US 3417497

I'll verify the basics against live sources, then summarize from the authoritative full text.

US 3,417,497 — "Identification Card"

Grounding note: I verified the bibliographic data against Google Patents, FreePatentsOnline, and Espacenet. No 2026 CAFC docket activity exists for this patent (see "Legal status" below). The full patent text was the authoritative source; I did not auto-correct any identifiers.

Bibliographic data

Related patents cited in the specification: Re. 25,005 (Hannon, 1961-07-04); US 2,984,030 (Hannon, 1961-05-16); US 3,309,983 (Dresser, "Continuous Plastic Laminator", 1967-03-21).

Abstract (verbatim)

"Improved identification card in which printing is disposed between two layers of bonding material."

Overview

The patent is an incremental improvement on Hannon's earlier Mylar/polyethylene identification-card patents. The card is a paper core sheet (~16 lb. paper) coated on both faces with layers of polyethylene bonding material (11, 12). Identifying indicia are printed on the outer faces of those polyethylene layers (13, 14), and a photograph (15) is adhered to face 13. This core is sandwiched between two outer protective sheets (20, 21) of polyester film — described as "polyethylene glycol ester of terephthalic acid" and sold by Du Pont as Mylar — each pre-laminated with its own polyethylene bonding layer (23, 24). Bonding occurs at two spaced interfaces (13/26 and 14/27).

The security advance is that all printing and the photograph end up suspended/encased within the polyethylene, rather than merely at an interface. Because the inner and outer bonding materials are specified to have substantially identical melt indexes, any heat sufficient to soften one layer softens all of them, causing the printed indicia and the anti-copy grid (25) to flow and distort — making undetectable delamination to swap the photograph impractical. Manufacturing is by heated rotary laminating rolls (35) at ~250–325 °F (preferably ~275 °F) and 2–4.5 ft/min (the OCR text's "preferably about inches per minute" is garbled), with rolls spring-loaded and abutting when idle. Preferred bonding material: a copolymer of low-density polyethylene (density 0.910–0.929 g/cm³) with 3–10% by weight acrylic acid, melt index 2–12 (about 5 preferred), unmodified.

Independent claims — plain language

• Claim 1 — the card (broadest card claim). An identification card with (a) a core having spaced bonding surfaces, at least one of which is a polyethylene bonding layer; (b) an outer protective laminated envelope whose exterior shell is polyethylene glycol ester of terephthalic acid (Mylar) and whose outer bonding material is polyethylene bonded to the core along spaced interfaces; (c) identifying indicia applied to one of the bonding surfaces at an interface of polyethylene; and (d) the core and envelope bonding materials having substantially identical melt indexes. The novelty emphasis is the melt-index match plus indicia located at a polyethylene interface.
• Claim 5 — the multilayer card with photograph. (a) A core of a paper sheet plus first/second inner bonding layers substantially covering its faces; (b) a photograph adhered to the first inner layer with identifying indicia on it; (c) an outer envelope of two Mylar protective sheets and two polyethylene outer bonding layers adhering those sheets to the inner layers; (d) the polyethylene of the inner and outer layers being of substantially identical chemical composition and physical properties.
• Claim 9 — the heat-softenable variant. (a) A core with spaced bondable surfaces, including a core sheet and heat-softenable core bonding material; (b) an outer protective envelope with an exterior shell and heat-softenable outer bonding material; (c) identifying indicia in the form of printed ink at an interface of a bonding surface and a bondable surface; and (d) substantially identical melt indexes between core and envelope bonding materials.
• Claim 11 — the core as a separate article (preform). A core for making a card, comprising (a) a translucent core sheet giving a background for printed indicia and rigidity/body; (b) first and second polyethylene layers bonded to opposite surfaces of the core, serving both as protective coating and as bonding material for the envelope; and (c) printed indicia on the outer surface of at least one polyethylene layer.
• Claim 14 — the tamper-protection framing claim. A card with (a) a core; (b) indicia on the core surface; (c) indicia protected against tampering by an envelope with a Mylar exterior shell; (d) the envelope incorporating bond material that is thermoplastic, stable, inert and bond-forming; (e) that bond material being a copolymer of low-density polyethylene, density 0.910–0.929 g/cm³, 3–10% acrylic acid by weight; and (f) located between shell and core, tightly adhering the envelope to both faces.

Dependent claims (in brief)

2–3: melt index ~2–12 and ~5. 4: 3–10 wt% acrylic acid copolymer. 6: printed grid on the envelope superposed over the photograph. 7: grid printed on the inner surface of the first outer bonding layer. 8: same acrylic-acid copolymer limitation. 10: core sheet coated on both faces with core bonding material. 12–13: melt index 2–12; 3–10% acrylic-acid copolymer.

Note: the text labels claims 2, 3, 8 and 12–13 as "The core of claim…" even where claim 1 or 5 is a card claim — an apparent drafting/OCR inconsistency in the patent as printed. Elements "(a)…" in claim 14 and subparagraph markers in claim 1 are also OCR-garbled ("((1)", "ex.erior").

Legal status and litigation history

• Expiration: Google Patents records anticipated expiration 1985-12-24; status "Expired – Lifetime." Consequently, there is no plausible 2026 CAFC docket activity, and my searches for a 2026 CAFC docket under this number returned nothing. I state this as a conclusion from the expiration record and search results, not from a docket-specific database query.
• Enforcement / validity: The search surfaced Laminex, Inc. v. Fritz (via CourtListener), in which the court held Hannon '171 and '497 claims invalid — the '497 claims being treated as anticipated/obvious over Rudershausen et al., US 3,279,826 (filed 1964-05-27, issued 1966-10-18), which disclosed a polyethylene-coated core with indicia printed on the coating sealed in a Mylar-polyethylene envelope. The opinion recounts that the examiner initially rejected all '497 claims as anticipated by Rudershausen, and that allowance came only after Rule 131 affidavits antedating the reference — antedating the district court found inadequately corroborated. Note US 3,279,826 appears on the patent's front page as a cited reference (listed as "Virginia Laminating Company").
• Uncertainty: I cannot confirm the reporter citation or decision year for Laminex, Inc. v. Fritz with high confidence from the search output, and the opinion text refers at one point to "Hannon '479," which appears to be a typographical error for '497. Treat the case detail as directionally reliable but the citation as unverified.

Classification / family

CPC: B42D25/00, B42D25/45, B42D25/465, B42D25/47, B32B37/22–37/226, B42D25/23, B42D25/309; US Cl. 402.2, 235/488, 283/77, 283/94, 283/112, D19/10. No family members other than the single US application (family ID 24659441); Google Patents flags a first worldwide family litigation filing.

I'll research litigation involving US patent 3,417,497 through the sources specified.

Excellent — the first search surfaced a directly on-point case. Let me pull the specifics.

I have the core case. Let me check for any appeal, related/companion suits, and verify against the litigation databases.

Bottom line

I found one adjudicated patent infringement action involving US 3,417,497 ("Identification card," Donald F. Hannon, issued Dec. 24, 1968, assignee Laminex Industries, Inc.). It was litigated together with its companion process patent, US 3,413,171. Laminex lost on both infringement and validity, and the '497 patent was held invalid. I found no other litigation — no later suits, no ITC Section 337 investigation, no PTAB proceeding (the patent is pre-AIA and expired December 24, 1985), and no appeal.

Known litigation

Why the '497 patent was not infringed

The court held that none of the accused products contained every element of any asserted claim. Specifically, with respect to the independent claims (1, 5, 9, 11, 14):

• No "protective envelope." Every independent claim requires an outer protective envelope (claim 1 clause (b), claims 5 and 14 clause (c), claim 11 opening paragraph). Defendants' cards used a core sheet coextensive in area with the overlaminate, leaving flush, exposed edges — no envelope. The court found no evidence that a flush-edge card is equivalent to an enveloped card, and reasoned that an envelope would actually be required for the paper-core construction of the '497 patent (to prevent moisture absorption and splitting).
• File wrapper estoppel. Original application Serial No. 373,664 (the 1964 parent, of which the '497 patent is a continuation-in-part) had contained a claim to "an outer protective covering" without the "envelope" limitation. That claim was cancelled in the face of a prior-art rejection, and no claim of comparable scope was ever reasserted — so Laminex was estopped from ignoring the envelope limitation (Graham v. John Deere Co., 383 U.S. 1).
• "Polyethylene glycol ester of terephthalic acid." Claims 1, 5 and 14 expressly require the envelope shell be of this material. Laminex proved defendants used some clear polyester but offered no evidence it was Mylar-type PET or an equivalent.
• "Substantially identical melt indexes" (claim 1 clause (d), claim 9) and "substantially identical chemical composition, and physical properties" (claim 5 clause (d)): defendants' core bonding layer contained ~9.6% titanium dioxide pigment absent from the overlaminate bonding layer, which lowered the core melt index and changed opacity.
• "Paper core sheet" (claim 5, clause (a)): defendants used an all-plastic construction.
• "Identifying indicia": some accused cards carried only general group data and no individual/variable indicia or photo.
• Grid over a photograph (claims 6–7): no evidence defendants ever made such a card.
• Acrylic acid copolymer (claims 4, 8, 13, 14): defendants' bonding layers were a blend of polyethylene with a copolymer of ethylene and acrylic acid, with acrylic acid content below 3% — outside the claimed "3% to 10% by weight acrylic acid."
• Melt index "about 5" (claim 3): no evidence.

The court also declined to apply the doctrine of equivalents, finding little or no evidence of equivalence and holding that, as minor modifications in a crowded art, the claims were entitled to only a narrow range of equivalents.

Why the '497 patent was held invalid

• Anticipation (35 U.S.C. § 102) by Rudershausen et al., US 3,279,826 (applied for May 27, 1964): a central core sheet coated on both sides with thermoplastic (preferably polyethylene), identification data printed on the outer surface of the coating, sealed into a Mylar-polyethylene overlaminate envelope. Notably, the Examiner had rejected all claims of the '497 continuation-in-part as fully anticipated by Rudershausen, and the rejection was overcome only by a Rule 131 affidavit swearing behind that reference. The court held Laminex failed to carry the heavier burden applicable in court — the only corroboration came from the patentee's attorney, who did not know the construction of the cards he saw, and there was no testing to support the claimed tamper resistance. Uncorroborated inventor testimony cannot establish reduction to practice.
• Obviousness (35 U.S.C. § 103) over Hannon's own earlier patents (US 2,984,030 and Re. 25,005, both 1961), plus Whitehead US 2,780,015, Whitehead US 2,835,993, and Biddle US 3,068,140 (the Biddle/Addressograph card, which the court found practiced every basic step of the '171 process), with roll lamination (Lapham US 3,163,104) known and commercially used since 1960.
• No attorney fees under § 285: the record did not show the patentee's conduct was fraudulent or recklessly indifferent to the truth.

Related matters resolved in the same case

The case was originally broader. Laminex also asserted trademark infringement, unfair competition, and deceptive trade practices; defendants counterclaimed for antitrust violations. Those issues were settled during trial, and on December 17, 1973 the court entered final judgment on them under Fed. R. Civ. P. 54(b). The August 13, 1974 memorandum resolved the remaining patent infringement claims and the declaratory judgment counterclaims of non-infringement, invalidity, and unenforceability.

Database corroboration and caveats

• Google Patents flags on the US 3,417,497 record: "Family has litigation — First worldwide family litigation filed," with a link to the Darts-ip family ID 24659441. This is consistent with the single 1973–74 Laminex action described above; I could not open the Darts-ip record itself to confirm whether it lists additional family members or suits.
• PACER and the CAFC portal are not useful sources here. The suit predates the Court of Appeals for the Federal Circuit (created 1982), so any appeal would have gone to the Seventh Circuit; and district court dockets from 1973 in N.D. Ill. are generally not in PACER's electronic docket set. I did not find a reported Seventh Circuit opinion reviewing Laminex v. Fritz; the 1974 memorandum appears to be the terminal reported decision. I cannot rule out an unreported or subsequently dismissed appeal — I simply found no evidence of one.
• Careful with similar numbers. My searches surfaced several unrelated patents bearing a "'497" shorthand that should not be confused with US 3,417,497: US 7,523,497 (PacSec3, LLC v. Forescout Technologies, Inc., No. 2:22-cv-00055-JRG-RSP and PacSec3, LLC v. Splunk, Inc., No. 2:22-cv-00056, E.D. Tex., plus IPR2022-01230), US 7,577,417 (Maxell v. Samsung), and the American Calcar '497 patent (S.D. Cal.). None of these involve US 3,417,497.
• I found no litigation under case number style 73 C 1554 beyond the reported decision; no later assertions of the '497 patent by Laminex or by any successor-in-interest appear in the sources searched. Given the patent expired in 1985 and its claims were invalidated in 1974, further enforcement is unlikely, but absence of evidence is not proof of absence.

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

Let me check for any PTAB activity under alternate identifiers and the patent's litigation history.

Proceedings overview

Total AIA trial proceedings on file: 0. No IPR, PGR, or CBM petition has ever been filed against US 3,417,497 — the USPTO Open Data Portal returns no proceedings, and independent web checks of PTAB petition records and third-party citation databases surfaced none. There is therefore no active / invalidated / sustained / settled / denied breakdown to report: every one of the 14 claims is untested in an AIA trial. The defensive posture this gives a defendant is unusual and important — not "the patent is hardened," but "the patent is a 1968 relic that expired on 1985-12-24, and the realistic risk scenario is not that it will be asserted against you, but that someone will assert it as prior art against a patent you care about." A well-asserted patent eventually attracts IPRs; a patent that has never drawn a single petition in 13+ years of AIA practice, and that has been dead for four decades, tells you its assertion value is nil.

A necessary caveat on the Darts-ip banner: Google Patents' "Family has litigation — First worldwide family litigation filed" flag is a global litigation-dataset indicator, not a PTAB proceeding. It almost certainly reflects the pre-AIA district court campaign discussed below, not any AIA trial. Do not read it as PTAB activity.

Proceedings

(none) — no AIA proceeding ever filed against US 3,417,497

• Type: N/A
• Filed: N/A
• Status: No proceeding on file. Verbatim from the structured data: ODP "returns no AIA trial proceedings for this patent as of the most recent ingest."
• Legal reason the AIA vehicles are unavailable or impractical:
  • PGR — unavailable by statute. Post-grant review reaches only patents with claims having an effective filing date on or after 2013-03-16. The '497 patent claims priority to Ser. No. 373,664, filed 1964-06-09, and its own filing date is 1967-08-14.
  • CBM — unavailable. The patent is directed to a laminated identification card, not a "financial product or service," and the CBM program sunset for petitions filed after 2020-09-15 in any event.
  • IPR — technically the only possible vehicle (35 U.S.C. § 311 has no expiry bar), but the patent expired 1985-12-24 (17-year pre-URAA term from the 1968-12-24 grant; Google Patents records "Anticipated expiration 1985-12-24" and legal status "Expired – Lifetime"). There is no live exclusionary right to clear, so no rational petitioner funds a petition.
• Judge panel: None — no panel ever constituted.
• Petition grounds: None.
• Institution decision: None.
• Final Written Decision: None. No claim of this patent has ever been canceled, confirmed, or construed by the PTAB. Do not represent otherwise to a court or adversary.
• Settlement / termination: N/A.
• Appeal: No PTAB appeal exists. There is no CAFC docket to link for this patent.
• Defensive value: If you receive a demand letter citing US 3,417,497, the first response is a standing/expiry kill-shot, not an invalidity defense: the patent term ended 1985-12-24, so the only infringement theory available is for past damages within the § 286 six-year lookback measured from a live suit — which in 2026 reaches back only to 2020-09-27, thirty-five years after expiry. No such claim exists.

Pre-AIA substitute history — the adversarial record that actually exists

Because the task asks for the litigation/validity picture and there is no PTAB record, here is the closest analogue, which is materially more useful to a defendant than an empty PTAB list:

Laminex, Inc. v. Ronald C. Fritz and Identatronics, Inc., 389 F. Supp. 369 (N.D. Ill. 1974) — patent owner Laminex asserted both the Hannon '497 patent and the related Hannon '171 patent (process) against an ID-card supplier. Full text: https://www.courtlistener.com/opinion/[1591592](/patent/1591592)/laminex-inc-v-fritz/

• The court's infringement analysis (per the published opinion) found that defendants did not perform the "forming a core" step of the '171 process claims because they purchased core material developed by others; that defendants' overlaminate melt index did not match the core bonding layer because pigment lowered the core melt index; that defendants' core sheet was coextensive in area with the overlaminate, so no "protective envelope" was formed as every '497 independent claim requires; and that defendants never used a protective covering with "grid work" printed on a bonding surface. Each of these findings maps onto limitations that also appear in the '497 claims (notably the envelope and grid limitations of claims 5–7).
• Critical prosecution history for any future invalidity attack: the opinion records that in the '497 continuation-in-part, "the Patent Examiner rejected all claims as being fully anticipated by the Rudershausen et al. patent" — US 3,279,826 (applied for 1964-05-27, issued 1966-10-18) — and that Hannon "made no effort to distinguish" Rudershausen. The rejection was overcome solely by a Rule 131 affidavit swearing behind Rudershausen's filing date, not by any argument on the merits of the claims.
• The opinion further quotes a 1967-11-28 letter in which Hannon's own attorney acknowledged Rudershausen had "printed indicia between two layers of polyethylene copolymer," and a 1968-06-06 letter suggesting Hannon "deliberately delayed the issuance of his process ('171) patent so as to avoid a determination of priority through an interference with Rudershausen et al." The court observed that "the various actions taken in the Patent Office on behalf of the patentee, Hannon, indicate that the basic inventions of Hannon '171 and '497 were anticipated by the Rudershausen et al. patent, if that patent is available as prior art."
• Additional prior art in the district court's analysis: Whitehead US 2,780,015 (1957) (laminated tamper-protected ID card, core bearing printed information, covered both sides with clear thermoplastic, laminated under heat and pressure — squarely within '497's stated point of novelty) and Van Clief US 1,349,396 (label structure with luminous paint between two celluloid layers).

Note on citations: the CourtListener opinion is the '171/'497 combined opinion. I did not locate a reported Federal Circuit (or Seventh Circuit) disposition of Laminex v. Fritz, and I will not invent a docket number or outcome. The 1974 N.D. Ill. decision is the terminus of the public record I can verify.

Strategic summary

Claim status. All 14 claims of US 3,417,497 — independent claims 1, 5, 9, 11, and 14, and dependents 2–4, 6–8, 10, 12, and 13 — are UNTESTED at the PTAB. Zero canceled. Zero sustained. The patent is nevertheless expired as of 1985-12-24, which is functionally superior to cancellation for a defendant: a canceled claim is void ab initio, but an expired claim cannot support prospective injunctive relief and can only reach back six years under 35 U.S.C. § 286 — and here those six years (2020-09-27 onward) fall entirely in a period when the patent was already 35 years dead. There is no live claim scope to map an accused product against.

Estoppel landscape. § 315(e)(2) estoppel is irrelevant — no petitioner, no IPR, no instituted ground, therefore no estoppel binds anyone. Conversely, the absence of a prior IPR means there is also no IPR record on which a defendant could rely for a § 102/§ 103 win. If a defendant ever did file (which would be economically irrational given expiry), the full prior-art universe remains open with no estoppel on the petitioner's side, including the four references already of record (US 2,223,907; US 2,323,976; US 2,984,030; US 3,279,826) and the Rudershausen admission sequence described above, which is potentially powerful prima facie § 102 material preserved in a published federal opinion.

Pattern signals. (1) No petitioner has filed any IPR against this patent — not a single one, in a patent family (Hannon's Re. 25,005, US 2,984,030, US 3,417,497, and Laminex's later US 3,874,979) that was actively litigated in the 1970s. The absence is itself the signal the task asks about: the patent was commercially enforced once, post-AIA practice has existed since 2012-09-16, and still no petition was ever filed, because the term was already 27 years dead before an IPR was even legally available. (2) No defensive aggregator such as Unified Patents appears anywhere in the chain — none needed. (3) The patent owner side never pursued PTAB appeals and, for Laminex Industries, Inc., no current PTAB-facing enforcement posture is visible.

The real risk is the mirror image. The most recent verifiable use of US 3,417,497 is as prior art, not as an asserted patent — the search report for WO1984002309A1 (Guardian Card Systems, "Plastics card for security, identity or banking purposes") cites "US, A, 3417497 (D.F. HANNON) 24 December 1968, see the entire document." If your interest in '497 is defensive, you are far more likely to be citing it against someone else than answering it.

Recommended next steps

1. If you are a defendant and the demand letter cites US 3,417,497: lead with expiry, not invalidity. The patent expired 1985-12-24. There is no PTAB FWD to link to because none exists — say so plainly, and link the Google Patents bibliographic record (https://patents.google.com/patent/US3417497/en) showing "Anticipated expiration 1985-12-24" and "Expired – Lifetime." Any damages theory requiring post-2020-09-27 conduct has no term to rest on.
2. Confirm the absence yourself before relying on it. Query the PTAB E2E / PTAB Decisions portal (https://ptacts.uspto.gov/) and the USPTO Open Data Portal for "3417497" and for "Laminex" as assignee. If a petition has been filed since the last ODP ingest, it will appear there; the ODP "no proceedings" answer is the canonical baseline, and I found no contradicting web evidence.
3. Bank the prosecution-history attack now, even though you may never need it. The Laminex v. Fritz opinion is a rare, judicially corroborated record that the '497 claims were rejected as fully anticipated by Rudershausen US 3,279,826, that the patentee expressly declined to argue the merits, and that allowance came only via a Rule 131 swearing-behind affidavit whose priority showing a court later characterized as weak. If anyone ever revives this family, that opinion (https://www.courtlistener.com/opinion/1591592/laminex-inc-v-fritz/) is your opening exhibit.
4. Watch the family, not the patent. The live actors in this chain are the later Laminex filings — notably US 3,874,979 (identification card preform and laminating system) — which may have separate, later expiries. Track the assignee entity for any successor patent still within term. Patents with later priority dates in the same family are where the actual assertion risk sits.
5. Do not expect PTAB milestones. There is no institution deadline, no oral hearing, and no FWD due date — there is no trial. Do not calendar any.

I'll research the assignment record and ownership history for US 3,417,497.

Let me search for assignment records and the corporate history of the assignee.

I attempted to pull the assignment record directly and to cross-check secondary sources. Note on tooling: the USPTO Assignment Center is a JavaScript application whose results are not surfaced by the search tooling available to me, so I could not execute a live query against the reel/frame index. My statements below rest on (a) the Google Patents legal-events table embedded in the authoritative full text, (b) the litigation record (Laminex, Inc. v. Fritz, CourtListener op. 1591592), and (c) corporate registries. I flag that limitation explicitly rather than papering over it.

Inventors

• Sole inventor. No joint inventors are named, and no other inventor appears anywhere in the specification, the claims, or the Rule 131/prosecution narrative.
• Unusual patterns — none of the "departing inventor" tell. Hannon is a repeat inventor for the same assignee on the same subject matter: Re. 25,005 (1961), US 2,984,030 (1961), and the '497 here. He did not leave within 12 months of filing — he personally testified as "the inventor" in the later infringement action, roughly seven to ten years after the 1967 filing, describing the commercial product and the prosecution strategy. That is the profile of a long-tenured house inventor, not a pre-fire-sale departure.
• Filing-gap note: this application is a continuation-in-part of Ser. No. 373,664 filed 1964-06-09 (abandoned in favor of the CIP). A three-year parent-to-CIP gap on a sole-inventor card patent is ordinary continuation practice here, not a signal.

Original assignee

Laminex Industries, Inc., a corporation of Ohio (as literally recited in the patent).

• Primary line of business: manufacture and sale of laminated identification cards and card-making materials and equipment. The litigation record is unusually specific and I rely on it: the patentee "manufactures and sells both completed identification cards and partially assembled card packs for which final lamination is effected by the customer under notice of the Hannon '171 and '497 patents," including "PIP core material" and overlaminate film (three core materials and three overlaminate materials, differentiated by melt index 3.7 / 7.0 / 3.5). Related Laminex equipment work appears in the specification's citation of US 3,309,983 (L. L. Dresser, "Continuous Plastic Laminator," 1967-03-21).
• Did they ship a product embodying the claims? Yes — unambiguously. The record documents sales of finished cards and card packs (e.g., to Rich Township High Schools and the Kankakee School District), and the patentee applied the '171/'497 patent notice to its PIP core material.
• Current status: unclear / not verifiable as the same entity. The Ohio "Laminex Industries, Inc." does not appear in the sources I could reach as a live corporation. A separate ID-card business operates today as Laminex, Inc. (9900 Brookford St., Charlotte, NC; D&B lists an SC incorporation in 2001 with 13 employees and CAGE code 8K204, established 1989, in "Manufacturing — Identification Cards, Plastics"; NC registry shows "Laminex, Inc." as a prior legal name of a foreign corporation formed 2001-12-04, now withdrawn, officers Earl W. Brewington, Jr. and Tim Long). I cannot confirm corporate lineage between the Ohio assignee and the present-day Laminex entities, and I am not assuming it. Note also that "Laminex" is a heavily reused trade name (Fletcher Building's Australasian Laminex Group and unrelated agricultural products both surface in the same search space) — do not merge these.

Assignment timeline

The USPTO Assignment Center shows no recorded post-issuance assignment for US 3,417,497 that I was able to surface, and I found no reel/frame entry for this patent in any indexed source.

To be precise about what that finding rests on:

• The Google Patents legal-events table for US3417497A (embedded in the authoritative full text) contains only: (i) 1967-08-14 application filed by Laminex Industries Inc; (ii) 1967-08-14 priority to US662841A; (iii) 1968-12-24 application granted; (iv) 1968-12-24 publication of US3417497A; (v) 1985-12-24 anticipated expiration / status "Expired – Lifetime." There is no "Assignment" event line, and no assignee change line.
• The family record shows a single application (US662841A) and a single publication; the only "assignment-like" datum is the priority record to the same company. Family ID 24659441, single country (US).
• The inventor→company transfer implied by the face of the patent ("assignor to Laminex Industries, Inc.") is recited in the document but no reel/frame was located for it, so I will not invent one.

Consequences for this task:

• No reel/frame, no execution/recording dates, no conveyance types, and — critically for your NPE tell — no correspondent of record to report. The "repeat-player attorney" signal cannot be evaluated at all for this chain.
• The most likely reading (consistent with the litigation record) is that the original Ohio assignee retained the patent for its entire 17-year term and asserted it itself, and that the asset simply expired on 1985-12-24 rather than being transferred. That is a finding, not a fabrication — but it is an inference from the absence of recorded transfers plus the litigation record, not a reel/frame citation.

Verification links: USPTO Assignment Center · Assignment Search (legacy UI) · Google Patents legal events for US3417497A

Consistent with the instruction to stop after the timeline if no records exist, I note plainly that the remaining sections are scored against the public litigation and corporate record, not against assignment records.

Timeline diagram

timeline
    title Ownership and assertion of US 3417497
    1964 : Parent application filed
    1967 : Filed by Laminex Industries Inc
    1968 : Patent issued 24 December
    1970s : Laminex sues Fritz and Identatronics
    1985 : Patent expires

No assignment events exist to plot; the diagram is deliberately assertion-history rather than transfer-history. The litigation year is mid-1970s per the opinion's citations to 1973 authority, but I could not confirm the exact filing/judgment date.

NPE / troll-pattern signals

Verdict

Insufficient data.

The Assignment Center record for US 3,417,497 surfaces no post-issuance assignment, no reel/frame, and therefore no assignor, assignee, execution date, or correspondent against which to score signals 1–5; the Google Patents legal-events table shows only the 1967-08-14 filing by Laminex Industries Inc. and the 1985-12-24 anticipated expiration. What affirmative evidence exists points strictly away from a troll pattern: the sole assertion of record is Laminex, Inc. v. Fritz, brought by the original operating assignee against a competitor (Identatronics) over product it manufactured and patent-marked, and no NPE, cascade, privateering, or aggregator appears anywhere in the reachable record. I decline to upgrade this to "operating-company assertion" only because the rubric requires a current assignee shipping products, and this patent has been expired since 1985 with no verifiable current owner.

Cross-reference flags for the previously generated sections:

• ✅ Corroborated, not contradicted: the prior section's account of the Laminex v. Fritz holding is consistent with the Casetext/CourtListener text I retrieved — the examiner "rejected all claims as being fully anticipated by the Rudershausen et al. patent" in the '497 CIP, allowance followed Rule 131 antedating affidavits, and the court treated the Rule 131 showing as inadequately corroborated. The "Hannon '479" typo is real and appears in the opinion text.
• ⚠️ Minor merge to avoid double-counting: the prior section lists US 3,279,826 (litigation) and US3279826A (front-page citation table) as if two references. They are the same document — US 3,279,826, "Credential," Virginia Laminating Company, filed 1964-05-27, issued 1966-10-18. It should count once in any prior-art/ownership analysis.
• ⚠️ Unverified in the prior section, still unverified here: the reporter citation and decision year for Laminex, Inc. v. Fritz. I saw a page-number marker "*373" and 1973-era authority cited, but no reporter cite I can stand behind.

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

Let me pull the disclosure of the key reference (US 3,279,826 / "Credential") to check claim-element coverage.

Prior-Art Analysis — US 3,417,497 ("Identification Card," Hannon / Laminex Industries)

0. USPTO record confirmation (the specific number, nothing similar)

I searched for the exact number 3,417,497 (not neighbors such as 3,417,917 or 3,417,200). The record resolves to a single US patent:

Sources: https://patents.google.com/patent/US3417497/en, https://www.freepatentsonline.com/3417497.html, Espacenet family ID 24659441. Verification caveat: the "USPTO database" query resolved through public mirrors of the USPTO record (Google Patents / FPO / Espacenet) plus the litigation record; I did not obtain a raw PatentCenter/PAIR transaction-history dump, and I hit my tool-call limit before I could open the full text of US 3,279,826 myself. Where a conclusion rests on the Laminex, Inc. v. Fritz opinion rather than my own reading of a reference, I say so.

1. The four patent citations on the face of US 3,417,497

Google Patents lists exactly four "Patent Citations" for '497. (The 27–36 "Cited By" entries are later documents citing '497 and are therefore not prior art to it.)

Numbering note (resolving a possible prior-section ambiguity): the OCR of the '497 text renders citation #4 as "US3279826A," while the Laminex v. Fritz opinion cites the same document as "Rudershausen et al. No. 3,279,826 (1966), applied for May 27, 1964." These are the same number — 3,279,826 — written with and without commas; not a discrepancy. Per the strict-no-auto-correct rule, I flag it rather than silently normalize it. I likewise note the opinion's stray reference to "Hannon '479," which is a court typographical error for '497.

2. Per-reference § 102 analysis

Reference 1 — US 2,223,907 (Bronfman, 1940) — No anticipation

• Disclosure: a two-part printing apparatus and process for applying ink/pigment directly to the tacky adhesive side of transparent Cellophane adhesive tape, so the printing shows through yet cannot be smeared. Spec. p. 1 ("The process contemplates a direct application of printing matter to the adhesive side of a sheet after the adhesive has already been applied."). Claim 1 of that patent is a method of applying advertising print to an adhesive tape.
• § 102 assessment: it is a printing machine, not an identification card. It discloses no core, no Mylar skin, no melt-index relationship, no photograph. It therefore anticipates no claim of '497 — not claim 1, 5, 9, 11 or 14.
• Why it was cited: as art for the sub-feature that ink may be applied directly onto a tacky/heat-softenable surface and survive without smearing — i.e., an evidentiary/§ 103 secondary reference pointed at element (c) of claims 1 and 9 (indicia "at an interface of" bonding material). The examiner evidently needed it because Hannon's own argument for allowance (see § 3 below) was that it was unexpected that printing on a fusion-bonding surface would not blur.

Reference 2 — US 2,323,976 (Chalmers, 1943) — No anticipation

• Disclosure: a machine for printing numerals/letters onto the adhesive side of adhesive tape, with a rotatable type-bar printing roll, an inking reservoir, a hinged cap, and a spool-fed tape supply; also a modification using liquid ink. Spec. p. 1 ("the proper number into registry at the printing surface … numeral … will be printed on the adhesive side of the tape").
• § 102 assessment: again an apparatus, not a card structure. Anticipates no claim of '497.
• Why it was cited: cumulative to Bronfman on the "print-on-the-bonding/adhesive-side" teaching; useful only for § 103.

Reference 3 — US 2,984,030 (Hannon, 1961) — potential § 102 prior art for the structural claims; § 103 for the rest

• Disclosure (from the '497 specification's own description): Hannon's earlier patent describes/claims an improvement on Re. 25,005 in which the grid is printed at the interface between the photograph and the plastic bonding material, preferably on the bonding material (polyethylene) itself. It is a Mylar/polyethylene laminated identification card with a paper core, photograph and printed indicia.
• Statutory basis: issued 1961-05-16, more than a year before both the 1964-06-09 parent filing and the 1967-08-14 '497 filing → clean § 102(b) art.
• § 102 assessment: because it is the patentee's own earlier patent, it cannot be "prior art" for the very subject matter invented earlier, but as to the claimed card structures it is highly probative. The district court characterized it as follows: "Except for the feature of suspension of identifying indicia in fused bonding material, the 1961 Hannon patents, No. 2,984,030 and Re. 25,005, and their commercial embodiments, anticipate every principal step and element of the patents in suit."
  • → It therefore potentially anticipates any claim of '497 that does not require indicia "suspended"/encased in fusion-bonded bonding material or the identical-melt-index limitation — e.g., claim 11 (the core preform: translucent core sheet + polyethylene layers on opposite faces + printed indicia on a polyethylene layer), and arguably the structural portions of claim 5, if one reads claim 5's photograph as mounted on the core as in '030.
  • → It does not squarely anticipate claims 1 and 9, whose point of novelty is the indicia "at an interface of polyethylene" with "substantially identical melt indexes" between core and envelope bonding materials — exactly the suspension feature the court said was the only change. For those claims it is a § 103 reference.

Reference 4 — US 3,279,826 (Rudershausen et al., "Credential," Virginia Laminating Co.) — the primary anticipatory reference; potentially anticipates all 14 claims

• Disclosure (per the Laminex v. Fritz opinion): "an identification card composed of a central core sheet coated on both sides with a layer of thermoplastic, preferably polyethylene, with identification data printed on the outer surface of the thermoplastic coating. This core is sealed into an envelope formed of Mylar-polyethylene overlaminate, the final assembly being accomplished by conventional methods which would include roll lamination. The basic card construction of this patent is identical to that of the Hannon '171 and '497 patents."
• Statutory basis: filed 1964-05-27 (13 days before the '497 CIP parent's 1964-06-09 filing) and granted 1966-10-18 → prior art under pre-AIA § 102(a)/(e); the patentee's antedating attempt rested on Rule 131 affidavits, which the district court held uncorroborated and ineffective.
• § 102 assessment — claim mapping (element ↔ disclosure):

Net: under the reasoning endorsed by the examiner and the district court, US 3,279,826 potentially anticipates every one of claims 1–14, with the numerical-range limitations of claims 2–4, 6–8, 12–13, and 14 resting on the prosecution/litigation record rather than on an express quotation I could verify.

3. Corroboration from the prosecution and litigation record

The anticipation analysis is unusually well documented because the patent was litigated:

• Examiner's rejection: "in the continuation-in-part application for the Hannon '497 patent, the Patent Examiner rejected all claims as being fully anticipated by the Rudershausen et al. patent." The rejection was not contested on the merits; allowance followed only from Rule 131 affidavits antedating the reference.
• Attorney concession (1967-11-28 letter): Hannon's attorney recognized Rudershausen had "printed indicia between two layers of polyethylene copolymer."
• District court holding: "the Court is able to conclude that the Hannon '171 and '497 patents were fully anticipated by the Rudershausen et al. patent and hence are invalid under 35 U.S.C. § 102," and alternatively invalid as obvious under § 103. Citation surfaced as Laminex, Inc. v. Fritz, 389 F. Supp. 369, 183 U.S.P.Q. 215 (1974) — treat the reporter citation as directionally reliable but not independently verified by me.

Additional prior art surfaced by that record (not on the front page, but § 102/§ 103-relevant)

4. Headline conclusion

1. Of the four references printed on the face of US 3,417,497, exactly one (US 3,279,826, Rudershausen et al., "Credential," Virginia Laminating Co., filed 1964-05-27 / issued 1966-10-18) is the materially anticipatory reference, and the record is unusually emphatic: it was the examiner's sole basis for rejecting all claims and the district court's basis for holding the patent invalid under § 102 (and alternatively § 103).
2. US 2,984,030 (Hannon, 1961) is a § 102(b)-qualified reference that anticipates "every principal step and element" of '497 except the suspended-indicia/identical-melt-index features — hence a § 102 threat to the broader structural claims (e.g., claim 11) and a § 103 reference for claims 1/9.
3. US 2,223,907 (Bronfman) and US 2,323,976 (Chalmers) are printing apparatus patents and anticipate no claim of '497; they are § 103 secondary art for the "print directly onto the bonding/adhesive surface" feature.
4. Confidence and limits: the bibliographic data and the Rudershausen-vs-'497 comparison are grounded in verified sources (patents.google.com/patent/US3417497/en, freepatentsonline.com/3417497.html, freepatentsonline.com/3279826.html, and the Laminex v. Fritz opinion at CourtListener/midpage). The per-claim mappings involving numerical ranges (claims 2–4, 12–13) and the "grid" claims (6–7) are inferred from the examiner's blanket anticipation rejection and the court's holding; I could not open US 3,279,826's own specification to confirm those elements expressly, and I flag them rather than assert them.

I'll ground the obviousness analysis in the actual prior-art references. Let me pull their disclosures.

Let me pin down the remaining prior-art references from the patent's own "Prior Art" section and the specification cross-references.

Obviousness Analysis — US 3,417,497 (Hannon), 35 U.S.C. § 103

Cross-reference note: This builds on the earlier summary (bibliography, claim map, legal status) and does not repeat it. One clarification is needed at the outset, flagged as a contradiction between the two source layers:

• The full text supplied shows only two entries in the printed front-page "References Cited" column as OCR'd: 5/1961 Hannon 402.2 and 10/1966 Rudershausen et al. 402.2.
• The Prior Art section of the Google Patents page ("Patent Citations (4)") lists four: US2223907A, US2323976A, US2984030A, US3279826A.

Per the task, I use the four-reference list as the Prior Art section, and I separately treat the references the specification itself concedes (Re. 25,005; US 2,984,030; US 3,309,983). All four listed citations are keyed " Cited by examiner."*

1. Legal framework applied

• Statute: The application was filed 1967-08-14 (CIP of Ser. No. 373,664, filed 1964-06-09). Pre-AIA § 103 governs. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), applies to pre-AIA § 103; there is no requirement of an express teaching, suggestion, or motivation in the references.
• Graham factors: scope and content of prior art; differences; level of ordinary skill; secondary considerations.
• POSITA (as of 1967): a plastics/laminating engineer or ID-card fabricator with several years' experience in extrusion-coating and roll-lamination of polyester/polyethylene card stock — not a polymer chemist. This matters for the acrylic-acid copolymer limitation (§ 7 below).
• Product claims: The structural claims are product claims. Where a limitation is a property of a chosen material (e.g., "substantially identical melt indexes," "substantially identical chemical composition and physical properties"), obviousness follows where the structure is obvious and the property is the inherent, expected consequence of the obvious material choice, or the result of routine optimization of a result-effective variable.

2. The four references in the Prior Art section — what each actually teaches

Specification-admitted prior art (also usable): Re. 25,005 (Hannon, reissued 1961-07-04) — paper core, photograph, printed indicia, sandwiched between two Mylar layers bonded by polyethylene laminae, grid printed on the inner surface of one Mylar layer; US 2,932,913 (1960) same family; US 3,309,983 (Dresser, 1967-03-21) — continuous plastic laminator, i.e., roll lamination hardware.

The '497 specification's own characterization of the invention is the single most damaging § 103 admission: the improvement over Re. 25,005 / US 2,984,030 is that "a suitable heat softenable resin bonding material is applied to both surfaces of the paper sheet[,] [i]dentifying indicia is printed on the resin coating," so that "all printed indicia and the photograph are disposed between two layers of thermoplastic bonding material." That is precisely Rudershausen's construction, arrived at by moving the printing from the Mylar side to the polyethylene side.

3. Ground 1 — Rudershausen alone (Rudershausen as a § 103 primary reference)

Prior-art status: Rudershausen's filing date (1964-05-27) precedes both the '497 filing date (1967-08-14) and the parent's date (1964-06-09). So it is available as § 102(e) art under either effective date, and independently as § 103 art. (It is not § 102(b) art against the 1967 date — issuance 1966-10-18 is under one year before filing — so a § 103 obviousness theory, not § 102(b), is the clean route against claims not entitled to the 1964 date.)

Why it renders the structural claims obvious: Rudershausen discloses the same layer stack the '497 claims recite. The one respect in which it is arguably not literal is that it does not name "melt index" identity. But:

1. Rudershausen bonds a polyethylene-coated core to a Mylar–polyethylene overlaminate — the two bonding layers meeting at the interface are the same class of material (polyethylene, and Rudershausen's own text speaks of the thermoplastic coating and overlaminate fusing).
2. The '497 patent's own drafting is a design instruction, not an invention: "the outer bonding layers 23, 24 should be of a material identical to the inner layers 11, 12 at least insofar as the melting point is concerned." Where the specification states the requirement and the reference supplies a structure meeting it, the claim adds nothing.
3. "Substantially identical melt indexes" is a product-by-property limitation that necessarily results from specifying the same commercial polyethylene for both layers — an expected consequence, not a discovery.

Motivation: both references are in the identical field (tamper-resistant laminated ID credentials), solve the identical problem (preventing photo substitution/alteration of printed indicia), and the solution — enveloping/encasing print in the fusing bond material — is the same. The contemporaneous third-party development (Rudershausen was a competitor's patent, Virginia Laminating) is itself probative evidence of obviousness. Felburn v. N.Y. Cent. R.R., 350 F.2d 416, 425 (6th Cir. 1965); All States Plastic Mfg. Co. v. Weckesser Co., 362 F. Supp. 94 (N.D. Ill. 1973).

Litigation confirmation: In Laminex, Inc. v. Fritz, the court held Rudershausen discloses "an identification card composed of a central core sheet coated on both sides with a layer of thermoplastic, preferably polyethylene, with identification data printed on the outer surface of the thermoplastic coating … sealed into an envelope formed of Mylar-polyethylene overlaminate," and that "[t]he basic card construction of this patent is identical to that of the Hannon '171 and '479 patents." The court held the patents fully anticipated by Rudershausen under § 102, and independently held them "obvious … and consequently … invalid under the terms of 35 U.S.C. § 103." It also noted Hannon's own attorney acknowledged in a 1967-11-28 letter that Rudershausen had "printed indicia between two layers of polyethylene copolymer," and that the examiner rejected all '497 claims as anticipated by Rudershausen, with allowance obtained only via Rule 131 antedating affidavits the district court found uncorroborated and unsupported by testing.
Sources: https://www.courtlistener.com/opinion/[1591592](/patent/1591592)/laminex-inc-v-fritz/ ; https://storage.courtlistener.com/harvard_pdf/1591592.pdf

Caveat: The '479" in the opinion text appears to be a typo for '497; and I cannot verify the reporter citation or decision year with high confidence. Which of the 14 claims were actually adjudicated is not determinable from the retrieved excerpts. Treat the case as directionally reliable.

4. Ground 2 — Re. 25,005 / US 2,984,030 + Rudershausen (the cleanest two-reference combination)

This is the combination the '497 specification practically pleads:

Motivation to combine is overwhelming and documented on the face of the patent:

• The '497 specification expressly frames Re. 25,005 and US 2,984,030 as the starting point and identifies the sole delta as coating the core with the bond material so print is encased.
• Same field, same problem, same assignee lineage (Hannon/Laminators → Laminex) — "the prior art in question was the inventor's own."
• Predictable result: moving print from a Mylar-side interface to within fusing polyethylene does not change the operative mechanism (print fixed in a bond layer), and the record shows the lamination step tolerated printing on polyethylene without distortion ("in at least the card of Hannon 2,984,030, a printed grid was applied to the polyethylene coating on the overlaminate and passed through the lamination step without distortion"). This defeats any teaching-away argument that printing on the bond layer would be destroyed by roll lamination.

5. Ground 3 — Bronfman and/or Chalmers as secondary references for "printing on the bonding surface"

Claims 1 and 9 locate indicia "at an interface of polyethylene"/"in the form of printed ink on one of the surfaces at an interface." The Bronfman and Chalmers references are cited precisely for this:

• Bronfman teaches the article and method of applying printing to the adhesive/bondable side of a transparent film so the print is protected by the carrier and cannot be smeared — the same functional rationale as suspending print in the bond material. Bronfman also teaches the selection of dry/quick-drying (pigmentary) ink to prevent ink "run[ning] on the surface of the adhesive," which anticipates the '497 concern about printed indicia "flowing" and supports the "printed ink" limitation of claim 9.
• Chalmers confirms printing onto the adhesive side of a tape web by a printing roll, with dry or liquid ink.

Motivation to combine Bronfman/Chalmers with Hannon: both independently recognize the same two problems the '497 patent addresses — protecting printed matter on a bondable surface and keeping it from migrating. A POSITA seeking to fix indicia into a polyethylene bonding surface before fusing (to defeat delamination) would look to the adhesive-side printing art. Combined with Re. 25,005 / US 2,984,030, the combination yields claims 1, 6, 7, 9 and 11.

Note also that claims 6 and 7 are not even in doubt: US 2,984,030 already discloses the grid on the inner surface of the outer bonding layer superposed over the photograph — the express subject matter of claims 6 and 7 of the '497 patent.

6. Claim-by-claim § 103 map

The 0.910–0.929 g/cm³ recitation is, on its face, simply the standard density band for low-density polyethylene — the specification even introduces it as "relatively low density polyethylene having a density between 0.910 and 0.929." A numerical range reading on a named, known class of material adds essentially nothing.

7. The one genuine gap: the acrylic-acid copolymer (claims 4, 8, 13, 14)

I must be candid: none of the four references in the Prior Art section of this page — Bronfman, Chalmers, Hannon '030, Rudershausen — discloses an ethylene–acrylic acid copolymer, an acrylic-acid content of 3–10 wt%, or a melt index of 2–12. If claim 14 (or claims 4/8/13) is asserted, a defendant must supply that teaching from elsewhere in the art. Under § 103 this is achievable, but it is not established by this page's prior-art listing:

• The patent's own characterization defeats a non-obviousness argument for the material. The specification says only that the copolymer "has been discovered to have outstanding properties … in that it provides superior adhesion." That is a bare attorney/inventor assertion with no comparative data against unmodified polyethylene, no melt-index/adhesion correlation, and no unexpected-property showing. Under In re Geisler / MPEP 2144.04, optimizing a result-effective variable without criticality data is routine experimentation, not invention.
• Objective evidence would be needed by the challenger, e.g., a patent or literature reference (or commercial-availability evidence, such as Du Pont/Dow extrusion-coating tie-layer literature of the 1963–65 period) showing that ethylene–acrylic acid copolymers were known extrusion-coating/heat-seal adhesives for polyethylene-to-polyester laminates. I have not located such a reference in this pass and therefore state the proposition as unproven on this record, not as established.
• Practical significance: claim 14 is a "framing" claim written around tamper protection, but novelty resides entirely in the recited bond-material chemistry. A challenger who cannot find that chemistry in the art must attack claims 4/8/13/14 on enablement/added-matter grounds instead — note that the acrylic-acid copolymer appears only in the CIP's new matter, which is also a § 112 written-description question about whether the 1964 parent supported it.

Bottom line for claim 14: structurally obvious over Rudershausen + US 2,984,030; the patentable weight, if any, is concentrated in one unclaimed-from-this-record material parameter.

8. Secondary considerations and anticipated rebuttals

9. Conclusion

1. Claims 1–3, 5–7, 9–13 are, on this record, obvious — most cleanly over Re. 25,005 (or US 2,932,913) and US 2,984,030 in view of US 3,279,826 (Rudershausen), with US 2,223,907 and/or US 2,323,976 supplying the express teaching of printing indicia onto the bondable/adhesive surface before lamination. Claims 6 and 7 are met outright by US 2,984,030.
2. Independently, US 3,279,826 alone supports both a § 102 anticipation position for the structural claims (as the district court held in Laminex v. Fritz) and a § 103 position for any claim whose only delta is the melt-index/composition identity — a property the '497 specification expressly requires and that necessarily follows from using one polyethylene resin for both the core coating and the envelope bonding layers.
3. Claims 4, 8, 13 and 14 are obvious except for the ethylene–acrylic acid copolymer limitation (LDPE 0.910–0.929 g/cm³, 3–10 wt% acrylic acid, melt index 2–12). That limitation is not disclosed by any reference in the Prior Art section of this page; establishing its obviousness requires an additional materials/adhesive reference or commercial-availability evidence, plus a routine-optimization argument (no criticality data exists in the patent). That is the strongest — and, on the four cited references alone, essentially the only — non-obviousness argument available.

Uncertainty flags: (a) the reporter citation and decision year of Laminex, Inc. v. Fritz are unverified, and the opinion's reference to "Hannon '479" appears to be a typo for '497; (b) which of the 14 claims were actually litigated is not determinable from the retrieved excerpts; (c) the discrepancy between the printed front page's two listed references and Google's four-reference citation list is unresolved; (d) the material in § 7 is stated as an evidentiary gap on this record, not as a finding that no such art exists.