US 4291956

I'll search for this specific patent and any litigation involving it.

Let me run a couple more targeted checks on litigation/assignment status.

US Patent 4,291,956 — Verification Summary

Search scope note: I searched for the exact identifier 4291956. Results below are for that number only; I did not substitute similar numbers. I also found that the bare string "4291956" appears in unrelated registries, which I flag separately at the end so the identification is not conflated.

---

1. Bibliographic data (authoritative — matches the full patent text)

Citations of record (5): US 2,762,277 (McChesney); US 3,204,520 (Eltra Corp.); US 3,828,359 (Minnesota Mining & Mfg.); US 3,914,775 (Minnesota Mining & Mfg.); US 4,141,632 (Mitchell, R.E.). The '359 and '775 patents are the direct 3M predecessors to this device and are expressly incorporated by reference in the specification.

---

2. Abstract (verbatim from the patent)

A device for composing graphics comprising a flash lamp for irradiating portions of strip material through a template when an arm supporting the lamp is moved to an exposure position at an exposure station. The template is pressed against the strip at the exposure station between a resilient frame-mounted pad and a transparent plate on the lamp arm by a toggle linkage between the frame and the arm. The template has a rectangular array of windows and is manually positionable on locating pins at the exposure station for different exposures. A positive image of each window is provided on the template, and the locating pins are movable via movement of the lamp arm from a preview position where the image is at the exposure station so the operator can see where the graphic will be formed to an exposure position with the associated window located at the exposure station for exposure. The template also has a code for each window optically readable by the device so that means in the device will advance the strip material a predetermined distance to provide appropriate spacing between graphics along the strip material.

---

3. Independent claim — plain-language overview

The patent contains exactly one claim (claim 1), and it is the sole independent claim; there are no dependent claims. It is drafted as a Jepson-style "improvement" claim: the preamble recites the prior-art device of US 3,914,775 as the environment, and the patentable improvement follows "the improvement wherein."

Structure:

1. Preamble (admitted prior art / environment): A device for forming graphics (letters, symbols, pictures) along a strip of radiation-sensitive material, comprising (a) means defining an exposure station; (b) means for positioning a predetermined portion of the strip at that station; and (c) means actuated at the station for momentarily irradiating that portion in a sharply defined graphic pattern — the irradiating means including a thin, radiation-transparent template with a radiation-blocking coating having sharply defined open areas shaped as the desired graphics (i.e., transmissive "windows"); means for mounting the template to register one window at the exposure station; and a flash lamp mounted for movement between a normal position (spaced from the station, allowing visible inspection of the template and strip) and an expose position (lamp close to the station), plus means for firing the lamp when it reaches the expose position.

2. The improvement — four interrelated features:

   • (a) Positive preview image. The template's coating has a viewing opening adjacent each window, and for each window the template carries a positive image of that window inside the viewing opening, positioned in a predetermined spatial relationship to the window. (This is the core of the "preview feature": the operator sees a positive of the graphic — not the negative window — before exposure, which the patent states is what makes accurate manual kerning/spacing adjustments possible, especially for letters lacking vertical adjacent edges.)

   • (b) Locating orifices. The template has locating orifices at predetermined locations relative to the windows.

   • (c) Two-position locating members. The template-mounting means comprises locating members that enter the orifices, and means mounting those members for movement between:

     • an exposure position, at which the window associated with the orifices sits at the exposure station; and
     • a preview position, at which the corresponding positive image is positioned at the exposure station — specifically at the very location the window will occupy during exposure.

   • (d) Automatic preview/expose interlock. Means coupled between the lamp-mounting means and the template-mounting means cause the locating members to sit in the preview position when the lamp is in its normal position, and in the exposure position when the lamp is in its expose position. In other words, lowering the lamp arm mechanically shifts the template so the window (rather than the preview image) registers over the strip.

Scope note: Because the claim is in improvement format, its scope is the combination of the recited prior-art environment plus the four improvement elements — not the lamp/toggle/pad structure alone. Notably, although the specification describes many other innovations in detail, those are not claimed in this patent:

• the toggle-linkage + resilient-pad + glass-plate-on-the-arm pressing mechanism (claimed in the sibling patent US 4,291,957, "Graphic forming device with toggle clamped lamp arm");
• the optically readable spacing opening 36 / sensor 92 / one-way clutch 81 / electric clutch 108 automatic advance system (described in this specification but absent from claim 1, and instead pursued in the copending US 4,266,863, "Device for forming graphics"); and
• the adjustable tube 124 for supplementary spacing.

This is consistent with a deliberate three-way divisional/companion filing strategy by 3M around the same disclosure.

---

4. Litigation / CAFC 2026 docket check

I found no evidence of any litigation, ITC proceeding, PTAB proceeding, or Court of Appeals for the Federal Circuit 2026 docket involving US 4,291,956. Search results for "4291956 + CAFC 2026" returned only unrelated Federal Circuit activity (e.g., Contour IP Holding LLC v. GoPro, Inc., Fed. Cir. No. 2026-2012, on appeal from N.D. Cal. 3:17-cv-04738; and the Ex parte Baurin obviousness-type double-patenting amicus activity) — none of which names this patent. Its 1999 expiration is consistent with no live dispute. I cannot, however, rule out proceedings that are not surfaced by public web indexing, so treat the absence of litigation as a high-confidence but not exhaustively verified finding rather than an affirmative clearance.

---

5. Identifier-collision warning (important — do not auto-correct)

The bare string "4291956" is not unique to this US patent in public registries:

• EP publication 4291956 is an entirely different document: EP 4291956 A1, "Cleaning blade, lubricant leveling blade, process cartridge, and image forming apparatus," Ricoh Company, Ltd., App. No. 22702526.9, filed 2022-01-27, granted 2024-11-20 (B1), with Japanese priority 2021-02-15 / 2021-06-29 (inventors Ohmori Masahiro, Juri Keiichiro, Kimura Hideki). It appears in Belgian and Irish national registers and lapsed 2025-01-31.
• That EP number is a different numbering series from the US patent number. It is not a family member, not a counterpart, and not related in subject matter.

Per the strict rule to interpret identifiers literally: US 4,291,956 ≠ EP 4291956. Any reference in a 2024–2025 European register entry is to the Ricoh cleaning-blade application, not to the 3M graphic-forming device.

---

6. Uncertainty disclosure

• Everything in §§1–3 is sourced directly from the authoritative full patent text you supplied and is cross-corroborated by Google Patents, Justia, Unified Patents, and uspto.report — high confidence.
• The "Current Assignee" field shows "3M Co," but Google Patents itself cautions that listed assignees may be inaccurate and that no legal analysis was performed. A 2002 merger/name-change assignment (Minnesota Mining and Manufacturing Company → 3M Company, Reel/Frame 2502/0547) is recorded in USPTO records for 3M marks, but I did not verify a specific recorded assignment chain for this patent's file. Treat current ownership as probable, not confirmed.
• The absence of litigation is an absence of evidence; I did not query PACER or Docket Navigator directly, only public web indices. Moderate confidence.
• I could not independently verify the Examiner's name against the official file wrapper; I report it as listed by Unified Patents.

I'll search litigation databases and other sources for US 4,291,956.

Let me search litigation-specific sources for this patent.

Let me check court docket sources and any related enforcement activity.

Litigation Search Results: US Patent No. 4,291,956

Bottom line

I found no evidence of any litigation involving U.S. Patent No. 4,291,956 — no district court action, no CAFC appeal, no ITC Section 337 investigation, and no PTAB proceeding (IPR/PGR/CBM). Below is what I checked, what I found, and the important caveats.

---

Patent identification (verified, so you can confirm we're discussing the same right)

---

Sources searched

1. Unified Patents litigation portal (as instructed)
I retrieved the Unified Patents page for this patent (https://portal.unifiedpatents.com/patents/patent/US-4291956-A). The page confirms bibliographic data, expiration (1999-12-17), "Lifetime Renewal Fees: $0," and "Referenced By (58)." It discloses no litigation entries — no district court case list, no PTAB case list. (In Unified's format, an asserted patent normally shows an associated case list on this page.)

2. Patent-litigation research databases (Docket Alarm, Justia Dockets, CourtListener, RPX Insight)
Keyword searches on the patent number and on "3M / Minnesota Mining" plus the patent subject matter returned no case naming this patent. Searches surfaced only unrelated 3M litigations (TransWeb respirator/antitrust; JJO orthopedic casting; Lake Country polishing pads; 3M v. KiniK ITC Section 337), none of which assert 4,291,956.

3. Google Patents "Cited By / Citations" and family data
The forward-citation set for '956 consists overwhelmingly of Flexiworld Technologies / William Ho Chang mobile-printing patents (2000–2022) — a citation-signal, not litigation. The only backward citations are US2,762,277; US3,204,520; US3,828,359; US3,914,775; US4,141,632. No assertion record.

4. Identification of a confusing near-hit (flagging explicitly)
Multiple results for the bare number "4291956" refer to EP 4 291 956 — a European patent granted to Ricoh Company, Ltd. ("Cleaning blade, lubricant leveling blade, process cartridge, and image forming apparatus," filed 2022-01-27, grant published 2024-11-20; e.g., https://eregister.ipoi.gov.ie/register/PTRegister.aspx?idappli=22702526.9). Also, Florida LLC document FEI 84-4291956. These are different, unrelated identifiers and are not auto-corrected to your patent number.

---

Requested table

---

Important caveats (please weigh before relying on this)

1. I could not directly query PACER or the CAFC docket. My tooling is web-search only; search engines index only a fraction of historical dockets. A negative keyword result is not the same as a verified "no records" PACER check.
2. Timing strongly disfavors digitized litigation data. The patent expired 1999-12-17. Any enforcement would have occurred roughly 1981–1999, largely in the pre-PACER/CM-ECF era. Old closed district court cases from that period are frequently absent from free litigation databases.
3. The patent is not an attractive assertion candidate — it has a single claim and expired over 25 years ago — which is consistent with (though does not prove) the absence of litigation.
4. If you need a legally defensible clearance/litigation opinion, commission a PACER/CM-ECF docket search and a Westlaw/Lexis or Docket Navigator search covering 1981–2000, including 3M's known enforcement campaigns of that era. I can draft search specifications for that if useful.

Conclusion: Based on the sources searched, no litigation is known involving US 4,291,956. I state this with moderate-to-good confidence for post-2000 records and lower confidence for the 1981–1999 window, for the reasons above.

Proceedings overview

Zero AIA trial proceedings are on file for US 4,291,956. The USPTO Open Data Portal structured block returns no IPR, PGR, or CBM for this patent, and independent web searches (Google Patents/Unified Patents patent pages, PTAB docket aggregators) surface no petition, institution decision, FWD, or appeal naming 4,291,956 — so the breakdown is 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied, and the bottom line for a defendant is not "hardened patent" but something stronger: there is no PTAB record at all on a patent whose sole claim expired on 1999-12-17, which means the absence here is structural, not strategic.

(No proceedings to list)

There is no IPR, PGR, or CBM number to report for US 4,291,956, and I will not invent one. For completeness, the reasons the list is empty (all verifiable from the patent's own front page and the ODP block):

• The patent is long expired. Priority/filing date 1979-12-17; granted 1981-09-29; ODP lists "Anticipated expiration" as 1999-12-17 and status "Expired – Lifetime." AIA trial practice (IPR/PGR/CBM under 35 U.S.C. §§ 311–329) only became available on 2012-09-16 — more than twelve years after this patent's enforceability ended. There is no live right to challenge and no damages window left in which a petitioner would have an incentive to pay PTAB fees.
• The patent has a single claim. The full text contains exactly one claim ("I claim: 1. ..."), an improvement claim to a graphic-forming device with a preview feature (positive image in a viewing opening, locating orifices/orifices-to-pins alignment, and locating members that shift between a preview position and an exposure position as the lamp arm moves). Any proceeding would have had total-claim exposure — and none was filed.
• No defensive aggregator footprint. Unified Patents' patent portal page for US-4291956-A shows only bibliographic data (assignee 3M Co / Minnesota Mining and Manufacturing, examiner Donald A. Griffin, zero lifetime renewal fees) — no PTAB tab entries, no litigation entries. Unified is not in the chain.
• The 57 "Cited By" hits are citation noise, not proceedings. The Google Patents "Cited By" list for this patent is dominated by Flexiworld Technologies / William Ho Chang wireless-printing patents from 2000–2022 (US 9,092,177; US 10,860,290; US 11,204,729, etc.). Those are later patents that cite 4,291,956 as background art — they are not challenges to it, and none of them is a PTAB proceeding on 4,291,956.

Strategic summary

Claim status: one claim, expired, untested, and un-canceled. US 4,291,956 issued with a single claim (claim 1), and because no IPR/PGR/CBM ever issued a Final Written Decision against it, there is no claim-level record of cancellation or survival — "untested" is the accurate characterization, not "sustained." The distinction matters: a patent that survived an IPR is a hardened patent; this one simply ran out its term before the AIA existed. The practical consequence is that the patent cannot be asserted for any infringing act occurring on or after 1999-12-17, so a modern demand letter invoking it is facially defective regardless of the PTAB picture.

Estoppel landscape: none, and irrelevant here. Because no petitioner ever filed, § 315(e)(2) estoppel never attached to anyone, and there is no petitioner-privity chain to check. Concretely, that means a defendant facing an assertion today has no IPR-derived estoppel constraint — but also no IPR-derived invalidity judgment to point to. The invalidity arsenal for this patent, if it were ever asserted, would be an Article III defense built from the references already on the face of the patent: US 2,762,277 (McChesney), US 3,204,520 (Eltra), US 3,828,359 (3M), US 3,914,775 (3M), and US 4,141,632 (Mitchell) — plus the § 102(b)/§ 103 on-sale and public-use exposure inherent in a 1979 filing. Those are court grounds, not PTAB grounds, at this point.

Pattern signals: none of the usual ones. The same petitioner did not file multiple IPRs (no petitioner filed at all); the patent owner did not pursue PTAB appeals because there was nothing to appeal; no defensive aggregator appears; and the only parallel proceedings in the family are foreign — CA1145991A, JPS5693569A, DE3067902D1, and EP0031670B1 (all claiming the same 1979-12-17 priority). The existence of a granted EP member (EP0031670B1) means European opposition was possible, but I did not verify any EPO opposition file and will not assert one exists.

Recommended next steps

• If you are a defendant and a demand letter cites US 4,291,956: there is no FWD to link to, because none exists. Your first-line response is the expiration date — ODP lists anticipated expiration 1999-12-17 with status "Expired – Lifetime," and the patent's own record shows no maintenance-fee activity (Unified's portal reports $0 lifetime renewal fees). Any asserted claim of infringement must therefore rest on conduct dating to 1999 or earlier, which is itself outside the § 286 six-year damages lookback and almost certainly outside any limitations period. Ask the sender to identify the accused acts and their dates in writing.
• If you want a fallback validity record: because there is no AIA trial history, there is also no § 315(b) one-year bar and no estoppel preventing you from raising any ground in court — but you cannot file a meaningful IPR against a patent with no live enforceable term, and the PTAB would have no practical reason to institute. Focus on Rule 11 / § 285 exposure if the patent is asserted in bad faith.
• If active proceedings are pending: they are not. There is no institution-decision deadline, no oral hearing date, and no FWD due date to calendar for this patent. The absence of PTAB activity on a 1979 patent is not the suspicious signal it would be for a modern patent — it is the expected result of a term that ended thirteen years before the AIA trial regime began.
• Verify before relying: the ODP block provided in this prompt is the canonical source and shows no proceedings; my searches were consistent with it but PTAB E2E (https://ptab.uspto.gov) and the USPTO Patent Center record for 4,291,956 remain the authoritative checks if you need a pristine declaration-grade confirmation rather than an analyst's summary.

I'll research the assignment chain for this patent, starting with the USPTO Assignment Center and cross-referencing public records.

Let me check the USPTO assignment records and Google Patents legal events directly.

Let me verify the assignment records specific to this patent.

I hit the search-step limit while querying the Assignment Center directly, so the following is built from the sources I did retrieve plus the authoritative patent text. Where I could not confirm a reel/frame against this patent's own file, I say so rather than filling it in.

Verification starting point: USPTO Assignment Center search — https://assignmentcenter.uspto.gov/ (patent number 4291956); the pre-2012 mirror is https://assignment.uspto.gov/patent/index.html. Google Patents legal events for this patent: https://patents.google.com/patent/[US4291956](/patent/US4291956)/en

---

Inventors

Pattern note: Vogelgesang is a prolific 3M in-house inventor; the patent is assigned on its face to Minnesota Mining and Manufacturing Company, which is the classic employee-inventor assignment pattern. I found no evidence of the inventor departing 3M within 12 months of filing, and no evidence of any personally-held interest in this patent. (Unlike the "all inventors left, then the portfolio was fire-sold" pattern, there is nothing here — the inventor never appears as an assignor after the original filing assignment.) I could not independently verify Vogelgesang's employment dates at 3M from a primary source, so treat "3M employee" as high-confidence inference from the face-of-patent assignment, not from an employment record.

---

Original assignee

• Minnesota Mining and Manufacturing Company ("3M"), Delaware corporation, 3M Center, 2501 Hudson Road, St. Paul, MN 55144.
• Primary line of business: diversified industrial/manufacturing conglomerate (adhesives, abrasives, tapes, office products, imaging/graphics). At the relevant time 3M marketed imaging and "graphics" products (Thermo-Fax, overhead-transparency and later lettering systems).
• Did it ship a product embodying the claims? The claims are directed to a lettering/graphics-forming device and its template-and-preview mechanism, which the specification presents as an improvement over 3M's own prior devices (US 3,914,775 and US 3,828,359). 3M was the operating manufacturer of the hardware and the consumable strip/template media. Product-shipment status is a probable-but-unverified commercial fact — I did not locate a specific commercial model name for this embodiment in the sources retrieved.
• Current status: Operating. Still the same legal entity; renamed "3M Company" effective 2002 (see timeline). Not bankrupt, not dissolved, not acquired. 3M remains a NYSE-listed company (ticker MMM).

---

Assignment timeline

I could not retrieve a patent-specific Assignment Center hit for 4291956 before hitting the search-step limit. What I did verify is the 2002 portfolio-wide 3M merger/change-of-name recording at Reel/Frame 2502/0547, which is the standard vehicle by which Minnesota Mining and Manufacturing Company patents and marks passed to "3M Company," and which is documented across multiple USPTO TSDR/TTAB records I retrieved. I therefore present the timeline in two tiers and flag confidence on each line.

Tier 1 — Confirmed original assignment (on the face of the patent)

• 1979-12-17 (executed) / recorded on or about 1979-12-17 — Reel/Frame not confirmed
  • Conveyance: Assignment (inventor → employer, standard pre-issuance assignment)
  • Assignor: Peter J. Vogelgesang
  • Assignee: Minnesota Mining and Manufacturing Company
  • Correspondent: not confirmed (I did not retrieve a reel/frame or correspondent for this filing-stage record)
  • Context: ordinary employee-inventor assignment to the original assignee.

Tier 2 — Confirmed corporate recording covering the 3M portfolio

• 2002-04-08 (executed) / recorded 2002-04-30 — Reel 2502/0547
  • Conveyance: Merger and Change of Name (40 pages — a portfolio-wide, not patent-specific, instrument)
  • Assignor: Minnesota Mining and Manufacturing Company
  • Assignee: 3M Company (Delaware corporation, 3M Center, 2501 Hudson Road, St. Paul, MN 55144)
  • Correspondent: James F. Voegeli, 3M Center, Bldg. 220-11W-01, P.O. Box 33427, St. Paul, MN 55133-3427. (Recurrence note: Voegeli is the recorded correspondent on multiple 3M merger/change-of-name recordings of the same vintage — he is 3M's own in-house recording contact, not an outside NPE filer. The recurrence is a corporate housekeeping signature, which is exactly the inverse of the NPE "one lawyer, many shells" tell.)
  • Context: internal reorg / change of name only. Not an acquisition, not a sale, not a fire-sale, not a transfer-to-asserter. The underlying transaction was the statutory merger of 3M's subsidiary into the parent under DGCL §253, with the parent surviving under the new name "3M Company," effective 8:00 a.m. ET, April 8, 2002, per 3M's Form 8-K (Date of Report April 9, 2002; SEC accession 0000897101-02-000248).

Not found (i.e., I have no evidence any of these exist): any post-2002 assignment of this patent to an NPE, holding company, or defensive aggregator; any security agreement / securitization lien; any release; any correction. The patent expired 1999-12-17 (20-year term from the 1979 filing) for failure to pay maintenance fees — which, notably, is before the 2002 name-change recording, so the 2002 filing is a change-of-name notation on an already-expired patent and carries no transferable economic value.

⚠️ Caveat on reel/frame 2502/0547: I verified the reel/frame number, dates, execution date, entity names, and correspondent from USPTO TSDR/TTAB assignment abstracts, but those abstracts were for 3M trademark registrations, not for this patent. The same reel/frame instrument is asserted by 3M to cover its patent and mark portfolios generally. I did not confirm that patent 4,291,956 is itemized in that instrument's 40 pages. Treat the linkage of this patent to 2502/0547 as probable but unconfirmed.

---

Timeline diagram

timeline
    title Ownership of US 4291956
    1979 : Filed by Vogelgesang
         : Assigned to Minnesota Mining and Manufacturing
    1981 : Patent issued
    1999 : Anticipated expiration lapsed
    2002 : Minnesota Mining renamed 3M Company

(I deliberately did not place the 2002 event as a separate "transfer" node with an : sub-line implying a change of beneficial owner — it is a name change on an already-expired patent. Kept the event text paren/slash/comma-free.)

---

NPE / troll-pattern signals

---

Verdict

Insufficient data — and the insufficiency is a good outcome here, not a gap that hides risk. The only post-issuance ownership event I could substantiate is the 2002 merger-and-change-of-name recording (Reel 2502/0547, executed 2002-04-08, recorded 2002-04-30) moving Minnesota Mining and Manufacturing Company → 3M Company, plus the ordinary filing-stage inventor assignment to 3M. No NPE, no shell LLC, no cascading transfers, no assertion history, and the patent expired 1999-12-17 — before the name change was even recorded. None of the eight NPE signals is present, but I am electing "Insufficient data" rather than "Defensive/non-asserting" because the chain terminates at an operating company (3M), not at a defensive aggregator, and because I was unable to pull a patent-specific Assignment Center record to prove the chain is complete.

Contradiction flagged for the record: the previously-generated summary §6 noted it had "not verified a specific recorded assignment chain for this patent's file." This section now supplies the most likely link — Reel 2502/0547 — but marks it probable, not confirmed, because I verified that reel/frame only in 3M trademark abstracts, not in a patent-file abstract for 4291956. That caveat is consistent with, not contradictory to, the earlier uncertainty disclosure.

Verify at: https://assignmentcenter.uspto.gov/ (search 4291956) and, for the corporate-event anchor, 3M's Form 8-K at https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000066740 (accession 0000897101-02-000248).

I'll verify the patent on USPTO/Google Patents and pull details on each cited reference.

Now let me pull the two remaining references (US 2,762,277 and US 3,204,520) and confirm the citation list from the patent.

Preliminary note on method and sources

I searched the patent number 4291956 as literal text (not a range, not a similar number) and located the corresponding US grant in the USPTO-derived records: uspto.report/patent/grant/4291956 and patents.google.com/patent/US4291956/en, cross-checked against the authoritative full text you supplied. I did not auto-correct the number, and I did not substitute results for adjacent numbers.

Identifier-collision caveat (carried forward, do not auto-correct): my search again surfaced EP 4291956 — Ricoh Company, Ltd., "Cleaning blade, lubricant leveling blade, process cartridge, and image forming apparatus," App. No. 22702526.9 (Irish register: https://eregister.ipoi.gov.ie/register/PTRegister.aspx?idappli=22702526.9). That is a different numbering series, different owner, different subject matter, and is not US 4,291,956. I exclude it from the prior-art analysis below.

---

1. The patent being analyzed (USPTO-record data)

Consistent with the earlier-generated sections, the sole claim is a Jepson-style improvement claim: the preamble admits the device of US 3,914,775 as the environment, and the patentable subject matter follows "the improvement wherein." Because there is only one claim, all anticipation analysis below is directed to claim 1.

---

2. The complete prior-art "references cited" of record

Per the patent's own front-page citation list (5 references, all cited by the examiner):

Statutory-date classification for the '956 filing date of 1979-12-17:

• References 1–4 published more than one year before filing → available under §102(a) and §102(b).
• Reference 5 ('162) published 1979-02-27, i.e. less than one year before filing → available under §102(a)/(e)-type art, not §102(b). (This date relationship matters if the file wrapper shows a §102(b) rejection over '162 — it could not properly have been §102(b).)

Also note: the Google Patents "Cited By" set (the Flexiworld/William Ho Chang mobile-printing family, 2000–2022) is forward citation traffic, not prior art to a 1979 filing, and is irrelevant to §102.

---

3. Element-by-element claim map (for the anticipation analysis)

Claim 1 — preamble (admitted prior art / environment):

• P1: exposure station;
• P2: means for positioning a strip portion at the station;
• P3: momentarily-irradiating means, including a template = thin radiation-transparent member + radiation-blocking coating + sharply defined open areas = radiation-transmissive windows;
• P4: means for mounting the template to register a window at the station;
• P5: flash lamp mountable between a normal position (spaced, allowing visible inspection) and an expose position, with operating means to fire at the expose position.

Claim 1 — the improvement (the patentable delta):

• A. coating has a viewing opening adjacent each window;
• B. for each window, a positive image of that window within the viewing opening, in a predetermined positional relationship to that window;
• C. template has locating orifices at predetermined locations relative to the windows;
• D. template-mounting means comprises locating members that enter the orifices;
• E. means mounting those locating members for movement between an exposure position (window at the station) and a preview position (the positive image at the station, at the very spot the window will occupy);
• F. interlock coupled between the lamp-mounting means and the template-mounting means: preview position when the lamp is normal, exposure position when the lamp is exposed.

---

4. Per-reference analysis

Reference 1 — US 2,762,277 A (Mcchesney, Roy, 1956-09-11)

• Description: Photographic typographical composing machine using a film strip A of 35 mm film bearing transparent characters, wound on reels and passed over a printing table; the operator selects a character by viewing it through a viewing tube 42 in a hinged cover; adjacent each character the patent provides indicia aa indicating the printer's point width; a sensitized strip B is fed through a groove for exposure.
• Relation to claim 1: Discloses strip handling past a print/exposure region and visual operator inspection of the character to be printed, plus width indicia — i.e., touches P1/P2 and is general evidence of the "inspect-before-print" and "width/spacing information" concepts.
• §102 anticipation of claim 1: NO. It has no template with a radiation-blocking coating and windows (P3), no flash lamp arm with normal/expose positions (P5), and none of improvement elements A–F. It is at most §103 background art for the general notion of previewing a character and encoding its width.
• Source: https://patents.google.com/patent/US2762277 ; https://www.freepatentsonline.com/[2762277](/patent/2762277).html

Reference 2 — US 3,204,520 A (Eltra Corp., 1965-09-07)

• Description: Apparatus for manufacturing font plates for phototypographical machines — i.e., equipment for making the character-bearing font plates used by phototypesetters, not a graphic-forming/exposure device itself.
• Relation to claim 1: Only tangentially relevant — it concerns production of a character master/font plate, which shares with P3 the general idea of a graphic-bearing master.
• §102 anticipation of claim 1: NO (and I flag a source limitation: my retrieval of the full text of this reference failed, so the description above rests on the title as listed in the '956 citation table and the specification's use of the reference; treat it as low-confidence on substance). This reference is the weakest of the five and does not approach the improvement elements A–F.
• Source: listed in US4291956 citation table (Google Patents).

Reference 3 — US 3,828,359 A (3M; Alexander, Lunquist, Vogelgesang, 1974-08-06)

• Description: "Template for a graphic forming device." A single-graphic slide-type template for the 3M graphic-forming device: a thin radiation-transparent member with a radiation-blocking (reflective) coating having a sharply defined open area = a window shaped as the graphic, used by inserting the slide under a fixed glass plate at the exposure station.
• Relation to claim 1: This is the direct antecedent of the '956 template. The '956 specification states the template "except for the location of the windows 20 and viewing areas 31, is made in accordance with the teachings in U.S. Pat. No. 3,828,359." So '359 supplies the P3 template structure (thin transparent member + blocking coating + sharply defined window).
• §102 anticipation of claim 1: NO. '359 is a single-graphic slide; it discloses no adjacent viewing opening (A), no positive image (B), no locating orifices (C), no movable preview/exposure locating members (D/E), and no lamp interlock (F). The '956 specification itself frames '359 as deficient precisely on these points (operator must insert the slide under the glass for every use). At most §103 base art.
• Source: https://uspto.report/patent/grant/3,828,359

Reference 4 — US 3,914,775 A (3M; Vogelgesang, Lunquist, 1975-10-21)

• Description: "Device for forming graphics" — the admitted-prior-art environment of claim 1. Discloses an exposure station, means for advancing a radiation-sensitive strip past it, a xenon flash lamp carried on an arm movable between a normal position (spaced from the station, permitting visual inspection of the template and strip) and an expose position (lamp adjacent the station), a highly reflective thin template with a radiation-transmissive window, clamping means with a transparent plate, and means for flashing the lamp on reaching the expose position. Its spacing scheme requires the operator to manually register the trailing edge of the prior graphic with a mark, using guide marks on the template.
• Relation to claim 1: Discloses essentially the entire preamble P1–P5 verbatim in substance; that is why '956's preamble reproduces it and why the specification says the invention is "of the type described above."
• §102 anticipation of claim 1: NO — but it is the case's controlling reference. Under Jepson practice, the preamble is admitted prior art, so '775 cannot be cited to "anticipate" the claimed invention; the claim stands or falls on improvement elements A–F, none of which '775 discloses. Its single-window/circular-array template in fact has no positive viewing image, no locating orifices, and no preview/exposure locating-member movement. '775 is thus §102 as to the preamble only, and the primary §103 springboard for the improvement.
• Note on dates: the '956 citation table lists 1972-12-26 for '775 (priority/CIP date); the actual application (US 406,548) was filed 1973-10-15.
• Source: https://patents.google.com/patent/US3914775 ; patenthub.cn record confirming 申请日 1973-10-15 and the claim-1 text.

Reference 5 — US 4,141,632 A (Mitchell, Roger E., 1979-02-27)

• Description: A photocomposing machine with a fiche-like font having two fields: a first field of characters in positive form viewable by the operator through a window of the machine, and a second field in negative image which is projected onto film. The positive and negative characters "are always spaced a constant distance from each other," and the font is carried by a frame freely movable in X and Y; indexing means lock the selected character into the optical path.
• Relation to claim 1: This is the most substantive prior art against the improvement, because it is the only reference that discloses the positive-image/negative-image pairing with a fixed spatial offset — i.e., the functional core of elements B (positive image in predetermined relationship to the graphic that will be printed) and, in spirit, E (the positive is used for operator viewing/preview while the negative is used for actual exposure).
• §102 anticipation of claim 1: NO. '162 discloses no radiation-blocking coating with transmissive windows on a template in the P3 sense; no locating orifices/locating members (C/D); no moving carriage between a "preview position" and an "exposure position" of the same station; and critically no interlock with a lamp arm (F). Its positive/negative offset is a constant, always-there relationship, not a two-position registration swap driven by lamp movement. '162 is therefore §102(a)-type art that supports a §103 obviousness rejection when combined with '775, not an anticipation.
• Source: https://patents.google.com/patent/US4141632 ; https://patentimages.storage.googleapis.com/ff/71/e8/28af9a7344e1cd/US4141632.pdf

---

5. Consolidated §102 table

Bottom line on §102: No single reference of record anticipates claim 1, because claim 1 is an improvement claim and each reference is missing at least one of improvement elements A–F. There is no reference that discloses, in one document, the combination of (i) a viewing opening with a positive image adjacent each window, (ii) locating orifices + locating members, (iii) locating-member movement between a preview position and an exposure position, and (iv) an interlock tying that movement to the lamp arm. The references are properly §103 art: '775 supplies the environment; '359 supplies the coated window template; and '162 supplies the positive/negative-offset notion.

---

6. Honest limitations

• I retrieved and read the substance of '277, '359, '775, and '162. I could not retrieve a full text of US 3,204,520; my characterization of it is based on its title in the '956 citation table and is low-confidence as to substance.
• I did not obtain the '956 file wrapper / examiner's actions, so I cannot confirm whether the examiner actually made a §102 rejection over any of these references, or only a §103 combination (the citation listing alone does not reveal the ground of rejection).
• The "patent citations" list I used is the one printed on the '956 front page and mirrored by Google Patents; there was no separate non-patent-literature (NPL) citation set of record.
• Per instruction, all identifier strings are reported literally ("US 4,291,956" ≠ "EP 4291956"); no auto-correction has been applied.

I'll gather the actual disclosures of the cited prior-art references before building the § 103 combinations.

Good material. Let me nail down the remaining references and the sibling/companion patents.

§ 103 Obviousness Analysis — US 4,291,956

⚠️ Date/record flag before I start: the task header states the current date as April 26, 2026, while the system prompt, the earlier-generated sections, and the Google Patents fetch stamp all state 2026-09-30. I take the fetch stamp as authoritative for "as-of" purposes; the April date does not change any conclusion, but I am flagging the inconsistency rather than silently harmonizing it.

Second flag (contradiction-in-part with the earlier sections): the "Patent summary" section states that the spacing system was "instead pursued in the copending US 4,266,863." That is correct for '863 claims 3–6, but incomplete: the '863 record (uspto.report/patent/grant/4266863) shows claims 1–2 also recite the preview/positive-image/locating-member combination (with two-spaced-pin and rectangular-array limitations), and claims 7–9 claim the template per se. So '863 is not a "spacing-only" sibling. This matters below because it tells us what the applicant itself regarded as a separate invention — and it partly cuts against the patentee on the preview feature.

---

1. Legal framework and the operative date

• Application filed 1979-12-17 → pre-AIA 35 U.S.C. § 103(a) governs; the Graham v. John Deere, 383 U.S. 1 (1966) factors control, as glossed by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (KSR applies to pre-AIA claims).
• § 102(b) art: anything published or patented more than one year before 1979-12-17, i.e., before 1978-12-17.
• § 102(a)/(e) art: anything before the invention date or filed before 1979-12-17.
• § 103(c) does not help the patentee here. '775 and '359 are 3M patents, and so is '956, but § 103(c) only removes § 102(e)/(f)/(g) art. '775 (issued 1975-10-21) and '359 (issued 1974-08-06) are § 102(b) art, and they are not "the same invention" by the same inventive entity anyway ('775 names Vogelgesang and Lunquist; '359 names Vogelgesang, Alexander and Lunquist; '956 names Vogelgesang alone). Common corporate ownership is irrelevant to them.

2. The claim, parsed — and what is not in it

Claim 1 is a single Jepson-style improvement claim. The preamble is expressly admitted prior art: the specification says "Like the device described in U.S. Pat. No. 3,914,775, the device according to the present invention comprises . . ." Applicant admissions in the specification are usable against the claim (In re Fout; MPEP 2129). The preamble therefore supplies — for free — the exposure station, the strip-positioning means, the coated template with transmissive windows, the template-mounting means, the flash lamp movable between normal and expose positions, and the lamp-firing means.

The contested matter is only four things: (a) viewing opening + positive image of each window in it, in predetermined relationship to the window; (b) locating orifices at predetermined locations to the windows; (c) locating members that move between an exposure position (window at the station) and a preview position (positive image at the station, at the very location the window will occupy); (d) means coupled between the lamp mount and the template mount so that preview = lamp normal, exposure = lamp expose.

The toggle/pad/glass-plate press, the spacing opening 36, the sensor 92, and the one-way/electric clutch drive are in the specification but not in this claim (they are in '957 and '863). That is significant: the § 103 inquiry is narrow. The obviousness attack does not need to reach any of the electromechanical complexity the patent spends most of its specification on.

§ 112 ¶ 6: all four improvement elements are means-plus-function or functional recitations. Under pre-AIA § 112 ¶ 6 the corresponding structures are: for (c), the drawer slide 40 / movable part 43 / bar 46 / cam slot 50 / projection 52; for (d), the drive pin 45 + bar 46 + cam plate 49 + cam slot 50. Prior art must disclose an equivalent, not identical, structure.

3. Person having ordinary skill in the art (PHOSITA)

A mechanical or optical engineer with a bachelor's degree and roughly 2–4 years of experience in photocomposition / phototypesetting apparatus or radiation-sensitive recording systems, or a technician of equivalent experience in that art. By 1979 this was a mature, crowded art (the '956 family itself is classified B41B17 in the EPO search report and G03B27 in the US — photocomposing machines "having fixed or movable character carriers," and contact-printing exposure apparatus). The PHOSITA would be thoroughly familiar with (i) movable character carriers — discs, drums, fiche, film strips; (ii) registering a coated flexible sheet on pins; and (iii) operator viewing/selection apertures.

---

4. The prior art of record and what each reference actually teaches

Also on the page but non-prior-art for this claim: the family members (CA1145991A, DE3067902D1, JPS5693569A, EP0031670B1) all post-date the 1979-12-17 filing and are not § 102(b) art; the 57+ "Cited By" hits are Flexiworld Technologies / William Ho Chang wireless-printing patents (2000–2022) — post-art, citation noise, no § 103 value. The "Family Cites Families" set (US 3,198,095 Cavanaugh; US 3,336,849 Photon; DE 2,258,669 Agfa-Gevaert; SE 387,304; US 4,003,654) ⚠️ I could not open these in this session either; I use them only as evidence of the crowdedness of the photocomposition art (movable character carriers + viewing apertures were ubiquitous), not for specific teachings.

---

5. Ground A (primary): US 3,914,775 in view of US 4,141,632

This is the strongest single combination and I would expect it to carry the day.

Why '775 alone nearly gets there. The preamble is admitted. Element (d) — a means coupled between the lamp mount and the template mount that shifts the template between two registered positions as a function of lamp position — is structurally disclosed by '775 claims 6–7 (turntable moved between "align" and "spaced" positions by means coupled to the lamp). Element (a)'s viewing opening adjacent each window is disclosed by '775 claim 6 (the discontinuous coating providing a viewing opening "beside each window"). Only the content of the viewing opening and the purpose of the two template positions differ: '775 puts nothing in the viewing opening (it lets you see the strip, for spacing), and its two template positions exist to align a mark with the trailing edge of the last-formed graphic.

Why '632 supplies exactly the missing content. Mitchell discloses the same physical idea in a sibling art: a positive image and its negative counterpart carried on one medium, always at a constant (predetermined) relative spacing, where the operator selects/positions using the positive and the machine exposes using the negative. That is element (a)'s "positive image of that window within said viewing opening, positioned with a predetermined relationship with respect to that window," read together with element (c)'s "preview position with the positive image . . . positioned at the exposure station at the position in which the window is located when the locating members are in their exposure position."

Motivation — and it is articulated by the patentee itself. The '956 specification recites the problem verbatim: the prior templates "require the operator to visually evaluate spacing . . . by comparing a positive graphic already formed along the strip material and a negative image of the next graphic to be formed on the template portion at the exposure station, which comparison causes difficulty in making manual adjustments . . . especially between those letters which do not have vertical adjacent edges." Mitchell is the art's own answer to the identical "you cannot judge a character from its negative" problem (Mitchell's stated purpose is to eliminate character-by-character search because "there is no way to go directly from one character to another"). When the problem is identified in the reference and the solution is known in the same field, the combination is a textbook KSR case.

Additional KSR rationales:

• Same field of endeavor / same problem. '956 and '775 are classified G03B27 (contact-printing exposure apparatus) and B41B17 (photographic composing machines); Mitchell is B41B17. Same field, and the EPO search report for the sibling EP 0 030 866 lists "G 03 B 27/04, B 41 B 17/02" together.
• Predictable result. Placing a positive image at a fixed offset from its negative window on the same coated sheet is a purely geometric/mechanical rearrangement; Mitchell expressly teaches that the offset is constant and can therefore be a fixed design parameter. No new technology is required.
• "Known technique to improve similar devices in the same way" (KSR). Flexible-sheet templates already had viewing openings ('359); the positive-image content is a substitution of one known indicium type for another for its known function (In re Japikse; In re Hammer).
• Design choice / obvious to try. The '775 apparatus already converts lamp arm motion into template motion. Selecting what sits at the station in the lamp-up position (window vs. positive image) is a selection among a finite number of identified, predictable options with a reasonable expectation of success.

Anticipation vs. obviousness: neither reference alone anticipates. '632 has no flash lamp, no contacting template, no exposure station of the '775 kind (it projects through a lens system). '775 has no positive image. But the combination maps 1:1 onto every element of claim 1. I do not, however, claim § 102 anticipation by combination — the correct statutory vehicle is § 103.

One residual gap to be candid about: '632 moves a freely X-Y movable font frame, not "locating members" that enter "locating orifices." Element (b)/(c) therefore is not met by '632 itself. That gap is closed by Ground B / the general art below, and it is a weak gap: registering a coated sheet on two pins is the most routine mechanical expedient in this art, and the '956 specification itself calls the corresponding hardware (a drawer slide) "commercially available."

---

6. Ground B: '775 + '359 + '632 (the "template-based" combination)

A second, independent route that closes the locating-orifice gap and makes element (a) almost an applicant admission:

• '359 supplies the thin flexible transparent member with reflective coating, the sharply defined window, and the viewing opening adjacent the window — and '956 says so: "which template 22, except for the location of the windows 20 and viewing areas 31, is made in accordance with the teachings in U.S. Pat. No. 3,828,359." The specification then says: "Unlike the template described in that patent, however, the template 22 has positive images 33 of the windows 20 in its associated viewing areas 31." That is an express admission that the only change to the '359 template is filling its existing viewing areas with positive images — and '632 teaches filling a viewing field with positive images.
• Locating orifices/pins: routine mechanical registration, well within the skill level (two pins + a close-fitting circular hole + a transversely elongated hole to absorb center-to-center tolerance, as claimed in '863 claim 2, is ordinary drafting-room practice).

Motivation: the patentee framed the invention as an improvement to the '359/'775 templates; a PHOSITA seeking to reduce kerning errors would modify the very template the patentee names, using the standard positive/negative-font expedient that '632 teaches for exactly the same purpose (letting a human see the character before it is committed).

---

7. Ground C: '775 + '632 + '277 (width-information and viewing-aperture combination)

• '277 teaches per-character width indicia carried on the same character medium ("indicia indicating the printer's point width of the particular character") plus a viewing tube for the operator to see the characters as they pass.
• Motivation: the automatic-spacing objective (encode the width so the apparatus can set the space) is squarely present in '277, and both '956 and '863 implement it as a spacing opening whose width relates to the window width.

Caveat: this combination is aimed at claim 1's "predetermined relationship" language and at the sibling '863 claims 3–6 and 7–9. It is weaker against '956 claim 1 specifically, because claim 1 does not recite the optically readable spacing code (compare '863 claims 3–4 and 7–9, which do). I present Ground C primarily as (i) a motivating-art ground for why a PHOSITA would put something per-window on the template, and (ii) the strongest ground against the sibling claims.

---

8. Ground D: pure design choice / "printed matter" — the patentee's own admission

Independent of any reference: the difference between the admitted prior art and element (a) is what image is printed in an opening that the prior art already provides. '956 itself concedes the prior templates show "a negative image of the next graphic to be formed on the template portion at the exposure station." Substituting a positive for a negative in a viewing aperture is the substitution of one known form of visual indicia for another, used for its known informational function, with no new structural cooperation and no unexpected mechanical result (KSR; In re Ngai / printed matter lines of cases, with the caveat that the printed matter here does have a mechanical cooperation with the lamp-position interlock — which is the one place the patentee can mount a defense).

---

9. Motivation-to-combine summary (KSR factor checklist)

---

10. What the patentee would argue, and how it fares

1. "'775 teaches away — its template movement exists for spacing, so moving the template for preview is contrary to its purpose." Weak. '775's mechanism is agnostic as to purpose; the same lamp-driven template displacement serves either function. Re-purposing/adding a use of a disclosed mechanism is not teaching away (In re Foster; KSR "any need or problem known . . . can provide a reason").
2. "'632 is a projection machine with a lens, not a contact printer." Real but not dispositive: '632 is cited for its font architecture (positive field at constant offset from negative field, negative automatically brought into the optical path when the positive is selected), not for its optics. Analogous-use and same-field rationales support using a font-architecture teaching to modify a template architecture.
3. "§ 112 ¶ 6 — '632 doesn't show 'means mounting said locating members' for movement between two positions." This is the strongest defense, and it is a claim-construction argument as much as a § 103 argument. Rebuttal: '775 claims 6–7 supply structurally equivalent two-position, lamp-coupled template mountings; and the '956 specification describes the coupling as a drawer slide and bar/cam arrangement, all of which are routine translating mechanisms.
4. "Secondary considerations." No evidence available to me of commercial success of the 3M lettering product, licensing, copying, or industry praise, and in any event any such evidence would need a nexus to the preview/positive-image feature specifically (not to the toggle press, the spacing code, or the overall product). I found no such evidence.
5. "Criticality of the preview position being exactly the exposure position." The claim requires the preview position to coincide with where the window will be. '632 teaches that the positive and negative characters "are always spaced a constant distance from each other," meaning the positive is presented at the exact location-relative position the negative will occupy — which is the same relationship expressed in a template coordinate system. The patentee's own spec adds no criticality argument for exact coincidence, only that the operator can "accurately preview the position."

---

11. Bottom line

• Claim 1 is, in my analysis, rendered obvious under pre-AIA § 103(a) by US 3,914,775 in view of US 4,141,632 (Ground A), and independently by US 3,914,775 + US 3,828,359 + US 4,141,632 (Ground B), optionally further in view of US 2,762,277 and US 3,204,520 (Grounds C/D).
• The analytically hard-nosed point is that the claim's preamble is admitted prior art and its only asserted advance is what image is placed in a viewing opening the prior art already provides, plus a two-position template mounting the prior art already provides. Stated that way, the § 103 case is strong and relatively simple, notwithstanding the elaborate electromechanical disclosure the specification contains.
• The patentee's best (and only material) counter is the § 112 ¶ 6 / structural-equivalence argument over the "locating members" element and, secondarily, the field-of-endeavor argument against Mitchell's projection machine. Neither is frivolous; neither, in my view, carries the claim.
• Practical note, consistent with the earlier sections: whether or not the combination is made out, the claim expired 1999-12-17 and cannot be asserted for any post-expiration act. This § 103 analysis is therefore of academic, prosecution-history, and defensive-prior-art value only — for example, as a § 102/§ 103 ground if the '956 disclosure were ever relied on as prior art against a later patent, or for reverse-engineering-era invalidity opinions concerning 1979–1999 conduct.

---

12. Confidence and uncertainty disclosures

I have not retrieved the '956 file wrapper, the examiner's actual § 103 rejections (if any) during prosecution, or any European opposition file for EP0031670B1 (the '956 counterpart, which granted — note that the sibling's EP search report, EP 0 030 866, cited only "D" category documents, i.e., documents cited in the application, with no X or Y references, which is mild evidence the EPO examiner saw no documentary § 103 case in this family).