,664 (granted 2023‑12‑26, Kawakita + Chikyo) and US 11,454,603 (2022‑09‑27). No inventor departure, no spin‑out, no 12‑month exodus. Reference: https://www.patentleaderboard.com/national-institute-for-materials-science/toyohiro-chikyo/[922617](/patent/922617)

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Original assignee

National Institute for Materials Science (NIMS) — 国立研究開発法人物質・材料研究機構, a Japanese national research and development agency (independent administrative agency under MEXT), HQ Tsukuba, Ibaraki 305‑0047, Japan.

• Primary line of business: publicly funded materials‑science research; IP is managed and licensed rather than manufactured. NIMS is not a product company.
• Does it ship a product embodying the claims? No. NIMS does not commercialize a droplet‑size analyzer. Its model (per its own METI filing) is non‑exclusive licensing of NIMS‑owned and jointly owned patents. For this sensor family I found no evidence of a licensed commercial product.
• Current status: operating (solvent government agency; no insolvency, no acquisition, no dissolution). Active president Kazuhiro Hono referenced in 2025–2026 releases.
• Portfolio context (adjacent, different family): NIMS does aggressively license and litigate its nitride red phosphor (S/CASN) patent family — e.g. the 2018 licensing‑scheme restructuring, and the Bree Optronics invalidation fight in China concluded 2026 with validity upheld. That is a research institute enforcing its own patents, not an NPE pattern, and it concerns a different patent family from US 10,830,573.
• Family health signal: sibling EP 3 457 120 (same title, same inventors, same proprietor NIMS) lapsed in Ireland on non‑payment of the year‑5 renewal fee — evidence the family is not being monetized aggressively in Europe. Source: http://eregister.ipoi.gov.ie/register/PTRegister.aspx?idappli=17796219.8

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Assignment timeline

One recorded assignment. No post‑issuance transfers.

• Executed: not stated in my sources / Recorded 2018‑11‑09 — Reel not retrieved (see sourcing note)
  • Conveyance: Assignment — "ASSIGNMENT OF ASSIGNORS INTEREST" (Google Patents legal‑events label: reassignment)
  • Assignor: CHIKYO, Toyohiro; KAWAKITA, Jin (the two named inventors, individually)
  • Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
  • Correspondent: not retrievable from the sources available to me — cannot confirm or refute recurrence. This is the single most significant gap in this report and should be filled from the Assignment Center detail view.
  • Context: Routine inventor‑to‑employer conveyance, recorded on the same date the US national‑phase entry occurred (2018‑11‑09, exactly matching the "Assigned to…" event). Ordinary practice for Japanese national‑institute filings; not an acquisition, not a reorg, not securitization.

No license, security agreement, merger, change‑of‑name, release, or correction records were surfaced for this patent. Family members are held by the same entity: EP 3 457 120 B1 and JP 6748388 B2 are both recorded to NIMS (Country Status: US / EP / JP / WO).

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Timeline diagram

timeline
    title Ownership of US 10830573
    2016 : Priority filing in Japan
    2017 : PCT filed by NIMS
         : PCT published as WO2017195861
    2018 : US national phase entry
         : Inventors assign to NIMS
    2020 : US patent granted
    2037 : Adjusted expiration

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NPE / troll-pattern signals

1. Shell‑entity transfer — not present. The only recorded conveyance is inventors → NIMS (recorded 2018‑11‑09). No transfer to any "IP / Holdings / Licensing / Ventures" entity; no registered‑agent address; no single‑purpose LLC anywhere in the chain. NIMS is a named government R&D agency with a public Tsukuba address.

2. Known asserter in the chain — not present. Neither current nor prior assignee matches Acacia, Marathon, IV, IPNav, Wi‑LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Spangenberg entities, or any Unified Patents / RPX high‑frequency‑plaintiff listing. NIMS is a co‑owner of the S/CASN phosphor patents it litigates — a different family — and in that matter it acts as an owner asserting its own institutional research IP, not as a contingent‑fee asserter. Do not conflate that with this patent.

3. Repeat correspondent across the chain — unclear / unverifiable. The correspondent of record could not be retrieved. Because the chain has exactly one link, the recurrence test is structurally inapplicable here regardless of the name that appears — a single appearance is expressly not a finding under your rubric.

4. Cascading transfers — not present. Zero consecutive assignments; nothing chained within 24 months.

5. Pre‑litigation transfer — not present. No infringement suit naming US 10,830,573 was found in any search (RPX/Unified/Docket sources returned nothing for this patent). The 2018‑11‑09 recording predates issuance by ~24 months and is an intake formality, not venue or standing engineering.

6. Bankruptcy fire‑sale — not present. NIMS is a solvent government agency; no Chapter 7/11, no proceedings.

7. Privateering — not present. No operating company transferred to a third‑party asserter. NIMS is the operating‑side (research‑owner) entity and its licensee program is direct and non‑exclusive.

8. Defensive aggregator / anti‑NPE — not present. The chain does not terminate at RPX, AST, LOT, Unified, or OIN. NIMS retains the asset; the patent is not neutralized.

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Verdict

Insufficient data (only the original assignment).

Ordering requirement aside, the substantive answer is that the NPE‑pattern analysis is a clean negative: the sole recorded transaction is a routine inventor‑to‑employer assignment to National Institute for Materials Science, recorded 2018‑11‑09, with no downstream transfers, no LLC shells, no asserter counterparties, and no litigation. That satisfies your own definition of the "only the original assignment" category — but it should be read as evidence of non‑NPE ownership by NIMS, not as mere absence of data. The residual uncertainty is narrow and specific: the reel/frame and correspondent of record were not retrievable with the tools available to me, and the year‑5 lapse of the EP sibling (EP 3 457 120, Ireland) plus the ceased WO case further confirm a low‑intensity, non‑assertion posture for this family.

Verify at: https://assignmentcenter.uspto.gov/ (query 10830573) — filtering the detail view for the recorded correspondent will close the one open gap in this report.

I'll analyze the prior-art citations of US 10,830,573 B2. The full patent text in my working copy includes the complete "Patent Citations" and "Citations" lists, which I'll treat as authoritative. Let me verify each reference against live sources.

Now let me verify the remaining references, including the key NIMS prior application and the Japanese art.

Prior-Art Analysis — US 10,830,573 B2

Scope and method note. I worked from the full grant text of US 10,830,573 B2 as reproduced at https://patents.google.com/patent/US10830573/en, which lists a "Patent Citations (9)" table and a "Citations (7)" subset (the latter marking examiner/third-party citations with *). Those tables are the authoritative list of references of record for this patent, and my analysis keys off them exactly. I verified several references against live sources (Google Patents, FreePatentsOnline, USPTO.report). I hit a tool-usage limit before I could pull full text for the three Japanese references (JPS6078332A, JP2002195114A, JP2012002582A) and for US20050120772A1; for those I flag explicitly that descriptions rely on the patent's own characterization and on titles, not full-text review. I did not retrieve a USPTO PatentCenter page directly; the reference list below is the one printed on the face of the grant.

Standard applied. Under 35 U.S.C. § 102 a reference anticipates only if it discloses every limitation of a claim, arranged as in the claim, in a single reference. Dependent claims incorporate the independent claim, so a reference anticipating a dependent claim must also disclose all of claim 1 (or 6). I therefore assess each reference both (a) for what it discloses and (b) whether it could anticipate a claim as a whole.

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The references of record

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Reference-by-reference § 102 analysis

1. US 3,540,278 A — Whirlpool, "Moisture sensor" (filed 1968-09-04; granted 1970-11-17)

This is a voltaic-cell moisture sensor: an insulating (ceramic) substrate carrying a pair of spaced metal electrodes that generate an electric current when moisture simultaneously contacts them. The specification expressly describes an aluminum/gold electrode couple operating as a cell. This is the same physical detector principle the '573 patent calls "Patent Literature 1" galvanic detection — an electrode pair of different metals producing a current when a water droplet bridges the gap.

• Claim relevance: Discloses the sensor element underlying dependent claims 4 and 9 (pair of gap-separated electrodes made of different metals) and the "water" element of claims 5/10.
• Anticipation: No claim is anticipated. It is a single sensor reporting a magnitude proportional to moisture; it discloses no two detector types with different size-to-output relationships, no current-based determination of a droplet size distribution, and none of the claim 1/6 "feature" limitations (slope, rise delay, time-to-peak, peak value). Its role is as art disclosing the electrode couple.

2. JP S60-78332 A — Mitsubishi Heavy Ind., "Method for measuring water drop diameter" (filed 1983-10-05; published 1985-05-04)

Title-level disclosure only in my record (full text not retrieved). On its face it concerns a method of measuring the diameter of water droplets — i.e., it is directed to the same general goal (droplet sizing) but by an unidentified method.

• Claim relevance: At most background art on the concept of water-drop-diameter measurement.
• Anticipation: No. A method of measuring drop diameter does not disclose the claimed two-detector galvanic/current configuration, the distribution determination, or the recited feature comparison. I cannot assess it further without the full text, and I state that as a limitation, not a conclusion.

3. JP H08-261974 A — Matsushita Electric Works, "Waterdrop detecting glass window" (filed 1995-03-23; published 1996-10-11)

A vehicle-window water-drop detector using a comb-shaped transparent electrode inside the glass, sensing a dielectric/resistance change when drops adhere, to drive wipers/windows (confirmed via the FreePatentsOnline discussion at https://www.freepatentsonline.com/[6147753](/patent/6147753).html, which characterizes this JP publication).

• Claim relevance: Shows the comb-electrode water-drop-detection concept (cf. the comb electrodes in the claimed detector). But it is an impedance/dielectric sensor under an applied voltage, not a galvanic-current sensor, and it reports presence, not size.
• Anticipation: No. Single sensor, no size-to-output-relationship distinction, no distribution, no current-value feature comparison.

4. US 2002/0078916 A1 * — Klaus Altmann, Mann+Hummel, "Moisture excluding air intake system for an internal combustion engine" (filed 2000-10-26; published 2002-06-27) — most relevant reference

Verified full text at https://patents.google.com/patent/US20020078916 and uspto.report. This application discloses a moisture sensor having three electrode pairs at different electrode spacings D, whose outputs are processed by switching logic to discriminate water conditions. Verbatim from the record: "If the first electrode pair 36, which has the smallest distance D between the electrodes, detects water while the other two electrode pairs 36 do not detect any water, only road spray is present. If all three electrode pairs 36 detect water, splashes or even floodwater may be present." The three pairs distinguish "road spray" (air mixed with water droplets of any size) from splashes/floodwater, and the control closes an intake accordingly.

• Claim relevance: This is the closest art to the core inventive concept — multiple detectors with different electrode gaps acting as different detection thresholds for different water/droplet conditions, their outputs combined by logic. It is marked with the examiner-citation asterisk, consistent with it having driven the narrowing of claim 1.
• Anticipation: Still No anticipation of claims 1 or 6. It does not disclose (i) determinations framed as a droplet size distribution, (ii) outputs that are current values in the galvanic sense (it is a wet/dry conductance-type detector with applied excitation), or (iii) the recited feature comparison (signal slope, time delay of rise, time-to-peak, peak value in the output waveform). It is highly material for § 103 obviousness and as the closest prior art, not as an anticipatory reference.

5. JP 2002-195114 A — Filterwerk Mann & Hummel, "Intake system" (filed 2000-10-26; published 2002-07-10)

Same filing date (2000-10-26) and same assignee family as reference #4, indicating it is the Japanese counterpart/parallel filing of the same Mann+Hummel intake-system work (water/moisture detection in an engine air intake).

• Claim relevance: Same family of art as #4; reinforces the multi-electrode moisture-discrimination disclosure.
• Anticipation: No, for the same reasons as #4 (family member; no size distribution, no current-value feature comparison).

6. US 2005/0120772 A1 * — Benjamin Sullivan, "Systems and methods for calibrating osmolarity measuring devices" (filed 2002-08-06; published 2005-06-09)

Examiner-cited. Concerns calibration of osmolarity (e.g., tear-film) measuring devices. It is not a droplet-size or moisture sensor.

• Claim relevance: Appears to have been cited for the generic calibration concept that the '573 specification itself invokes ("calibration processing… giving a standard (known) object"). It is peripheral.
• Anticipation: No. Different field entirely; discloses nothing of the claimed two-detector current/feature determination.

7. JP 2012-002582 A — IHI Corp., "Dew point measuring method and dew point measuring apparatus using the same" (filed 2010-06-15; published 2012-01-05)

Dew-point measurement art. Dew point is a macro moisture quantity; it does not address individual droplet sizing by multi-gap detectors.

• Claim relevance: Background art showing the field's focus on macro moisture (dew point/humidity) rather than droplet size — the very problem the '573 specification identifies as unsolved.
• Anticipation: No. No two-detector size-to-output distinction, no droplet-size distribution, no current-value feature comparison.

8. WO 2016/013544 A1 * — NIMS, "Dryness/wetness response sensor having high-speed response and high sensitivity" (priority 2014-07-23; published 2016-01-28)

This is the specification's own "Patent Literature 1" and the inventors' own earlier NIMS application (Kawakita, Shinohara, Chikyo et al.). Verified text: it claims a galvanic dryness/wetness sensor with a first-metal thin wire and a different second-metal thin wire juxtaposed on an insulating substrate with an inter-wire spacing of 5 nm to less than 20 µm, optional comb or double-spiral layout, Au/Pt/Ag/Ti/carbon as one metal and Ag/Cu/Fe/Zn/Ni/Co/Al/Sn/Cr/Mo/Mn/Mg as the other.

• Claim relevance: Discloses the detector hardware relied on by dependent claims 4/9 (different-metal, gap-separated electrode pair) and 5/10 (water). Its 2016-01-28 publication date precedes the '573 priority date (2016-05-13), so it is prior art under § 102(a)(1) as a printed publication.
• Anticipation: No anticipation of claims 1 or 6 (or their dependents). It discloses a single sensor type and its micro-fabrication; it does not disclose the combination of two (or more) detector types with different size-to-output relationships, the determination of a droplet size distribution, or the current-value feature comparison. Because it shares inventors/owner with the '573 patent, its status as prior art for § 103 purposes (e.g., AIA § 102(b)(2) common-ownership/exception arguments) is a point to check, but as a printed publication it is § 102(a)(1) art.

9. EP 3,173,778 A1 — NIMS, same subject as #8 (filed 2015-07-21; published 2017-05-31)

The European regional filing of the WO 2016/013544 family (EP 20150824136), same 2014-07-23 priority and same disclosure.

• Claim relevance: Same substance as #8.
• Anticipation: No, and note a date problem for § 102 purposes: its publication date (2017-05-31) is after the '573 priority date (2016-05-13). As an EP publication it is not a US patent or US application publication, so it cannot serve as § 102(a)(2) art either. Accordingly, EP 3,173,778 A1 by itself is effectively not qualifying prior art by date; the operative sibling is the earlier-published WO 2016/013544 A1.

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Non-patent literature cited (for completeness)

• NPL 1: Engaji et al., Toyota Tech. Rep., vol. 40 (1987) — relationship between ACM-sensor electrode-gap distance and sensitivity. The '573 specification distinguishes this by noting it addresses gap-vs-sensitivity, not droplet size.
• NPL 2: EKO Instruments, dew-condensation detector MH-045, instruction manual Ver. 2 — a commercial gold-plated comb-electrode dew sensor read by applied voltage/resistance; per the specification the opposing-electrode gap is ≳100 µm and it treats dew only macroscopically.

Neither NPL anticipates; both are context/§ 103 art.

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Bottom line on "most relevant prior art"

1. US 2002/0078916 A1 (Altmann / Mann+Hummel) — closest art. Discloses multiple gate-spaced electrode pairs whose different gap distances are used to discriminate different water-droplet/water conditions and whose outputs are combined by logic. This anticipates the architecture of the claimed multi-detector device but not the full claims.
2. WO 2016/013544 A1 (NIMS, same inventors) — discloses the galvanic, different-metal, small-gap detector element (the "Patent Literature 1" sensor) that underlies the dependent claims, and supplies the enabling hardware.
3. US 3,540,278 A (Whirlpool) — early art for the different-metal electrode couple generating current on bridging moisture (claims 4/5 elements).
4. Remaining references (JP S60-78332, JP H08-261974, JP 2002-195114, US 2005/0120772, JP 2012-002582) are secondary/background art on droplet-diameter measurement, comb-electrode drop sensing, moisture detection, calibration, and dew point, respectively.

No single cited reference anticipates independent claim 1 or claim 6, and therefore none anticipates any dependent claim either (each dependent claim incorporates the full independent claim). The strongest reading consistent with the record is that the examiner's § 102 rejection(s) during prosecution were overcome by adding the claim 1/6 limitations of (i) current values, (ii) determination of a size distribution, and (iii) the specific waveform feature (slope / rise delay / time-to-peak / peak value); the cited references disclose the sensor element (#1, #8) and multi-gap discrimination (#4) but not those three limitations in combination. These references are material principally as § 103 obviousness art.

Caveats

• Full text for JPS6078332A, JP2002195114A, and JP2012002582A (and US20050120772A1) was not retrieved before my search limit; descriptions of those four rest on their titles and, where available, third-party characterizations, and should be confirmed against the original documents before being relied on in a validity opinion.
• Publication dates above are the printed dates from the patent's citation table; I did not independently re-derive the § 102 date status of the two NIMS family members beyond the reasoning shown for #8/#9.
• The "Citations (7)" vs. "Patent Citations (9)" discrepancy reflects that Google Patents prints an examiner/third-party subset separately; the nine references above are the union of both tables and are the complete set of record.

I'll ground this analysis by examining the specific prior-art references cited on the patent's face and in its specification.

Let me look up the remaining cited references to characterize them precisely.

Let me try to retrieve the specific content of the two most potentially anticipatory references.

Obviousness Analysis under 35 U.S.C. § 103 — U.S. Patent No. 10,830,573 B2

Source note and confidence

This analysis builds on the previously generated sections (bibliography, claim summary, litigation summary). Per the task instruction, I use the Prior Art section of the patent record — i.e., the "Patent Literature" and "Non Patent Literature" citation lists and the antecedent "Citations (7)/(9)" tables reproduced in the grant — as the universe of references.

I was able to independently retrieve and read the text of the primary reference, WO 2016/013544 A1 (and its family members EP 3,173,778 A1 and US 2017/0167995 A1), and I obtained a secondary characterization of JP H08-261974 A from the description of JP Hei 8-261974 given in U.S. 6,147,753. I was not able to retrieve the full text of JP S60-78332 A, U.S. 3,540,278 A, U.S. 2002/0078916 A1, JP 2002-195114 A, U.S. 2005/0120772 A1, JP 2012-002582 A, or the Engaji et al. Toyota Technical Review paper. For those, my characterization rests on the titles as listed literally in the patent's Prior Art section, on the patent's own description of them, and on general knowledge of the field. I flag each such inference explicitly below. I also could not retrieve the file wrapper/office actions, so I cannot state which reference the examiner relied on for the specific limitations added during prosecution — that is an inference, labeled as such.

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1. Legal framework applied

Under Graham v. John Deere Co., 383 U.S. 1 (1966), obviousness is assessed against four factual inquiries: (1) scope and content of the prior art; (2) differences between the prior art and the claims; (3) the level of ordinary skill; and (4) secondary considerations.

Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), the prior art need not come from the same field, need not address the same problem, and a claim is obvious where it "does no more than yield predictable results" from combining known elements, where there is a "finite number of identified, predictable solutions," or where the combination was "obvious to try." A reference need not be directed to the applicant's problem; it is enough that it is "reasonably pertinent."

Critically, a property that is inherent in a prior-art structure cannot confer patentability. In re Best, 562 F.2d 1252 (CCPA 1977); In re Kao (Fed. Cir.) line of authority for inherent characteristics. This doctrine is central here because the claim-1 "feature" limitation is, I argue below, inherent in the physical operation of differently-gapped galvanic detectors.

Applicant statements in the specification can also constitute admissions that a technique is conventional and can be weighed in the obviousness analysis. In re Nomiya; MPEP 2129.

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2. Level of ordinary skill in the art (PHOSITA)

Given the subject matter — thin-film metal electrode arrays, galvanic corrosion ("ACM") sensors, and micro-fabrication — a PHOSITA would be a person with an M.S. or Ph.D. in materials science, applied physics, physical chemistry, or electrical/sensor engineering, with approximately 2–4 years of experience (or a B.S. with ~5 years) in electrochemical sensor design and thin-film electrode microfabrication for atmospheric corrosion or condensation monitoring. This is a modest-to-moderate skill level; the field is mature (ACM sensors date to at least the 1980s, per Non-Patent Literature 1), so a great deal of the claimed subject matter is within routine engineering reach.

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3. Scope and content of the prior art of record

Applicant admissions inside the specification (usable under MPEP 2129):

• "the detection output change of an ordinary liquid droplet detector is not linear to the size of a liquid droplet, but has high sensitivity only in the vicinity of a specific size" (spec., ¶ discussing FIG. 1 detectors).
• "calibration processing that is a technique frequently adopted in various measurements for eliminating/reducing adverse influences of various disturbances" (spec.).
• "various techniques widely known in the fields of statistics and the like can be used in conducting the estimation" of size distribution (spec.).
• The listed output features are introduced with "include, but are not limited to, the slope of the output signal, the time delay of the rise, the time to reach the peak, and the output value at the time of the peak" (spec.) — an explicit acknowledgment that these are non-exhaustive, conventional signal parameters.

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4. Differences between the prior art and the claims

Claim 1 requires elements (a)–(g):

• (a) first detector type with a first size↔output relationship; (b) second type with a different relationship. → D1 discloses the detector and discloses three different gap widths (0.5, 1, 10 µm), which necessarily produce three different current-response relationships. D2 supplies the explicit teaching that gap width governs sensitivity. D3 supplies the purpose (water-drop diameter).
• (c) determination from both outputs. → The combination of D1's plurality-of-sensors system with D3's diameter-measuring purpose; or by D2's sensitivity framework.
• (d) outputs are current values. → D1 discloses this literally (galvanic current).
• (e) the size determined is a distribution of sizes. → Not disclosed in D1/D2 on their face; requires the inference that a population of droplets yields a spread of bridging behavior across gaps.
• (f) first output has a feature different from second output, the feature being slope / rise delay / time-to-peak / peak value. → Not expressly disclosed, but inherent: two detectors with different gap widths, receiving the same droplet population, will physically produce different rise times, slopes and peaks (the patent's own FIG. 7 demonstrates the 1 µm channel rising in <1 s and the 20 µm channel only after ~15 s).
• (g) determination is performed on the basis of that feature. → A data-processing/analysis step.

Dependents: claim 3 (a third detector type) maps onto D1's three-gap example; claim 4/9 (electrode pair with a gap, made of different metals) is disclosed squarely by D1; claim 5/10 (water) is inherent to D1 (galvanic water sensor); claims 11/12 (monodisperse-droplet calibration outputs) map onto routine calibration (D8; applicant's own admission).

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5. Combination-by-combination obviousness analysis

5.1 Combination A — D1 + D2 (strong as to structure; the "gap-as-threshold" scaffolding)

Rationale / motivation:

1. Same field, same principle of operation. Both D1 and D2 concern ACM/galvanic wetness sensors; D2 is the field's report on the gap-vs-sensitivity relationship, and D1 expressly builds its whole disclosure around narrowing the gap (5 nm–<20 µm) to raise sensitivity.
2. Express teaching of the operative variable. D2 tells the artisan that gap width drives the current response — i.e., that changing the gap changes the relationship between wetting condition and output. A PHOSITA seeking to characterize a range of wetting conditions would predictably reach for multiple, differently-gapped detectors.
3. D1 already provides the hardware and the plurality. D1's worked example fabricates three different gaps (0.5, 1, 10 µm) in one disclosure, and D1 discloses a "system comprising a plurality of" such sensors. Placing several differently-gapped detectors on one substrate is therefore no more than using a known technique to scale a known device — a KSR rational (b)-type combination.
4. Limited, finite, predictable options. The selectable gap values are a finite set (sub-µm to tens of µm) with a predictable monotonic effect on bridging probability. KSR, 550 U.S. at 421 ("finite number of identified, predictable solutions").

Gap: Combination A alone most cleanly reaches elements (a)–(d) and the dependent claims 3, 4, 5; it is weaker on (e)–(g).

5.2 Combination B — D1 + D3 (the combination most likely to have driven prosecution)

Rationale / motivation:

1. The purpose is the claim. D3 is literally titled "Method for measuring water drop diameter." A reference whose stated object is to measure droplet diameter is reasonably pertinent to a claim whose object is to determine droplet size and its distribution — even if D3's sensing modality differs (optical, photographic or otherwise; I could not retrieve its text and therefore do not assert its content).
2. The artisan's toolkit points to threshold arrays. Once D3 supplies the objective (droplet diameter) and D2/D1 supply a sensor whose gap operates as an apparent size threshold, the remaining step — provide two or more detectors with different thresholds and read both currents — is a predictable engineering implementation of D3's objective using D1's hardware.

Why this matters: The claim-1 "feature" limitation (slope/rise-delay/time-to-peak/peak value) and the "distribution" limitation read as deliberate narrowing amendments — the kind of language added to traverse a reference that teaches "measure droplet diameter" (D3) coupled with a reference that teaches the multi-gap galvanic detector (D1). I cannot confirm this from the file wrapper (not retrieved), so I present it as a strong inference, not a fact.

5.3 Combination C — D1 + D2 + D4 (electrode-structure reinforcement)

D4 (JP H08-261974 A) teaches a comb-shaped electrode pair used to detect water droplets on a surface via a change in dielectric/resistance. It corroborates that comb-electrode droplet detection was a well-known design choice, supporting claims 4/9's "pair of electrodes arranged with a gap." D4 uses (transparent) electrodes that need not be of differing metals, so it is a secondary, not primary, reference — but it reinforces the routine nature of the comb geometry that D1 already discloses.

5.4 Combination D — D1 + D2 + D10 (and/or D9) for the water/condensation context

D10 (EKO MH-045) and D9 (IHI dew-point method) place the general activity — reading a comb-electrode sensor's response to condensed water — squarely in the art. Their utility is contextual: they show that a PHOSITA working on condensation/wetness was expected to read the electrical response of comb electrodes, reinforcing claims 5/10 (water).

5.5 Combination E — for claims 11–12 (monodisperse calibration)

Claims 11–12 require determining size further on the basis of outputs when monodisperse droplets are attached, including a group of outputs as the monodisperse size is varied over a predetermined range. This is textbook calibration:

• D8 is expressly about calibrating measuring devices (with a known standard).
• The specification itself admits that "calibration processing … is a technique frequently adopted in various measurements for eliminating/reducing adverse influences of various disturbances."
• Generating a calibration curve by sweeping a known size across a range is the paradigm of routine optimization.

Motivation: A PHOSITA calibrating any threshold-based sensor would sweep the known quantity (droplet size) across the operating range and record outputs — the exact subject matter of claim 12.

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6. The critical vulnerability: the "feature" limitation is inherent

The narrowest limitations in claims 1 and 6 are (f)/(g): the first detector's output must have a feature — slope, rise time delay, time-to-peak, or peak value — different from the second's, and determination must be based on it.

This limitation is inherent in the prior-art combination:

• Two galvanic detectors of different gap widths on the same substrate, exposed to the same droplet population, will necessarily bridge at different times and rates. The patent's own FIG. 7 confirms the physical inevitability: a 1 µm-gap channel shows a current response "in a short period of time (within 1 second)" while a 20 µm-gap channel "took a long period of time (around 15 seconds)" and exhibited "gentler" rise/fall inclinations.
• Therefore any two differently-gapped detectors of D1 will inherently differ in at least one of the four recited features. Under In re Best, discovering and reciting a property inherent in a prior-art structure does not make the claim patentable.
• The listed features are, moreover, admitted by the applicant to be non-exhaustive ("include, but are not limited to") and are the standard descriptive parameters of any time-resolved current curve. Measuring slope, rise time, time-to-peak and peak height of a signal is elementary data analysis; the specification even says "various techniques widely known in the fields of statistics" may be used.

Consequently, a PHOSITA would view recording the current-vs-time trace of each channel and comparing its slope, delay, time-to-peak or peak value as routine, predictable analysis, not as an inventive advance.

A caveat the patentee can and will press: the insight that these time-domain features quantitatively encode the incoming droplet size distribution (rather than merely the presence of water) is a genuine physical observation, and the patent reports a counter-intuitive result — that under certain distributions the 10 µm-gap channel produced a larger peak output than narrower channels, which the patent describes as "not necessarily a common tendency." That observation is at least colorable evidence of an unexpected result and would be the strongest secondary-consideration argument available. It is, however, a double-edged one: the specification also frames it as something "confirmed" by routine experimentation, which supports "obvious to try."

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7. Secondary considerations (Graham factor 4)

On the record available:

• No evidence of commercial success, licensing, copying, industry praise, or long-felt need — and none would be expected: the assignee is a Japanese national research institute (NIMS) with no known U.S. assertion activity (consistent with the litigation summary; that conclusion is a "nothing found," not a verified negative).
• No evidence of teaching away by D1/D2/D3. D1's statement that "a conventional humidity sensor cannot detect the size of water droplets attached to the surface of the sensor element" describes the shortcomings of resistance/capacitance humidity sensors; a statement of a deficiency in a different class of device is generally not a teaching away (In re Fulton; MPEP 2145). Even if read broadly, D1's own disclosure of three gap widths and a multi-sensor system undercuts any teaching-away inference.
• Unexpected results: the counter-intuitive 10-µm peak behavior is the one non-trivial argument; it is not, on its face, commensurate in scope with the full claim breadth (which covers any two detector types).

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8. Claim-by-claim conclusion

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9. Adjacent validity risks worth noting (not § 103, but relevant to overall vulnerability)

1. § 112 / IPXL Holdings mixing. Claim 1 is an apparatus claim that also recites a method step ("wherein sizes … are determined at least on the basis of output signals …"). This apparatus-plus-method form raises a IPXL Holdings v. Amazon.com indefiniteness concern (a person would not know whether infringement occurs on making the device or on using it). This is a separate invalidity theory from § 103 but strengthens the overall attack.
2. § 101 / Mayo–Alice. The determination "on the basis of the feature" (slope, rise delay, time-to-peak, peak value) is a mental/data-analysis step applied to naturally occurring droplet behavior; a § 101 abstract-idea challenge is plausible given Cybersource v. Retail Decisions (mental processes) and In re BRCA line.

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10. Summary of the strongest single obviousness theory

D1 (WO 2016/013544 A1) in view of D2 (Engaji et al., Toyota Tech. Rep. 40 (1987)), and further in view of D3 (JP S60-78332 A). D1 discloses (i) the galvanic-pair droplet detector with differently-metaled thin wires separated by a gap, (ii) the galvanic current output, and (iii) three different gap widths (0.5, 1, 10 µm) in a single disclosure, plus a multi-sensor system. D2 expressly teaches that the electrode gap width governs the sensor's current-response sensitivity, supplying the motivation to provide multiple, differently-gapped detectors. D3 supplies the express purpose of measuring water-drop diameter. The remaining limitations — determining a distribution and using a time-domain feature difference (slope / rise delay / time-to-peak / peak value) — are either inherent in the operation of differently-gapped detectors exposed to the same droplet population (In re Best) or the product of routine signal analysis of an elementary current-vs-time curve (a technique the specification itself concedes is "widely known in the fields of statistics"). Accordingly, claims 1 and 6, and dependents 2–5 and 7–12, would have been obvious to a PHOSITA at the 2016 priority date.

Weakest link in the theory: the "determine a distribution of sizes" element, because it requires a processing/analytical step that no single reference expressly discloses; it is defeated only by the combination of (i) the inherency of the differently-gapped detectors' behavior and (ii) the applicant's own admissions that the statistical/calibration techniques are conventional. If the patentee can show genuine unexpected results (the counter-intuitive 10-µm peak) tied to the claimed scope rather than to a narrow embodiment, that is the one argument with real traction against a § 103 attack.

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11. Explicit uncertainties

• The full texts of JP S60-78332 A, U.S. 3,540,278 A, U.S. 2002/0078916 A1, JP 2002-195114 A, U.S. 2005/0120772 A1, JP 2012-002582 A, and the Toyota Technical Review paper (NPL1) were not retrieved; characterizations of D3, D5, D6/D7, D8 and D9 rest on their titles as listed literally in the patent and on general field knowledge. Any statement about what those references disclose should be treated as tentative until verified against the primary documents.
• I could not access the file wrapper/office actions, so the claim that particular limitations were added to overcome specific art is an inference from claim structure and the patent's own discussion, not a documented fact.
• Non-Patent Literature 1's citation is truncated in the source ("Engaji et al, Toyota Tech. rep., 40 (1987), p."), so the analysis uses only the proposition the patent itself attributes to it ("the relationship between the distance of an electrode gap … of the ACM sensor and the sensitivity (current response) of the sensor").