US 6240346

I'll verify the patent record and check for any current litigation/docket activity.

US Patent 6,240,346 B1 — Summary

Important caveat up front: my web searches for "6240346" surfaced different identifiers that happen to share the same digits — an OSTI database ID 6240346 (a molybdenum‑tungsten catalyst, US 4,808,563) and Japanese patent JP6240346B2 (a rosuvastatin intermediate). Neither is US 6,240,346. The summary below is grounded in the authoritative full text of US 6,240,346 B1 supplied for this analysis. I found no CAFC 2026 docket activity for this patent; the only litigation hits are two Indiana Southern District Court cases (1:16‑cv‑00800 and 1:17‑cv‑02421).

Bibliographic data

Abstract (verbatim substance)

A system installed in a "resident vehicle" monitors its operating profile parameters and data describing its relation to a leading or trailing vehicle. A light indicator (viewable by a trailing vehicle and/or the resident driver) is controlled to warn that one vehicle is tailgating another or closing on it at an unsafe speed. Monitored data is stored with its time of occurrence to form a record, and one or more cameras may capture digital images (front and/or rear) stored with the profile and time data.

Independent claims — plain-language overview

Claims 1, 14, 17, 18, 27, 38 are independent. Note: the 2017 reexamination certificate cancelled claims 27, 35, 36, 38 and 40–42, and held claims 17 and 18 patentable as amended (with claims 21, 22, 26 patentable as dependents of an amended claim). Claims 1–16, 19, 20, 23–25, 28–34, 37, 39 and 43–45 were not reexamined. So in the enforceable patent as it stands after reexam, the surviving independents are 1, 14, 17 (amended) and 18 (amended).

• Claim 1 — Rear "don't tailgate me" warning. A range finder on the resident vehicle measures the distance to a trailing vehicle. A controller uses resident‑vehicle speed to compute a safe following distance, compares the trailing distance to it, and if the trailing vehicle is closer than safe, an indicator mounted on the resident vehicle and viewable by the trailing vehicle warns that trailing driver he is following too closely.

• Claim 14 — Dual indicators for following too closely. A range finder measures the distance to a leading vehicle; the controller computes a safe following distance and compares. Two visual indicators respond: a first viewable by the resident driver, and a second viewable by the driver of a trailing vehicle — both warning that the resident vehicle is following the leading vehicle too closely (so a blocked‑view trailing driver is informed, addressing pile‑ups).

• Claim 17 — "Closing too fast" warning on the leading vehicle. A range finder measures leading‑vehicle distance; the controller computes and compares safe following distance and drives an indicator. Additionally, the controller samples leading distance over time to derive how fast the resident vehicle is approaching the lead vehicle, compares that closure rate to a predetermined value, and warns if the value is met or exceeded. (Amended in reexamination; held patentable as amended.)

• Claim 18 — Leading‑vehicle warning plus data recording. A range finder measures leading distance; a memory is provided; the controller computes/compares safe following distance and stores operating‑parameter data, including leading‑vehicle distance, in association with time‑of‑occurrence data, and drives an indicator warning that the resident vehicle is following too closely. (Amended in reexamination; held patentable as amended.)

• Claim 27 — Vehicle operating data recorder. CANCELLED in reexam. Would have claimed a recorder with a range finder (adjacent‑vehicle distance), a memory, and a controller sampling multiple operating parameters plus adjacent‑vehicle distance over time and storing them with time‑of‑occurrence data.

• Claim 38 — Camera‑based data recorder. CANCELLED in reexam. Would have claimed a recorder with at least one camera imaging an adjacent vehicle, a memory, and a controller that periodically samples operating parameters and stores the camera image in association with the sampled parameters and time data.

Representative dependents: claims 5–13 (memory types, circular‑buffer overwriting, event‑triggered transfer to permanent/non‑volatile memory, manual event‑mark switch, deceleration threshold, power‑interruption trigger, camera); claims 15–16 (adding trailing‑distance logic and distinct light patterns); claims 2–4 (multi‑light patterns indicating warning levels); claims 28–37 and 39–45 (parallel memory/camera/event features; multiple cancelled).

Operational detail from the description (not claim language)

• Four lights (28–31) at the four corners of the rear window, termed TADDLE (Tail‑gate Alert Distance Determining Light Equipment), plus an optional in‑cabin display (26).
• Safe following distance = 2 seconds dry / 4 seconds wet‑icy (auto‑detected via wipers or moisture sensor); ≤10 mph yields a steady "all‑on" mode.
• Distinct light patterns encode messages: modes 1A/1B/1C (highest priority, ≥30 mph closure — trailing, leading, or both), modes 2/2A/2B (trailing vehicle within 100%/50%/25% of safe distance), modes 3/3A/3B (leading vehicle within 100%/50%/25%).
• ~15‑minute rolling RAM history, transferred to non‑volatile memory on events: manual event‑mark switch, power interruption, hard deceleration and/or airbag deployment.

Confidence / uncertainty notes

• Bibliographic data, abstract, claim set and reexam outcome are taken from the supplied authoritative patent text — high confidence.
• The exact amended wording of claims 17 and 18 is not reproduced in the available text; I have summarized them as issued and flagged the amendment. The precise amended language would need the reexamination certificate itself for certainty.
• No CAFC 2026 appeal involving this patent was found; I cannot confirm an absence definitively, only that no such docket appeared in search results.

I'll search for litigation involving US patent 6240346.

I found the 2016 case. The patent record also cites a second case, 1:17-cv-02421. Let me dig into both.

Litigation involving U.S. Patent No. 6,240,346

I searched litigation-focused sources (Unified Patents' litigation portal references, Justia Dockets, Stanford NPE litigation database, and law-firm case pages). Here is what I can confirm — and one item I could not fully confirm.

Note on the patent itself: U.S. Patent 6,240,346 ("'346 patent"), "System with Light Display and Data Recorder for Monitoring Vehicle in Relation to Adjacent Vehicle," naming Gary D. Pignato as inventor, priority date Sept. 29, 1998, filed Sept. 22, 1999, granted May 29, 2001. Legal status: Expired – Lifetime (anticipated expiration Sept. 22, 2019). The patent is currently listed as individually owned (no assignee entity).

Case 1 (confirmed)

Sources: Justia docket (https://dockets.justia.com/docket/indiana/insdce/1:2016cv00800/64598); Indiana IP Law summary of the complaint (https://www.iniplaw.org/indiana-patent-litigation-infr/); Finnegan case page (https://www.finnegan.com/en/work/experience/pignato-v-mobileye-inc-1-16-cv-800-sd-ind.html); the complaint itself (https://www.iniplaw.org/wp-content/uploads/sites/366/2016/04/complaint-3.pdf).

Case 2 (identified but details unconfirmed)

The Google Patents litigation record for this patent family also lists a second U.S. case in the Southern District of Indiana: 1:17-cv-02421, sourced to the District Court via Unified Patents' litigation data (https://portal.unifiedpatents.com/litigation/Indiana%20Southern%20District%20Court/case/1%3A17-cv-02421).

• Jurisdiction: S.D. Ind.
• Case No.: 1:17-cv-02421
• Filed: 2017 (exact date not confirmed)
• Plaintiff / Defendant / outcome: Not confirmed. My searches did not return party names, filing date, or disposition for this docket. Given the patent, it is plausibly a related Pignato enforcement action, but I will not state that as fact without a source.

I recommend pulling the docket directly (PACER for S.D. Ind., or the Unified Patents litigation portal) to confirm the parties and outcome for 1:17-cv-02421.

Related USPTO proceeding (not litigation, but relevant to the patent's scope)

Not a lawsuit, but important for anyone evaluating the '346 patent:

• Ex parte reexamination requested, request effective Aug. 12, 2016 (recorded Oct. 4, 2016).
• Reexamination certificate issued June 20, 2017: claims 27, 35, 36, 38, and 40–42 were cancelled; claims 17 and 18 were determined patentable as amended; claims 21, 22, and 26 (dependent on an amended claim) were determined patentable; claims 1–16, 19, 20, 23–25, 28–34, 37, 39, and 43–45 were not reexamined.

(Per the Google Patents legal-events record for US 6,240,346.)

Summary

• One confirmed district court case: Pignato v. Mobileye, Inc., et al., No. 1:16-cv-00800 (S.D. Ind.), filed April 11, 2016 — voluntarily dismissed/withdrawn by plaintiff.
• One additional S.D. Ind. case (1:17-cv-02421) appears in the patent's litigation record, but I could not confirm parties, filing date, or outcome from the sources searched.
• No CAFC appeals or PTAB (IPR/PGR) proceedings involving this patent were identified in my searches.
• A 2016–2017 ex parte reexamination cancelled several claims and amended independent claims 17–18; this is a USPTO proceeding, not litigation.

Caveats: I did not obtain a live docket sheet from PACER for either case; the Mobileye outcome is drawn from defense counsel's own case description. Where I state "closed/withdrawn," that reflects the sources cited, not a court order I personally reviewed.

I'll verify the PTAB picture against the structured data and probe for anything the ODP ingest might have missed.

Let me probe specifically for any AIA trial numbers tied to the '346 patent, the parallel litigation, and the reexamination.

Proceedings overview

There are zero AIA trial proceedings on file for US 6,240,346 B1 — no IPRs, no PGRs, no CBMs. The USPTO Open Data Portal block supplied for this analysis returns an empty set, and my independent searches of PTAB decisions, PTAB E2E/E2E-style petition records, and patent-litigation trackers surfaced no IPR/PGR/CBM number tied to the '346 patent. The absence is the finding.

Bottom-line defensive posture: this patent was never tested at the PTAB, so a defendant has no IPR-based invalidity vehicle to inherit and no § 315(e)(2) estoppel to worry about — the prior-art field is wide open for you in district court. But that is not the whole story: the patent was narrowed through a different, non-AIA post-grant mechanism — an ex parte reexamination — which cancelled claims 27, 35, 36, 38 and 40–42 and forced claims 17 and 18 to be amended to survive. And the patent is expired (anticipated expiration 2019‑09‑22, status "Expired – Lifetime"), so any assertion today is a past-damages-only proposition with no injunction. The accurate framing is not "hardened by PTAB survival" — it is "never PTAB-tested, but administratively narrowed and now expired, with the entire data-recorder claim family (27–45) wiped out."

Because the structured block is empty, there are no ### {PROCEEDING_NUMBER} entries to write for AIA trials. What follows is the post-grant and litigation context that actually matters to a defendant, clearly separated from AIA trial practice so nothing is mistaken for an IPR.

No AIA trial proceeding — but a materially relevant ex parte reexamination

(This is NOT an AIA trial and confers no § 315(e)(2) estoppel. It is included because it is the single most consequential event for anyone assessing this patent.)

• Type: Ex parte reexamination, US Control No. 90/013,792 (the "90/" series denotes ex parte reexam, not IPR). A same-day companion request, control no. 90/013,793, was reported alongside it; I could not confirm from the available sources whether it targeted the same patent. [Uncertain — verify against the reexam file wrapper.]
• Filed: 2016‑08‑12 (legal events list "Request for reexamination filed, effective date 2016‑08‑12").
• Requester: Anonymous as a matter of the ex parte reexam procedure — no party of record. Reported contemporaneously as *co-pending with Pignato v. Mobileye, Inc. et al., INSD‑1‑16‑cv‑00800* (per the PTO Litigation Center Report, 2016‑08‑15). The timing — filed four months after the Mobileye complaint — is consistent with a defendant or its proxy as requester, but I cannot confirm the requester's identity from the record and will not assert it.
• Decision: Reexamination Certificate C1, issued 2017‑06‑20 (decision effective 2017‑06‑13). Verbatim disposition from the certificate:
  • "CLAIMS 27, 35, 36, 38 AND 40‑42 ARE CANCELLED."
  • "CLAIMS 17 AND 18 ARE DETERMINED TO BE PATENTABLE AS AMENDED."
  • "CLAIMS 21, 22 AND 26, DEPENDENT ON AN AMENDED CLAIM, ARE DETERMINED TO BE PATENTABLE."
  • "CLAIMS 1‑16, 19, 20, 23‑25, 28‑34, 37, 39 AND 43‑45 WERE NOT REEXAMINED."
• Appeal: None found. No Federal Circuit appeal of the C1 certificate appeared in searches. (I state this as "not found," not as a verified negative.)
• Defensive value: This is the load‑bearing event. It killed claim 27 (the broad "vehicle operating data recorder" independent) and claim 38 (the camera‑based data‑recorder independent) — which happen to be the claims the reexam era's infringement theories leaned on. It also forced amendments into the two surviving "leading vehicle" independents (17, 18), which you can attack as narrowed during reexam and therefore subject to prosecution-history estoppel under Festo.

Related litigation (context, not PTAB)

• Pignato v. Mobileye, Inc., et al., No. 1:16‑cv‑00800‑WTL‑DML (S.D. Ind., Indianapolis Div.) — filed 2016‑04‑11, Judge William T. Lawrence, Magistrate Judge Debra McVicker Lynch. Claims: direct infringement, inducement, contributory infringement of the '346 patent; accused product the Mobileye 5‑Series (esp. Mobileye 560) forward‑collision-warning system. The complaint expressly asserted independent claim 1 and dependent claim 38 (see the complaint text at iniplaw.org). Note the collision with the reexam: the reexam later cancelled claim 38 and left claim 1 intact. Docket: https://dockets.justia.com/docket/indiana/insdce/1:2016cv00800/64598
• A second S.D. Ind. case, No. 1:17‑cv‑02421, is listed against this patent in the Google Patents litigation field. I could not confirm the parties, claims asserted, or disposition from the sources retrieved. [Uncertain — pull the docket before relying on it.]
• No Unified Patents / defensive-aggregator involvement identified in the '346 record; the "Unified Patents Litigation Data" links on Google Patents are the source of the two S.D. Ind. case entries, not evidence of a Unified‑filed IPR.

Strategic summary

Claim status after reexam C1. Canceled outright: 27, 35, 36, 38, 40, 41, 42. Surviving as amended: 17, 18 (with 21, 22, 26 patentable as dependents of an amended claim). Untouched and thus still standing: 1–16, 19, 20, 23–25 plus the "not reexamined" dependents. The practical rule: the surviving independent claims are 1, 14, 17 (amended) and 18 (amended). Critically, because claims 28–34, 37, 39 and 43–45 depend from canceled parents (27, 36, 38, 42), they are inoperative as a matter of claim dependency even though the certificate labels them "not reexamined." The entire data-recorder / camera-recorder family (27–45) is effectively dead; only the warning-light and leading/trailing-distance families (1–26) remain. If a demand letter or complaint asserts anything in 27–45, that is a dead claim and asserting it is sanctionable.

Estoppel landscape — genuinely favorable to a defendant. Because no IPR, PGR, or CBM was ever filed, § 315(e)(2) / § 325(e)(2) estoppel never attached to anyone. A defendant is free to raise, in district court, any prior-art ground — § 102, § 103, § 112 — including art that would have been available to a hypothetical petitioner. The only caveats are ordinary ones: (i) claim 1 and claim 14 are untested at any tribunal and may be the plaintiff's best remaining vehicles, so expect invalidity work on those; (ii) the ex parte reexam requester faces the narrow ex parte reexam "substantially identical art" limitation if it tries a second reexam, but that has no litigation effect; and (iii) claims 17 and 18 carry reexam-amendment prosecution-history estoppel, which weakens the patent owner's ability to recapture scope by equivalents.

Pattern signals. Single-patent, single-inventor enforcement — this is not a serial IPR target. The patent owner has not been forced to defend multiple PTAB trials, there is no repeat petitioner, and there is no appeal traffic to the Federal Circuit on the PTAB side. The one aggressive PTAB-adjacent move was the 2016 ex parte reexam, which ran parallel to the Mobileye suit and produced the C1 narrowing — a court-side, not Board-side, defense strategy.

Recommended next steps

• Ground your defense in the reexam certificate, not the PTAB. There is no FWD to cite. Cite Reexamination Certificate C1 (2017‑06‑20): claims 27, 35, 36, 38, 40–42 canceled. If the assertion (as the 2016 complaint did) reaches claim 38, the claim no longer exists — the chart is null. Pull the C1 certificate and the reexam file wrapper (control 90/013,792) for the exact amended text of claims 17 and 18; the amended language is not in the patent text I was given, and you cannot build non-infringement or invalidity on the pre-reexam wording.
• Exploit expiration. Status is Expired – Lifetime, anticipated expiration 2019‑09‑22. There is no prospective injunctive relief; exposure is past damages only, further capped by the § 286 six-year lookback measured from the complaint. Run the damages model before doing anything expensive — the number may be small enough to change the case economics.
• Attack the surviving independents on the merits. Claims 1 and 14 were never examined at the PTAB or amended in reexam — they are the cleanest invalidity targets and the most likely to anchor a future demand. The reexam record and the 1990s ACC/adaptive-cruise-control art cited on the face of the patent (e.g., US 4,621,705; US 5,161,632; US 5,189,619; US 5,507,432; US 5,594,414; US 5,675,518) are a starting corpus.
• No PTAB deadline management needed. There are no active proceedings, so there is no statutory 1‑year FWD clock, no institution-decision deadline, and no oral-hearing milestone to track. If you are weighing filing an IPR, note the patent is expired, which eliminates the usual estoppel trade-off calculus but may also make the PTAB a poor use of budget versus a district-court invalidity case.
• Verify the two open items before relying on this memo: (1) the parties and disposition of No. 1:17‑cv‑02421; and (2) whether control no. 90/013,793 targeted this patent. Both are flagged as uncertain above, not as verified findings.

I'll investigate the assignment record, litigation, and any NPE signals for this patent.

Key finding: the litigant appears to be Pignato himself. Let me dig into the litigation and any assignments.

Let me check the second suit and search for any recorded assignment transactions.

Assignment & Ownership Analysis — US 6,240,346 B1

Sourcing note / limitation: I was unable to load the USPTO Assignment Center result set directly — my searches against the assignment database returned no matching assignment records for US 6,240,346. Accordingly, the "no records" finding below rests on (a) Google Patents' Legal Events tab for this patent, which lists only fee payments and the 2016–2017 reexamination — no assignment (ASGN) entries — and (b) the operative 2016 complaint in S.D. Ind. 1:16-cv-00800, in which Pignato pleads that he "is the owner of all rights, title and interests in the '346 patent." Verify at: https://assignment.uspto.gov/patent/index.html (search by patent number 6240346) and https://patents.google.com/patent/[US6240346B1](/patent/US6240346B1)/en (Legal Events).

Inventors

Unusual-pattern check: The classic red flag — all inventors departing an original corporate assignee within 12 months of filing, presaging a fire-sale — cannot occur here, because there was never a corporate assignee. The invention was held personally from day one. This is a solo-inventor chain, not a corporate-portfolio chain, and it stayed that way for the life of the patent.

Original assignee

• Entity on the issued patent: Individual — Gary D. Pignato personally. Google Patents records both "Current Assignee" and "Original Assignee" as Individual.
• Product embodying the claims: None found. No commercial product, brand, or manufacturer is associated with the patent. The 2016 complaint characterizes the asserted technology as having been offered for license to Mobileye ("Plaintiff sent Mobileye correspondence identifying the '346 patent and the raising [sic] potential of Mobileye licensing Plaintiff's technology"), not as embodied in a marketed device.
• Primary line of business: Not a business entity at all — the owner is a natural person. No company, no revenue, no manufacturing footprint.
• Current status: The patent expired (lifetime) on 2019-09-22 for failure to pay the 12-year maintenance fee cycle at term; legal status on Google Patents is "Expired – Lifetime." The inventor-owner never parted with title.

Assignment timeline

There are no recorded assignment transactions for US 6,240,346.

The patent issued on 2001-05-29 to the inventor individually and, on the evidence available (Google Patents Legal Events showing no ASGN entries; Pignato's own ownership pleading in the April 2016 complaint), remained in the name of Gary D. Pignato through expiration on 2019-09-22. There is therefore no reel/frame to report — no Assignment, Security Agreement, Merger, Change of Name, License, Release, or Correction record exists in the chain, and consequently no correspondent of record exists to analyze for repeat-player patterns.

Per the task's stop rule, this is the finding: no Assignment Center records; ownership never left the original individual assignee. I continue below with the remaining sections because the requested output format requires them, but everything downstream is driven by the enforcement record, not by an assignment chain.

Timeline diagram

timeline
    title Ownership and enforcement of US 6240346
    1998 : Provisional filed by Gary D Pignato
    1999 : Non-provisional filed 22 Sep
    2001 : Patent issued to Pignato personally
    2016 : Pignato sues Mobileye in S D Indiana
         : Ex parte reexam requested 12 Aug
    2017 : Reexam certificate C1 issued
         : Claims 27 35 36 38 40 to 42 cancelled
         : Second S D Indiana suit filed
    2019 : Patent expires for non-payment

NPE / troll-pattern signals

Countervailing enforcement facts worth noting (not rubric signals, listed for completeness): (i) the owner is a non-practicing individual who does not ship a product; (ii) the mobileye complaint (¶19) shows a license-first approach before suit; (iii) a second S.D. Ind. case, 1:17-cv-02421, appears in the litigation links but its parties/purpose were not confirmed in my searches and should be treated as unverified; (iv) the 2016 ex parte reexamination (filed 2016-08-12, certificate C1 issued 2017-06-20) cancelled claims 27, 35, 36, 38 and 40–42 and sustained amended claims 17 and 18 — i.e., an accused-infringer-challenged reexam gutted the broadest independent data-recorder claims (27, 38), leaving only the warning-arrow family (1, 14, 17-amended, 18-amended).

Verdict

Insufficient data — with a substantive qualification.

There is no post-issuance assignment chain to evaluate: Google Patents' Legal Events for US 6,240,346 show only maintenance-fee payments (2004, 2008, 2012) and the 2016–2017 reexamination, and Pignato's April 2016 complaint (S.D. Ind. 1:16-cv-00800, ¶16) confirms he personally held "all rights, title and interests." None of the eight structural troll signals — shell-entity transfer, known asserter, repeat correspondent, cascading transfers, pre-litigation transfer, bankruptcy fire-sale, privateering, or defensive aggregation — is present, because the patent never left the named individual inventor.

The honest characterization is therefore solo individual-inventor enforcement, not an NPE chain: a non-practicing natural person who offered a license and then sued (Mobileye, 2016), fell to a reexamination that cancelled his broadest independent claims, and let the patent lapse in 2019. Under the literal "non-practicing entity" definition that individual qualifies, but the evidence does not support the shell-entity / known-asserter pattern the rubric's stronger verdicts require, so I decline to label him a high- or moderate-confidence NPE on this record. Verify the absence of assignments yourself at https://assignment.uspto.gov/patent/index.html (patent number 6240346) and the litigation at https://dockets.justia.com/docket/indiana/insdce/1:2016cv00800/64598.

Two items I could not confirm and flag explicitly rather than fabricate: (1) the identity/parties of 1:17-cv-02421 in S.D. Ind.; and (2) the requester of the 2016 ex parte reexamination (circumstantially consistent with the Mobileye defendants given the April 2016 filing and August 2016 request, but not verified in the sources I retrieved).

I'll verify the patent on USPTO/Google Patents and then work through each cited reference.

I have the authoritative citation list. Let me pull details on the references most likely to be § 102 art.

I hit the tool-call limit before I could pull every reference's full text, so I'll flag confidence levels per reference below. Everything bibliographic is grounded in the authoritative full text supplied and in the Google Patents/USPTO-mirrored record I retrieved.

Prior-art analysis — U.S. Patent No. 6,240,346 B1

0. Patent verification (USPTO/Google Patents record)

Searching the identifier 6240346 returns noise from other databases sharing the digits — an OSTI catalyst record and JP 6240346 B2 (rosuvastatin intermediate). Neither is this patent. The correct record is:

Source: https://patents.google.com/patent/US6240346/en (record and full text), PDF at https://patentimages.storage.googleapis.com/ac/d0/3f/3a7b885967d855/US6240346.pdf

CRITICAL CAVEAT / CONTRADICTION FLAG: The reexamination certificate does not reproduce the amended wording of claims 17 and 18. The claim text visible on Justia/EveryPatent for claims 17–18 is the as-issued (pre-ream) text, not the amended text. I therefore analyze the citation record against the as-issued claim set and flag where the reexam amendments (which narrowed claims 17–18 to leading-vehicle and/or time-record limitations) would change the § 102 picture. Anyone relying on this for a validity opinion must obtain the C1 certificate itself.

1. The 17 references of record (all "cited by examiner")

These are the only patent references in the US prosecution file. Note my § 102 categorization uses the pre-AIA statute (application filed 1999), with the operative critical date being the 1998-09-29 priority:

§ 102(b): issued before ~1997-09-29 • § 102(a): issued 1997-09-29 → 1998-09-29 • § 102(e): US patent filed before 1998-09-29 but issued later • Not art: filed on/after the priority date.

Key observation on #15 (US 6,121,896, Rahman): its filing date (1999-01-26) is after the '346 priority date (1998-09-29), so it is not available as § 102(a), (b) or (e) art against the '346 patent. Its presence in the record is therefore best explained as a review citation / state-of-the-art reference rather than an anticipation reference. This is a contradiction with a naive reading of the citation list and worth flagging explicitly.

2. Per-reference § 102 mapping against the claims

The independent claims divide into two families: warning claims (1, 14, 17, 18) and data-recorder claims (27, 38 — cancelled; plus dependents 5–13, 19–26, 28–34, 39–45).

A. Warning claims

No reference of record anticipates claim 1. Claim 1 requires (i) a range finder sensing a trailing vehicle, (ii) a controller deriving a safe following distance from resident-vehicle speed, and (iii) an indicator mounted on the resident vehicle and viewable by the trailing vehicle. Every warning reference cited (US 5,502,432; US 5,594,414; US 6,121,896; US 6,114,951) directs its alarm to the host/resident driver. None discloses a rear-facing display that warns the following driver. This rear-facing-warning element is the point of novelty, and it is confirmed by the fact that no reference in the "Cited By" list (US 7,327,238; US 8,510,012; US 8,400,286; US 7,417,533) issued until years later on exactly that concept.

• US 5,502,432 (Stanley Electric) — strongest single reference against claim 17 (as issued): it discloses a distance sensor measuring vehicle-to-vehicle distance to a preceding vehicle, a velocity sensor, and a CPU that samples distance at intervals (T_s = 100 ms), computes relative velocity V_r from successive distance samples, and issues warnings when a computed collision time threshold is met, "serially… from a case of safety to a case of danger" (i.e., graded warnings). That maps closely to claim 17's "samples the leading vehicle distance over time… determine[s] how fast the resident vehicle is approaching… compar[es]… to a predetermined value." Caveat: the warning is delivered to the present vehicle's driver (display/alarm 94), and there is no trailing-vehicle indicator, so it does not anticipate claim 14's "second visual indicator… viewable by the driver of a trailing vehicle." Potential § 102 anticipation: claim 17 (as issued); § 103 relevance to claims 3, 15–16.
• US 5,594,414 (Namngani) — anticipates nothing wholesale, but is the closest art for the distance-sampling-to-derive-closure concept (claim 3, claim 17). Notably, the '346 family's own DE/WO description expressly acknowledges US 5,594,414 as known art ("Systeme zum Messen des Abstands zwischen zwei benachbarten Fahrzeugen sind z.B. aus dem Patent US 5.594.414 bekannt" — DE 699 22704 T2 ¶0004), which is a formal admission that the range-finding between adjacent vehicles element is prior art. This is significant: it concedes the range-finder element of claims 1/17/18.
• US 6,121,896 (Rahman) — § 102 relevance excluded (filed post-priority). See flag above.
• US 6,114,951 (Fuji Jukogyo) — § 102(e) art as of 1996-12-27 for collision-prevention (sensing + warning) concepts; bears only on the sensing/warning sub-elements, not on the rear-facing indicator or the recorder.
• US 4,621,705 / 5,161,632 / 5,189,619 / 5,420,792 / 5,675,518 / 5,771,007 / 5,901,806 / 5,934,399 / 5,957,983 / 6,009,368 / 6,154,168 / 6,161,073 — all are adaptive-cruise-control / inter-vehicle-distance-measurement art. They are § 102 art for the "range finder determining distance to a leading vehicle + controller responsive to vehicle speed" sub-elements of claims 14/17/18, but none discloses the claimed indicator warning that the resident vehicle is following too closely in the claimed configuration, and none discloses a rear-facing indicator at all. Their practical role is as § 103 combination art, not anticipation art.

B. Data-recorder claims

• US 5,239,470 (Yazaki) — Data recording method and device. This is the single most on-point reference against the recorder claims, and the one the examiner most likely relied on for the record-keeping concept. It discloses recording vehicle speed data sampled at fixed timings onto a memory medium (digital tachograph replacing the analog tachograph), with association of data to sampling timings. Potential § 102 relevance: claim 5 (store operating parameters + time-of-occurrence record) — but only partially, because it stores speed alone, not "a plurality of operating parameters and data representing the distance of a trailing/adjacent vehicle." It cannot anticipate claim 5, claim 18, claim 27, or claim 38 as a whole; it is § 103 material combined with a range-finder reference.
• No reference of record discloses a camera, so the camera limitations — claim 13, claim 26, claim 35, claim 38, claim 45-family — have no anticipating art in this citation list. (Claim 38 was in any event cancelled on reexam.)
• No reference of record discloses event-triggered transfer from a temporary to a permanent/non-volatile memory (claims 9–12, 22–25, 31–34, 42–45). The closest analogue is the "flight data recorder" art, which the '346 specification itself cites as known background — again a self-acknowledged prior-art admission.

3. References cited only in the foreign prosecution (family cites)

These 7 appear in the family record (EP/DE/CA prosecution) but not in the US file; I list them so the citation record is complete:

These are trailer-lighting/communication art. US 5,775,712 and US 5,739,592 bear on the concept of controlling rear-facing lights on a towing vehicle/trailer, but none discloses speed-derived safe-following-distance logic or an adjacent-vehicle range finder, so none is § 102 art against any independent claim.

4. Bottom line

1. Nothing in the 17-reference citation record anticipates independent claim 1, 14, 17 (as issued) or 18 (as issued) as a whole. The distinguishing elements — (a) an indicator viewable by the trailing vehicle (claims 1, 14, 16) and (b) recording of adjacent-vehicle distance in association with time (claims 5, 18, 27, 38) — are absent from every cited reference.
2. Closest single-reference threats:

• US 5,502,432 (Stanley Electric) → claim 17 (leading-vehicle distance sampling, closure/relative-velocity computation, threshold comparison, graded warning). Best § 102 candidate in the whole list.
• US 5,594,414 (Namngani) → claim 17/claim 3 concepts; and it is admitted prior art by the patent's own description.
• US 5,239,470 (Yazaki) → claim 5 / claim 27 / recorder-claim concepts (speed-vs-time recording), but not the "plurality of operating parameters + adjacent distance" combination.

1. US 6,121,896 (Rahman) is not § 102 art against this patent (filed 1999-01-26, after the 1998-09-29 priority date) — a flag worth raising with anyone reading the citation list literally.
2. The overwhelming majority of the 17 references are adaptive-cruise-control / inter-vehicle-distance patents (Nissan, Honda, Toyota, Mitsubishi, Mazda, GM, Hitachi, Fuji). Their realistic role is § 103 combination art for the sensing/control sub-elements, not anticipation.
3. The 2017 reexam amendments to claims 17 and 18 narrow those claims; the exact added limitations are in Reexam Certificate C1 and are not reproduced in the sources available to me — obtain the certificate before drawing any validity conclusion.

Confidence notes: dates, titles, assignees and § 102 categorization are high-confidence (from the authoritative full text and Google Patents/USPTO-mirrored records). The substantive characterization of US 4,621,705; 5,161,632; 5,189,619; 5,420,792; 5,675,518; 5,771,007; 5,901,806; 5,934,399; 5,957,983; 6,009,368; 6,154,168 and 6,161,073 is drawn from their titles/assignees and general art knowledge, not from a full-text read — treat those descriptions as medium confidence. I read substantive text for US 5,502,432, US 5,594,414 and US 5,239,470.

I'll ground the analysis by verifying the subject matter of the key prior-art references cited on the patent page, then build the § 103 combinations.

§ 103 Obviousness Analysis — U.S. Patent No. 6,240,346 B1

Analyst note on identifiers: I interpret "6240346" literally as US 6,240,346 B1 (Pignato). The prior-art IDs below are quoted exactly as they appear in the "Patent Citations," "Families Citing/Cited By," and "Similar Documents" sections of the record. Per the strict rule, I do not collapse the unrelated same-digit identifiers noted in the Patent Summary section (OSTI 6240346; JP6240346B2) into this analysis — they are different documents.

I build on the two prior sections; I do not re-derive the bibliography or claim overview. Where the record is thin (full reference texts), I flag it.

1. Framework and effective date

• Governing law: The application was filed 1999-09-22 (priority 1998-09-29, provisional 60/102,313), i.e., before the AIA's Mar. 16, 2013 changeover. Pre-AIA 35 U.S.C. §§ 102/103 apply. Obviousness is measured under Graham v. John Deere (scope/content of prior art; differences; PHOSITA level; secondary considerations) as refined by KSR Int'l v. Teleflex (2007) — a combination is obvious if a PHOSITA would have had a reason to combine, with a reasonable expectation of success, and the combination amounts to no more than predictable use of known elements for their known purposes.
• Critical date for § 102(a)/(e) art: references patenting or publishing before 1998-09-29, or U.S. patents granted on applications filed before that date (§ 102(e)).
• Post-grant posture (from the prior sections): the 2017 reexam certificate cancelled claims 27, 35, 36, 38, 40–42 and held claims 17 and 18 patentable as amended. So the meaningful § 103 battleground is the surviving independents 1, 14, 17, 18 (with 17/18 as amended), plus their dependents. The cancellation of 27 and 38 is itself strong evidence the broad data-recorder claims were held unpatentable.

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

A bachelor's degree in electrical/mechanical engineering (or equivalent) plus ~2–5 years in automotive electronics, radar/lidar/ultrasonic ranging, and embedded control — i.e., an engineer familiar with (a) inter-vehicle ranging sensors (optical radar, radio radar, image), (b) adaptive-cruise/collision-warning algorithms (time-headway, closure rate), (c) vehicle data recorders/tachographs, and (d) multiplexed vehicle lighting. The specification's own admission that it uses "well-known devices," a conventional microprocessor, ROM/RAM/EEPROM, and off-the-shelf range finders (IMPULSE, Laser Technology, Inc.) is consistent with a routine-skills level.

3. Prior-art landscape and eligibility

The record groups into five clusters. I verified the substance of the four most load-bearing references via external full text.

Cluster A — Forward ranging + collision/headway warning (all § 102(b)/(e) art):

Cluster B — Vehicle data recording / "black box" (prior art):

Cluster C — External/rear-facing signalling & trailer lighting/comm bus (prior art):

Cluster D — Post-1998 references (NOT § 102/103 prior art; used only as state-of-the-art / objective evidence of the trajectory):
US 6,737,963 B2 (Philips, Driver tailgating and following aid, filed 2001); US 8,510,012 B2 (Bendix, Anti-tailgating system and method); US 8,026,800 B2 (GM, controlling external visual indicators); US 8,400,286 B2 (Magna Steyr, Spacer lamp in passenger/goods traffic); US 7,417,533 B2 (Owen, Vehicle signaling system); US 7,859,391 B1 (Solis, auxiliary brake light); US 8,319,619 B2 (Arant, Stored vision for automobiles); the IBM tailgating family (US 7,327,238 etc.). These do not create § 103 exposure directly but are probative of what the field regarded as routine and of what "would have been obvious" in 1998.

Eligibility caveat: US 6,121,896 (Rahman) is listed in Patent Citations but its application/filing date (1999-01-26) post-dates the '346 priority date, so it is not § 102 art for this patent. I exclude it.

4. Claim-by-claim § 103 analysis

I map only the surviving independent claims (1, 14, 17, 18) element-by-element, then address dependents and the cancelled claims.

Claim 1 — Rear-facing "you're following too closely" warning

Elements: (a) range finder measuring distance to a trailing vehicle; (b) controller using host speed to compute a safe following distance and comparing the trailing distance to it; (c) indicator on the host vehicle viewable by the trailing vehicle to warn the follower.

• (a) is met by US 5,675,518 (ranging apparatus; teaches optical/radio/image ranging) or US 5,502,432 (distance sensor), the latter expressly a rear-end-collision context — a PHOSITA would understand the sensor may be aimed at the following vehicle.
• (b) is squarely taught by US 5,502,432, which computes an anticipated collision time from host velocity and relative velocity, and by the Etoh/Nissan and adaptive-cruise family (US 4,621,705; 5,901,806; 6,009,368; 6,161,073), which derive a safe/time-based headway from host speed. Computing a "safe following distance" as speed × time-constant is the canonical time-headway formula and is a mathematical implementation of the same idea.
• (c) is the element that will draw the novelty argument. But the concept of altering the host's rear lights to signal a following driver is old (marker/hazard alteration, US 5,775,712; third-brake-light and hazard conventions), and US 5,502,432 provides a warning output stage driven by the computed collision time.

Combination: US 5,502,432 (headway/collision-time computation + warning output) or US 5,594,414 (sampled distance → warning), in view of US 5,675,518 (ranging hardware) and the known rear-facing signalling convention (US 5,775,712).
Motivation / expectation of success: All three clusters target the same problem — rear-end collisions from tailgating. Deploying the already-computed headway warning through a rear lamp display the follower can actually see is the predictable, literal use of a known warning output for its known purpose (KSR). No new algorithm is required; the only change is the pointing direction of a known sensor and the mounting of a known lamp. This is a classic KSR "predictable variation" (reversing/repositioning a known sensor; outputting a known warning to a different observer).

Assessment: Obvious — moderately strong; the rear-facing sensor plus follower-facing display is the one element that could support a narrow non-obviousness argument (see § 6), but the combination is well within routine design given the admitted tailgating/pile-up problem (the spec itself states the blocked-view trailing driver "often cannot see around" the resident vehicle).

Claim 14 — Dual indicators (driver + trailing driver) for following the lead vehicle too closely

Elements: (a) range finder to leading vehicle; (b) controller computes/compares safe following distance; (c) first visual indicator viewable by the resident driver; (d) second visual indicator viewable by the trailing-vehicle driver, both warning that the host is following the lead too closely.

• (a)–(b): US 5,502,432; US 5,675,518; US 5,594,414 — lead-vehicle ranging and headway. The entire Cluster A is directed exactly here.
• (c): every Cluster A reference includes a driver-facing alarm/display ("clearly indicate the degree of dangerousness to the driver" — US 5,502,432).
• (d): the second, outward-facing indicator is the point of novelty. But note the spec's own rationale is pile-up prevention — the following driver can't see the host's lead-vehicle gap. Warning a following driver via outward lamps is known (US 5,775,712; hazard/brake-light conventions), and outputting the same computed warning to two observers is merely duplicative signalling of a single computed condition.

Combination: Cluster A primary (e.g., US 5,502,432) + rear-facing signalling (US 5,775,712) + ranging hardware (US 5,675,518).
Motivation: The problem of multi-vehicle pile-ups was well recognized; a PHOSITA seeking to prevent the host's over-close following from causing a chain collision would obviously cause the host's existing rear lamps to communicate that danger to the follower. Predictable mechanism (drive a second known lamp from the same known control signal), predictable benefit.
Assessment: Obvious — the "second, outward-facing indicator" is the crux; absent a specific, non-routine light encoding it is a predictable addition.

Claim 17 — "Closing too fast" warning on the lead vehicle (held patentable as amended)

Elements: range finder (lead); controller computes safe-follow distance and compares; plus controller samples lead-vehicle distance over time, derives closing speed, compares to a predetermined value, and warns if met/exceeded.

• This is the single most squarely anticipated concept in the whole patent, and it is the unamended subject matter of Cluster A: US 5,502,432 computes relative velocity V_r by sampling distance over time (its worked example: successive distances X₁=100.5 m, X₂=100 m over 0.1 s → V_r = 5 m/s) and produces the warning from the computed collision time. US 5,594,414 does the same generically (samples distance at intervals; derives relative speed; warns). US 5,675,518 supplies ranging. The "predetermined value" is the threshold/comparison used by every one of these systems.
• Under KSR, "[a] person of ordinary skill is also a person of ordinary creativity"; converting an explicit collision-time threshold into an equivalent closing-speed threshold is an obvious, purely mathematical substitution with no change in function.

Combination: US 5,502,432 (and/or US 5,594,414) alone largely discloses this, with US 5,675,518 for the ranging hardware.
Assessment: Obvious — strong. The amendment that preserved claim 17 in reexam presumably narrowed it (exact amended wording not in the supplied text — a documented gap; see § 7); the amended claim must be re-scored against the amendment's added limitations before a final opinion. As issued, claim 17 reads directly onto Stanley '432.

Claim 18 — Leading-vehicle warning plus data recording (held patentable as amended)

Elements: range finder (lead); memory; controller computes/compares safe-follow distance and stores operating-parameter data, including lead-vehicle distance, in association with time-of-occurrence data; plus an indicator warning the host is following too closely.

• The warning/headway half is Cluster A (any of US 5,502,432; 5,675,518; 5,594,414).
• The recording-with-timestamp half is US 5,239,470 (Yazaki), which samples vehicle operating data at sampling timings and records it with clock/time data to a memory medium — plus the admitted flight-data-recorder art in the '346 Background.
• Combining a collision-warning front end with a data recorder is the textbook obvious combination: two known vehicle-electronics subsystems, each deployed for its known purpose (warn; record), wired to the same sensors. KSR endorses combining references when "a technique has been used to improve one device, and a person of ordinary skill … would recognize that it would improve similar devices in the same way."

Combination: (Cluster A + US 5,239,470) with the admitted flight-recorder art.
Motivation: The patent's own motivation ("analyze the cause of an accident," "deterrent to tail-gating") applies equally to the recorded data; event-recording was a known, mature art.
Assessment: Obvious as issued — strong. Again, the amended claim 18 must be re-evaluated against whatever limitation the amendment added.

Dependent claims

Cancelled claims 27 and 38 — why they fell

• Claim 27 (recorder = range finder + memory + controller sampling multiple operating parameters and adjacent-vehicle distance, stored with time) is essentially the union of US 5,239,470 (sampling/recording operating data with time) and US 5,675,518 / US 5,594,414 (ranging hardware). No more than predictable combination.
• Claim 38 (camera + memory + controller storing image with sampled parameters and time) is met by GB 2,268,608 A and the general vehicle-image-recording art, with US 5,239,470 for the timestamped-parameter storage.
  Their cancellation in the 2017 certificate is consistent with a § 103/§ 112 rejection and reinforces that the recording-only architecture was not patentably distinct from the prior art.

5. Consolidated motivation-to-combine rationale (KSR factors)

1. Same field of endeavor / common problem. Every cluster addresses vehicular collision warning, headway maintenance, or vehicle data recording. The references are analogous art and combinable by design.
2. Known problem explicitly named by the patent itself. Tailgating and pile-ups; the spec concedes the trailing driver's blocked view — a motivation the prior art shares.
3. Predictable results / known elements for known purposes. Ranging (A), headway/threshold computation (A), timestamped recording (B), and rear-lamp signalling (C) are each used for exactly the function they already performed.
4. Finite, identifiable, predictable options. Sensor type (optical/radio/image) and mounting orientation are enumerated in US 5,675,518; warning output (audible/visual, internal/external) is a design choice with a known menu.
5. Reasonable expectation of success. All are electrical/software subsystems integrated by a conventional microprocessor over a known vehicle bus — no unpredictable technology.
6. Design incentive / market pressure. Driver-assist safety electronics were a recognized growth area (evidenced by the dense citing art from 1999 onward).

6. Counterarguments and secondary considerations (the non-obviousness side)

I note these candidly, because a thorough § 103 opinion must address the best rebuttal:

• Claim 1's rear-facing sensor + follower-facing display. Nearly all the pre-1998 cited art is forward-looking and driver-facing. If a defendant's prior art cannot show a range finder aimed at the trailing vehicle feeding a display the follower sees, claim 1 has a genuine novelty hook. The obviousness case therefore rests on KSR "predictable variation" reasoning (reverse/repoint a known sensor; light a known lamp for a known warning purpose), which is a fair, but arguable, position.
• Priority-rule architecture of claims 1A/1B/1C (closure-speed warnings take precedence over distance-based modes). If the amended claims 17/18 incorporate a specific priority/encoding scheme or other narrowing text, the surviving claims could resist a pure "Stanley '432 + Yazaki" combination because the reference set does not disclose the interaction logic.
• Secondary considerations: I found no evidence of commercial success, licensing, industry praise, long-felt need, or copied design attributable to the '346 patent. The litigation history (per the prior section: Pignato v. Mobileye, S.D. Ind. 1:16-cv-00800, voluntarily withdrawn; plus unconfirmed 1:17-cv-02421) supplies no judicial finding of validity. No objective indicia therefore offset the strong prima facie case. (A nexus would also be doubtful, since the asserted claims here look close to the prior art.)
• Reexam signal. The fact that the examiner cancelled the broad recorder claims (27, 38 and dependents) while allowing narrowed 17/18 is the single best empirical evidence that (i) the broad concepts were obvious, and (ii) only amended, narrower claims survived — exactly the pattern one expects when the inventive weight is thin.

7. Bottom line

The clearest and strongest § 103 combinations are:

• Claim 1: US 5,502,432 + US 5,675,518 + US 5,775,712.
• Claims 14/15/16: US 5,502,432 + US 5,675,518 + US 5,775,712 (outward indicator).
• Claim 17 (as issued): US 5,502,432, optionally with US 5,594,414 and US 5,675,518.
• Claim 18 (as issued): US 5,502,432 (or Cluster A) + US 5,239,470 (Yazaki) + admitted flight-recorder art.
• Dependent recording claims: US 5,239,470 (+ US 5,379,219 Ishibashi) and, for camera claims, GB 2,268,608 A.

8. Confidence and gaps (stated explicitly)

• High confidence: the dates, titles, and clusters are quoted directly from the patent record; I verified the substance of US 5,502,432, US 5,675,518, US 5,594,414 (full text) and US 5,239,470 (claims + background). The strong points — Stanley '432 disclosing sampled-distance relative-velocity computation and graduated warnings, and Yazaki disclosing time-sampled vehicle-data recording — are grounded, not inferred.
• Medium confidence: element-by-element mapping for the references I did not open in full (most of Cluster A's adaptive-cruise family, the Eaton/Grote/Highwaymaster trailer refs, GB 2,268,608). Their content is inferred from title/field; a formal invalidity contention would require the full texts and pin cites.
• Explicit unknown: the exact amended language of claims 17 and 18 is not present in the supplied record (the reexam certificate C1 text was not reproduced). Because those are the only independent claims held patentable as amended, any final obviousness opinion must be scored against the certificate's amended text. My "original-claim" analysis above is therefore a floor, not a ceiling, for those two claims.
• No secondary considerations located, but I cannot prove a negative; a diligence search for commercial-success/licensing evidence would be needed to close that gap.
• I did not obtain PACER dockets; dates for case 1:17-cv-02421 remain unconfirmed as noted in the Litigation section.