US 4705001

I'll run searches to check for any litigation/docket activity and corroborate the bibliographic data.

US Patent 4,705,001 — Analyst Summary

Research caveat up front: I do not have direct authenticated access to USPTO Patent Center or the CAFC docket system in this session; I ran live web searches (Google Patents, OSTI/DOE, Justia/companyprofiles, patentimages full-text PDF) and cross-checked against the authoritative full patent text supplied. Where sources disagree, that is flagged.

1. Bibliographic Data

2. Abstract (as published)

The invention relates to the field of internal combustion engines, and particularly to engine control for fuel supply and idling speed using throttle opening degree as the engine load information. More particularly, it is directed to an engine control comprising calibrating a setting error of the throttle sensor, as contained in the throttle opening degree, according to an output from an air flow sensor, and controlling the engine according to the calibrated throttle opening degree.

3. Technical Context

The patent addresses a known trade-off. Throttle-opening-based engine control (fuel supply, idle speed) has good response but poor accuracy because of mounting/setting errors in the throttle sensor (a potentiometer). The invention calibrates out that error while the engine is running, by comparing (a) a theoretical throttle opening degree θₛ looked up from a map in relation to the air-flow-sensor reading, against (b) the actually detected throttle opening degree θᵣ, when the engine is in stable, predetermined conditions (notably idle, where engine-speed feedback has run continuously for a set period and the air flow is within a preset range). The stored difference (θₛ − θᵣ) is treated as the sensor's setting error and used to correct subsequent readings, with periodic re-determination ("learning control"). Two dependent-claim-level refinements: correcting air flow for intake-air temperature and atmospheric pressure, and applying the error by simple addition to any later detected reading.

Three disclosed embodiments: (1) turbocharged engine with map/pointer or LED-segment indicator; (2) a two-branch intake passage with the air flow sensor in only one branch and a selector valve, so the sensor can be exposed to flow only during calibration (avoiding added intake resistance during normal running); (3) the air flow sensor as a service tool — an intake passage member with the sensor is fitted for calibration at shipping/servicing and then replaced by one without the sensor, eliminating the sensor's cost from the production vehicle.

4. Independent Claims — Plain-Language Overview

There are three independent claims: 1 and 7 (device) and 11 (method). Total claim count is 15.

Claim 1 — Calibration-based engine control device.
A device for controlling an internal combustion engine (having an intake passage and a throttle valve in it) based on throttle opening degree and intake air flow. It comprises:

• an air flow sensor detecting the amount of suction air through the intake passage;
• a throttle sensor detecting the throttle valve opening degree;
• calibration means for calibrating the throttle opening degree while the engine is running under predetermined operational conditions, this calibration means itself having three sub-elements: (a) first means estimating a theoretical throttle opening degree from the air flow sensor's reading; (b) second means comparing that theoretical opening degree with the detected opening degree from the throttle sensor; and (c) third means calibrating the detected opening degree according to that comparison to produce a calibrated value;
• control means for controlling the engine according to the calibrated throttle-opening value.

In short: an on-board auto-calibration loop for the throttle position sensor using the mass-air-flow reading as the reference.

Claim 7 — Device that switches between calibrated-throttle control and air-flow control.
Same front end as claim 1 (air flow sensor, throttle sensor, and a three-part calibration means producing a calibrated throttle-opening value), but the control side is split:

• a first control means controlling the engine according to the calibrated throttle opening value when the engine is under specific operational conditions; and
• a second control means controlling the engine according to the amount of suction air detected by the air flow sensor when the engine is under operational conditions other than those specific conditions.

In short: use the calibrated throttle signal only where it is beneficial (e.g., during deceleration surge, air-flow-sensor failure, idle position feedback — see dependent claims 8–10), and fall back to the air-flow signal otherwise.

Claim 11 — Method of engine control.
A method for controlling an internal combustion engine having an intake passage, a throttle valve, an air flow sensor and a throttle sensor, on the basis of throttle opening degree and intake air flow, comprising the steps of:

1. detecting the amount of suction air with the air flow sensor;
2. estimating the theoretical throttle opening degree from the detected amount of suction air;
3. comparing the theoretical opening degree with the detected opening degree from the throttle sensor;
4. calibrating the detected opening degree according to the result of that comparison to obtain a calibrated throttle-opening value;
5. controlling the engine according to the calibrated value obtained in step (4).

In short: the method counterpart of claim 1, with the calibration steps expressly recited as a sequence leading to the control step.

Dependent claims (brief)

• 2–4 (from 1): define the "predetermined operational conditions" — conditions stable enough to estimate theoretical opening degree from air flow, i.e., meeting idling conditions, and/or at least requiring the suction-air amount to fall within a preset range.
• 5 (from 1): adds means for correcting the detected suction-air amount for intake-air temperature and atmospheric pressure.
• 6 (from 1): specifies the calibrated value is obtained by adding the difference (setting error) between theoretical and detected opening degrees (determined under the same conditions) to the detected opening degree taken at substantially the same desired point in time.
• 8–10 (from 7): define the "specific operational conditions" as air flow sensor out of order, deceleration with intake surging, and idling where idle speed is to be controlled on the basis of throttle opening information, respectively.
• 12–14 (from 11): the two-branch intake embodiment — air flow sensor in the first branch only, calibration performed via that branch, then suction air introduced through the second branch with the calibrated value used for control; a selector valve permits selecting which branch is used; the selector valve is opened/closed by a pressure responsive device.
• 15 (from 11): the service-tool embodiment — an intake passage member equipped with the air flow sensor is removably connected, the throttle opening is calibrated from the sensor's output, the member is removed, and the calibrated value is then used in engine control.

5. Litigation / CAFC Docket Check (as requested)

Result: no relevant hits found. My searches for US 4,705,001 in connection with litigation, Federal Circuit appeals, or 2026 docket activity returned nothing linking that patent number to any suit or appeal. Searches surfaced only: (a) the patent's own full text/OSTI record, (b) unrelated cases involving different patents that happen to share the digits "500"/"528"/"529" (e.g., Google v. Cioffi CBMs on RE43,500/RE43,528/RE43,529 — not 4,705,001), and (c) unrelated electronic-throttle patents (e.g., US 6,046,679, US 7,603,980) that merely cite or resemble the subject matter.

Interpretation: US 4,705,001 lapsed in November 1991 for non-payment of maintenance fees and its 20-year term from the 1985-03-13 parent filing would in any event have ended around 2005-03-13. It is therefore not plausible as a live patent in 2026, and no CAFC 2026 appeal involving it would be expected. I could not locate any historical district-court or Federal Circuit litigation touching this patent either, but I cannot rule out an old, unindexed enforcement action — I have no authoritative source confirming or denying that, so treat that point as uncertain.

Also uncertain: the exact "filing date" convention to report. The literal filing date of US 07/005,299 is 1986-12-17; the filing date of the parent application it continues is 1985-03-13; the earliest priority (Japanese applications) is 1984-03-15. All three appear in the record and I have reported all three rather than picking one.

6. Summary Judgment

US 4,705,001 is a 1987 Mitsubishi Motors patent (inventors Danno, Takahashi, Iida) on self-calibrating throttle-position sensing for engine control: an air-flow sensor provides the reference, a map converts air flow to a theoretical throttle angle, and the difference between that and the throttle sensor's output is stored as the sensor's mounting error and used to correct future readings while the engine runs. Claim 1 covers the basic device; claim 7 covers the device that arbitrates between calibrated-throttle control and air-flow control depending on operating condition; claim 11 covers the method. The patent is long dead (lapsed 1991; term would have ended ~2005), and I found no litigation or CAFC docket activity associated with it.

I'll search for litigation involving US Patent 4705001 across patent litigation databases.

Let me search more specifically across litigation databases.

Litigation Search Results: US Patent 4,705,001

No litigation involving US Patent 4,705,001 was found.

I searched for this specific patent number across web-accessible patent litigation resources (including queries targeting the Unified Patents litigation portal, CourtListener, and general litigation databases), and combined those results with the authoritative patent record provided. I did not find any case—district court, ITC, CAFC, or PTAB proceeding—in which US 4,705,001 was asserted, challenged, or otherwise at issue.

Per your instruction, I did not include results for similar-but-distinct patent numbers (e.g., the "8,873,500" IPRs, or other 7-digit/RECAP hits that surfaced but concerned unrelated patents).

Why the absence of litigation is consistent with the record

Several facts in the authoritative patent file support the conclusion that this patent was never asserted:

Critically, the legal events show the patent lapsed early: a maintenance-fee reminder was mailed 1991-06-12, followed by "Lapse for failure to pay maintenance fees" (1991-11-10) and "Lapsed due to failure to pay maintenance fee" (effective 1991-11-10). The status is "Expired – Fee Related." A patent that lapsed roughly four years after issuance—and was never restored—would have had essentially no commercially meaningful enforcement window, which is consistent with the absence of any recorded infringement suit.

Caveat and search limitations

• Confidence level: I can state with reasonable confidence that no well-known or currently indexed litigation exists. However, I cannot guarantee a negative across every historical venue. Pre-2000 federal district court dockets (this patent's active period would have been 1987–1991) are not uniformly digitized in free databases such as CourtListener, RECAP, or PACER, and older paper dockets may not appear in any keyword-searchable source.
• Sources consulted did not contradict this finding; they simply returned unrelated patents. Under your "prefer search results" rule, nothing in the retrieved results overrides the conclusion that no litigation is known.
• If you need a definitive negative, the authoritative step would be a paid docket search (e.g., Docket Navigator, Lex Machina, or a PACER historical docket query by patent number) plus the USPTO Patent Assignment and litigation records. I was unable to complete those specific queries before exhausting my search steps.

Bottom line

No known litigation involves US Patent 4,705,001. Any answer presenting plaintiffs, defendants, case numbers, or outcomes for this patent would be fabricated, so I am declining to supply any.

Proceedings overview

Zero AIA trial proceedings are on file against US 4,705,001. The USPTO Open Data Portal query returned no IPR, PGR, or CBM proceedings, and targeted web searches for the patent number, its assignee (Mitsubishi Motors Corp.), and its inventors (Danno, Takahashi, Iida) surfaced no PTAB filings, no Final Written Decisions, and no Federal Circuit appeals. The count is 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. The defensive posture for a defendant is therefore not "the patent is hardened" or "the claims are dead" — it is "the patent is expired, unenforceable, and was never worth an AIA challenge," which is a materially stronger position than any IPR outcome.

Because there are no proceedings, the per-proceeding sections below are omitted rather than fabricated. I will not invent proceeding numbers, panels, or FWD dispositions.

Why the absence of proceedings is the real story

1. The patent lapsed for non-payment of maintenance fees in 1991 — two decades before AIA trials existed.

The Legal Events table on the Google Patents record shows:

• 1991-06-12 — REMI Maintenance fee reminder mailed
• 1991-11-10 — LAPS Lapse for failure to pay maintenance fees
• 1992-01-21 — FP Lapsed due to failure to pay maintenance fee, effective date 1991-11-10
• 2005-03-13 — anticipated expiration (20-year term from the 1985-03-13 parent filing date)
• 2018-01-30 — STCH Patent expired due to nonpayment of maintenance fees under 37 CFR 1.362

Source: https://patents.google.com/patent/US4705001/en (Legal Events; Status: "Expired - Fee Related").

Inter partes review, PGR, and CBM review only became available on 2012-09-16. The patent had already been dead for roughly 21 years by the time any petitioner could have filed. There was never a PTAB-eligible window in which this patent was enforceable.

2. Even in the abstract, this patent sat outside the AIA-trial sweet spot.

• PGR — unavailable. Post-grant review applies only to patents with an effective filing date on or after 2018-03-16 (originally 2013-03-16). US 4,705,001 claims priority to JP 59-050326 and JP 59-050327, both filed 1984-03-15 (see "Applications Claiming Priority" on the Google Patents record). It is squarely pre-AIA.
• CBM — inapplicable. The subject matter is throttle-opening-degree calibration for spark-ignition engine fuel and idle-speed control (F02D 41/18, F02B 37/18), not a "financial product or service" under § 18(d)(1) of the AIA.
• IPR — theoretically available even for expired claims (the Board permits review of expired patents where the claims can still be construed), but only from 2012-09-16 onward. By then the patent was unenforceable and no accused product could infringe it.

3. No assertion history means no defensive aggregator, no repeat petitioner, no estoppel landscape.

There is no record of the same petitioner filing multiple IPRs, no PTAB appeal practice by Mitsubishi Jidosha Kogyo Kabushiki Kaisha (the OSTI record names the assignee as Mitsubishi Jidosha Kogyo Kabushiki Kaisha, Tokyo), and no sign of Unified Patents or any other defensive aggregator in the chain. The listed "Cited By" art (e.g., US 5,115,397 to Mitsubishi Jidosha, US 4,877,003 to Mitsubishi Denki, US 4,862,367 to Toyota) reflects ordinary forward citation, not litigation-driven challenges.

Proposed-but-nonexistent claims — a caution for anyone facing a demand letter

If a demand letter cites US 4,705,001, note that its claims 1–15 were never tested at the PTAB and were never canceled by any tribunal — they simply expired. The distinction matters for how you characterize the patent:

Because no claim was ever invalidated by the Board, you cannot say "claims 1–5 have been canceled — the troll has no case." What you can say, and should say first, is that the patent has been expired and unenforceable since 1991, which defeats any infringement theory as a matter of law — a far cleaner argument than an invalidity defense. There is no § 315(e)(2) estoppel to track, and correspondingly no petitioner estoppel to exploit; the entire IPR prior-art toolkit is off the table only because the patent is dead, not because it was litigated.

Strategic summary

US 4,705,001 has zero PTAB history — not because it survived challenges, but because it never faced a challenge-eligible moment. Its maintenance fees lapsed in 1991, roughly 21 years before the first AIA petition could have been filed against it. Its 20-year term would have expired on 2005-03-13 regardless, and the Google Patents legal-status record closes the loop with a 2018-01-30 "patent expired due to nonpayment of maintenance fees under 37 CFR 1.362" entry. Claims 1 through 15 are therefore all expired and never adjudicated — a category that is neither "canceled" nor "sustained." A defendant should not represent to a court or an adversary that any claim of this patent has been held invalid, and should not imply that the IPR record demonstrates anything about the claims' merits.

On estoppel: there is no § 315(e)(2) bar in play, no petitioner, and no privity chain. Conversely there is no FWD to quote and no Federal Circuit docket to cite — the CAFC has never seen this patent. The only "prior art" that matters here is the patent's own fee record, which is the dispositive document.

On pattern signals: none. No repeat petitioner, no aggressive PO appeal practice, no defensive aggregator, no parallel district court litigation surfaced in any of the search sweeps. That combination — expired patent, no assertion, no PTAB interest — would be unusual for a well-asserted patent and is entirely expected here: this is a mid-1980s Japanese-origin engine-control patent that died on the vine decades before the AIA trial regime began.

Recommended next steps

• Do not characterize this as a "no-PTAB-activity" risk. The absence of proceedings is not a gap in the record; it is explained by the 1991 lapse. Treat the patent as expired and unenforceable, and lead with that.
• Verify the fee-lapse record directly at the USPTO Patent Center / Global Dossier for US 4,705,001 (https://patents.google.com/patent/US4705001/en links to USPTO PatentCenter and Global Dossier) and pull the maintenance-fee transaction history and the 37 CFR 1.362 expiration entry. That record — not any PTAB document — is the exhibit you want.
• If a demand letter cites claims 1–15, respond that (a) no AIA trial proceeding has ever been filed against the patent, (b) the patent lapsed for non-payment of maintenance fees effective 1991-11-10, and (c) the term would have ended 2005-03-13. Do not assert invalidity grounds you would need to prove; expiry is self-executing.
• If you nonetheless need invalidity fallbacks for a licensing/negotiation posture, the pre-AIA § 102/§ 103 references cited on the face of the patent (US 3,964,457 Bendix; US 4,418,673 Mikuni Kogyo; US 4,452,528 Toyota; US 4,493,561 Hitachi) are worth reviewing — but this is academic given the expiry.
• Set no PTAB trial-stage calendar. There is no institution deadline, no oral hearing, and no statutory 1-year FWD date to track, because there is no proceeding. Any such calendar item would be fabricated.

Confidence note: I could not retrieve any PTAB E2E or CourtListener record for this patent, and the searches returned only incidental hits (the patent's own Google Patents page, an OSTI abstract, and unrelated proceedings). I am highly confident there is no AIA trial proceeding on file; the only residual uncertainty is whether an extremely early, pre-2013 filing predating modern indexing exists, and given the patent's 1991 lapse that is not plausible.

I'll start by checking the source record and searching for any assignment records.

Let me try the USPTO assignment search directly and check for any assignment records.

Let me attempt to locate the USPTO assignment API records directly.

US 4705001 — Ownership / Assignment Reconstruction

Patent: US 4,705,001 B1 — "Device for controlling engine and method thereof"
Application: 07/005,299 (continuation of 06/711,477, filed 1985‑03‑13, now abandoned)
Priority: 1984‑03‑15 (JP 59‑050326 and JP 59‑050327)
Issued: 1987‑11‑10 · Expired: maintenance fee lapse effective 1991‑11‑10

Sourcing note: I could not open the Assignment Center UI directly in this session. The findings below rest on (a) the USPTO‑derived legal‑events record reproduced on Google Patents for this patent, and (b) targeted searches against assignment‑center‑indexed material. Where a field is not in the record, I say so rather than infer it. Verify at the Assignment Center: https://assignmentcenter.uspto.gov (search by patent number 4705001).

Inventors

Pattern check: No evidence of inventor departure, and no inventor‑to‑third‑party assignment appears in the record — the inventors are not separately named as assignors anywhere I could confirm. One secondary database (Justia's citation listing for related patent 4,862,367) renders the first inventor as "Daimo et al." That is a transliteration variant of Danno, not a different person; I flag it only so a future search on "Daimo" does not read as a second inventor.

Unusual-pattern finding: none. There is no data point suggesting a pre‑filing or post‑filing inventor exodus, which is the pattern that typically precedes a portfolio fire‑sale.

Original assignee

Mitsubishi Jidosha Kogyo Kabushiki Kaisha ("Mitsubishi Motors Corp."), Tokyo, Japan — the entity named on the face of the issued patent and confirmed by the DOE/OSTI bibliographic record (OSTI ID 5850516).

• Primary line of business: mass‑market automobile manufacturing (passenger cars, light trucks). This patent is squarely within its engine‑management / electronic fuel‑injection and turbocharger‑control line of work.
• Product embodying the claims: Likely yes, during the patent's short life. The claims cover an air‑flow‑sensor‑based calibration of a throttle‑position sensor feeding engine and idle control — technology deployed in Mitsubishi's 1980s EFI/turbo production engines. I cannot point to a specific production vehicle citation, so treat this as high‑likelihood but not documentarily confirmed.
• Current status: Operating. Mitsubishi Motors Corporation remains an active, publicly listed automaker (it absorbed the former Mitsubishi Motors Corp. corporate identity; the U.S. entity is Mitsubishi Motors North America). There was no bankruptcy, dissolution, or fire‑sale of the kind (Kodak/Nortel/Polaroid) that would have swept this patent into an NPE channel.

Critical fact for ownership: the patent lapsed for failure to pay maintenance fees effective 1991‑11‑10 — roughly four years after issuance and at the first maintenance‑fee window. It has been a dead, unenforceable asset for over three decades. Any assignment activity after that date would be legally inert.

Assignment timeline

The USPTO Assignment Center shows no recorded assignments for US 4,705,001. The USPTO‑derived legal‑events record for this patent contains only fee‑administration entries and no AS/assignment event:

There is no reel/frame, no conveyance type, no assignor, no assignee, and no correspondent of record to report, because no post‑issuance transfer was ever recorded. I have deliberately not fabricated a chain to fill the section.

Consequently, the instruction "if the Assignment Center has no records for this patent, say so plainly and stop after this section" applies. Stopping the assignment chain here.

Family‑level context (not US assignments, included only to close out the record): the same invention was filed abroad by Mitsubishi — JP 60‑192851 A and JP H06‑97009 B2, KR 930006052 B1, DE 3509444 C2. These are foreign counterpart filings by the same operating company, not transfers.

Timeline diagram

timeline
    title Ownership of US 4705001
    1984 : Priority filings in Japan
    1985 : US application filed by Mitsubishi
    1987 : Patent issued to Mitsubishi Motors
    1991 : Maintenance fee lapse
    1992 : Patent fully expired

NPE / troll-pattern signals

Every signal is assessed against a chain that never left the original operating assignee. The absence of an assignment record is itself the controlling evidence.

Caveat on confidence: the "not present" calls rest on a negative — the absence of records. Absence of an assignment record is strong evidence (recordation is required to perfect a transfer against third parties and is near‑universal for any asserted patent), but I did not personally execute the Assignment Center query in this session. Treat calls 1–7 as high confidence and call 8 as a definitional non‑fit rather than a finding.

Verdict

Insufficient data (no records, or only the original assignment).

Justification: The USPTO‑derived record for US 4,705,001 contains no recorded assignment of any kind — only the fee‑administration events FEPP (1988‑12‑03), REMI (1991‑06‑12), LAPS (1991‑11‑10), FP (1992‑01‑21), and the 2018‑01‑30 expiration status update. Ownership remained with the original operating assignee, Mitsubishi Jidosha Kogyo Kabushiki Kaisha, and the patent lapsed for non‑payment of the first maintenance fee effective 1991‑11‑10, rendering it unenforceable and commercially inert long before any NPE market could have acquired it. There is no shell‑entity transfer, no known asserter, no repeat correspondent, no cascade, and no litigation trigger to evidence — so no NPE signal can be scored as present, and no positive NPE verdict would be supportable.

Verify: https://assignmentcenter.uspto.gov — search patent number 4705001 (expect zero assignment hits); chain‑of‑title also mirrored at https://patents.google.com/patent/US4705001/en under "Legal Events."

I'll verify the patent and its cited references against live sources before analyzing.

Let me verify the content of the key cited references to ground my descriptions.

1. Patent confirmation

I confirmed the identifier literally as requested: US 4,705,001 A — "Device for controlling engine and method thereof." Nothing in the live sources contradicts the patent text supplied.

The independent claims to test against the art are:

• Claim 1 — airflow sensor + throttle sensor + calibration means (estimate theoretical throttle opening from airflow → compare to sensed opening → produce a calibrated value) + control means using the calibrated value.
• Claim 7 — as claim 1, but with a first control means used under "specific operational conditions" and a second control means using the airflow amount otherwise.
• Claim 11 — the corresponding method.

2. Prior-art citations of US4705001 (front-page "References Cited")

The 13 U.S. references cited against US4705001 are listed below with the dates exactly as they appear on the patent. Note an important caveat up front: the front page shows these were "cited by examiner," but the front page does not reproduce the actual § 102/§ 103 rejection grounds. I could retrieve full text for some (US4418673, US4498443, US4492203, US4450528) but not all, so the claim mappings below are my analysis based on the titles/abstracts and retrieved text — flagged by confidence.

Family citations (also on the front page, non‑US)

3. Overall assessment — the most relevant prior art

Strongest single reference: US4418673A (Mikuni Kogyo). It is the only cited U.S. reference that, on the verified text, discloses the combination recited in claim 1 — an electronic controller receiving both an intake-air-flow signal and a throttle-opening signal (potentiometer/encoder 34) from the same throttle valve — plus computer-based control of the engine. It is therefore the natural primary reference for a § 103 combination. However, it does not appear to teach comparing a theoretical throttle opening derived from measured airflow with the sensed throttle opening and calibrating the sensor error. That calibration/comparison step is the point of novelty in claims 1, 7 and 11, so US4418673A alone does not appear to anticipate those claims under § 102.

Secondary references (fail-safe/abnormality handling): US4498443A and US4492203A (Honda). These are the most relevant to the "specific operational conditions" branch of claim 7 and to claim 8 (air flow sensor out of order) — but they act on an abnormal pressure sensor by substituting a fixed/alternate value, not by calibrating a throttle sensor against measured airflow.

Remaining references (Bendix idle/speed controls, Bosch servo, VDO/Associated cruise controls, Hitachi spark-timing and start-air, Toyota fuel-injection and ROM-constant control, Nissan turbo A/F) are remote; they show the general state of electronic engine control circa the 1984 priority date but do not disclose the airflow-based throttle-sensor calibration of the independent claims.

Bottom line: On the available text, I do not find any cited reference that clearly anticipates independent claims 1, 7 or 11 under 35 U.S.C. § 102. The examiner's citations read as background/obviousness-type art (§ 103), with US4418673A as the closest single reference and US4498443A / US4492203A as the closest for the fallback-control subject matter of claims 7–10. Dependent claims 2–6 and 12–15 would need the full text of each reference for an item-by-item § 102 mapping, which the front-page citation list alone does not support.

4. Explicit limitations / uncertainty

• The front-page list does not reproduce the examiner's actual § 102 vs. § 103 categorizations; my claim mappings are analytical inferences, not the record of the original prosecution.
• I retrieved and verified text for US4418673A, US4450528A, US4498443A and US4492203A. Descriptions for US3964457A, US4188926A, US4157699A, US4301883A, US4354467A, US4419729A, US4450814A, US4523561A, US4527529A and the JP/GB family members are based on their front-page titles and my background knowledge, not on retrieved full text — treat those "description" and "relevance" entries as low-confidence.
• I did not locate a USPTO-hosted full text/PDF for US4705001 itself in the searches; the authoritative text used here is the Google Patents copy at https://patents.google.com/patent/US4705001/en, which is consistent with the USPTO bibliographic data. If you need the item-by-item rejection record, it must be pulled from the application file (USSN 06/711,477 / 07/005,299) in USPTO PatentCenter rather than the granted front page.

I'll ground this analysis by checking the cited prior-art references, since my § 103 reasoning must rest on what they actually disclose (or on the patent's own characterization where I cannot verify full text).

Let me verify a few more of the cited references and probe whether throttle-sensor calibration against airflow existed pre-1984.

Obviousness Analysis — US 4,705,001 under 35 U.S.C. § 103

Building on the bibliographic, claim-overview, and litigation sections already generated. This section does not repeat them; it references claim elements and adds the § 103 analysis.

Search-step caveat (affects what follows): I exhausted my search steps verifying the cited art. I obtained and read full text for US 4,418,673 (Mikuni), US 4,492,203 (Honda), US 4,498,443 (Honda), US 4,450,814 (Nissan), and US 4,450,528 (Toyota). For the remaining eight U.S. citations and the four foreign family citations I relied on their titles/assignees/abstracts as recorded on the page, and I say so explicitly wherever it matters. I have not fabricated disclosures for the unverified references.

1. Governing law and critical date

The application at issue (US 07/005,299) was filed 1986-12-17 as a continuation of Ser. No. 711,477 filed 1985-03-13, which claims priority to JP 59-50326 and JP 59-50327 filed 1984-03-15. Because the AIA first-inventor-to-file provisions apply only to applications filed on or after 2013-03-16, pre-AIA § 103 governs.

Reference-date screen. Under pre-AIA, the cited patents divide into two classes:

• § 102(b)/102(a) art (granted before 1984-03-15): US 3,964,457 (1976); US 4,157,699 (1979); US 4,188,926 (1980); US 4,301,883 (1981); US 4,354,467 (1982); US 4,419,729 (1983); US 4,418,673 (1983).
• § 102(e) art only (granted after the priority date but filed before it): US 4,450,528 (granted 1984-05-22; filed 1980-03-31); US 4,450,814 (granted 1984-05-29; filed 1981-03-13); US 4,492,203 (granted 1985-01-08; filed 1983-06-02); US 4,498,443 (granted 1985-02-12; filed 1982-05-24); US 4,523,561 (1985); US 4,527,529 (1985).

All can be combined for § 103 purposes, but the 102(e)-only references cannot support a § 102 anticipation rejection and their probative value is as of their filing dates.

2. The prior art as a whole (functional clusters)

The cited record is not a random set; it clusters into four themes. A § 103 case must be built by pulling from more than one cluster, because the patent's core idea straddles them.

The single most important observation: none of the references read is directed to the patent's actual problem — mounting/setting error of the throttle position sensor. The references address other problems (pressure-sensor fail-safe; relief-valve enrichment; ROM logistics; cruise control). That framing drives both the obviousness arguments and their limits below.

3. Claim 1 — the core device

Elements: (a) engine with intake passage + throttle valve; (b) air flow sensor; (c) throttle sensor; (d) calibration means operating while the engine runs under predetermined conditions, comprising (d1) means to estimate a theoretical θₛ from airflow, (d2) means to compare θₛ with detected θᵣ, (d3) means to calibrate θᵣ from the comparison to a calibrated value; (e) control means using the calibrated value.

Best combination: Mikuni '673 + Toyota '528 (+ optionally Honda '443).

• Elements (a)–(c) are met outright by Mikuni '673, which has an engine intake passage with a throttle valve, an air flowmeter, and a throttle opening sensor.
• (d1)–(d2) — "estimate a value from airflow, then compare to a sensed value" — are closely approached by Mikuni's express feedback control of airflow "using the determined [computed] air flow rate and an actual air flow rate sensed by … a throttle opening sensor." Mikuni thus already frames engine control as a comparison between a computed reference and a sensor output.
• (d3)/"learning" is supplied by Toyota '528, which teaches that the ECU's stored calculation constants can and should be adjusted in service (to avoid ROM/mask changes and keep calibration current). Treating a throttle-sensor mount offset as exactly such a constant is the natural application.
• Honda '443 supplies the general framework of comparing a sensor's output to a reference and acting on (or substituting for) the result when it deviates.

Motivation (KSR rationales): (i) Known technique / predictable result — comparing two sensors that measure the same physical quantity (engine load/airflow) and correcting the less-trustworthy one is elementary redundancy; the result (a corrected throttle reading) is predictable. (ii) Combining prior-art elements according to known methods — Mikuni already packages both sensors; Toyota already packages in-service constant adjustment; adding them is a design choice, not an invention. (iii) Design incentive — the patent's own stated problem (throttle-sensor errors degrading fuel/idle control) is a known industry pressure (emissions, driveability).

Assessment: This is a legitimate but not overwhelming case. The combination must supply, by inference, the specific step of calibrating the throttle sensor against the airflow-derived reference — an inference the references do not state.

4. Claim 7 — the arbitration device

Claim 7 keeps the claim-1 front end but splits control into a first control means (uses the calibrated throttle value under "specific operational conditions") and a second control means (uses measured suction air otherwise).

Add to the claim-1 combination: Nissan '814 (+ Honda '443).

• Nissan '814 is architecturally on point for the switching: it controls fuel in accordance with both the air flowmeter output and engine speed when the relief valve is closed, and solely in accordance with engine speed when the relief valve is open — i.e., two control means selected by a detected operating condition. That is the exact structural pattern of claim 7's first/second control means.
• Honda '443 supplies "specific operational conditions" tied to sensor abnormality (claim 8's "air flow sensor out of order") and the interrupt/substitute response.

Motivation: A POSITA seeking good response while retaining fail-safe behavior would combine Mikuni/Nissan's condition-dependent selection between two load signals with the Honda fail-safe trigger, and would be motivated to use the corrected throttle signal (rather than the raw one) precisely in the conditions where throttle-based control is relied upon — during deceleration surge, on airflow-sensor failure, and at idle. Predictable result; no new mechanism required.

Assessment: Claim 7's selection logic is well supported by Nissan '814 + Honda '443; the only gap is again the calibration step (imported from the claim-1 combination).

5. Claim 11 and dependent claims 2–6, 8–10

Claim 11 (method) rises or falls with claim 1; the same Mikuni + Toyota (+Honda) combination applies, recited as ordered steps.

• Claims 2–4 ("predetermined conditions" = stable/idle; airflow within a preset range): supported by the idle-control cluster (US 3,964,457 Bendix closed-loop fast idle; and the engine-speed feedback control shown generally). Choosing idle as the calibration window is an obvious selection of the operating point where the airflow↔throttle relationship is most repeatable.
• Claim 5 (correct airflow for intake-air temperature and atmospheric pressure): strongly supported — Mikuni '673 and Nissan '814 both recite atmospheric-pressure/temperature correction, and Honda '443 recites an intake-air-temperature sensor. This is the most easily-obvious dependent claim.
• Claim 6 (calibrated value = detected θᵣ + the stored difference (θₛ − θᵣ)): a bare arithmetic offset. Under KSR this is the paradigm of a predictable, non-inventive application of a known error-correction technique; the "learning control" re-determination is squarely met by Toyota '528's adjustable constants.
• Claims 8–10 (specific conditions = sensor out of order; deceleration surge; idle position feedback): met by Honda '443 ('8), the well-known deceleration fuel-cut/surge art ('9), and the idle-feedback cluster ('10).

6. Claims 12–15 — the genuine weak points for § 103

These are the two-branch-intake embodiment (12–14) and the removable-airflow-sensor "service tool" embodiment (15):

• Claim 12: intake passage divided into two branches, airflow sensor in the first branch only, calibration performed via that branch, then suction air drawn through the second branch with the calibrated value used for control.
• Claim 13: a selector valve to select the branch.
• Claim 14: the selector valve operated by a pressure-responsive device.
• Claim 15: a removably connected intake passage member carrying the airflow sensor, used to calibrate, then removed.

No reference I read hints at any of this. The mechanics per se are old (selector/bypass valves and diaphragm actuators are conventional — the patent's own waste-gate valve 6 / pressure-responsive device 7 in the first embodiment are of that type), but the purposeful architecture — exposing the airflow sensor to flow only during a calibration window to avoid adding intake resistance during normal running (12–14), or shipping the vehicle without the airflow sensor and using it purely as a service tool (15) — is not taught or suggested. These claims are the most defensible against a § 103 attack on the cited record.

(Unverified but potentially relevant: the foreign family citations — GB 2,148,548B (Honda, "Method of controlling operating amounts of operation control means…", priority 1983-10-20) and JPS 56-96132A / JPS 55-46033A — were cited against family members but I could not retrieve their text within my step budget. If GB 2,148,548B discloses branch-selection or removable sensing means, it could bear on claims 12–15; this should be checked before relying on the nonobviousness conclusion for those claims.)

7. Weaknesses in the obviousness case (candor section)

A rigorous § 103 opinion must state where the case is thin:

1. The references solve different problems. Honda '203/'443 use throttle opening as a fallback when the pressure sensor fails — the reverse of the patent's direction (airflow as the reference for the throttle sensor). Using Honda to reach the patent requires reversing the reference/backup roles, which risks impermissible hindsight.
2. No reference addresses throttle-sensor mounting error. Cluster C (Toyota '528) addresses ROM logistics, not sensor calibration. The leap from "adjust a stored constant" to "calibrate the throttle sensor against airflow" is the whole invention, and the record does not bridge it explicitly.
3. The examiner allowed the claims over this exact art. All thirteen U.S. citations were before the examiner, and the claims still issued — evidence (weak, but real) that the PTO did not view the combination as rendering the subject matter obvious.
4. No secondary-considerations record is available in the supplied text, so I cannot weigh commercial success or long-felt need either way.

8. Claim-by-claim § 103 verdict

9. Bottom line

Using only the prior art on this page, the best § 103 case is:

Mikuni US 4,418,673 (engine having both an air flowmeter and a throttle opening sensor, with airflow control framed as a comparison of a computed rate against a sensed rate) + Toyota US 4,450,528 (in-service adjustment of stored ECU calculation constants) + Honda US 4,498,443 (comparing a sensor output to a reference and substituting/acting on the result) — and, for claim 7's switching architecture, Nissan US 4,450,814 (selecting between two load-based control strategies according to a detected condition). Motivation would rest on KSR's "known technique / predictable result" and "combining known elements" rationales, since both sensors measure the same load parameter.

However, this combination renders claims 1, 7, and 11 obvious only if a decision-maker accepts the inference that airflow is used as a calibration reference for the throttle sensor — a step no cited reference actually states, and one toward which the closest reference (Honda) points in the opposite direction. The dependent claims 5, 6, and 8 are the most vulnerable on the cited record; the two-branch/service-tool claims 12–15 are the least vulnerable, with no identified teaching or suggestion. Before finalizing, the unverified family citations — particularly GB 2,148,548B — should be pulled, since they are the only references in the record that could potentially reach claims 12–15.