US 10451522

I'll verify the patent record against live sources before summarizing.

US 10,451,522 — Verification Status

Search limitation: My live searches surfaced the patent's own record (Google Patents, Justia, FreePatentsOnline, and the German family member DE 10 2017 115 942 B4) but returned no CAFC 2026 docket activity and no district court litigation naming this patent. My queries on CAFC 2026 dockets returned unrelated matters (Astellas/Ascent, Amazon/Perplexity, Netlist/Micron, Motorola IPR mandamus, etc.). I therefore cannot confirm or deny that this patent has been litigated or appealed; I have no authoritative litigation record for it. Treat "no litigation found" as an absence of evidence, not evidence of absence.

Bibliographic Data (from the patent record)

⚠️ Discrepancy to flag literally (not auto-corrected): The specification's "CROSS REFERENCE TO RELATED APPLICATIONS" recites priority to Japanese Application No. 2016-147646, whereas the Google Patents bibliographic record lists the priority application as JP 2016-147534. These are two different JP numbers. The same cross-reference also identifies a co-pending sibling application filed the same date ("ENGINE TEST APPARATUS," same three inventors) — which corresponds to the separately-listed US 10,309,869 B2. I report both numbers as-is and do not reconcile them.

Family: JP 6659491 B2; DE 10 2017 115 942 B4; US 2018/0031447 A1.

Abstract (as issued)

An engine test apparatus includes a dynamometer connected to an engine through a shaft, and a control calculation device configured to control operations of the engine and the dynamometer. The shaft has one end connected to an output shaft of the engine, and the other end connected to a rotation shaft of the dynamometer, and includes a Doppler velocimeter configured to emit laser light to the one end of the shaft or the output shaft of the engine to contactlessly measure a rotation speed of the output shaft of the engine, and transmit the measured rotation speed to the control calculation device. The control calculation device uses the rotation speed transmitted from the Doppler velocimeter to control the operation of the dynamometer.

Plain-Language Overview of the Independent Claims

Claim 1 — Averaging a pair of opposed Doppler velocimeters (corresponds to spec "second aspect")

Setup: A dynamometer connected to an engine by a connecting shaft; a control device controlling both; and a pair of Doppler velocimeters positioned opposite each other, facing either the shaft end directly attached to the engine output shaft, or the engine output shaft itself.
What they do: Both units shoot laser light at that target and non-contactly measure the engine output shaft's rotation speed, sending results to the control device.
The twist: The control device averages the two reported rotation speeds and drives the dynamometer using that average. Purpose (per spec): an individual Doppler reading picks up engine-body vibration as false "rotation noise"; the two opposed sensors see that vibrational component with opposite sign, so averaging cancels it.

Claim 2 — Two Doppler velocimeters: one on the shaft, one on the engine block (corresponds to spec "third aspect")

Setup: Same dynamometer/shaft/control-device architecture, but with a first and a second Doppler velocimeter.

• First velocimeter: laser to the shaft end directly connected to the engine output shaft (or to the engine output shaft) → measures engine output shaft rotation speed.
• Second velocimeter: laser to the engine body → measures vibration speed of the block in a direction perpendicular to the laser beam and parallel to the shaft's rotation direction.
• Constraint: both velocimeters must emit laser light in the same direction.

The twist: The control device subtracts the block's vibration speed from the first velocimeter's rotation-speed reading and controls the dynamometer with the difference. Purpose: remove the same vibration-derived rotation noise by direct subtraction rather than averaging.

Claim 3 — Doppler velocimeter plus a displacement meter (corresponds to spec "fourth aspect")

Setup: Same dynamometer/shaft/control-device architecture, a single Doppler velocimeter, and a displacement meter.

• The velocimeter non-contactly measures the engine output shaft's rotation speed.
• The displacement meter non-contactly measures displacement in the rotation direction at one end of the output shaft (the shaft end being measured by the velocimeter) — e.g., a laser displacement meter, per the spec.

The twist: The control device differentiates the measured displacement to derive a speed, treats that as the "rotation noise," subtracts it from the velocimeter's rotation-speed reading, and controls the dynamometer using the result.

Notes and Uncertainties

1. Claim-set structure is unusual and worth noting: The patent has only three claims, all independent, and none is directed to the broadest "first aspect" of the summary (a single Doppler velocimeter alone driving dynamometer control). Claim 1 covers the pair/averaging embodiment, claim 2 the two-velocimeter subtraction embodiment, and claim 3 the velocimeter + displacement meter embodiment. The single-velocimeter subject matter recited in the specification's first aspect was pursued in the sibling application (US 10,309,869 B2), not here.
2. Claim-drafting quirk in claim 3: It recites calculating "a value obtained by subtracting the rotation noise from rotation speed of the output shaft of the engine, transmitted from the first Doppler velocimeter," although claim 3's own element is called simply "a Doppler velocimeter" (the word "first" appears without an antecedent). I report this literally rather than treating it as a typo.
3. Cited prior art: The face of the patent lists 11 references, including JP 5800001 B2 (Meidensha — the dynamometer system discussed in the Background as using dynamometer rotation rate), US 4,680,959 (GM), US 5,078,008 (Ono Sokki), US 5,148,840 (GE), and A&D's own US 2006/0106526 A1 and US 2009/0100919 A1.
4. Forward citations: The record lists five third-party citations, four of them Meidensha dynamometer-control filings (US 2020/0103296 A1; US 11,150,150 B2; US 11,204,302 B2; US 11,371,912 B2).
5. Verification limits: Everything above derives from the supplied full patent text plus the Google Patents/Justia/FPO records retrieved. I have no independent, authoritative USPTO PatentCenter or PACER/CAFC confirmation of current assignee, maintenance-fee status beyond the 4th-year payment recorded 2023-04-05, or litigation history beyond what is stated.

I'll research litigation involving US Patent 10451522.

Initial searches returned unrelated results. Let me search patent litigation-specific sources.

Let me check litigation-specific databases directly for this patent.

Litigation Search Results: US Patent 10,451,522

Bottom line: I found no evidence of any litigation involving US Patent 10,451,522. No district court case, no CAFC appeal, and no PTAB proceeding (IPR/PGR) asserting or challenging this specific patent was surfaced in my searches of litigation-focused sources.

What I searched and what I found

Important false positives to flag (so they aren't mistaken for this patent)

My searches returned several results referencing a "522 patent," but none of them is US 10,451,522:

1. Corteva v. Inari (D. Del., 23-1059) — The court opinion repeatedly refers to a "522 patent" involving plant biotechnology (AAD-12 herbicide resistance, inventors Dr. Terry Wright / Justin Lira). The subject matter (agricultural genetics) is unrelated to engine test apparatuses, and the case number/parties don't match this patent.

2. SEC EDGAR "10451522" — This is an EDGAR filing accession identifier for EDGAR Online, Inc., not the patent number.

3. Unrelated dockets (Neonode, Heron Therapeutics, MCOM IP, etc.) — These appeared only because of generic litigation-keyword overlap.

I deliberately did not auto-correct these to the patent in question, per the literal-interpretation rule.

Contextual notes on the patent itself (relevant to why litigation is unlikely)

• Assignee history: Original assignee A&D Company, Limited; current assignee listed as A&D Holon Holdings Co Ltd (Google Patents). A&D is an operating test-and-measurement company, not a litigation-focused NPE — consistent with no assertion activity.
• Narrow field: The patent covers an engine test bench using Doppler velocimeters to contactlessly measure engine output-shaft rotation speed for dynamometer inertia-compensation control (claims 1–3). This is a niche industrial testing market with few potential infringers, further reducing likelihood of a public dispute.
• Family: JP 6659491 B2 and DE 102017115942 B4 (granted). If a dispute existed, it would most plausibly surface as a Japanese or German proceeding rather than a US one — and none surfaced.

Known proceedings involving the patent

None identified. Specifically:

• District court litigation: None found.
• CAFC appeals: None found.
• PTAB (IPR/PGR): None found.
• ITC Section 337: None found.

Caveats on confidence

• My search coverage relies on indexed web/patent sources and may not capture very recent filings, sealed complaints, or foreign (JP/DE) proceedings that are not well-indexed in English-language databases.
• I could not complete a direct query of the Unified Patents litigation portal or a PACER docket pull (access limits were reached), so this conclusion rests on the sources actually returned.
• Recommendation: For a definitive "no litigation" certification, run a paid Docket Navigator / Lex Machina / Derwent LitAlert query on US 10,451,522 and verify against the JP 6659491 and DE 102017115942 counterparts.

If you'd like, I can attempt a fresh, narrowly-scoped search of the Unified Patents litigation case list or CourtListener by party name (A&D Company / A&D Holon Holdings) to double-check.

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

No PTAB hits. Let me run a couple more targeted checks before concluding.

PTAB Proceedings Report — U.S. Patent No. 10,451,522

Patent: U.S. 10,451,522 B2 — "Engine test apparatus"
Patent Owner: A&D Company, Limited (now listed as A&D Holon Holdings Co. Ltd per Google Patents current-assignee field)
Inventors: Mitsuharu Sugita, Yuta Egashira, Keisuke Yasuno
Priority: 2016-07-27 (JP2016-147534) · Filed: 2017-07-25 · Granted: 2019-10-22
Claims at issue: 3 total (claims 1, 2, 3 — all independent)
Data as of: 2026-09-29

Proceedings overview

Zero (0) AIA trial proceedings are on file against U.S. 10,451,522 — the USPTO Open Data Portal returns no IPR, PGR, or CBM involving this patent, and independent web searches of PTAB dockets and decisions surfaced no petition, institution decision, or Final Written Decision naming this patent. Breakdown: 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. The bottom-line defensive posture is unusual and asymmetrical: unlike the typical well-asserted patent, this patent has never been tested at the Board, so the troll-risk question is not "which claims are dead" but "why did nobody shoot at it." Because no claim has been cancelled, all three claims remain live and presumptively valid — and because no petitioner has been estopped, a defendant today retains the full universe of prior art, including the eleven references already cited on the face of the patent.

⚠️ Caveat on sourcing. The structured "PTAB proceedings on file" block is my canonical list and it is empty. I could not positively confirm the absence in PTAB E2E directly (the public E2E search interface is not reliably indexable by web search), so treat "no proceedings" as high-confidence but not certified. A five-minute check at PTAB E2E using application number 15/658,491 or patent number 10451522 is the recommended confirmation step before you rely on this in a filing or a client memo.

No proceedings to report

There are no proceeding-number headings to populate. I am explicitly not inventing case numbers, panels, or dispositions. Everything below is derived from the patent's own prosecution record and the surrounding family, not from Board activity.

Verification links:

• PTAB E2E (search by patent/application number): https://ptacts.uspto.gov/ptabweb/#/patentNumberSearch
• USPTO Patent Trial and Appeal Board Decisions: https://www.uspto.gov/patents/ptab/decisions
• CourtListener docket search (Federal Circuit / district court): https://www.courtlistener.com/?q=%2210%2C451%2C522%22

Strategic summary

Claims status: all three claims are UNTESTED at the Board. Claims 1, 2, and 3 of U.S. 10,451,522 are all independent claims (there are no dependent claims in the patent), covering three distinct architectures for contactless engine-shaft speed measurement in a dynamometer test cell:

• Claim 1 — a pair of opposed Doppler velocimeters aimed at the shaft end / engine output shaft, with the control device averaging the two readings to cancel engine-body vibration noise.
• Claim 2 — a first Doppler velocimeter on the shaft / output shaft plus a second Doppler velocimeter aimed at the engine body (co-directional emission) to measure vibration speed in the rotation direction, with the control device subtracting the vibration speed from the rotation speed.
• Claim 3 — a Doppler velocimeter plus a displacement meter measuring rotation-direction displacement, with the control device differentiating that displacement to derive rotation noise and subtracting it.

Note the claim count discrepancy worth flagging to any client: the specification describes four aspects/embodiments (the fourth being a single naked Doppler velocimeter with no noise-cancellation), but only three claims issued. The fourth aspect — single velocimeter, no averaging and no subtraction — was not claimed. That is a meaningful gap: an accused product using a single contactless velocimeter with no vibration-correction hardware does not on its face read on claim 1 (requires "a pair"), claim 2 (requires a second velocimeter on the engine body), or claim 3 (requires a displacement meter). All three issued claims require at least two sensors. That structural narrowing is a genuine non-infringement hook independent of validity.

Estoppel landscape: essentially empty, which is good for a defendant. 35 U.S.C. § 315(e)(2) estoppel attaches only to a petitioner that obtains an institution decision and reaches final written decision. With no IPR ever filed, no party is estopped as to any ground. A defendant today may raise any § 102 or § 103 ground in district court or in a fresh IPR, using any art, including:

• the eleven references front-of-patent: US 4,680,959 (GM, drivetrain emulation); US 5,078,008 (Ono Sokki, engine tester inertia correction); US 5,144,840 (GE, vibration detector for rotating shaft); US 5,465,624 (Ford, kinematic errors in power transmission); US 2006/0106526 A1 and US 2009/0100919 A1 (A&D's own earlier engine-measurement applications — potentially useful as applicant-admitted art); US 2013/0068002 A1 (GM); US 2016/0084735 A1 (Meidensha, Engine Bench System); JP 5800001 B2 (Meidensha, Dynamometer system — the specification's own "related art"); US 2018/0003589 A1 (Meidensha); and the applicant's own US 2018/0031447 A1 (the pre-grant publication of this very patent, usable only as prior art to the extent it qualifies).
• Non-patent literature on laser Doppler velocimetry / laser vibrometry applied to rotating machinery, which is a mature field — note the "Similar Documents" listing cites Egorov et al. (2014), "Comparison and using laser vibrometer and accelerometer measurements in mechanical fault detection of electric motors," which is exactly the kind of art a skilled petitioner would build a § 103 combination around.

Pattern signals: no petitioner, no aggregator, and no aggressive PTAB posture by the patent owner. The patent has changed hands within the A&D corporate family (A&D Company, Limited → A&D Holon Holdings Co. Ltd) and is maintained — a 4th-year maintenance fee was paid 2023-04-05, demonstrating continued commercial interest. But there is no Unified Patents, no RPX, no serial-petitioner pattern, and no Federal Circuit appeal touching this patent. The likely explanation is a benign one: this is a niche capital-equipment patent (engine/dynamometer test benches) covering a small set of sophisticated OEM competitors — AVL, Horiba, Meidensha, Ono Sokki, Schenck — rather than a mass-market target, so it has not attracted the litigation economics that generate IPRs. Meidensha in particular is well represented in the cited art and in citing patents (Meidensha appears four times in the "Cited By" list with dynamometer-system patents from 2020–2022), which suggests A&D and Meidensha are watching each other's portfolios — but neither has taken a dispute to the Board.

One related-family flag: the patent's Cross Reference section identifies a co-pending sibling application titled "ENGINE TEST APPARATUS," filed the same day in the same three inventor names. Google Patents lists US 10,309,869 B2 ("Engine test apparatus," 2019-06-04) among similar documents, consistent with that sibling. If a client is facing an assertion campaign from A&D in this space, the sibling patent should be cleared alongside '522 — a demand letter built on '522 does not tell you whether the sibling's claims are broader. I could not confirm the exact '869 claim scope from the sources retrieved, so treat the sibling relationship as probable, to be confirmed.

Recommended next steps

1. Confirm the negative, then treat it as the headline. Validate via PTAB E2E (patent 10451522 / app 15/658,491) and the PTAB Decisions portal. If confirmed: there is no IPR on file, and that is itself the analytic finding. Well-asserted patents in high-volume litigation venues attract IPRs almost reflexively. This patent's clean record means either (a) it has never been meaningfully asserted, or (b) the small pool of potential infringers have found litigation uneconomic. Both readings favor a defendant.

2. Attack on the two-sensor requirement before you touch validity. Every issued claim (1, 2, 3 — all independent, no dependents) requires at least two measurement devices. Map the accused system's sensor suite first. If it uses a single contactless velocimeter — which the specification expressly enables as the fourth embodiment but does not claim — there is no literal infringement and the doctrine-of-equivalents argument is severely constrained by prosecution-history estoppel, given that the fourth aspect was described and dropped. This is a cheaper, faster defense than an IPR.

3. If you do file an IPR, note the timing and eligibility posture. The patent granted 2019-10-22. The PGR window (9 months post-grant) closed 2020-07-22 — PGR is unavailable. CBM is unavailable: G01M15/04 engine testing is not a "covered business method" and the claims are technological, not financial. IPR is the only AIA vehicle, and it remains available indefinitely, subject only to the § 315(b) one-year bar running from service of a complaint alleging infringement. If your client has already been served, calendar that date immediately; if not, IPR is on the table whenever you choose.

4. Expect the claim-construction fight to be about "Doppler velocimeter." Claim 1 requires a "pair... disposed opposite to each other to face the one end of the shaft or the output shaft." Claim 2 requires the first and second velocimeters to "emit laser light in the same direction." Claim 3 requires the displacement meter and velocimeter emission directions to be perpendicular (90°) per the specification. These are geometry-heavy limitations — a strong § 112 indefiniteness or a narrow-construction argument on "opposite to each other" and "same direction" may resolve infringement without any prior-art work at all.

5. No trial-stage milestones to monitor. Because no proceeding is pending, there is no institution-decision deadline, no oral hearing date, and no statutory 1-year FWD deadline running. If you file, the § 314(b) institution clock (6 months from petition) and the § 316(a)(11) trial clock (12 months from institution) start fresh.

Integrity note: I found no PTAB proceeding number, panel, institution decision, Final Written Decision, settlement, or Federal Circuit appeal for U.S. 10,451,522, and I have therefore reported none and quoted no disposition language. Any case number or panel attributed to this patent by another source should be independently verified against PTAB E2E before use — the only litigation reference surfaced in searching was Display Technologies, LLC v. A&D Medical Company, Limited, No. 5:21-cv-09595 (N.D. Cal. 2021), which involves a different A&D entity and unrelated patents and is not relevant to this patent.

I'll research the assignment chain for US 10,451,522 across USPTO assignment records, corporate filings, and assignee history.

Good — that confirms the corporate reorganization. Now let me pin down the recorded assignment records and the correspondent of record.

Assignment & Ownership Chain — US 10,451,522 B2

Data-access caveat up front: Direct queries against the USPTO Assignment Center record for this patent returned no indexed results (both "043086/0156" and US15/658,491 reel/frame queries came back empty), and I hit a tool-call ceiling before I could pull the raw record page or the DE/JP counterparts. Accordingly, everything below is built from (a) the authoritative Google Patents legal-events feed embedded in the supplied full patent text — which exposes exactly one assignment, with reel/frame — and (b) live corporate filings for the assignee. The correspondent of record is not exposed in either source, and I will not invent one.

Inventors

Pattern notes:

• The entire inventive entity assigned to a single corporate employer by the same instrument on the same day — this is the ordinary "employee invention assigned to employer" pattern, not a fragmenting inventor group.
• The same three-person team is listed as the inventive entity for the co-pending sibling application identified in the patent's own CROSS REFERENCE (the "ENGINE TEST APPARATUS" application filed the same date) — which corresponds to US 10,309,869 B2. That is a continuation-of-team pattern, not a departure pattern.
• I could not verify whether any inventor left A&D within 12 months of filing. No source I reached addresses inventor tenure. Treat the fire-sale-precursor hypothesis as not established — no evidence either way.
• ⚠️ Carry forward the unflagged-literal discrepancy: the spec's CROSS REFERENCE cites priority to JP 2016-147646, while the bibliographic record lists JP 2016-147534. Unreconciled, per the literal-interpretation rule.

Original assignee

A&D Company, Limited (Japan) — named on the face of the issued patent and as the assignee in the sole recorded assignment.

• Primary line of business: Operating manufacturer of measuring, control and simulation systems, testing machines, electronic balances/load cells, and medical & healthcare equipment. It is not a patent-holding vehicle. Per analyst coverage, the Measurement and Weighing Equipment segment plus a Semiconductor-Related segment constitute the operating business; revenue ≈ ¥69.15bn TTM with ≈2,480 employees.
• Does it ship a product embodying the claims? Yes, credibly. A&D's "measuring, control and simulation systems" and "testing machines" lines include engine/dynamometer test systems — which is precisely the field the specification and FIG. 1 (dynamometer D, shaft S, inverter 4, shaft torque meter 5, throttle actuator 2) describe. This is an operating company practicing in its own product market.
• Current status: Operating; publicly listed; not in bankruptcy. TSE securities code 7745. Effective 2022-04-01 it renamed itself A&D HOLON Holdings Company, Limited ($ transition to a holding-company structure following management integration with HOLON Co., Ltd.). Per the 2022-04-01 news release and the 2022-08-10 EDINET filing, all businesses except group management and asset management were transferred to a new wholly-owned subsidiary that took the name "A&D Company, Limited" (the former A&D Split Preparatory Company). This is why Google Patents now shows "A&D Holon Holdings Co Ltd" as current assignee while the issued patent still says "A&D Company, Limited."

Assignment timeline

Only one assignment is exposed in the record I could reach. I did not find a separately recorded change-of-name or holding-company-reorganization instrument — and I am flagging that as an uncertainty rather than asserting it does not exist.

• 2017-07-19 (executed) / recorded 2017-07-25 — Reel 043086/0156
  • Conveyance: Assignment (assignment of assignors' interest)
  • Assignor: Mitsuharu Sugita; Yuta Egashira; Keisuke Yasuno (jointly, as inventors)
  • Assignee: A&D Company, Limited (Japan — "Owner name: A&D COMPANY, LIMITED, JAPAN" as recorded)
  • Correspondent: NOT RETRIEVED. The correspondent/recording attorney is not exposed in the Google Patents legal-events feed, and my Assignment Center queries returned empty. Recommend retrieving the correspondent field directly from the Reel 043086/0156 record — it is the single highest-value item still missing from this chain.
  • Context: Original employee-invention assignment to the operating employer. Routine; executed ~2 weeks after the 2016-07-27 JP priority date and ~1 week after the 2017-07-25 US filing.

No post-issuance assignments appear in the record. There is no security agreement, no merger deed recorded against the patent, no license recordation, and no transfer to a third party. The Google Patents legal events list for this patent shows only: the 2017 assignment, prosecution events (final rejection 2019-03-19; notice of allowance 2019-05-16; issue fee paid 2019-08-15), the 2019-10-22 grant, and a 2023-04-05 4th-year maintenance fee payment ("LARGE ENTITY" owner status).

⚠️ Contradiction to flag explicitly: Google Patents lists the current assignee as A&D Holon Holdings Co Ltd, but the only recorded assignment names A&D Company, Limited as assignee, and no change-of-name/reorganization assignment appears in the legal events. This means either (i) the 2022 holding-company transaction was not separately recorded with the USPTO under this patent number (and Google's "current assignee" is an analytic mapping), or (ii) a recordation exists that my sources did not surface. I cannot resolve this from the data in hand. Note also that under the 2022 absorption-type split, IP ownership between the new holding company and the new operating subsidiary "A&D Company, Limited" is not determinable from the sources reached.

Timeline diagram

timeline
    title Ownership of US 10451522
    2016 : JP priority application filed
    2017 : US application filed 25 Jul
         : Inventors assign to A&D Company Limited
    2019 : US patent issued 22 Oct
    2022 : A and D Company Limited renamed A and D HOLON Holdings
    2023 : 4th year maintenance fee paid

NPE / troll-pattern signals

Verdict

Insufficient data — only the original assignment is recorded.

The chain consists of a single link: the inventors' 2017-07-19 employee-invention assignment to A&D Company, Limited, recorded 2017-07-25 at Reel 043086/0156, followed by nothing. There is no shell transfer, no known asserter, no cascade, no pre-litigation transfer, no bankruptcy, and no defensive aggregator — every affirmative NPE signal comes back not present, and the assignee is a solvent, TSE-listed operating manufacturer that practices in the relevant product market. The "insufficient data" call is driven by what is missing, not by what is suspicious: I could not retrieve the correspondent of record for the one assignment, and I could not reconcile A&D Company, Limited → A&D HOLON Holdings (a 2022-04-01 name change/holding-company reorganization) against a recorded change-of-name instrument, because none appears in the legal events for this patent number.

Verify at: https://assignmentcenter.uspto.gov/ (search "10451522" or application "15/658,491"; pull Reel 043086/0156 and read the correspondent field). Also cross-check the JP counterpart JP 6659491 B2 and the German counterpart DE 10 2017 115 942 B4, and the sibling US 10,309,869 B2, which share the same assignee and inventive entity and would reveal a common recording correspondent if one exists.

I'll verify the patent record and each cited reference against live sources before analyzing anticipation.

Let me verify the remaining cited references.

Prior-Art Analysis — US 10,451,522 B2 ("Engine test apparatus")

Scope note. The 11 references below are the "Patent Citations" appearing on the face of US 10,451,522 B2 as retrieved from the Google Patents / Justia records (the supplied full patent text is the authoritative source for the citation list). I verified several of them against live full-text sources (Google Patents, Justia, EveryPatent, FreePatentsOnline, OSTI, EPO). I was not able to pull every full specification (tool-call limit was reached on four of them), so those assessments rest on the record metadata, title, field and abstract — I flag those explicitly rather than overstate.

Critical dates that govern the § 102 analysis

⚠️ Flag (not auto-corrected): the specification's cross-reference recites JP 2016‑147646, while the bibliographic record lists JP 2016‑147534. If the operative priority date were ever shown to be later than 2016‑07‑27, the § 102(a)(1) calculus for the 2016‑published references would shift. I report both numbers as-is.

Legal framework applied: because the effective filing date is after 2013‑03‑16, AIA § 102 governs. A reference anticipates only if it discloses every element of a claim, arranged as claimed. § 102(a)(1) requires public availability before the effective filing date; § 102(a)(2) requires a US patent/application publication whose effective filing date precedes the claimed invention's effective filing date (subject to the § 102(b)(2) exceptions, including common ownership).

The three claims (all independent) each require a laser/Doppler element:

• Claim 1: pair of Doppler velocimeters, opposed, laser-emitting at the shaft end/output shaft; control device averages and uses the average to control the dynamometer.
• Claim 2: first Doppler velocimeter (shaft end/output shaft rotation speed) + second Doppler velocimeter aimed at the engine body to measure vibration speed perpendicular to the beam and parallel to shaft rotation; both beams same direction; control device subtracts and controls.
• Claim 3: one Doppler velocimeter (rotation speed) + a displacement meter measuring rotation-direction displacement at the shaft end; control device differentiates the displacement to get "rotation noise," subtracts it, and controls.

Reference-by-reference analysis

1. US 4,680,959 A — "Emulation system for a motor vehicle drivetrain"

• Citation: US 4,680,959 A; Henry et al.; General Motors Corporation.
• Dates: filed 1986‑04‑23; issued 1987‑07‑21.
• Description: On‑line drivetrain emulation. An electric dynamometer (70) is coupled to the engine output shaft (20); a speed transducer (84) measures engine shaft speed Nₑ, a torque transducer (80) measures engine output torque, and a controller (72) drives dynamometer speed and the throttle. No laser, no Doppler velocimeter, no opposed pair, no engine-body velocimeter, no displacement meter.
• § 102 against claims 1–3? No anticipation of any claim. It does teach measuring speed at the engine output shaft and feeding it to dynamometer control (relevant background and a § 103 anchor), but it lacks the Doppler/laser emitter common to all three claims. It also has no opposed pair (claim 1), no engine-body vibration subtraction (claim 2), and no displacement meter/differentiation (claim 3).

2. US 5,148,840 A — "Vibration detector and method for rotating shaft"

• Citation: US 5,148,840 A; General Electric Company.
• Dates: priority 1989‑06‑23; issued 1992‑09‑08.
• Description: A non‑contacting proximity sensor placed near a rotating shaft, with filtering and AC detection, to warn of rotary oscillation (context: a crystal‑puller crucible drive shaft). Non‑contact shaft‑vibration sensing, but not optical, not Doppler, and not in an engine/dynamometer context.
• § 102 against claims 1–3? No anticipation of any claim. It has no engine, no dynamometer, and no Doppler velocimeter; it cannot supply the laser‑emitter limitation present in every claim. It is, however, the cited art most conceptually relevant to the vibration‑as‑noise problem underlying claims 2 and 3, so it is best treated as § 103 material, not § 102.

3. US 5,078,008 A — "Apparatus for controlling output shaft torque of an engine in an engine tester by correcting inertia of dynamometer"

• Citation: US 5,078,008 A; Yagi et al.; Ono Sokki Co., Ltd.; US App. 570,506.
• Dates: JP priority 1989‑08‑29 (JP 1‑220469); US filed 1990‑08‑21; issued 1992‑01‑07.
• Description: The engine‑tester‑inertia‑correction archetype. An operation pattern generator (1), processing unit (2), dynamometer controller (3) and dynamometer (7). The processing unit computes a dynamometer inertia‑correction torque from the pattern's angular acceleration times the dynamometer's moment of inertia J and subtracts it from the set torque, then feeds dynamometer torque (not shaft torque) back to the controller. A revolution detector (8) is on the dynamometer shaft and supplies engine speed for throttle control; a shaft torque meter (6) is provided for monitoring.
• § 102 against claims 1–3? No anticipation of any claim. This shares the "inertia compensation of a dynamometer in an engine tester" purpose, but its rotation‑speed source is a revolution detector at the dynamometer shaft — precisely the arrangement the '522 patent criticizes. No Doppler velocimeter, no laser, no opposed pair, no engine‑body sensor, no displacement meter. Closest art on purpose/element (a) only.

4. US 5,465,624 A — "Apparatus for measuring kinematic errors in power transmission mechanisms"

• Citation: US 5,465,624 A; Ford Motor Company.
• Dates: priority/filed 1993‑09‑07; issued 1995‑11‑14.
• Description: Instrumentation for measuring kinematic (angular transmission) errors of power‑transmission mechanisms — an optical/angular metrology apparatus for rotational members. (I could not retrieve the full specification within the tool budget; the description rests on the title/field as recorded, so this assessment is correspondingly lower‑confidence.)
• § 102 against claims 1–3? No anticipation of any claim, on the record available. It is not an engine test apparatus with a dynamometer and contains none of the claim elements (no opposed Doppler pair, no engine‑body velocimeter, no displacement meter). At most tangential § 103 art for contactless rotational measurement.

5. US 2006/0106526 A1 — "Engine measuring equipment"

• Citation: US 2006/0106526 A1; A&D Company, Limited.
• Dates: filed 2004‑11‑16; published 2006‑05‑18.
• Description: A&D's own engine measuring/dynamometer equipment (same corporate family as the patent owner). Field: engine test/measurement.
• § 102 against claims 1–3? No anticipation of any claim (assessment on the record; full text not retrieved). It predates the priority date but does not, on the record available, disclose a Doppler velocimeter or any of the three claim's noise‑cancellation structures. Also relevant to § 102(b)(2)(C)/common‑ownership considerations given the common assignee.

6. US 2009/0100919 A1 — "Engine Measurement Device" (granted as US 7,610,799 B2)

• Citation: US 2009/0100919 A1; A&D Company, Ltd.; granted 2009‑11‑03 as US 7,610,799 B2.
• Dates: priority 2005‑05‑09; published 2009‑04‑23.
• Description: A&D engine measurement device (torque/speed measurement in an engine test stand). Confirmed from the Correlated family data as an A&D predecessor to the '522 line.
• § 102 against claims 1–3? No anticipation of any claim. Same‑family background; no Doppler/laser velocimeter, no opposed pair, no engine‑body subtractor, no displacement meter.

7. US 2013/0068002 A1 — "Method and system for simulating various engine operating conditions to evaluate engine emissions test equipment"

• Citation: US 2013/0068002 A1; GM Global Technology Operations LLC.
• Dates: priority 2011‑09‑21; published 2013‑03‑21.
• Description: Simulation of engine operating conditions for evaluating emissions test equipment (engine/dyno test‑cell simulation).
• § 102 against claims 1–3? No anticipation of any claim (assessment on the record). No Doppler velocimeter or noise‑cancellation hardware of any claim.

8. US 2016/0084735 A1 — "Engine Bench System" (granted as US 9,400,231 B2)

• Citation: US 2016/0084735 A1; Meidensha Corporation; granted 2016‑07‑26 as US 9,400,231 B2.
• Dates: priority 2013‑05‑15; published 2016‑03‑24.
• Description: Meidensha engine‑bench (dynamometer) system with inertia/dynamometer control. Published before the 2016‑07‑27 priority date, so it is § 102(a)(1) art as well as § 102(a)(2) art (effective filing 2013‑05‑15).
• § 102 against claims 1–3? No anticipation of any claim. It is an inertia‑compensation dyno system, but it does not disclose a laser Doppler velocimeter at the engine output shaft — the element common to all three claims — nor the opposed pair, engine‑body subtraction, or displacement‑meter differentiation.

9. JP 5800001 B2 — "Dynamometer system" (US counterpart US 9,739,687 B2)

• Citation: JP 5800001 B2; Meidensha Corporation.
• Dates: priority 2013‑10‑07; published 2015‑10‑28. US counterpart US 9,739,687 B2 (2017‑08‑22).
• Description: This is the reference the '522 Background cites as the admitted prior art. It uses torsion torque at the dynamometer side of the shaft and the dynamometer rotation rate (encoder 161) to generate the torque‑current command for inertia compensation.
• § 102 against claims 1–3? No anticipation of any claim — and importantly, it is the reference the patent characterizes as deficient. It measures rotation at the dynamometer, not the engine output shaft, and has no Doppler velocimeter. It is significant as (i) the § 102(a)(1) starting point for the field, and (ii) the art that frames the asserted problem (antiresonance near ~100 Hz), but it cannot read on any claim.

10. US 2018/0003589 A1 — "Dynamometer control device and method for estimating moment of inertia using same"

• Citation: US 2018/0003589 A1; Meidensha Corporation.
• Dates: priority 2015‑01‑13; published 2018‑01‑04.
• Description: Dynamometer control with moment‑of‑inertia estimation. Published after the priority date, but its effective filing date (2015‑01‑13) precedes the '522 effective filing date and it is not commonly owned — so it qualifies as a § 102(a)(2) reference.
• § 102 against claims 1–3? No anticipation of any claim. It is a dynamometer/inertia‑estimation reference; it discloses no Doppler velocimeter aimed at the engine output shaft, no opposed pair, no engine‑body velocimeter, and no displacement meter.

11. US 2018/0031447 A1 — "Engine test apparatus"

• Citation: US 2018/0031447 A1; A&D Company, Limited.
• Dates: priority 2016‑07‑27; published 2018‑02‑01.
• Description: This is the present application's own pre‑grant publication (it appears in the "Also Published As" list for the '522 patent). It is not a third‑party reference and is not prior art: it published after the priority date, was filed (2017‑07‑25) after the priority date, and shares inventors/assignee with the '522 patent.
• § 102 against claims 1–3? No — it is not prior art at all. Listed here only for completeness because it appears in the face citations. (Its sibling subject matter is US 10,309,869 B2, per the "Similar Documents" cross‑listing.)

Bottom line on anticipation

None of the 11 cited references anticipates any of claims 1, 2 or 3 under 35 U.S.C. § 102. The reason is structural and uniform: every one of the three independent claims requires a Doppler velocimeter that emits laser light at (i) the shaft end directly connected to the engine output shaft, or (ii) the engine output shaft itself — plus claim‑specific additions (an opposed pair with averaging in claim 1; a second velocimeter on the engine body with same‑direction beams and subtraction in claim 2; a displacement meter with differentiation‑and‑subtraction in claim 3). Not one cited reference discloses a laser Doppler velocimeter in an engine‑test/dynamometer setting at all.

Closest references by element (for § 103, not § 102):

• Element (a)/purpose — engine‑tester inertia compensation: US 5,078,008; JP 5800001 B2 / US 2016/0084735.
• Measuring speed at the engine output shaft (not the dynamometer): US 4,680,959.
• Non‑contact detection of shaft vibration (the problem behind claims 2–3): US 5,148,840.

Supplementary art (not on the US face citations)

The JP family member (JP 6659491 B2) cites several Japanese references that are not in the US citation list but are worth noting for a full validity picture — most relevantly JPH0710507Y2 (Toyota, "Laser doppler velocimeter," 1995‑03‑08) and JP4020513B2 (Toyota, "Prime mover testing equipment," 2007‑12‑12). I did not retrieve the substance of these within the tool budget, so I flag them as candidate § 103 art for the velocimeter/sensor element only, with no § 102 conclusion drawn.

Forward citations (not prior art): the five third‑party citations of record (US 2020/0103296 A1; US 11,150,150 B2; US 11,204,302 B2; US 11,371,912 B2; CN 109959477 A) all carry priority dates later than 2016‑07‑27, so they cannot be prior art against the '522 patent; four are Meidensha dynamometer‑control filings and evidence the patent's citation footprint in the field.

Confidence and limitations

• High confidence: the citation list, dates, assignees and titles (from the authoritative full text and corroborated by Google Patents/Justia/EveryPatent/OSTI/EPO).
• Medium confidence: descriptions of US 5,465,624, US 2006/0106526, US 2009/0100919, US 2013/0068002 and US 2018/0003589 — I could not retrieve their full specifications, so their "no anticipation" conclusions rest on record metadata, title, field of invention and (for US 7,610,799) the family cross‑reference. A definitive § 102 pass on these needs their full claim sets compared element‑by‑element against claims 1–3.
• Prosecution context: the record shows a Final Rejection mailed 2019‑03‑19 followed by Notice of Allowance 2019‑05‑16, consistent with the cited art being overcome; the "no anticipation" conclusion is consistent with that outcome but is my independent element‑by‑element reading, not a restatement of the examiner's grounds.
• I could not complete a direct USPTO PatentCenter full‑text pull; the citation set is taken from the authoritative patent text provided and corroborated against the indexed Google Patents/Justia records.

I'll ground the §103 analysis in the actual prior-art references from the patent's record. Let me pull their disclosures.

Now let me pull the A&D references, the LDV reference, and the Meidensha engine bench reference.

Obviousness Analysis — US 10,451,522 B2 under 35 U.S.C. § 103

Building on the previously generated summary, claim overview, and litigation sections. The patent text supplied in the record is authoritative; where a cited reference's full text was not retrievable, I say so.

1. Governing framework and level of ordinary skill

Legal test (§ 103; Graham v. John Deere; KSR v. Teleflex): Determine (1) scope/content of the claims, (2) scope/content of the prior art, (3) differences, (4) level of ordinary skill, and weigh secondary considerations. Under KSR, a combination of known elements is obvious where it yields predictable results, where the prior art contains an express or implied motivation, or where the solution is a "predictable variation" of what the art already teaches. A mere statement that a problem is hard does not, by itself, establish non-obviousness.

PHOSITA: A control/test-bench engineer with a bachelor's degree in mechanical or electrical engineering and roughly 2–5 years of experience in engine dynamometer test systems and/or non-contact optical metrology (laser Doppler velocimetry), or equivalent. This person would be familiar with (a) inertia-compensation control of dynamometers, (b) non-contact shaft speed/vibration measurement, and (c) standard common-mode noise-rejection techniques (differential/opposed sensors, reference-channel subtraction).

Critically, the '522 claims recite the control step broadly — "uses the … rotation speed … to control the operation of the dynamometer." They do not claim the specific inertia-compensation algorithm of FIG. 3/FIG. 4 (LPF → resonance correction → phase correction → torque-command generation). This breadth matters: nearly any feedback of measured engine-output-shaft speed into dynamometer control satisfies the claims, which materially weakens the position that the "inventive core" (whatever it may be) is captured by the claim language.

2. The prior-art landscape (from the patent's own Prior Art section)

I could not retrieve the full text of US 5,465,624, US 2009/0100919, US 2013/0068002, US 2016/0084735, JP 5800001, JP 2000-105172, or JP H07-10507. Statements below about those references are limited to their titles/abstracts as reflected in the record and are flagged where load-bearing.

3. Claim-by-claim obviousness

Throughout, the "architecture" elements (dynamometer + connecting shaft + control device controlling engine and dynamometer) are admittedly well known — they appear verbatim in US 4,680,959, US 5,078,008, and JP 5800001 (the admitted Background art in FIG. 8). The only live questions are the speed-sensor hardware and the noise-cancellation signal processing.

Claim 1 — pair of opposed Doppler velocimeters + averaging

Differences over the art:

1. Non-contact (laser) measurement of rotation speed, at the engine-side shaft end or engine output shaft — taught by JP H07-10507 Y2 (LDV) and JP S57-161653 A (non-contact rotation detection), and the location is taught by US 4,680,959 (speed transducer 84 on engine output shaft 20) and US 2006/0106526 (detector on the engine output shaft).
2. A pair of them, opposed, with averaging — the noise-rejection architecture.

Combination A: US 4,680,959 + JP H07-10507 Y2 + US 5,148,840.

• US 4,680,959 already measures engine output-shaft speed and uses it to control the dynamometer (i.e., it discloses the claimed use, minus the specific transducer).
• A POSITA wanting a non-contact engine-side speed signal — motivated by the admitted heat/vibration problems at the engine and by the desire to avoid a coupling that loads the shaft — would substitute an LDV (JP H07-10507 Y2; JP S57-161653 A). Substituting one known speed transducer for another known speed transducer that measures the same physical quantity is a classic predictable variation (KSR).
• GE's US 5,148,840 teaches that shaft-motion sensing is corrupted by vibration and that the remedy is plural sensors whose signals are combined (there, a 90°-offset pair, high-pass filtered and added).

Motivation / rational underpinning: The patent's own Background supplies it — dynamometer-rotation-rate inertia compensation has a 100 Hz antiresonance that drops loop gain and limits the compensation band (FIG. 9A/9B), and the engine output-shaft rotation rate is expressly identified as the theoretically superior signal ("since there is no antiresonance point in the rotation speed … of the output shaft of the engine"). That is an articulated design incentive to move the speed sensor to the engine side and to make it non-contact. The remaining step — mounting two velocimeters on opposite sides and averaging — is the textbook common-mode/differential rejection technique: a translational (vertical) engine-body vibration appears with opposite sign at diametrically opposed sensors but with the same sign at collocated ones, so averaging an opposed pair cancels it. US 5,148,840 confirms the "multiple sensors + combine to separate vibration from shaft motion" concept was known.

Verdict: Claim 1 is reasonably likely obvious over US 4,680,959 + JP H07-10507 Y2 + US 5,148,840 (with JP 5800001/DE-cited JP 2000-105172 supplying the inertia-compensation context). The broad "uses the average value … to control the operation of the dynamometer" recitation does the applicant no favors.

Claim 2 — first DV on shaft/engine shaft + second DV on the engine body (same emission direction), subtract

Differences: (i) two velocimeters aimed in the same direction, (ii) the second aimed at the engine block and measuring block vibration speed perpendicular to the beam and parallel to the rotation direction, and (iii) subtraction.

Combination B: US 4,680,959 + JP H07-10507 Y2 + US 5,148,840 (reference-channel subtraction).

• US 5,148,840 is the closest art: it detects vibration of a rotating shaft non-contactly, and its whole teaching is how to isolate the vibration (of interest there) from other motion — a POSITA here wants the inverse (isolate rotation from vibration), which is the same signal-separation problem addressed by subtracting a separately measured vibration/reference channel.
• Measuring the engine body (rather than the shaft) vibration speed with a second same-direction LDV is a predictable choice: placing the reference sensor on the nearby static/block structure so that the beam geometry is identical is the standard way to get a matched common-mode reference.
• Subtracting a reference-channel signal from a measurement to remove common-mode noise is a ubiquitous, near-axiomatic engineering technique (active noise cancellation, differential sensing). KSR makes combining known elements for their known function, with predictable results, obvious.

Motivation: The same Background rationale (need a clean engine-side speed signal) plus the express recognition in the art (US 5,148,840) that vibration contaminates shaft-motion measurements. "Same direction" is a design constraint that merely guarantees the two beams sample the same vibration mode — a predictable implementation choice.

Verdict: Claim 2 is also likely obvious, though it is somewhat more specific than claim 1 because of the "engine body / same direction" recitations. This is the claim the German examiner's Hauptanspruch tracks (per DE 10 2017 115 942 B4, whose main claim is the pair-of-Doppler version — i.e., the counterparts diverge on which claim is primary, which is itself notable).

Claim 3 — single DV + displacement meter; differentiate displacement → "rotation noise" → subtract

Differences: (i) a displacement meter instead of a second velocimeter, and (ii) differentiating the measured displacement to obtain a speed and subtracting it.

Combination C: US 4,680,959 + JP H07-10507 Y2 + (laser/optical displacement meter art, e.g. JP 2007-24793 A rotary encoder / JP S57-161653 A) + US 5,148,840.

• Contactless displacement metrology (capacitive, eddy-current, laser-triangulation) is decades-old, and the family/DE record shows the examiner considered JP 2007-24793 A and JP 2000-105172 A relevant.
• The conversion step is elementary kinematics: velocity is the time-derivative of displacement (v = dx/dt). Differentiating a displacement signal to obtain a velocity signal is a predictable, mechanical step, not an inventive contribution.
• Once one accepts the "measure a second signal that contains the same vibration noise, then subtract it" principle (claim 2's philosophy, supported by US 5,148,840), swapping the second transducer from a velocimeter to a displacement meter—while adding the mathematically necessary differentiation—is a predictable substitution of one known sensor for another that measures the same underlying quantity.

Verdict: Claim 3 is likely the most vulnerable claim, because the differentiation step is trivial and the second-transducer placement mirrors claim 2. The only meaningful distinction from claim 2 is the sensor modality, and the art is replete with contactless displacement measurement.

Note (non-obviousness-irrelevant defect): As flagged in the prior section, claim 3 recites subtracting from "the first Doppler velocimeter" although it introduces only "a Doppler velocimeter." That antecedent-basis defect is an indefiniteness issue, not an obviousness issue, and does not affect the § 103 analysis.

4. Consolidated motivation-to-combine narrative

A single, coherent rationale supports all three claims:

1. Art-recognized problem: Dynamometer-side rotation rate gives a limited compensation band (admitted; FIG. 9A/9B). → motive to move the speed sensor to the engine side.
2. Art-recognized obstacle & solution direction: Engine-side measurement is degraded by heat/vibration (applicant's own admission). → motive to measure non-contactly (LDV: JP H07-10507 Y2, JP S57-161653 A) and then to de-noise the signal.
3. Art-recognized denoising tools: Multiple sensors whose signals are combined to separate vibration from shaft motion (US 5,148,840); reference-channel subtraction and differentiation are standard engineering.
4. Art-recognized control use: Feeding measured engine-aside speed into dynamometer control (US 4,680,959); inertia compensation is the control regime of interest (US 5,078,008; JP 5800001).
5. Reasonable expectation of success: Every component (LDV, displacement meter, averaging/subtraction, dynamometer feedback control) is individually known and their combination yields no more than the predictable aggregate of their known functions (KSR).

5. Anticipated applicant rebuttals and their strength

6. Weaknesses of this analysis / confidence

1. Full texts not retrieved for US 5,465,624, US 2009/0100919, US 2013/0068002, US 2016/0084735, US 2018/0003589, JP 5800001, JP 2000-105172, and JP H07-10507. My reliance on JP H07-10507 Y2 ("Laser doppler velocimeter") and JP S57-161653 A rests on their titles as listed in the '522 record's family-citation table, not on inspected disclosure text. If JP H07-10507 is directed only to a vehicle/engine rotational-frequency LDV and not to a test-bench context, it is still probative as art teaching LDV-for-rotation, but a definitive § 103 conclusion would want its full text.
2. Prosecution history not obtained. The record shows a final rejection (2019-03-19) followed by a notice of allowance (2019-05-16). I do not have the Office actions or the applicant's amendments/arguments. It is therefore possible a specific § 103 rejection was made and overcome — but I cannot say on what basis, so I cannot confirm or contradict how the examiner resolved obviousness. This is the single most important gap.
3. DE counterpart divergence: DE 10 2017 115 942 B4's independent claim corresponds to the pair-of-Doppler subject matter, and its search report cites two JP references (JP 2000-105172 A; JP 2007-24793 A) not on the US face. A full analysis should reconcile the US and DE claim scopes.
4. No judicial/PTAB precedent exists for this patent (consistent with the earlier litigation section's "no litigation found"), so there is no court-crafted validity gloss to rely on.
5. I do not have the US 10,309,869 B2 sibling text, which the summary notes carries the single-velocimeter "first aspect" — the two-family-member split is itself evidence that the broadest concept was pursued elsewhere, reinforcing that the claims here target the de-noising architectures specifically.

7. Bottom line

• All three claims of US 10,451,522 are, in my assessment, at meaningful risk of invalidation under § 103, with the strongest prima facie cases being:
  • Claim 1: US 4,680,959 + JP H07-10507 Y2 + US 5,148,840 (engine-side non-contact speed measurement + multi-sensor vibration separation/averaging) + JP 5800001 (inertia-compensation context).
  • Claim 2: same primary set, with US 5,148,840 supplying the "measure a second signal containing the vibration, then combine (subtract)" teaching; "engine body / same direction" is a predictable matched-reference implementation.
  • Claim 3: same primary set plus known contactless displacement metrology; the differentiation step is elementary kinematics.
• The most defensible feature family is the specific noise-rejection architecture (opposed-pair averaging; same-direction reference subtraction; displacement-differentiation subtraction), but each maps onto a recognized engineering technique, so the non-obviousness case is not strong absent a teaching-away or unexpected-results showing that is not present in the record I reviewed.
• Caveat repeated: This conclusion is based on the patent's own Prior Art listing and the abstract/claim text of those references I could retrieve. The unknown prosecution history (final rejection → allowance) and the unretrieved full texts (especially JP H07-10507 and the A&D/Meidensha references) are the principal uncertainties. For a filing-grade opinion I would (a) pull the USPTO Image File Wrapper for the 2019-03-19 final rejection and the subsequent amendment/argument, and (b) obtain the full text of JP H07-10507 Y2, JP 2000-105172 A, and JP 2007-24793 A before finalizing.