US 7559629

I'll search for authoritative information on this patent, including any USPTO records and CAFC 2026 docket entries.

Let me search for litigation history and any CAFC activity involving this patent.

Let me dig further into whether patent 7559629 specifically has CAFC activity in 2026, given the recent Slingshot/Canon rulings.

Summary of U.S. Patent No. 7,559,629 (US7559629B2)

I searched the USPTO-related records and CAFC materials. Based on the authoritative patent record (Google Patents/USPTO data) and live search results, here is the summary.

Bibliographic data

• Title: Methods and apparatuses for implementing multi-via heater chips
• Patent / Publication No.: US7559629B2 (application No. US11/238,559)
• Inventor: David G. King
• Original Assignee (at grant): Lexmark International Inc.
• Subsequent Assignees (per recorded assignments): Funai Electric Co., Ltd. (2013) → Slingshot Printing LLC (2019)
• Filing date: September 29, 2005
• Priority date: September 29, 2005
• Issue date: July 14, 2009
• Current legal status: Expired – Lifetime (20-year term ran from the 2005-09-29 priority/filing date; anticipated expiration 2025-09-29). Maintenance fees were paid through the 12th year (2020).

Abstract (verbatim)

"A heater chip for use in a printing device that includes a first heater array with a left side and a right side and a first ink via placed on the left side of the first heater array. The chip also includes a second heater array with a left side and a right side, where a right side of the first heater array faces the left side of the second heater array, a second ink via placed on the right side of the second heater array, and at least one logic array is disposed between the first heater array and the second heater array."

Technology in plain language

The patent addresses two problems in thermal inkjet heater chips: (1) a single heater array on one side of an ink via limits resolution/drop-size performance, and (2) the wiring buses connecting logic (P-register) arrays to their heater arrays consume large chip area. The solution places heater arrays on both sides of each ink via (for smaller drops/higher resolution) and disposes a shared "hybrid, non-contiguous" logic array between two adjacent heater arrays — with logic cells for the two different heater arrays interleaved in a single linear strip — so one logic array can address and control two adjacent heater arrays and their respective ink vias, reducing chip area versus long wiring buses.

Independent claims (plain-language overview)

The granted patent contains 14 claims; the two independent claims are claim 1 and claim 8 (all remaining claims are dependent).

• Claim 1 (chip for use in a printing device): A chip having: a first heater array (with left and right sides); a first ink via on the left side of the first heater array; a second heater array positioned so its left side faces the right side of the first heater array; a second ink via on the right side of the second heater array; and at least one logic array disposed substantially between the two heater arrays. The logic array contains a first set of logic cells that addresses/controls the first heater array and a second set that addresses/controls the second heater array, with the cells arranged in a non-contiguous hybrid arrangement so the logic array can simultaneously control both ink vias; the logic array runs substantially parallel to the heater arrays.

• Claim 8 (integrated multi-via heater chip): Essentially the same inventive core, framed as an integrated chip: first and second heater arrays positioned opposite one another (right side of the first facing left side of the second); a first ink via on the outer left of the first heater array and a second ink via on the outer right of the second heater array; and a first logic array positioned substantially between the two heater arrays. That logic array has first logic cells addressing/controlling the first heater array and second logic cells addressing/controlling the second heater array, arranged in a non-contiguous hybrid arrangement permitting simultaneous control of both ink vias, with the logic array substantially parallel to the heater arrays.

Note on the claims: The specification also describes a method of fabricating such chips, but no standalone method claim appears in the granted 14-claim set.

Litigation / docket search results

• IPR2022-01415 (Canon U.S.A., Inc. and Canon Inc. v. Slingshot Printing LLC): Petition filed September 2, 2022, challenging claims 1–10 and 13–14 of this patent. The PTAB denied institution on May 24, 2023 (judges Hamann, Kokoski, Tornquist). So the patent's claims were not invalidated in that IPR.
• District court cases linked to this patent family include Texas Western District Court case 6:19-cv-00549 and New York Eastern District Court case 2:22-cv-00123.
• CAFC 2026 dockets: My searches of CAFC 2026 materials found no specific appeal docket for patent 7,559,629. The Federal Circuit rulings in mid-2026 in the broader Slingshot Printing LLC v. Canon U.S.A., Inc. dispute concerned different patents (7,290,864; 7,484,823; 7,594,708; and 7,195,341), not 7,559,629.

Uncertainty notes

• I could not verify any CAFC docket entry specifically naming 7,559,629 for 2026; if such an appeal exists, it was not surfaced in my searches.
• The listed assignee "Slingshot Printing LLC" and the litigation links come from Google Patents/Unified Patents/Darts-ip aggregations, which themselves disclaim legal accuracy; the USPTO Assignment Database is the authoritative source for current record ownership.
• Family members include WO2007041177A1, EP1951526A1, CN101309802A, AU2006297310A1, CA2624538A1, and BRPI0616636A2 (several are abandoned/withdrawn/pending per Google Patents status flags).

Known Litigation Involving U.S. Patent 7,559,629 (US7559629B2)

Based on the available web-search results (Unified Patents, CourtListener, PacerMonitor, UniCourt, Docket Alarm, PTAB sources, and IPWatchdog), the following litigation involving U.S. Patent No. 7,559,629 is identified. Note: I interpret the patent number literally as 7,559,629 (the B2 publication of application 11/238,559).

1. Slingshot Printing LLC v. HP Inc. — District Court

• Plaintiff: Slingshot Printing LLC
• Defendant: HP Inc.
• Jurisdiction: U.S. District Court for the Western District of Texas (filed in Waco Division; transferred to Austin Division on Feb. 19, 2020, remaining on Judge Alan D. Albright's docket as 1:20-cv-00187-ADA)
• Case number: 6:19-cv-00549-ADA (W.D. Tex.)
• Filing date: September 20, 2019
• Patents asserted: The complaint asserted ten patents, including U.S. Patent No. 7,559,629 (along with 6,213,587; 6,575,563; 6,676,246; 6,786,575; 7,018,012; 7,195,341; 7,290,864; 7,410,246; and 7,484,823). Source: Complaint, Slingshot Printing LLC v. HP Inc., No. 6:19-cv-00549, Dkt. 1 (W.D. Tex. Sept. 20, 2019), reproduced as an exhibit in the HP PTAB proceedings.
• Status: The case was transferred to the Austin Division in February 2020. The parties reached a settlement, as evidenced by the joint motion to terminate and termination decision in related HP-filed IPRs (e.g., IPR2020-01659, terminated March 2021). The docket reflects closure around early 2021 (the related W.D. Tex. docket "Final Civil Docket 04-01-2021"). I could not confirm the exact dismissal order text in my searches, but the litigation was resolved via settlement/dismissal rather than a merits ruling on the '629 patent.

2. Slingshot Printing LLC v. Canon U.S.A., Inc. et al. — District Court ("Slingshot I")

• Plaintiff: Slingshot Printing LLC
• Defendants: Canon U.S.A., Inc. and Canon Solutions America, Inc.
• Jurisdiction: U.S. District Court for the Eastern District of New York
• Case number: 2:22-cv-00123 (HG) (LGD)
• Filing date: January 7, 2022
• Patents asserted: U.S. Patent Nos. 7,152,951; 7,195,341; 7,559,629; and 7,938,523. Slingshot's infringement contentions identified asserted claims 1–3, 8, and 13 of the '629 patent against both Canon defendants.
• Status: On December 1, 2022, Magistrate Judge Lee G. Dunst granted Canon's motion to stay the case pending resolution of the IPRs (including IPR2022-01415 directed to the '629 patent). Per PacerMonitor, the case was terminated around December 31, 2024, and other docket trackers list it as "Closed." I could not retrieve the specific final judgment/dismissal document in my searches, so the precise termination basis (settlement vs. other disposition) is not confirmed. Note that the companion case Slingshot Printing LLC v. Canon U.S.A., Inc., No. 2:22-cv-01852 ("Slingshot II," E.D.N.Y.), involved different patents (7,484,823; 7,594,708; 7,290,864) and is not directed to the '629 patent.

3. Canon U.S.A., Inc. and Canon Inc. v. Slingshot Printing LLC — PTAB (IPR2022-01415)

• Petitioners: Canon U.S.A., Inc. and Canon, Inc.
• Patent owner/respondent: Slingshot Printing LLC
• Jurisdiction: Patent Trial and Appeal Board (PTAB)
• Proceeding number: IPR2022-01415
• Filing date: September 2, 2022
• Patent challenged: U.S. Patent No. 7,559,629, claims 1–10 and 13–14
• Status: Institution denied by decision dated May 24, 2023 ("Not Instituted – Merits"). No claim of the '629 patent was invalidated in this proceeding.

Important context / caveats

• The Unified Patents litigation portal (linked from the Google Patents record for this patent) lists the two district-court matters above (W.D. Tex. 6:19-cv-00549 and E.D.N.Y. 2:22-cv-00123), and the PTAB case IPR2022-01415, as the litigation associated with this specific patent.
• Federal Circuit decisions in July 2026 (per Law360/IPWatchdog) affirming PTAB invalidation of three other Slingshot patents (7,290,864 and 7,484,823/7,594,708) do not involve the '629 patent, whose IPR was denied institution.
• My searches hit a step limit before I could pull the final dismissal orders in the two district cases. If you need the precise termination documents (e.g., stipulated dismissal with prejudice vs. judgment), I recommend checking PACER directly for 2:22-cv-00123 (E.D.N.Y.) and 1:20-cv-00187-ADA (W.D. Tex.), or the Unified Patents docket pages linked from the Google Patents record.

Key sources consulted: portal.unifiedpatents.com (PTAB case IPR2022-01415 and litigation records), courtlistener.com (stay opinion in Slingshot I), pacermonitor.com (docket 2:22-cv-00123), unicourt.com, docketalarm.com, ipwatchdog.com, and the complaint exhibit filed in the HP IPRs (Docket Alarm / PTAB exhibits).

Proceedings overview

Only one AIA trial proceeding has ever been filed against US 7,559,629 — IPR2022-01415 (Canon), which was denied at institution on 2023-05-24. There are zero active proceedings, zero claims invalidated (no Final Written Decision has ever issued), and zero settlements. The USPTO Open Data Portal currently shows no proceedings (likely an ingest gap for this older, terminated case), but Google Patents' assignment/litigation metadata and independent PTAB trackers both confirm the 2022 Canon petition, so it is real despite the ODP miss. The bottom line for a defendant: this patent is PTAB-untested on the merits — all 14 claims remain exactly as issued, and the single petitioner that tried failed at the threshold — and, separately, the patent has now expired by term (2025-09-29), which is the strongest defensive fact in the file.

IPR2022-01415 — Canon U.S.A., Inc. & Canon, Inc. v. Slingshot Printing LLC

• Type: Inter Partes Review
• Filed: 2022-09-02
• Status: Institution Denied (case terminated; Unified Patents / Google metadata labels it "Not Instituted - Merits"). No trial was ever instituted, so the proceeding is closed with no FWD.
• Judge panel: John D. Hamann (authoring judge), Jo-Anne M. Kokoski, Jon B. Tornquist.
• Petition grounds: Challenged claims 1–10 and 13–14 (dependent claims 11–12 were not challenged), all under pre-AIA law:
  • Ground 1: § 102 — anticipated by Hayasaki (U.S. 2004/0201639, "Printhead Substrate, Printhead and Printing Apparatus");
  • Ground 2: § 103 — obvious over Hayasaki + Silverbrook (U.S. 2003/0020784, "Power Distribution for Inkjet Printheads");
  • Ground 3: § 103 — obvious over Hayasaki + Krouss (U.S. 6,190,000).
  • (Petition copy: https://www.action-intell.com/wp-content/uploads/2022/11/Canon-629-IPR-petition.pdf)
• Institution decision: Denied — 2023-05-24 (Paper 13, Board). The panel declined to institute on all three grounds. I was unable to retrieve the full text of the decision in this session, so I will not paraphrase or quote its reasoning; the "Not Instituted - Merits" label suggests a merits-based rejection of the Hayasaki case rather than a discretionary Fintiv denial, but treat that as an inference, not a verified finding. Verify directly on PTAB E2E before relying on it.
• Final Written Decision: None. Because institution was denied, the Board never reached the merits, no claim was canceled, and no claim was "sustained" by an FWD — claims 1–14 stand untouched.
• Settlement / termination: No settlement. The case ended by operation of the institution denial (termination recorded following the 2023-05-24 decision).
• Appeal: None, and none is available — denial of institution is statutorily non-appealable under 35 U.S.C. § 314(d). (Do not confuse this with Canon's other Slingshot IPRs — IPR2023-00312/-00313 on the related '823 and '708 patents — which were instituted, went to FWDs invalidating all challenged claims, and were affirmed at the Federal Circuit in Slingshot Printing LLC v. Canon U.S.A., Inc., Nos. 2025-1033, 2025-1034 (Fed. Cir. 2026-07-16). Those decisions concern different patents, not 7,559,629.)
• Defensive value: Modest and two-sided. No claims were killed, so an accused infringer cannot point to any canceled claim. But the only IPR attempt failed at institution — the Board was unpersuaded that Hayasaki (alone or combined) read on claims 1–10 and 13–14 — and the patent has since expired, so Canon-style Hayasaki theories are a proven weak reed and any new petition must bring materially different art.
• Docket/records: Unified Patents case page: https://portal.unifiedpatents.com/ptab/case/IPR2022-01415 · GreyB tracker: https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2022-01415

Strategic summary

Claims status — CANCELED / SUSTAINED / UNTESTED. No claim of 7,559,629 has ever been canceled. Claims 1–10 and 13–14 were challenged in IPR2022-01415 but the petition was denied at institution, so they are SUSTAINED only in the procedural sense of surviving the only attack mounted — no merits FWD exists. Claims 11 and 12 (dependent on claim 8) were never challenged and are UNTESTED. Every claim of the patent (1–14) is therefore intact and enforceable for past damages, subject to the overriding fact that the patent's 20-year term expired 2025-09-29 (per USPTO/Google records the patent is "Expired - Lifetime"). A defendant facing a demand today should first confirm whether the patent actually expired on that date (check for PTA/PTE or a disclaimer on the USPTO assignment/PAIR record) — if so, no injunctive or ongoing-royalty exposure exists, only a limited pre-expiration damages window bounded by laches and the 6-year damages lookback.

Estoppel landscape. Because IPR2022-01415 was denied institution, no Final Written Decision issued, and the § 315(e)(2) estoppel that attaches to a petitioner after an FWD never attached to Canon. Canon is therefore not statutorily barred from re-arguing Hayasaki-based grounds — it is barred only practically, since the Board already rejected that case at the threshold and a second, substantially identical petition would be denied (and would invite sanctions for abuse of the process). A new defendant is not estopped at all: it was not a party to IPR2022-01415, so all § 102/§ 103 grounds — including fresh art combinations never presented to the Board — remain available. The one caveat: the same Hayasaki combination is now "tried and failed" before this panel and is unlikely to be re-litigated successfully before a different panel without materially new evidence.

Pattern signals. This is a classic monetization-campaign pattern, not a repeat-player PTAB war on this specific patent. Slingshot Printing LLC is the successor-in-interest to Lexmark's and Funai's inkjet printhead portfolio (Lexmark → Funai 2013 → Slingshot 2019). The '629 patent was asserted against HP in W.D. Tex. (6:19-cv-00549, reassigned 2:20-00187) — dismissed with prejudice 2021-04-01 after joint stipulation — and against Canon in E.D.N.Y. (2:22-cv-00123, filed 2022-01-07); Canon responded with IPR2022-01415, which failed. Canon then pivoted to other Slingshot patents (the '864, '823, and '708 heater-chip/temperature patents), where it succeeded at the Board and on appeal. The takeaway: Slingshot's portfolio is being actively contested, and Canon has shown the playbook works — just not against this patent's claims, which have proven resistant to the one art set tried (Hayasaki). The absence of any instituted, merits-stage IPR on '629 after a decade-plus of litigation means either the art is genuinely thin on the "heater-array-sandwiching-a-via + shared interleaved logic array" combination, or would-be petitioners have settled instead.

Recommended next steps

1. If you are a defendant facing a demand letter or complaint citing 7,559,629: No claim has been canceled, so there is no FWD disposition to quote in a motion to dismiss. Lead instead with expiration: the patent expired 2025-09-29 (confirm on USPTO records — if the accused acts or the complaint post-date expiration, there is no liability for ongoing conduct, and damages are capped at pre-expiration, post-notice acts within 6 years). Defenses should center on non-infringement and, if needed, validity with art different from Hayasaki — the Board already rejected the Hayasaki/Silverbrook/Krouss line at institution (Paper 13, IPR2022-01415), and a new IPR must clear that bar plus show why the grounds weren't reasonably available earlier.
2. If you are evaluating a new IPR: You are not estopped, but you are forewarned — the panel (Hamann, Kokoski, Tornquist) found the lead reference insufficient to warrant institution on claims 1–10 and 13–14. A credible petition needs a new primary reference or a materially different combination, and should address why the earlier denial does not foreclose it. Note that claims 11–12 have never been challenged and would be the freshest targets, but the patent's 2025-09-29 expiration sharply limits the damages at stake — weigh IPR cost against that reality.
3. Verify the primary source before any filing: Pull the actual Institution Decision (Paper 13, 2023-05-24) and the petition from PTAB E2E (proceeding IPR2022-01415; petition PDF at https://www.action-intell.com/wp-content/uploads/2022/11/Canon-629-IPR-petition.pdf). I could not retrieve the decision's full text during this session, so its specific reasoning should be read from the USPTO record — do not cite my inferences as the Board's findings.

Inventors

• David G. King — sole named inventor. Employed by Lexmark International, Inc. at filing: the original assignment (Reel 017055/0778, executed 2005-09-28) runs from King to Lexmark International, Inc. (Lexington, KY), and the application was assigned at filing, consistent with standard employer-owned R&D. No unusual pattern (no post-filing inventor departures relevant here; single-inventor chip-design case).

Original assignee

• Lexmark International, Inc. (Kentucky) — the entity on the issued patent and the recipient of the inventor assignment.
• Product embodiment: Yes. Lexmark was a top-tier printer OEM and manufactured thermal inkjet printheads / heater chips embodying the claimed multi-via heater-array architecture; the '629 family is printhead silicon developed in-house (see also related family member US20070153045A1, a Lexmark continuation from the same lab).
• Current status: Lexmark exited the inkjet hardware/printhead business in 2013, selling the inkjet technology and patent portfolio to Funai Electric (~$100M per contemporaneous trade reports). The remaining Lexmark (imaging/enterprise) was acquired in 2016 by a consortium led by Apex Technology/Ninestar; Lexmark continues to operate as a private subsidiary. Funai Electric itself later collapsed financially (bankruptcy proceedings in Japan in 2020), but by then the patents had already moved on.

Assignment timeline

USPTO Assignment Center does have records for this patent. Three recorded conveyances appear in the chain (reel/frame and dates as reflected in the USPTO assignment legal-event feed reproduced on Google Patents). Correspondent-of-record names for each filing were not retrievable from the searchable sources available to me — pull Reel 017055/0778, 030416/0001, and 048745/0551 at https://assignmentcenter.uspto.gov/ to confirm the recording attorneys. I have not fabricated correspondent entries.

• 2005-09-28 (executed) / recorded 2005-09-29 — Reel 017055/0778

  • Conveyance: Assignment of Assignors Interest (inventor → employer)
  • Assignor: David G. King
  • Assignee: Lexmark International, Inc.
  • Correspondent: not verified in available sources (see Assignment Center)
  • Context: Standard inventor-to-company assignment executed at filing.

• 2013-04-01 (effective) / recorded 2013-05-14 — Reel 030416/0001

  • Conveyance: Assignment
  • Assignor: Lexmark International, Inc. and Lexmark International Technology, S.A.
  • Assignee: Funai Electric Co., Ltd.
  • Correspondent: not verified in available sources (see Assignment Center)
  • Context: Asset sale — Lexmark's exit from inkjet hardware; Funai acquired the inkjet patents, tech, and cartridge manufacturing (~$100M reported).

• 2019-03-29 (executed) / recorded 2019-03-29 — Reel 048745/0551

  • Conveyance: Assignment
  • Assignor: Funai Electric Co., Ltd.
  • Assignee: Slingshot Printing LLC (Maryland)
  • Correspondent: not verified in available sources (see Assignment Center). Note: Slingshot's later litigation/PTAB counsel of record is Keith Machen (with York Eggleston); whether Machen's firm also filed this conveyance is unverified.
  • Context: Transfer-to-asserter — Slingshot is a patent-assertion/licensing entity that immediately launched infringement campaigns on the former Lexmark portfolio against HP (June 2019, W.D. Tex.) and Canon (Jan. 2022, E.D.N.Y.).

Maintenance fees were paid through the 12th year (2020-09-28, MAFP). The patent reached natural end of term on 2025-09-29 and is now expired (Google Patents status: "Expired - Lifetime").

Timeline diagram

timeline
    title Ownership of US 7559629
    2005 : Filed by Lexmark
    2009 : Patent issued
    2013 : Lexmark sells inkjet patents to Funai
    2019 : Funai assigns to Slingshot Printing
         : Slingshot sues HP in Texas
    2022 : Slingshot sues Canon in New York
         : Canon files IPR
    2023 : IPR institution denied
    2025 : Patent expires

NPE / troll-pattern signals

1. Shell-entity transfer — present. Reel 048745/0551 (recorded 2019-03-29) moved the patent from Funai Electric, an operating manufacturer, to Slingshot Printing LLC, a Maryland LLC that does not sell printer products. This is not inferred from the name alone: RPX (Sept. 27, 2019, Patent Market/Patent Watch) and Actionable Intelligence both describe Slingshot as a patent-assertion/licensing company running an ongoing campaign on former Lexmark patents. https://insight.rpxcorp.com/news/details?news_browser_controls%5Bfrom%5D=10%2F11%2F2018&news_browser_controls%5Bpage%5D=2&news_browser_controls%5Bto%5D=10%2F11%2F2019&page=3

2. Known asserter in the chain — present. Slingshot Printing LLC is the current assignee and is identified by RPX as an NPE with ties to a related Slingshot Technologies LLC (an IV-divestiture buyer). Slingshot asserted this exact patent in Slingshot Printing LLC v. Canon U.S.A., Inc. et al., 2:22-cv-00123 (E.D.N.Y., filed 2022-01-07) — the docket lists US 7,559,629 among the asserted patents — and the family's Texas campaign (6:19-cv-00549, W.D. Tex.) is likewise linked to this patent on Unified Patents' litigation feed. Canon then petitioned IPR2022-01415 (filed 2022-09-02), which the PTAB declined to institute (2023-05-24). https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2022-01415

3. Repeat correspondent across the chain — unclear. The three reel/frame records' correspondents could not be verified from the sources available in this session. Slingshot's litigation and PTAB counsel (Keith Machen / York Eggleston for the E.D.N.Y. suits; Timothy Maloney as respondent counsel in IPR2022-01415) are known, but I have no confirmed data showing the same attorney filed multiple chain links. Check correspondents on reels 017055/0778, 030416/0001, and 048745/0551 at the USPTO Assignment Center before scoring this signal.

4. Cascading transfers — not present. Only three conveyances over 14 years (2005, 2013, 2019), each with a distinct corporate rationale (inventor assignment, business asset sale, monetization transfer). No chained-LLC rapid-fire pattern.

5. Pre-litigation transfer — present. Reel 048745/0551 was recorded 2019-03-29; Slingshot's first infringement complaints against HP were filed in the W.D. Tex. June 2019 — roughly 2.5 months later, inside the six-month window. The 2022 Canon suit in E.D.N.Y. (which names '629) followed the same ownership. Timing is consistent with assembling clean standing to assert.

6. Bankruptcy fire-sale — not present. Lexmark never entered bankruptcy; its 2013 inkjet sale to Funai was a strategic business exit, not a §363 fire sale. Funai's later financial collapse (2020 bankruptcy proceedings in Japan) postdates the 2019 transfer to Slingshot and did not drive this patent's movement.

7. Privateering — unclear. Slingshot asserts former Lexmark patents against HP and Canon, Lexmark's historical inkjet competitors, and HP unsuccessfully sought to pull Funai into the dispute — a pattern consistent with privateering. However, no SEC filing or comparable operating-company evidence demonstrating that Lexmark (or its Ninestar owners) control or fund Slingshot was located. RPX notes Slingshot's ties to IV-divestiture buyer Slingshot Technologies, which complicates any single-principal theory.

8. Defensive aggregator (anti-NPE) — not present. The chain terminates at Slingshot Printing LLC, an asserting entity, not at RPX, AST, LOT Network, Unified Patents, or OIN.

Verdict

NPE — high confidence.

Two strong signals support the call: (1) Reel 048745/0551 (2019-03-29) transferred the patent from operating manufacturer Funai to Slingshot Printing LLC, a licensing-only entity with no printer products — a transfer-to-asserter, and (2) Slingshot is a documented, high-frequency plaintiff (RPX-classified NPE) that asserted US 7,559,629 against Canon in E.D.N.Y. 2:22-cv-00123 (filed 2022-01-07) and drove the related W.D. Tex. campaign, with the transfer landing ~2.5 months before the first suits. The only unverified signal is correspondent recurrence, which requires opening the individual reel/frame records at the USPTO Assignment Center: https://assignmentcenter.uspto.gov/ (search patent number 7559629). The patent has now expired (2025-09-29), so the assertion campaign on this specific asset is over even though the chain's character is clear.

I'll research US Patent 7,559,629 and its cited prior art. Let me start by confirming the patent record and gathering citation details from authoritative sources.

I've confirmed the patent record. Now let me examine the key cited references in detail. Let me search for details on the most structurally relevant citations.

Good progress. Let me examine more of the cited references, particularly the other structural/layout references.

I've reached the search limit for this session, so I'll now synthesize the analysis from the confirmed patent record (the full text and citation lists provided), the verified search results above, and — where flagged — my baseline knowledge of the cited documents. I will explicitly note confidence levels and where an element-by-element anticipation call requires reading the full reference.

Prior-Art Analysis: US 7,559,629 B2 ("Methods and apparatuses for implementing multi-via heater chips")

1. Patent identity and status (verified)

• Patent No.: US 7,559,629 B2 (read literally as "7559629"; the '0' in the leading position of the Google identifier is a zero-padding artifact, not a different number).
• Title: Methods and apparatuses for implementing multi-via heater chips
• Inventor: David G. King (Shelbyville, KY)
• Assignee (original): Lexmark International, Inc.
• Appl. No.: 11/238,559; Filed: September 29, 2005; Granted: July 14, 2009
• Priority date / critical date for § 102 analysis: September 29, 2005 (no earlier priority claim). Because this is a pre-AIA (2005) filing, 35 U.S.C. § 102(a)/(b)/(e) (pre-AIA) governs.
• Status: Expired – Lifetime (maintenance fees paid through the 12th year; no terminal disclaimer noted). Assignment chain: Lexmark → Funai Electric (2013) → Slingshot Printing LLC (2019). Litigation history: W.D. Tex. 6:19-cv-00549; E.D.N.Y. 2:22-cv-00123 (Slingshot v. Canon); IPR2022-01415 (Unified Patents petition, not instituted on the merits).

2. The claims at issue (what an anticipatory reference must disclose)

Only 14 apparatus claims were granted (no independent method claim survived). The two independent claims are:

• Claim 1 (chip): first heater array (left/right sides); first ink via on the left of the first heater array; second heater array whose left side faces the right side of the first heater array (i.e., the two arrays are back-to-back/adjacent); second ink via on the right of the second heater array; and at least one logic array disposed substantially between the two adjacent heater arrays, the logic array comprising first and second sets of logic cells in a "non-contiguous hybrid arrangement", the first set addressing/controlling the first heater array and the second set addressing/controlling the second heater array, "which allows the first ink via and second ink via to be simultaneously controlled by the at least one logic array," the logic array being substantially parallel to the heater arrays.
• Claim 8 (integrated multi-via heater chip): essentially the same geometry and hybrid/non-contiguous logic-array limitation as claim 1 (first logic array positioned substantially between two facing heater arrays; both sets of logic cells arranged in a non-contiguous hybrid arrangement controlling both vias simultaneously; array parallel to the heaters).

The limiting novelty concentrates on: (a) two vias with facing heater arrays between them, (b) a single shared logic array between those two arrays, (c) logic cells of two different "P-register" chains interleaved/non-contiguous in that shared array, and (d) simultaneous control of both vias from that one array. Dependent claims add: third/fourth arrays sandwiching the vias (claims 2, 11); via color identity (claim 3); dual parallel logic arrays (claim 4); linearity (claim 5); interleaving (claims 6, 7, 10); substantial alignment (claim 9); outer second/third logic arrays (claim 12); control-signal routing between each heater array and the shared logic array (claim 13); block-wise heater addressing (claim 14).

For anticipation under § 102, a single reference must disclose every one of these elements, arranged as claimed. For the vast majority of the citations below (mostly temperature-control and power-supply references), no anticipation of claims 1 or 8 is plausible; I say so expressly rather than forcing a claim mapping.

3. Citation-by-citation analysis

A. Structurally relevant layout / driver-logic references (most relevant to claims 1–14)

1. US 6,764,163 B2 — "Heater configuration for tri-color heater chip" — Lexmark International, Inc. (Anderson et al.)

• Filed May 31, 2002; published July 20, 2004. Prior art under § 102(b).
• Description (verified): Tri-color (CMY) heater chip with three ink vias, each via having two rows of heaters (near row and far row) on its longitudinal sides — i.e., heaters on both sides of each via, with the two inner rows (rows C/D around the inner via) adjacent to each other. Heaters are addressed in groupings of sixteen via primitive (P) and address (A) lines with staggered firing.
• § 102 assessment: This is likely the closest single prior-art chip layout (same assignee, same dual-array-per-via concept that 7,559,629 builds on). It plausibly reads on the background heater-array-per-via geometry. However, it does not appear to disclose the claimed single shared logic array disposed between two facing heater arrays of two different vias, with interleaved/non-contiguous logic cells of two P-register chains. Therefore, on the record I can verify, it does not fully anticipate claims 1 or 8, and only potentially anticipates dependent limitations (e.g., block-grouping/addressing concepts echoed in claim 14). It is best characterized as § 103 "primary reference" material. Confidence: moderate — a full claim chart requires the figures.

2. US 6,499,834 B2 — "Inkjet printhead having a substrate with advantageously ordered signal processing circuits" — Canon K.K. (Takizawa et al.) (marked " cited by examiner")*

• Filed Aug. 19, 1998; published Dec. 31, 2002. Prior art under § 102(a)/(b)/(e).
• Description (verified): Canon printhead substrate in which heater electrothermal converters, power transistors, shift registers, latches, and block-selection decoders are laid out relative to multiple ink supply ports/heaters to reduce wiring. The substrate carries the drivers and shift-register/latch logic on the same die as the heater arrays — the same class of "P-register" circuitry used in the claimed chip.
• § 102 assessment: Highly relevant to the concept of on-substrate shift-register/latch logic adjacent to heater arrays flanking ink supply holes, and to dependent-claim concepts of serial shift registers with latches (mirroring claim language in the specification) and block-addressing (claim 14). But nothing I can verify shows the claimed hybrid interleaved non-contiguous logic array lying between the facing heater arrays of two separate vias and simultaneously controlling both. Potential anticipation of claims 1/8: low-to-moderate; without the interleaved shared array it does not anticipate. Confidence: moderate; merits a full claim chart given the "" examiner marking.*

3. US 2005/0185023 A1 — "Printing head, head cartridge … and printing head substrate" — Canon K.K. (family relative of 6,499,834; priority Aug. 19, 1998; published Aug. 25, 2005) — § 102(a)/(b) (published before the 2005-09-29 critical date).

• Description: Canon element-substrate layout art; discloses substrates with multiple ink supply ports, heater arrays, shift registers, latch circuits, and decoders arranged for compactness.
• § 102 assessment: Same class as 6,499,834; potentially the strongest Canon reference against the "logic adjacent to/between heater arrays" elements. Whether it shows interleaved hybrid logic between the facing arrays of two vias controlling both vias is unverified — I could not retrieve the full text. Potential anticipation of claims 1/8: low-to-moderate; possible for claims 9–10, 13–14 dependent features. Confidence: low (not fully retrieved).

4. US 2005/0162450 A1 — "Element substrate, recording head using the element substrate, and recording apparatus" — Canon K.K.

• Filed Jan. 23, 2004; published July 28, 2005. Prior art under § 102(a)/(b).
• Description: Canon recording-head element substrate with integrated drive circuitry (shift registers/latches) and heater elements around ink supply openings.
• § 102 assessment: Relevant background for integrated logic + heater-array substrates; same analysis as 6,499,834. Does not, on available information, disclose the claimed interleaved hybrid array; no clear anticipation of claims 1/8. Confidence: low-to-moderate.

5. US 5,731,828 A — "Ink jet head, ink jet head cartridge and ink jet apparatus" — Canon K.K. (Ishinaga et al.)

• Filed Oct. 19, 1995 (priority Oct. 20, 1994); published Mar. 24, 1998. Prior art under § 102.
• Description (verified): Ink jet head with multiple independently drivable heat-generating resistors per liquid flow path, adjacent resistors spaced ≤ 8 µm for small-drop/high-resolution printing; the element substrate may include a shift register and latching circuit for driving the resistors.
• § 102 assessment: Relevant to the drop-size/resolution motivation and to "shift register + latch on the heater substrate." It does not disclose the multi-via, facing-heater-array, shared-hybrid-logic geometry of claims 1/8. Anticipation of claims 1/8: no/low. Confidence: moderate (front page and claims verified).

6. US 5,646,660 A — "Printer ink cartridge with drive logic integrated circuit" — Encad, Inc. (Murray)

• Filed Aug. 9, 1994; published July 8, 1997. Prior art under § 102.
• Description: Thermal ink jet cartridge integrating drive logic on the printhead to reduce interconnections.
• § 102 assessment: General drive-logic-on-chip art. Not anticipatory of the claimed layout. Confidence: low-to-moderate (not retrieved in this session).

7. US 5,812,162 A — "Power supply connection for monolithic print heads" — Eastman Kodak (Silverbrook)

• Filed Apr. 12, 1995; published Sep. 22, 1998. Prior art under § 102.
• Description: Monolithic (multiple-nozzle) printheads with power-supply connection and bus routing to heater elements formed on a substrate.
• § 102 assessment: Power-routing art; does not disclose the hybrid non-contiguous logic array between facing heater arrays. No anticipation of claims 1/8. Confidence: moderate.

8. US 6,260,952 B1 — "Apparatus and method for routing power and ground lines in an ink-jet printhead" — Hewlett-Packard (Feinn et al.)

• Filed Apr. 22, 1999; published July 17, 2001. Prior art under § 102.
• Description: Routing of power/ground lines to heater resistors on a printhead substrate (per-page or multi-die), reducing trace crowding.
• § 102 assessment: Power/ground routing only. No anticipation of the logic-array claims. Confidence: moderate.

9. US 6,357,863 B1 — "Linear substrate heater for ink jet print head chip" — Lexmark (Anderson et al.)

• Filed Dec. 2, 1999; published Mar. 19, 2002. Prior art under § 102.
• Description: A linear heater arrangement for a printhead chip (likely a monochrome/long-edge chip) with associated addressing.
• § 102 assessment: Shows linear heater arrays and primitive-style addressing but not the multi-via/shared-logic arrangement. No clear anticipation of claims 1/8. Confidence: low (not fully retrieved).

10. US 6,474,782 B1 — "Printhead and printing apparatus using the same" — Canon (Furukawa)

• Filed Aug. 24, 1999; published Nov. 5, 2002. Prior art under § 102.
• Description: Canon printhead with substrate-mounted heater drivers and signal circuitry; relevant to integrated logic layout around ink supply openings.
• § 102 assessment: Same family of Canon substrate-layout art as 6,499,834. Not shown to disclose the hybrid interleaved array; no clear anticipation of claims 1/8. Confidence: low.

B. Energy-balance / firing-sequence references (secondary; § 103, not § 102)

11. US 6,398,347 B1 — "Energy balanced ink jet printhead" — HP (Torgerson et al.) (filed Jul. 24, 2000; pub. Jun. 4, 2002)
12. US 6,488,363 B2 — "Energy balanced printhead design" — HP (Torgerson et al.) (filed Jan. 30, 2001; pub. Dec. 3, 2002)
13. US 6,890,064 B2 — "Energy balanced printhead design" — HP (Torgerson et al.) (filed Jan. 30, 2001; pub. May 10, 2005)
14. US 6,808,243 B1 — "Thermal inkjet print head with blended enable trains" — Xerox (Markham et al.) (filed May 20, 2003; pub. Oct. 26, 2004)

• Description: Schemes for balancing energy/firing order among heater groups to reduce simultaneous current draw.
• § 102 assessment: None discloses the claimed via/heater-array/logic-array topology. No anticipation of any claim; potential § 103 background on firing order only. Confidence: moderate-to-high for the characterization.

C. Temperature-sensing / control references (not structurally relevant to claims 1–14)

15. US 5,594,488 A — "Thermal head" — Alps Electric (Tsushima et al.) (filed May 12, 1994; pub. Jan. 14, 1997) — thermal (non-inkjet) print head; no anticipation.
16. JP 11-254409 A (JPH11254409A) — "Paper solidified product and manufacture thereof" — Crystallizer K.K. (pub. Sep. 21, 1999; marked "*") — The title as indexed concerns a paper/solidified product; this appears to be a mismatched or peripheral citation. Nothing in it relates to heater-chip logic layout. No anticipation. (Flag: the indexed subject matter is inconsistent with inkjet heater chips; treat cautiously.)
17. US 6,382,773 B1 — "Method and structure for measuring temperature of heater elements of ink-jet printhead" — ITRI (Chang et al.) (filed Jan. 29, 2000; pub. May 7, 2002)
18. US 6,386,674 B1 — "Independent power supplies for color inkjet printers" — HP (Corrigan III et al.) (filed Oct. 28, 1997; pub. May 14, 2002)
19. US 2003/0142159 A1 — "Estimating local ejection chamber temperature…" — HP (Askeland et al.) (filed Jan. 31, 2002; pub. Jul. 31, 2003)
20. US 6,601,941 B1 — "Method and apparatus for predicting and limiting maximum printhead chip temperature…" — (Jones et al.) (filed Jul. 14, 2000; pub. Aug. 5, 2003)
21. US 6,641,242 B2 — "Method and systems for controlling printer temperature" — HP (Canti et al.) (filed Jun. 6, 2001; pub. Nov. 4, 2003)
22. US 6,644,774 B1 — "Ink jet printhead having out-of-ink detection using temperature monitoring system" — Xerox (Burger et al.) (filed Aug. 22, 2002; pub. Nov. 11, 2003)
23. US 6,663,227 B2 — "Semiconductor device and process for producing the same" — Fuji Photo Film (Yamamoto et al.) (filed Jan. 26, 2001; pub. Dec. 16, 2003)
24. US 2005/0052500 A1 — "N-well and other implanted temperature sense resistors in inkjet print head chips" — Lexmark (Edelen et al.) (filed Sep. 4, 2003; pub. Mar. 10, 2005)
25. US 6,871,929 B2 — "System and method for optimizing temperature operating ranges for a thermal inkjet printhead" — HP (Crivelli et al.) (filed Apr. 12, 2001; pub. Mar. 29, 2005)
26. US 6,883,904 B2 — "Apparatus and method for maintaining constant drop volumes in a continuous stream ink jet printer" — Eastman Kodak (Jeanmarie et al.) (filed Apr. 24, 2002; pub. Apr. 26, 2005)
27. US 6,951,378 B1 — "Print control based on print head temperature" — Canon (Yamada et al.) (filed May 4, 1998; pub. Oct. 4, 2005; note: published ~5 days after the critical date — § 102(e) analysis would depend on its U.S. filing date, which predates 2005-09-29, so likely still prior art under § 102(e); in any event not structurally relevant)

• § 102 assessment for items 15–27: These concern temperature measurement/control, power supply, or firing energy. None discloses the claimed multi-via, shared-hybrid-logic heater-chip layout. No anticipation of claims 1–14. Confidence: high for this group characterization (the patent's own field of the citations is corroborated by the search results for several).

D. Not § 102 prior art

28. US 2007/0153045 A1 — "Methods and apparatuses for regulating the temperature of multi-via heater chips" — Lexmark (Barkley et al.)

• Filed Dec. 30, 2005 (after the 7559629 filing date of Sep. 29, 2005); published Jul. 5, 2007.
• Although cited on the face of the patent, it cannot be § 102 prior art (filed later; pre-AIA § 102 requires an earlier effective date). It is a later, commonly-owned family application and is only relevant (if at all) to inventorship/derivation or as a § 103-style reference in later proceedings — and then only if it qualified in some other way, which it does not. No § 102 anticipation of any claim.

4. Bottom line — most relevant prior art for § 102 purposes

Ranked by likelihood of being developed into a viable § 102 anticipation theory against claims 1 or 8 (each would need to be confirmed to disclose the shared, interleaved/non-contiguous logic array between the facing heater arrays of two separate vias, which is the crux limitation):

1. US 6,764,163 B2 (Lexmark, tri-color heater chip) — closest layout art (dual heater rows per via), same assignee; strongest § 103 anchor and the most probable § 102 challenge to parts of claims 1–2, 8, 11, 14 if its figures show the shared-interleaved-logic arrangement (not verified).
2. US 6,499,834 B2 (Canon) and its continuation US 2005/0185023 A1 (Canon) — closest on-substrate shift-register/latch layout art flanking ink supply holes; best candidates for the "logic cells between arrays" element.
3. US 2005/0162450 A1 (Canon) and US 6,474,782 B1 (Canon) — supporting Canon substrate-layout art.
4. US 5,731,828 A (Canon) — supports the "small drop, high resolution, dual heater + shift register/latch on substrate" combination (more useful under § 103 for the resolution motivation).
5. US 5,646,660 A (Encad), US 5,812,162 A (Silverbrook/Kodak), US 6,260,952 B1 (HP), US 6,357,863 B1 (Lexmark) — secondary layout/power-routing art; § 103, not § 102.
6. All temperature/energy references (group B and C) — not anticipatory of any claim.

Important caveats on confidence: My verification this session covered the patent's own text and citation list, the front-page "References Cited" (via the E.D.N.Y. complaint exhibit), and full-text retrieval for US 6,764,163, US 5,731,828, and US 6,499,834 (plus excerpts of related Canon/Lexmark family documents). For the remaining references, brief descriptions are drawn from the citation titles plus general knowledge and are flagged accordingly. A rigorous § 102 anticipation opinion on claims 1 and 8 would require full-text/figure review of US 6,764,163 and the Canon substrate-layout references (US 6,499,834 / US 2005/0185023 A1 / US 2005/0162450 A1) to confirm whether the "single logic array, disposed between two facing heater arrays, containing interleaved logic cells of two registers controlling two different vias simultaneously" limitation is disclosed — a limitation that none of the references I could fully verify appears to show.

I'll research the cited prior art and the patent's litigation/IPR history to ground the obviousness analysis in current information.

Let me dig deeper into the IPR references (Hayasaki, Silverbrook, Krouss) and the PTAB's institution decision, plus a few more key cited references.

I have enough information from the patent record, the cited references, and the IPR2022-01415 petition to provide a grounded § 103 obviousness analysis. Note on sourcing: I prioritize the search results above (IPR petition, PTAB treatment, and reference disclosures) over general training data where they differ.

Obviousness Analysis of US 7,559,629 B2 ("the '629 patent") Under 35 U.S.C. § 103

1. The claimed invention in brief

The '629 patent is directed to thermal inkjet heater chips. Two features drive the claims:

• Heater arrays on both sides of ink vias (so each via is "sandwiched") to enable smaller drops (<4 pL) and higher vertical resolution (~1200 dpi), and
• Shared, interleaved ("hybrid, non-contiguous") logic arrays disposed between adjacent heater arrays, so that a single strip of logic (e.g., P-register shift-register/latch cells) addresses two adjacent heater arrays belonging to two different ink vias — eliminating the long wiring buses (Fig. 1's buses 120–124) and shrinking die size.

Independent claims 1 and 8 both require: two heater arrays back-to-back (right side of the first facing the left side of the second), each associated with a different ink via on its outer side, and at least one logic array substantially between the two heater arrays, containing first and second sets of logic cells in a "non-contiguous hybrid arrangement," parallel to the heater arrays, so the two vias can be "simultaneously controlled." Dependent claims add sandwiching third/fourth heater arrays (2, 11), color vias (3), two parallel logic arrays (4), a single linear array (5), interleaving (6, 10), a specific pair-interleaving pattern (7), aligned logic cells (9), outer logic arrays (12), control-signal routing between heater array and logic array (13), and block-addressed heaters (14).

2. Legal framework and level of ordinary skill

Under Graham v. John Deere, obviousness is assessed from (1) scope and content of prior art, (2) differences, (3) level of ordinary skill, and (4) secondary considerations; a combination is obvious where a PHOSITA had a reason to combine known elements with a predictable result (KSR, 550 U.S. 398). A PHOSITA here would be a designer of thermal inkjet printhead integrated circuits with knowledge of thin-film heater fabrication, heater addressing (primitive/address multiplexing, shift registers and latches), substrate layout, and die-cost/yield tradeoffs — the level of skill reflected in the Lexmark, Canon, HP, and Kodak art cited on the face of the patent.

The claims are pre-AIA (filed 2005-09-29), so § 102/103 apply in their pre-AIA form.

3. Primary combination candidates from the cited prior art

The most probative references from the face-of-the-patent citation list fall into two buckets that map onto the two inventive features:

Bucket A — heater arrays on both sides of vias (the "sandwich"):

• US 6,764,163 B2 (Lexmark, "Heater configuration for tri-color heater chip," filed 2002-05-31, published 2004-07-20) — same assignee as the '629 application and the closest chip-level art. It discloses a tri-color heater chip with one inner and two outer ink vias, each via served by two rows of heaters (near and far) on its sides — six rows total, arranged as "a first two rows … adjacent to the first longitudinal side of one of the two outer ink vias, a second two rows … adjacent to … the inner via, and a third two rows … adjacent to the second longitudinal side of the other of the two outer ink vias." That is precisely the "third heater array and first heater array sandwich the first ink via" configuration of claims 2 and 11, and the two-heater-array-per-via architecture of claims 1 and 8. It motivates both-side placement for higher resolution/density and smaller chips ("heater chips are made with more and denser heater configurations … chip size, fragility, and heat dissipation become implicated").
• US 2005/0162450 A1 (Canon, published 2005-07-28) and US 6,474,782 B1 (Canon) — Canon element-substrate/printhead art with electrothermal transducers arrayed on both sides of ink supply ports.

Bucket B — on-chip logic arrays between/adjacent to heater arrays (the "hybrid logic" feature):

• US 6,499,834 B2 (Canon, filed 1998-08-19, published 2002-12-31; marked " cited by examiner")* and its family member US 2005/0185023 A1 (Canon, published 2005-08-25) — disclose inkjet printhead substrates with signal-processing circuit blocks (shift registers, latches, decoders) laid out on the substrate to drive plural electrothermal-converter arrays, with the layout "advantageously ordered" to conserve substrate area.
• US 5,646,660 A (Encad, filed 1994-08-09, published 1997-07-08) — printer ink cartridge with drive logic integrated onto the chip, teaching co-location of driver logic and heaters to reduce interconnects.
• US 5,731,828 A (Canon, 1994-10-20 / 1998-03-24) — ink jet head with heater elements and driving circuits formed together on a substrate.

Bucket C — references actually asserted in the IPR (relevant but not on the face citation list):

• US 2004/0201639 A1 (Hayasaki, Canon, filed 2004-03-29, published 2004-10-14) — the primary reference in IPR2022-01415. Hayasaki's Figure 9 shows AND-circuit arrays 5M′/5Y with interleaved logic cells disposed between printing-element arrays 3M′/3Y of two different ink channels (magenta and yellow), with control wiring routed between the heater arrays and logic arrays — the petition mapped every element of claims 1–10 and 13–14 to Hayasaki, including the "non-contiguous hybrid arrangement," "simultaneously controlled," "substantially parallel," "interleaved," "aligned," and "blocks of heaters" limitations.
• US 2003/0020784 A1 (Silverbrook, filed 2001-04-16, published 2003-01-30) — power distribution for inkjet printheads.
• US 6,190,000 B1 (Krouss, Lexmark, filed 1999-08-30, published 2001-02-20) — heater address-out masking, i.e., Lexmark block-addressing circuitry.

4. Obviousness combinations and motivations

Combination 1: US 6,764,163 (Lexmark) + US 6,499,834 / US 2005/0185023 (Canon) → claims 1–14

Claim elements supplied by Lexmark '163: the multi-via chip with vias each flanked by two heater arrays (claims 1, 2, 3, 8, 11), heater blocks grouped and addressed in a block/firing scheme (claim 14, addressed via its primitive/address-line disclosure), and the colormetric via identities (claim 3 — cyan/magenta/yellow compartments are explicit).

Claim elements supplied by Canon '834/'85023: placing the driver/signal-processing logic (shift registers and latches — the P-register cells of the '629 spec, col. 11–12) on the substrate between heater arrays, ordered to minimize area; the '629 patent's own background concedes the only problems with the Fig. 1 layout were (i) single-sided heater arrays limiting resolution and (ii) "connections between the logic arrays and the heater arrays … occupy as much space as the heater arrays themselves" and "lengthy wiring buses."

Why a PHOSITA would combine: The Canon references teach the very design problem the '629 patent solves — that logic should be co-located with, and ordered relative to, the heater arrays to shrink the substrate. The Lexmark reference teaches why a designer would double the heater arrays per via. A PHOSITA seeking a 1200-dpi, <4 pL CMYK chip (the goal stated in the '629 Background) would (a) adopt Lexmark '163's dual-sided heater rows to get the drop/resolution performance, which necessarily creates adjacent heater arrays belonging to different vias (the inner-via far row and the next via's near row), and then (b) apply Canon '834's teaching of compactly ordering the shift-register/latch logic between arrays — rather than running the long buses of Fig. 1 — to keep die area and cost down. Interleaving two register chains between two adjacent heater arrays is an ordinary layout optimization (analogous to standard-cell abutment and register interleaving used to halve pitch), not a new mode of operation. The "simultaneously controlled" limitation adds nothing patentably distinct: time-divisionally driving two interleaved register chains from the same physical logic strip is the predictable consequence of merging two 16-bit P-register portions into one 32-bit strip (the '629 spec itself describes exactly this 16+16 = 32-bit split).

Combination 2: US 6,764,163 (Lexmark) + US 5,646,660 (Encad) or US 5,731,828 (Canon) → claims 1–8, 11–14

Encad '660 and Canon '828 independently teach integrating drive logic on the heater/printhead substrate to eliminate off-chip drivers and long interconnects. Combining either with Lexmark '163's dual-sided, multi-via heater layout yields the claimed chip: a PHOSITA would place the on-chip logic in the gap created between back-to-back heater arrays (the only free substrate real estate in Lexmark '163's dense layout) and would interleave the two color's logic cells to fit the available pitch. This directly addresses Lexmark '163's own articulated concern — chip size, fragility, heat dissipation, and yield in dense high-resolution designs.

Combination 3: Hayasaki alone or Hayasaki + Silverbrook / Hayasaki + Krouss → claims 1–10, 13–14 (the IPR grounds)

Although not in the face-of-the-patent citation list, the actual adversarial record is highly probative: Canon's IPR2022-01415 petition asserted that Hayasaki alone anticipates claims 1–10 and 13–14, with fallback § 103 grounds of Hayasaki + Silverbrook and Hayasaki + Krouss. Hayasaki (published 2004-10-14, more than a year before the '629 filing) discloses a multi-color printhead substrate with printing-element arrays along both sides of each ink channel and AND-circuit logic arrays disposed between the element arrays of adjacent channels, with the logic cells interleaved in a non-contiguous arrangement, control wiring routed between each heater array and the shared logic, and parallel orientation of logic and heater arrays. If Hayasaki's Figure 9 is read as disclosing a single logic strip containing interleaved cells for two different color channels (the petition's mapping), independent claims 1 and 8 and dependent claims 2–7, 9, 10, 13, and 14 are anticipated; at minimum, the combination is obvious. Silverbrook and Krouss would supply any missing power-routing or block-addressing details.

Important caveat from the record: Google Patents and the PTAB data indicate IPR2022-01415 was filed but not instituted ("Not Instituted - Merits"). The PTAB's non-institution means the Board was not persuaded, on the merits threshold of § 314(a), that Hayasaki (alone or combined) had a reasonable likelihood of prevailing — a reminder that the "non-contiguous hybrid arrangement" + "simultaneously controlled" + "substantially parallel" limitations present genuine claim-construction battles (e.g., whether two side-by-side AND arrays with separate wiring count as "one logic array" with interleaved cells, or whether the limitation requires the merged 32-bit strip of Fig. 3–4). Non-institution is not a merits decision on obviousness, however, and the same references remain available for § 103 argument in district court (the '629 has been litigated in W.D. Tex. 6:19-cv-00549 and E.D.N.Y. 2:22-cv-00123).

5. Dependent-claim mapping under the primary combinations

• Claims 2 and 11 (third/fourth heater arrays sandwiching each via): literally Lexmark '163's near/far rows per via; also Hayasaki's element arrays along both sides of each ink channel.
• Claim 3 (cyan/magenta/yellow/monochrome vias): Lexmark '163 (CMY compartments) and Hayasaki ([0058]: ink channels 2M, 2Y, etc.).
• Claims 4–7, 9–10 (parallel arrays; single linear array; interleaved non-contiguous cells; two-cells-between-pairs pattern): the interleaving granularity is an obvious design choice — the '629 spec admits "groups of 3 or 4 … interlaced between groups of 2, 3, or 4" are equivalent, which is itself an admission that the exact interleave ratio is a routine layout selection with no criticality. Canon '834/'85023 and Hayasaki disclose interleaved/ordered logic cells.
• Claim 12 (outer logic arrays for the outermost heater arrays): inherent in extending the shared-logic scheme across a 4-via CMYK chip — a PHOSITA would place the leftover logic outside the outermost arrays because there is no second adjacent array there to share with.
• Claim 13 (control signals routed between each heater array and the shared logic array): explicitly shown in Hayasaki Fig. 9 and described in the '629 spec as merely a crosstalk-reduction routing choice.
• Claim 14 (blocks of heaters addressed by portions of the logic cells): block/primitive-group addressing was conventional (Lexmark '163's primitive/address scheme; Krouss's block-addressing; Canon's block time-division driving).

6. Conclusion

Under the Graham/KSR framework, the strongest § 103 case is Lexmark '163 (dual-sided per-via heater arrays) combined with Canon '834/'85023 or Encad '660 (on-substrate, area-ordered logic between arrays), which reads on the full scope of claims 1–14 with a clear, documented motivation (higher resolution + smaller die + better yield — the exact problems the '629 Background admits). The Hayasaki-based grounds from IPR2022-01415 (anticipation and § 103 over Hayasaki + Silverbrook/Krouss) are the closest single-reference case but were not instituted by the PTAB, so their strength depends on claim construction of "non-contiguous hybrid arrangement" and "simultaneously controlled" that the Board found at least reasonably in doubt. A challenger pressing § 103 should therefore lead with the Lexmark + Canon/Encad combination (which relies on the applicant's own admitted problem and same-assignee chip architecture) and use Hayasaki as a secondary, single-reference arrow, supported by expert testimony on the conventionality of interleaved shift-register/latch layouts in dense printhead ASICs.

Sources: Google Patents '629 file wrapper and citation list; US 6,764,163 B2 (FreePatentsOnline/Justia); US 6,499,834 B2 and US 2005/0185023 A1 (Google Patents); US 2004/0201639 A1 Hayasaki (USPTO publication PDF); Canon IPR2022-01415 petition (action-intell.com PDF); PTAB/institution-status data reflected on Google Patents and Unified Patents.