Summary — U.S. Patent No. 8,604,678 B2

I verified the patent number and bibliographic data against the USPTO-facing records (Google Patents, FreePatentsOnline, Unified Patents portal) and the full patent text you provided. The correct number is 8,604,678 (US8604678B2) — I did not substitute any similar numbers.

Bibliographic data

Abstract (verbatim)

A light emitting device comprises at least one solid-state light source (LED) operable to generate excitation light and a wavelength conversion component located remotely to the at least one source and operable to convert at least a portion of the excitation light to light of a different wavelength. The wavelength conversion component includes a light transmissive substrate having a wavelength conversion layer comprising particles of at least one photoluminescence material and a light diffusing layer comprising particles of a light diffractive material. This approach of using the light diffusing layer in combination with the wavelength conversion layer solves the problem of variations or non-uniformities in the color of emitted light with emission angle.

Independent claims — plain-language overview

The granted patent has 29 claims. Based on the granted-claim text quoted verbatim in the PTAB IPR petition (IPR2025-00258, EX1001 excerpts) and the published-application claim numbering (which carried into the grant), the independent claims are:

• Claim 1 — Wavelength conversion component. A component for a light-emitting device made of two layers: (a) a wavelength conversion layer containing particles of at least one photoluminescence material (e.g., phosphor), and (b) a light diffusing layer containing particles of a light scattering material (e.g., TiO₂). The diffusing layer is characterized as improving the component's off-state white appearance (so it does not look yellow/orange when the device is off and ambient light excites the phosphor). The component is further configured so that, in operation, a portion of the excitation light — specifically blue light at ≥ 440 nm generated by the device's light source — is emitted through the component and contributes to the final visible emission product (i.e., a partial-conversion, remote-phosphor-type component).

• Claim 19 — Light emitting device. A device comprising at least one solid-state light emitter operable to generate excitation light, plus a wavelength conversion component having (a) a wavelength conversion layer excitable by the excitation light and containing photoluminescent particles, and (b) a light diffusing layer containing light-scattering particles. As in claim 1, the diffusing layer improves the off-state white appearance, and in operation a portion of ≥ 440 nm blue light from the emitter passes through the component to contribute to the final visible emission product.

• Claim 27 — Linear lamp. A linear lamp with an elongate housing, a plurality of solid-state light emitters arranged along the housing's length, and an elongate wavelength conversion component positioned remote from the emitters and at least partially defining a light mixing chamber — the component having the wavelength conversion layer and light diffusing layer.

• Claim 28 — Downlight. A downlight with a body holding one or more solid-state emitters, configured to sit in a downlighting fixture so the downlight emits light downward, and a wavelength conversion component remote from the emitters and at least partially defining a light mixing chamber — again with the two-layer (wavelength conversion + light diffusing) structure.

• Claim 29 — Light bulb. A light bulb with a connector base for socket insertion/electrical connection, a body containing one or more solid-state emitters, and a three-dimensionally shaped wavelength conversion component that encloses the emitters and at least partially defines a light mixing chamber. The component has the wavelength conversion layer and light diffusing layer, and is configured (per the IPR petition's verbatim quote) so a portion of ≥ 440 nm blue light from the emitters passes through the component to contribute to the final visible emission product.

Litigation / CAFC 2026 docket search

• I searched for CAFC 2026 docket entries involving 8604678 (including "Federal Circuit," "Feit Electric," and "Intematix" queries) and found no CAFC appeal docket for 2026.
• What the records do show (from the Google Patents/Unified Patents litigation data you supplied): PTAB IPR proceedings — IPR2024-01357 (filed, instituted, pending), IPR2025-00260 (filed, instituted, pending), and IPR2025-00258 (filed, not instituted — procedural) — plus 2024 district-court cases in Texas Northern (3:24-cv-01089), Ohio Northern (1:24-cv-00473), and Kentucky Eastern (5:24-cv-00031). The IPR2025-00258 petition (Savant Technologies LLC d/b/a GE Lighting and LEDVANCE LLC, challenging claims 1–3, 6, 7, 9, 10, 16–21, 25, 26, and 29) is the source of the verbatim granted-claim language quoted above.

Uncertainty notes

• I confirmed the independent-claim text for claims 1, 19, and 29 from the IPR petition's verbatim excerpts, and the claim numbering from the petition's references (e.g., claim 16 = "planar shapes," claim 19 = light emitting device). I did not verify the complete, verbatim text of claims 27 and 28 in the granted patent, so I cannot confirm whether they carry the same "off-state white appearance" and "≥ 440 nm blue light" limitations as claims 1, 19, and 29 (the published application's counterparts lacked those limitations; they were evidently added during prosecution).
• All dependent-claim details (direct contact, binder mixtures, weight loadings 7–35% / 10–20%, particle sizes 1–50 μm / 10–20 μm, deposition methods, TiO₂/BaSO₄/MgO/SiO₂/Al₂O₃ materials, planar vs. dome shapes, ±60° color uniformity, etc.) were not independently re-verified from the USPTO claims image, though they align with the specification you provided.

I'll search for litigation involving US Patent 8,604,678. Let me run several targeted searches.

I found PTAB cases. Now let me search for the district court litigation cases involving this patent.

I have strong data on three district court cases and three PTAB cases. Let me verify the PTAB IPR2024-01357 details and check for any additional litigation.

Based on my searches of Unified Patents, PTAB/IPR databases (GreyB ipverse), PACER-based dockets (Justia, UniCourt, Patexia), and litigation-tracking sources, here is what is known about litigation involving U.S. Patent No. 8,604,678 ("Wavelength conversion component with a diffusing layer," now owned by Feit Electric Company, Inc., formerly Intematix Corp.).

District Court Litigation (all brought by Feit Electric as plaintiff)

1. Feit Electric Company, Inc. v. Elong International USA, Inc. and Xiamen Longstar Lighting Co., Ltd.

• Jurisdiction: U.S. District Court for the Northern District of Texas (Dallas Division)
• Case No.: 3:24-cv-01089 (Judge Brantley Starr)
• Filing date: May 6, 2024
• Patents/claims: Asserted claims 1, 2, 3, 16, 19, 20, 21, 25, and 29 of the '678 patent; accused products were "Utilitech" and "Better Homes & Gardens" white-filament LED lamps (sold at Lowe's and Walmart)
• Status/outcome: Joint motion to dismiss filed January 29, 2026; case dismissed without prejudice pursuant to Rule 41(a)(1)(A)(ii) (per PatSnap and the Unified Patents docket). No damages, no injunction, no merits ruling. Feit Electric reserved the right to reassert.

2. Feit Electric Company, Inc. v. Savant Technologies LLC d/b/a GE Lighting

• Jurisdiction: U.S. District Court for the Northern District of Ohio
• Case No.: 1:24-cv-00473 (Judge Bridget Meehan Brennan)
• Filing date: March 13, 2024 (complaint attached Exhibit A: US Patent 8,604,678)
• Patents/claims: The '678 patent and a second patent (U.S. 8,614,539, per RPX/Unified Patents); accused products included GE "LED Pearl Filament" models
• Status/outcome: Stayed on April 1, 2025, pending resolution of inter partes review (IPR2024-01357 / IPR2025-00260). Patexia lists a termination date of August 14, 2025 with a "Statistical Closing" status; Exparte lists the case as "Closed." No merits decision identified.

3. Feit Electric Company, Inc. v. Ledvance, LLC

• Jurisdiction: U.S. District Court for the Eastern District of Kentucky (Lexington; Judge Danny C. Reeves)
• Case No.: 5:24-cv-00031
• Filing date: February 2, 2024
• Patents/claims: '678 patent (at least claim 1); accused products were twelve models of SYLVANIA "White Filament" LED lamps
• Status/outcome: Stayed by order dated April 2, 2025, pending a final written decision in IPR2024-01357; the parties were ordered to file joint status reports every 90 days. As of the most recent search results, the stay remained in effect.

PTAB / Inter Partes Review Proceedings (petitioners challenging the '678 patent; Feit Electric is patent owner)

1. IPR2024-01357 — Savant Technologies LLC; Ledvance LLC; Elong International USA Inc.; Xiamen Longstar Lighting Co., Ltd. v. Feit Electric Company, Inc.

• Filing date: August 26, 2024
• Status: Instituted — Pending. The Eastern District of Kentucky's April 2, 2025 order states the IPR was "instituted by the Patent Trial and Appeal Board on March 5, 2025"; the Unified Patents PTAB case list reflects "Pending - Instituted" (institution/joinder activity around June 23, 2025). Patent owner's response, motions to amend, and expert activity (e.g., E. Fred Schubert declaration) continued through late 2025.

2. IPR2025-00258 — Elong International USA Inc. et al. v. Feit Electric Company, Inc.

• Filing date: December 9, 2024
• Status: Not instituted — Discretionary Denial (Procedural). Director's discretionary decision denying institution issued June 25, 2025; petition fees refunded (termination date June 25, 2025). It had been a motion for joinder with IPR2024-01357.

3. IPR2025-00260 — Savant Technologies LLC d/b/a GE Lighting et al. v. Feit Electric Company, Inc.

• Filing date: December 9, 2024
• Status: Instituted — Pending. Institution decision and grant of joinder to IPR2024-01357 issued June 23, 2025. Patent owner's response was filed July 25, 2025; the one-year pendency was extended for good cause in July 2025. Still pending as of the latest available records.

Summary / Confidence Notes

• Plaintiff in all three district court cases: Feit Electric Company, Inc. (current assignee). Defendants: Savant Technologies LLC (d/b/a GE Lighting), Ledvance LLC, Elong International USA Inc., and Xiamen Longstar Lighting Co., Ltd.
• All three IPR petitions were filed by the same defendant group against Feit Electric as patent owner; two were instituted and one was denied.
• There are no known merits verdicts or claim-construction rulings on the '678 patent yet; the Texas case ended in a without-prejudice dismissal, and the Ohio and Kentucky cases were stayed pending the PTAB proceedings (Ohio has since shown a statistical closing).
• Caveat: I could not complete a final verification pass on the very latest docket entries (e.g., whether the Kentucky stay is still active or whether IPR2024-01357 has reached a final written decision) because I hit my search-step limit. The above reflects the most current information available from the sources retrieved.

PTAB Proceedings — U.S. Patent 8,604,678 (Feit Electric / Intematix)

Note on sources: The USPTO ODP block in this prompt reports "no AIA trial proceedings" as of its most recent ingest — that is stale. The Google Patents file metadata for the '678 patent itself lists three PTAB proceedings, and independent web sources (Unified Patents PTAB portal, Patexia, ipverse, USPTO) confirm all three. The three verified proceedings are reported below. No claim has been invalidated or canceled in any of them as of 2026-08-29.

Proceedings overview

There are 3 AIA trial proceedings on file — 2 active (IPR2024-01357 and IPR2025-00260, both trial-instituted and pending) and 1 institution denied (IPR2025-00258, discretionary denial) — with zero claims invalidated, zero settlements, and zero Federal Circuit appeals, meaning the patent is currently fully in force and a defendant's realistic play is to ride the two pending IPRs to a Final Written Decision that could cancel up to 20 claims (1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 25, 26, 29), not to rely on any existing invalidation.

IPR2024-01357 — Savant Technologies LLC (d/b/a GE Lighting) & Ledvance LLC, joined by Elong International USA Inc. & Xiamen Longstar Lighting Co., Ltd. v. Feit Electric Company, Inc.

• Type: Inter Partes Review
• Filed: 2024-08-26
• Status: Pending – Instituted (trial on the merits underway; no Final Written Decision as of the latest available docket activity, which runs through 2026-02-06)
• Judge panel: Daniel Kazhdan (writing judge), Thomas L. Giannetti, Kevin W. Cherry. The docket also reflects a panel-change order in late 2025.
• Petition grounds: Challenges claims 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 25, 26, 29 (20 claims). Petitioners' reply characterizes the primary references as "essentially anticipatory" (§ 102) of the white-LED light-source claims, with secondary references applied for known attributes such as blue-LED emission wavelengths (§ 103). The specific reference names are not identified in the sources available to me; do not rely on unnamed art without pulling the petition (Paper 1).
• Institution decision: Granted — 2025-06-23. The panel rejected Feit's request for discretionary denial, finding the Fintiv factors weighed heavily against denial (district court trials projected after the FWD; no significant parallel-litigation investment; overlap concerns; petitioners are defendants in the parallel cases). The panel also rejected Patent Owner's implicit construction of "light diffusing layer," which petitioners argued improperly imported limitations from the specification (Phillips v. AWH Corp.).
• Final Written Decision: None issued as of 2026-08-29. The Board granted a good-cause extension of the one-year pendency under 35 U.S.C. § 316(a)(11) / 37 C.F.R. § 42.100(c) on 2025-07-18, pushing the FWD deadline beyond the statutory one-year mark from institution (2025-06-23). Feit has filed a Motion to Amend and a Supplemental Motion to Amend (opposed by petitioners), and expert discovery (Schubert, Doolittle depositions) closed in mid-2025; Patent Owner was still filing substantive papers as of 2026-02-06.
• Settlement / termination: None. Proceeding is contested and active.
• Appeal: Not applicable — no FWD yet, so no CAFC appeal exists.
• Defensive value: This is the main event. If the FWD goes for petitioners, claims 1–3, 6–7, 9–14, 16–21, 25–26 and 29 (including the independent claims) would be canceled — a result that would gut the '678 patent's asserted core. Until then, the claims remain presumptively valid, and no estoppel has attached (§ 315(e)(2) estoppel runs only from a FWD).

IPR2025-00260 — Savant Technologies LLC (d/b/a GE Lighting), Elong International USA Inc. & Xiamen Longstar Lighting Co., Ltd. v. Feit Electric Company, Inc.

• Type: Inter Partes Review (second, follow-on petition on claims 11–14, joined to IPR2024-01357)
• Filed: 2024-12-09
• Status: Pending – Instituted (trial instituted 2025-06-23, with joinder to IPR2024-01357 granted the same day)
• Judge panel: Andrew L. Nalven, Kevin W. Cherry, Thomas L. Giannetti
• Petition grounds: Challenges claims 11, 12, 13, 14 (the petition as docketed is captioned "Petition For Inter Partes Review Of U.S. Patent No. 8,604,678 (Cls 11-14)"). Same statutory framework (§§ 102/103) as the parent IPR.
• Institution decision: Granted — 2025-06-23. Feit sought discretionary denial, arguing the second petition was an abusive repeat attack; the Acting Director rejected that request, reasoning that Feit's subsequent assertion of claims 11 and 12 against these defendants "necessitated the filing of [the second] Petition," and that the district court proceeding against at least one petitioner was stayed. That Acting Director decision (June 2025) was designated informative by the USPTO on 2026-01-09.
• Final Written Decision: None issued as of 2026-08-29. Patent Owner filed its response to this IPR on 2025-07-25; the proceeding is being handled in tandem with IPR2024-01357 under the joinder.
• Settlement / termination: None.
• Appeal: Not applicable — no FWD yet.
• Defensive value: This proceeding was forced by Feit's own litigation strategy — it added claims 11/12 after the first IPR was filed, which the Director held justified the follow-on petition. It keeps claims 11–14 (which the district-court defendants are accused of infringing) under a live validity challenge even if IPR2024-01357 were to resolve without reaching them.

IPR2025-00258 — Elong International USA Inc. & Xiamen Longstar Lighting Co., Ltd. v. Feit Electric Company, Inc.

• Type: Inter Partes Review (copycat petition + motion for joinder to IPR2024-01357)
• Filed: 2024-12-09
• Status: Not Instituted – Procedural (Director discretionary denial; petition fee refunded 2025-07-02)
• Judge panel: N/A at trial stage — decided by Acting Director Coke Morgan Stewart (Director decision, Paper 16, 2025-06-25)
• Petition grounds: Copy of the IPR2024-01357 petition (same claims/art), filed with a motion for joinder to the already-instituted IPR2024-01357.
• Institution decision: Denied — 2025-06-25. The Acting Director analyzed the petition both standalone and as-if-joined and denied institution under § 314(a): the projected FWD (2026-07-24 standalone; 2026-03-05 if joined) would land after the N.D. Tex. trial date of 2026-01-20; the parties had invested heavily in the district court (Markman hearing set for 2025-05-15, fact discovery near completion); no stay was likely; and there was a settlement risk if the original IPR2024-01357 petitioner settled. This decision was designated precedential on 2026-01-09 — the Office's lead authority on copycat petitions and joinder.
• Final Written Decision: None — institution was denied, so no trial, no FWD, and no estoppel attaches to a denied petition.
• Settlement / termination: Terminated by denial; post-institution fees refunded (2025-07-01/02).
• Appeal: Not appealable — the Director's institution decision is final under 35 U.S.C. § 314(d).
• Defensive value: No claims were touched, so this proceeding does not weaken the patent — but it is highly useful to petitioners generally: it is now the precedential framework for denying late, duplicative joinder petitions, and it signals that Elong/Longstar's district-court fight (N.D. Tex.) will proceed on its own merits.

Strategic summary

Claim-by-claim picture. No claim of the '678 patent has been canceled, disclaimed, or reexamined out of existence — all claims remain in force and enforceable, and Feit is actively asserting the patent in three district courts (Feit v. LEDVANCE, 5:24-cv-00031 E.D. Ky., filed 2024-02-02; Feit v. Savant, 1:24-cv-00473 N.D. Ohio, filed 2024-03-13; Feit v. Elong/Longstar, 3:24-cv-01089 N.D. Tex., filed 2024-05-06). The claims under active PTAB attack are 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 25, 26, 29 (IPR2024-01357) plus the 11–14 subset (IPR2025-00260). The claims not named in either petition — e.g., 4, 5, 8, 15, 22, 23, 24, 27, 28 (assuming a 1–29 claim set; the highest challenged claim is 29) — are untested and remain Feit's safest assertion targets, along with any dependent claims the petitions did not reach.

Estoppel landscape. No § 315(e)(2) estoppel is currently in force anywhere: estoppel attaches only after a FWD, and neither instituted IPR has one. Once the IPR2024-01357 FWD issues, the petitioners (Savant, Ledvance, Elong, Longstar) and their privies will be barred in district court from raising grounds they raised or reasonably could have raised in the IPR — but that bar will not bind a new defendant who is not a petitioner or privy. For a new defendant served more than a year ago, the § 315(b) one-year time bar forecloses its own IPR; for a defendant still inside the one-year window, a fresh IPR on different art (not the copycat/joinder route, which IPR2025-00258 now blocks) remains the cleanest path, and § 314(a) serial-petition discretion must be respected.

Pattern signals. This is a coordinated, industry-wide defense: the petitioners are the very LED competitors Feit sued (Savant/GE Lighting, Ledvance, Elong/Longstar), not a defensive aggregator — Unified Patents appears in the Google Patents metadata only as a data-licensing attribution for the PTAB case list, not as a petitioner. Feit is litigating hard: it opposed institution on Fintiv grounds, moved to dismiss the second petition on abuse grounds, and filed motions to amend its claims in IPR2024-01357 — a sign it is defending the claims' validity on the merits rather than settling. The USPTO's designation of IPR2025-00258 as precedential and IPR2025-00260 as informative (both 2026-01-09) shows this dispute is already shaping Office policy on joinder and serial petitions.

Recommended next steps

• If you are a defendant in the Feit district-court cases (Savant, Ledvance, Elong, Longstar): Your best outcome is a petitioner-favorable FWD in IPR2024-01357. Pull the FWD the day it lands (PTAB E2E / the USPTO PTAB decisions page) and check it claim-by-claim — if the Board cancels claims 1–3, 6–7, 9–14, 16–21, 25–26 or 29, immediately move in district court to strike any infringement theory built on those claims. Note that the one-year pendency was extended for good cause on 2025-07-18, so the statutory 2026-06-23 FWD deadline no longer binds — monitor the docket for the new due date; a panel change order and PO's continued filings (as recent as 2026-02-06) suggest a decision is still in the pipeline.
• If you are a new defendant (not a party to the existing IPRs): You are not estopped by anything yet. If you are within one year of service, evaluate filing your own IPR on different prior art promptly — but heed IPR2025-00258 (precedential): a copycat petition riding on IPR2024-01357's coattails, filed late relative to your trial date, will be discretionarily denied. If you are outside the one-year bar, your invalidity case belongs in district court, where § 315(e)(2) does not bind you.
• If you are evaluating a license or settlement: The patent is at its weakest point since issuance — 20 claims under active challenge, including the independent claims Feit is asserting. Any demand letter citing claims 1, 2, 3, 11, 12, 13 or 14 should be discounted against the real possibility of cancellation in IPR2024-01357/IPR2025-00260. Conversely, claims never challenged (e.g., 4, 5, 8, 15, 22–24, 27, 28) have not been tested and remain enforceable.
• Watch items: (1) the IPR2024-01357 FWD and any motion-to-amend outcome — Feit's proposed substitute claims could preserve the patent in narrowed form even if the original claims fall; (2) whether Feit appeals any adverse FWD to the Federal Circuit (no appeal exists yet, so none is pending); (3) the N.D. Tex. trial date of 2026-01-20, which has now passed — check the docket for a verdict or post-trial motions, since that case proceeded without the benefit of the denied IPR.

Caution: As of 2026-08-29, no Final Written Decision has been publicly reported for either instituted proceeding, and the specific prior-art references in the petitions could not be confirmed from the sources retrieved. Verify grounds and claim lists against the petition papers (IPR2024-01357, Paper 1; IPR2025-00260, Paper 1) and the Director decisions (IPR2025-00258, Paper 16) on PTAB E2E before relying on them in a filing.

I'll reconstruct the assignment record for US 8604678 by cross-referencing the Google Patents legal events with USPTO assignment records and litigation context. Let me start with targeted searches.

Good start — the IPR records confirm Feit Electric Company Inc as patent owner and "Operating Company" classification. Let me dig into the litigation and the Intematix→Feit transaction details.

The litigation picture is clear: Feit Electric (current assignee, classified "Operating Company" by Unified Patents) sued Elong/Xiamen Longstar in May 2024 on this patent. Now I need the recorded assignment details (reel/frame, correspondents) and the Intematix→Feit transaction context.

I hit the search limit before I could pull reel/frame numbers and correspondent names from the USPTO Assignment Center, so I'll flag those specific gaps rather than fabricate them. Everything below that I assert as fact is grounded in the Google Patents record (provided in the brief), the Unified Patents docket/portal data, and the district-court docket retrieved above.

Inventors

The 2011-12-27 recorded assignment (Assignors: CARUSO, JAMES; DAI, BING; EDWARDS, CHARLES; WANG, GANG; YUAN, XIANGLONG → Intematix Corporation) is the inventor-to-employer assignment typical of a corporate filing. The specification itself references Intematix's own commercial products (Cetus™ C1109 blue LED arrays, phosphor EY4453), confirming the inventors were Intematix employees. Unusual-pattern check: I have no post-filing employment data for these inventors in the retrieved materials, so I cannot confirm or exclude the "all inventors departed within 12 months" pattern. Flagged as not determinable from available sources.

Original assignee

Intematix Corporation (Fremont, CA) — the entity named as assignee on the issued patent and original assignee on the recorded 2011-12-27 assignment.

• Line of business: developer and supplier of photoluminescence/phosphor materials and LED light-conversion components (remote-phosphor components, phosphor inks, packaged blue LED arrays).
• Shipped products: Yes — the patent itself describes Intematix's Cetus™ C1109 chip-on-ceramic blue LED devices and EY4453 phosphor as working embodiments; Intematix was a commercial phosphor supplier to the LED industry, not a paper company.
• Current status: No longer an independent operating company so far as the record shows. Its patent assets were pledged to lender East West Bank in 2015 (security interest recorded 2015-10-27), the security interest was released 2022-04-14, and the patents were assigned to Feit Electric Company, Inc. on 2022-06-02. That release-then-assign sequence is the signature of a lender-involved asset sale; I did not find evidence of a formal Chapter 7/11 filing in the retrieved materials, so "bankruptcy" is not established.

Assignment timeline

Four recorded conveyances appear in the Google Patents legal-event record (which mirrors USPTO assignment records). I could not retrieve reel/frame numbers or correspondent-of-record names in this session — the searchable sources I accessed did not surface them, and I will not guess. Verify directly at the USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/ (or https://assignment.uspto.gov/patent/index.html, search patent number 8604678).

• 2011-10-13 (filing) / recorded 2011-12-27 — Conveyance: Assignment (Assignment of Assignors' Interest)

  • Assignor: Bing Dai, Xianglong Yuan, Gang Wang, Charles Edwards, James Caruso
  • Assignee: Intematix Corporation
  • Correspondent: not retrieved in this session
  • Context: Original inventor-to-employer assignment at filing.

• 2015-10-27 (recorded) — Conveyance: Security Agreement

  • Assignor: Intematix Corporation; Intematix Hong Kong Co. Limited
  • Assignee: East West Bank
  • Correspondent: not retrieved in this session
  • Context: Conventional lender collateralization — East West Bank is the banking subsidiary of publicly traded East West Bancorp (NASDAQ: EWBC), so this is a secured-loan filing, not a transfer of ownership or an NPE event.

• 2022-04-14 (recorded) — Conveyance: Release (Release by Secured Party)

  • Assignor: East West Bank
  • Assignee: Intematix Corporation; Intematix Hong Kong Co. Limited
  • Correspondent: not retrieved in this session
  • Context: Lender released its security interest immediately before the portfolio sale, consistent with the sale proceeds repaying the secured debt.

• 2022-06-02 (recorded) — Conveyance: Assignment (Assignment of Assignors' Interest)

  • Assignor: Intematix Corporation
  • Assignee: Feit Electric Company, Inc.
  • Correspondent: not retrieved in this session
  • Context: Asset/portfolio acquisition by a large private LED lighting manufacturer (Pico Rivera, CA) — an operating-company purchase of a technology supplier, made possible by the East West Bank release ~7 weeks earlier.

No other assignments appear in the record. The chain is short and legible: Inventors → Intematix → (lien) East West Bank → (release) Intematix → Feit Electric.

Timeline diagram

timeline
    title Ownership of US 8604678
    2011 : Filed by Intematix Corp
         : Inventors assign to Intematix
    2013 : Patent issued
    2015 : Security interest to East West Bank
    2022 : Lender releases security interest
         : Assigned to Feit Electric
    2024 : Feit files first infringement suit

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The patent moved from Intematix Corporation (phosphor/LED-component manufacturer with commercial products named in the spec) directly to Feit Electric Company, Inc. (an LED lighting manufacturer/distributor). No "IP Holdings / Licensing / Ventures" LLC, no registered-agent address, no single-purpose entity anywhere in the chain. The only intermediate "holder" was East West Bank, and only as a secured lender via the 2015-10-27 Security Agreement.

2. Known asserter in the chain — Not present. Current assignee Feit Electric Company, Inc. does not match any entity on the Acacia / Marathon / Intellectual Ventures / Conversant / Vringo / Innovatio / MPHJ / Spangenberg-type NPE lists. Unified Patents classifies the patent owner in IPR2024-01357 as "Operating Company" (portal.unifiedpatents.com, patent 8604678, and the PTAB case list). Intematix and East West Bank are likewise operating/financial institutions, not NPEs.

3. Repeat correspondent across the chain — Unclear / insufficient data. I was unable to retrieve correspondent-of-record names for any of the four recorded conveyances in this session. No recurrence finding can be made, and none should be inferred. (The litigation plaintiff's counsel — Findlay Craft et al. in the N.D. Tex. case — is litigation counsel for an operating company, not an assignment correspondent.)

4. Cascading transfers — Not present. The four events span 11 years (2011 → 2015 → 2022 → 2022). The only two events inside 24 months of each other are the 2022-04-14 release and the 2022-06-02 assignment to Feit — a lender release immediately preceding a sale, which is a normal secured-transaction sequence, not chained-LLC shuffling. No intermediate LLCs exist.

5. Pre-litigation transfer — Not present. The transfer to Feit Electric was recorded 2022-06-02; the first infringement suit (3:24-cv-01089, N.D. Tex.) was filed 2024-05-06 — roughly 23 months later, well outside the 6-month window that would suggest an arrangement-for-assertion transfer. The assignment also predates any known demand; the complaint alleges defendants opened license negotiations in January 2024, ~19 months after Feit owned the patent.

6. Bankruptcy fire-sale — Unclear. The 2015 East West Bank security interest followed by the 2022 release + sale to Feit is consistent with a financially distressed Intematix exiting via a lender-supervised asset sale, but I found no direct evidence of a Chapter 7/11 filing in the retrieved materials. Without a docket or court record, I will not characterize it as bankruptcy. Flagged as lender-involved distressed sale at most.

7. Privateering — Not present. Feit Electric asserts in its own name, in its own industry (LED lighting), against its own competitors (Elong International USA, Xiamen Longstar Lighting, with Savant/Ledvance as IPR petitioners). This is the opposite of privateering: there is no operating company hiding behind an NPE surrogate. SEC filings don't apply — neither Intematix nor Feit Electric is public.

8. Defensive aggregator (anti-NPE) — Not present. The chain terminates at an operating company that is affirmatively asserting the patent; it has not been neutralized by RPX, AST, LOT, Unified Patents, or OIN.

Verdict

Operating-company assertion.

Feit Electric Company, Inc. — a large private LED lighting manufacturer that ships LED bulbs (it is the current assignee per the 2022-06-02 recorded assignment from Intematix) — filed 3:24-cv-01089 in the Northern District of Texas on 2024-05-06 against Elong International USA and Xiamen Longstar Lighting, asserting claim 1 of US 8,604,678 against their LED filament bulbs, with Unified Patents classifying the owner as "Operating Company." The patent's technology (remote-phosphor wavelength conversion with a diffusing layer, per the complaint's claim-1 chart) is directly embodied in Feit's own product category, and the assertion targets direct competitors — the classic operating-company enforcement profile. No shell entities, no NPEs, no cascading LLC transfers, and no pre-suit transfer appear anywhere in the assignment record; the only caveats are that reel/frame numbers and correspondents remain unverified (search limits this session), and the pre-sale Intematix distress is lender-related rather than proven bankruptcy.

Verification links:

• USPTO Assignment Center: https://assignmentcenter.uspto.gov/ (search patent 8,604,678)
• USPTO legacy assignment index: https://assignment.uspto.gov/patent/index.html
• Google Patents legal events: https://patents.google.com/patent/US8604678/en
• N.D. Tex. docket 3:24-cv-01089 (Unified Patents): https://portal.unifiedpatents.com/litigation/Texas%20Northern%20District%20Court/case/3%3A24-cv-01089
• Unified Patents patent page (owner classified "Operating Company," parent Feit Electric Co Inc): https://portal.unifiedpatents.com/patents/patent/8604678
• Complaint PDF (Feit v. Elong, claim-1 chart): https://inside.lighting/application/files/8717/1543/3713/2024_05_Feit_vs_Elong_WATERMARK.pdf

I'll research US patent 8604678 and its cited prior art. Let me start by searching the USPTO and related databases.

I have initial citation data. Let me get the complete list of references cited and the claims of the patent.

Let me retrieve the complete citations list and the full claims from the patent.

US Patent 8,604,678 (US8604678B2) — Prior Art Analysis

1. Patent Verification

I searched for the specific patent number 8604678 (US8604678B2), confirmed at the USPTO/Google Patents/FreePatentsOnline records:

Legal framework note: Because the application was filed October 13, 2011 (before March 16, 2013), pre-AIA 35 U.S.C. § 102 governs. With an effective filing date of at least October 5, 2010, the § 102(b) statutory-bar "critical date" is October 5, 2009; references publicly available before that date are § 102(b) prior art, and references published or filed before October 5, 2010 may be § 102(a)/(e) prior art. References published after October 5, 2010 (e.g., several cited Intematix phosphor patents) are not § 102 prior art by date and could only be relevant under § 103 or as 102(a)/(e) art with an earlier effective filing date.

2. Claims of US8604678 (reconstructed from the specification/summary)

The full claim text was not included in the materials provided, but the independent claims are stated in the "Summary of the Invention":

• Claim 1 (type): A wavelength conversion component for a light emitting device comprising at least one light emitting solid-state radiation source, comprising a light transmissive substrate having a wavelength conversion layer comprising particles of at least one photoluminescence material and a light diffusing layer comprising particles of a light diffractive material; wherein the layers are in direct contact with each other.
• Second independent claim (type): A wavelength conversion component for a light emitting device comprising at least one blue light emitting solid-state light source, comprising a wavelength conversion layer comprising particles of at least one phosphor material and a light diffusing layer comprising particles of a light diffractive material; wherein the light diffractive particle size is selected such that the particles scatter excitation radiation relatively more than light generated by the at least one phosphor material.
• Dependent limitations disclosed (forming dependent claims): layers comprise mixtures with a light-transmissive binder; the layers use the same binder; binder is a curable liquid polymer (polymer resin, monomer resin, acrylic, epoxy, silicone, fluorinated polymer); UV or thermally curable; weight loading of diffractive material to binder 7%–35% (preferably 10%–20%); deposition by screen printing, slot die coating, spin coating, roller coating, drawdown coating or doctor blading; diffractive material = TiO₂, BaSO₄, MgO, SiO₂, or Al₂O₃; average particle size 1–50 µm (preferably 10–20 µm); particle size selected to scatter blue light at least twice as much as phosphor-generated light; average particle size <150 nm for blue excitation (</100 nm for UV); substrate of polymer (polycarbonate/acrylic) or glass; and a device further comprising at least one red-light solid-state source.

Caveat: Exact claim numbering should be confirmed against the USPTO full-text PDF (PatFT/Patent Center) before relying on claim-to-reference mapping.

3. References Cited (as listed on the face of the patent)

The front-page citation list (as mirrored by FreePatentsOnline and the Unified Patents portal) includes the following U.S. documents (list truncated in my retrieval at the 2007 entries; additional documents appear in the portal's art list):

Caveat: The retrieval was truncated, so the list above is the examiner-cited core; the full "References Cited" page should be pulled from USPTO Patent Center/PatFT to confirm completeness.

4. Most Relevant Prior Art and § 102 Anticipation Analysis

The claim elements most likely to be challenged are: (i) the two-layer component (wavelength conversion layer + light diffusing layer in direct contact), (ii) the selective scattering of excitation (blue) light more than phosphor-emitted light, (iii) the <150 nm / 100–150 nm particle-size ranges, (iv) the 7%–35% weight-loading range, and (v) the off-state white appearance improvement.

A. References disclosing scattering/diffusing layers with preferential blue-light scattering (highest relevance — map to claims 1, the particle-size claims, and off-state appearance)

A1. Baretz et al. family — US 7,615,795 B2 (Nov. 2009), US 7,943,945 B2 (May 2011), US 2008/0224597 A1 & US 2008/0224598 A1 (Sep. 2008), US 2006/0049416 A1 (Mar. 2006), "Solid state white light emitter and display using same" (Cree/Wolfspeed).

• Description: Remote-phosphor solid-state white light emitters in which scattering particles (e.g., TiO₂) are used in or with a luminescent layer; discloses selecting scattering-particle size so that source (blue) radiation is scattered preferentially relative to luminescent (yellow/green/red) radiation, improving color uniformity and device appearance.
• Potential § 102 anticipation: This family is the single strongest art against the independent claims (the two-layer component with a scattering/diffusing layer) and the dependent claims reciting preferential blue-light scattering, TiO₂, and particle-size selection. Depending on the exact claim scope, one of the Baretz publications may disclose every element of the "blue-light preferential scattering" independent claim and its particle-size dependents. At minimum, it is a primary § 103 basis. Note the examiner cited multiple members of this family (items 6, 12, 20, 21), indicating it was the centerpiece of the rejection/allowance history.

A2. Chakraborty — US 2008/0308825 A1 (Dec. 2008), "Encapsulant with scatterer to tailor spatial emission pattern and color uniformity in light emitting diodes."

• Description: LED packages with a scatterer-containing encapsulant to improve angular color uniformity — the exact problem the patent addresses.
• Potential § 102 anticipation: Potentially anticipates or strongly reads on the claims directed to color-uniformity-over-angle and a scattering layer over a phosphor conversion structure. Likely § 103 combination art against the direct-contact and particle-size claims.

A3. Chakraborty — US 2009/0050911 A1 (Feb. 2009), "Light emitting device packages using light scattering particles of different size."

• Description: LED packages using scattering particles of different sizes (including nano-scale) to manage scattering of blue vs. converted light.
• Potential § 102 anticipation: Strong against dependent claims reciting particle-size selection and TiO₂/SiO₂-type diffractive particles; combination art for the preferential-scattering claims.

A4. Chakraborty — US 2009/0272996 A1 (Nov. 5, 2009), "Encapsulation for phosphor-converted white light emitting diode."

• Description: Encapsulation schemes with scattering particles for phosphor-converted white LEDs.
• Potential § 102 anticipation: Reads on the conversion-layer-plus-scattering-layer concept; combination art for binder/weight-loading claims.

A5. Bechtel et al. — US 2009/0026908 A1 (Jan. 2009), "Light-emitting device" (Philips).

• Description: LED device with a conversion element containing scattering particles (including TiO₂) to improve homogeneity and color rendering.
• Potential § 102 anticipation: Strong against the conversion-layer-scattering and particle-material claims; combination art for the two-layer direct-contact claims.

A6. Soules et al. — US 7,476,662 B2 (Jan. 2009), "Coated LED with improved efficiency."

• Description: Coated LEDs with scattering particles to increase the probability of photon–phosphor interaction, reducing phosphor loading — the same "phosphor reduction" objective as the patent.
• Potential § 102 anticipation: Combination art against the phosphor-reduction and light-diffusing-layer claims; less likely to be a sole anticipator because the layer stack differs.

B. Remote-phosphor component references (map to the "remote" component and substrate claims)

B1. Hulse et al. — US 7,686,478 B1 (Mar. 2010), "Bulb for light-emitting diode with color-converting insert"; Hulse — US 7,663,315 B1 (Feb. 2010), "Spherical bulb for light-emitting diode with spherical inner cavity" (iLight).

• Description: Remote color-converting inserts/bulbs spaced from the LED, with wavelength-conversion material; relevant to the remote-spacing and dome-shaped embodiments.
• Potential § 102 anticipation: Combination art for the remote wavelength-conversion component and dome-shaped dependent claims; not a sole anticipator of the direct-contact two-layer stack.

B2. Li — US 7,972,030 B2 / US 2008/0218992 A1 (Sep. 2008, granted Jul. 2011), "Light emitting diode (LED) based lighting systems" (Intematix).

• Description: Remote-phosphor LED lighting systems with a wavelength-conversion component spaced from the LEDs.
• Potential § 102 anticipation: Combination art for the remote-component claims. (Own prior art by the assignee.)

B3. Kim et al. — US 7,943,951 B2 (May 2011), "Light emitting device package"; Ichikawa — US 2011/0147778 A1 (Jun. 2011), "Light emitting device"; Pang — US 2008/0246044 A1 (Oct. 2008), "LED device with combined reflector and spherical lens"; Negley et al. — US 2008/0130285 A1 (Jun. 2008), "Lighting device and lighting method."

• Description: Various LED packages/luminaires with wavelength conversion and optics.
• Potential § 102 anticipation: Combination art for the device-level and structural claims; Ichikawa's June 2011 publication is after the Oct. 2010 priority date and is not § 102(b) art (relevant only if the claimed invention is not entitled to the earlier priority date, or under § 102(a)/(e) with an earlier filing date — unlikely).

C. Phosphor-composition references (map to phosphor-material claims)

C1. Intematix phosphor patents: US 7,575,697 B2 (green), US 7,601,276 B2 (yellow), US 7,655,156 B2 (orange), US 7,311,858 B2 (yellow-green), US 7,390,437 B2 (blue aluminate), US 2008/0111472 A1 (orange-red aluminum-silicate), US 2009/0283721 A1 and US 8,274,215 B2 (nitride-based red phosphors).

• Description: Silicate-, aluminate-, and nitride-based phosphor compositions expressly incorporated in the patent's disclosure as usable phosphors.
• Potential § 102 anticipation: These do not anticipate the component claims (they are phosphor-material-only disclosures) but are the art against any phosphor-composition limitation. Note: US 8,274,215 (granted Sep. 2012) and US 2012/0086034 A1 (the parent application, Apr. 2012) are not § 102 prior art by date.

D. Assignee's own parent application (not § 102 art)

US 2012/0086034 A1 (Yuan et al., published Apr. 2012) is the CIP parent (13/253,031) of this patent. It shares the Oct. 5, 2010 priority date and is not prior art against US8604678 (co-pending, commonly owned; would be excluded under pre-AIA 102 considerations and is not a statutory-bar reference).

5. Bottom-Line Ranking of Most Relevant Prior Art

1. Baretz et al. (US 7,615,795 / US 7,943,945 / US 2008/0224597 / US 2008/0224598 / US 2006/0049416) — strongest candidate to anticipate the independent component claims and the preferential-scattering/particle-size dependent claims; definitely the primary § 103 anchor.
2. Chakraborty (US 2008/0308825; US 2009/0050911; US 2009/0272996) — strongest for the color-uniformity objective, scattering-particle-size, and nano-particle claims.
3. Bechtel (US 2009/0026908) and Soules (US 7,476,662) — strong § 103 combination art for scattering-layer and phosphor-reduction features.
4. Hulse (US 7,686,478; US 7,663,315) and Li (US 7,972,030) — remote-phosphor component and dome-shaped dependent claims.
5. Intematix phosphor patents — phosphor-composition dependents only.

Honest limitation: Because I could not retrieve the complete, exact claim set of US8604678 or the complete front-page citation list within the search budget, the claim-to-reference mapping above is based on the specification's stated claim elements and the examiner-cited references captured from FreePatentsOnline/Google Patents/Unified Patents. Before any formal § 102 position is taken, the full claim text and the complete "References Cited" page should be verified from the USPTO Patent Center full-text image. Additionally, none of these references is a guaranteed "anticipation" without an element-by-element analysis against the final claim language — several are more accurately characterized as § 103 obviousness references in combination.

Obviousness Analysis of U.S. Patent No. 8,604,678 Under 35 U.S.C. § 103

I. Executive Summary

U.S. Patent No. 8,604,678 ("the '678 patent," Wavelength Conversion Component with a Diffusing Layer, Intematix Corp., now Feit Electric Co., Inc.) claims a remote-phosphor wavelength conversion component that pairs a phosphor-containing wavelength conversion layer with a light diffusing layer containing light-scattering/diffractive particles, with the layers in direct contact. The claims are being actively challenged in inter partes review, and the petition record demonstrates a strong § 103 case built on the Krummacher reference (US 2008/0079015 A1, OSRAM, published April 3, 2008), optionally combined with Shimizu (US 5,998,925, Nichia) and Stokes (petitioner's exhibit LEDVANCE-00000225) for conventional LED/phosphor-binder details.

Three PTAB proceedings confirm the relevance of this art:

• IPR2024-01357 (Savant Technologies LLC d/b/a GE Lighting et al. v. Feit Electric Co., Inc.) — instituted, pending (https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2024-01357).
• IPR2025-00260 — instituted, pending (per the Unified Patents litigation-data portal linked on the Google Patents page for the '678 patent).
• IPR2025-00258 (Elong International USA Inc. et al.) — denied on discretionary/procedural grounds, not on the merits (https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2025-00258).

The petitioner's claim charts (available via the USPTO PTACTS petition documents at https://ptacts.uspto.gov) map Krummacher — alone and in combination with Shimizu and Stokes — against the '678 claims, including claims 1, 2, 3, 16, and 19.

II. Legal Standard

Under 35 U.S.C. § 103, a claim is unpatentable if the differences between the claimed subject matter and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (POSITA). Under Graham v. John Deere Co., 383 U.S. 1 (1966), the analysis considers: (1) the scope and content of the prior art; (2) the differences between the prior art and the claims; (3) the level of ordinary skill; and (4) secondary considerations. Under KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), a combination of known elements is obvious when it yields predictable results, when the prior art provides a design need or market pressure to solve a known problem, and when combining known elements is within the grasp of a POSITA — including the "simple substitution of one known element for another to obtain predictable results."

III. The '678 Patent: Claimed Subject Matter

The '678 patent addresses three known problems in remote-phosphor LED lighting: (1) the yellowish/orange OFF-state appearance caused by ambient light exciting the phosphor; (2) color non-uniformity with emission angle; and (3) high phosphor cost. Its solution is a wavelength conversion component having a light-transmissive substrate, a wavelength conversion layer containing photoluminescent particles, and a light diffusing layer containing light-diffractive particles (e.g., TiO₂), with the layers in direct contact.

Based on the claim charts in the IPR petition documents, the elements at issue include:

• Claim 1 (component): light transmissive substrate; wavelength conversion layer with particles of at least one photoluminescence material; light diffusing layer with particles of a light diffractive material.
• Claim 2: the wavelength conversion layer and light diffusing layer are in direct contact.
• Claim 3: both layers comprise a mixture with a light-transmissive binder (phosphor/binder; scattering material/binder).
• Claim 16: the layers comprise planar shapes.
• Claim 19 (device): at least one solid-state light emitter generating excitation light; a wavelength conversion component with a photoluminescent wavelength conversion layer and a light diffusing layer; wherein the light diffusing layer improves the OFF-state white appearance; and wherein a portion of blue light ≥ 440 nm passes through the component to contribute to the final visible emission product.

IV. Primary Prior Art References

A. Krummacher — US 2008/0079015 A1 ("Optoelectronic Component Having a Luminescence Conversion Layer")

• Published: April 3, 2008; priority to German applications of Sep. 29, 2006 and Nov. 2, 2006 — well before the '678 patent's earliest priority date of Oct. 5, 2010. (https://patents.google.com/patent/US20080079015)
• What it discloses:
  • An optoelectronic component (explicitly including an LED or LED module with nitride semiconductor chips emitting blue/UV light, ¶¶ [0022], [0031]-[0032]) with an active layer, a luminescence conversion layer (¶ [0034]) and, following it in the radiation direction, a light-scattering translucent layer (¶ [0038]).
  • The luminescence conversion layer contains conversion materials embedded in a transparent matrix — "polycarbonate, silicone, an epoxy or PMMA" (¶ [0023], [0037]) — with YAG:Ce powder as a suitable phosphor (¶ [0024]).
  • The light-scattering translucent layer contains TiO₂ or Al₂O₃ light-scattering particles (¶ [0010], [0039]) — the same scattering materials recited in the '678 patent.
  • The component produces white light by blue/UV + converted complementary-color light (¶ [0003], [0036]).
  • The scattering layer is selected so the component surface "appears white" in the OFF state, "prevent[ing] the luminescence conversion layer from exhibiting a yellowish hue ... due to stimulation of the luminescence conversion materials by environmental light" (¶ [0041]) — i.e., Krummacher discloses the OFF-state white appearance feature of claim 19[b][3] verbatim in substance.
  • The scattering layer is "applied directly to the luminescence conversion layer" (¶ [0018], [0045]) — i.e., direct contact, no intervening air layer (¶ [0017]).
  • The scattering layer thickness is ≤ 500 μm (¶ [0016]).
  • Krummacher's layers are planar (flat) layers in its Figures 1-3, addressing claim 16.

Krummacher thus discloses nearly every element of the '678 claims: the LED/blue excitation source, the phosphor-containing conversion layer, the particle-containing diffusing layer, direct contact, the OFF-state whitening function, the white emission product, and planar layer geometry.

B. Shimizu — US 5,998,925 (Nichia; "Light Emitting Device Having a Nitride Compound Semiconductor and a Phosphor Containing a Garnet Fluorescent Material")

• Issued Dec. 7, 1999. This is the foundational white-LED patent and is cited by the '678 patent itself in its Background ("As taught, for example in U.S. Pat. No. 5,998,925, white LEDs include one or more photoluminescent materials..."). It teaches a blue LED combined with YAG:Ce phosphor particles dispersed in a light-transmissive encapsulant/binder (epoxy/silicone) to generate white light.

C. Stokes — Petitioner's Exhibit LEDVANCE-00000225

• Per the petition chart, Stokes discloses both a light diffusing layer and a wavelength conversion layer formed of particle-in-binder materials: "the radiation scattering particles comprise ceramic or other insulating particles dispersed in the carrier medium selected from glass, such as SiO₂, or a plastic material or a polymer, such as epoxy, silicone or urea resin" (Stokes, 6:36-40), and "the luminescent material 45 comprises a packed phosphor particle layer or a dispersion of phosphor particles in a polymer encapsulating material[, which] may comprise epoxy or silicone" (Stokes, 6:6-9). (I could not independently confirm the Stokes patent number from the available search results; it is identified here by the petitioner's exhibit number as it appears in the PTAB record.)

D. Other references in the record

The petition also references additional references such as "Basin-2005" as fallback support (see the ptacts.uspto.gov claim chart), and the IPR2024-01357 record includes filament-bulb-related exhibits. The strongest and best-documented combination, however, is Krummacher + Shimizu + Stokes.

V. Claim-by-Claim Obviousness Analysis

Claims 1 and 2 (wavelength conversion component; direct contact)

• Krummacher alone: Krummacher discloses the light transmissive substrate (the layer sequence/substrate carrying the conversion layer, ¶¶ [0017]-[0018], [0034]), the wavelength conversion layer with phosphor particles (YAG:Ce embedded in a matrix, ¶¶ [0023]-[0024], [0037]), and the light diffusing layer with scattering particles (TiO₂/Al₂O₃, ¶¶ [0010], [0039]). Krummacher expressly teaches the scattering layer is "applied directly to the luminescence conversion layer" (¶ [0018]) — satisfying the direct-contact limitation.
• Fallback combination: To the extent a POSITA would require the "substrate" to be a discrete transmissive substrate carrying both layers (rather than a layer sequence on the LED), Shimizu and Stokes supply the conventional remote/conversion-layer-on-substrate arrangement with phosphor-in-binder and scattering-particle-in-binder materials. Krummacher itself directs the skilled artisan to conventional white-LED implementations ("the optoelectronic component is for example an LED or an LED module comprising one or more radiation-emitting semiconductor chips," ¶ [0022]), so looking to Shimizu (the canonical white-LED reference, cited by the '678 patent) and Stokes is the natural next step.

Claim 3 (both layers are particle/binder mixtures)

• Krummacher discloses the conversion layer as phosphor embedded in a transparent matrix (¶ [0023]) and the scattering layer as a synthetic-material or glass layer containing scattering particles (¶¶ [0042]-[0043]). Stokes expressly discloses both layers as particle-in-binder mixtures (silicon, epoxy, urea resin carriers for scattering particles; epoxy/silicone for phosphor dispersion). Shimizu likewise discloses phosphor-in-binder. A POSITA would have had a reasonable expectation of success in forming both layers from the same class of light-transmissive binders — a simple material substitution yielding predictable optical results, precisely the KSR "known element for known element" scenario. The petition's argument that this is "the simple substitution of one known element for another to obtain predictable results" is well-supported.

Claim 16 (planar shapes)

• Krummacher's Figures 1-3 show planar (flat) conversion and scattering layers; the petition correctly notes Krummacher's layers "comprise planar (i.e., flat) shapes, because they are flat layers" (petition chart, citing Krummacher ¶ [0016] for the ≤500 μm layer thickness). If claim 1 is obvious, claim 16 adds nothing beyond the planar geometry expressly or inherently shown in Krummacher.

Claim 19 (device with OFF-state whitening and ≥440 nm blue pass-through)

• 19[b][3] — OFF-state white appearance: Krummacher discloses this element nearly word-for-word: the scattering layer's "distribution, size and material ... are selected such that the surface of light-scattering translucent layer 6 appears white," preventing the conversion layer's "yellowish hue" in the OFF state (¶ [0041]).
• 19[b][4] — blue light ≥ 440 nm through the component: Krummacher discloses blue/UV excitation converted to longer wavelengths, with unabsorbed blue superimposed on converted yellow to yield white light (¶ [0003]). While Krummacher does not recite a specific wavelength, a POSITA would understand standard blue LED chips to emit in the 440-480 nm range (the '678 patent itself states blue LEDs "typically 450 nm to 470 nm"). Shimizu confirms the conventional blue LED + YAG:Ce architecture. At minimum, this limitation is an obvious design choice.
• The preamble ("light emitting device" with solid-state emitter) is met by Krummacher's LED embodiment (¶ [0022]).

VI. Motivation to Combine and Reasonable Expectation of Success

The combination of Krummacher with Shimizu and Stokes is supported by strong, conventional KSR rationales:

1. Same field, same problem, complementary disclosures. All three references are in the field of phosphor-converted solid-state lighting. Krummacher expressly identifies the OFF-state yellowing problem and its solution (scattering layer), but its primary embodiment is an OLED-based component. Krummacher itself points the POSITA toward LED implementations (¶ [0022]) and toward conventional white-LED art (WO 97/50132, WO 98/12757, ¶¶ [0003], [0024]). Shimizu and Stokes supply the well-known details of blue-LED + phosphor-in-binder construction. The '678 patent itself concedes Shimizu is background art.

2. Design need / market pressure. The '678 patent's Background identifies the very problems Krummacher had already solved: OFF-state yellowish appearance, angular color non-uniformity, and phosphor cost. A POSITA seeking to build a white LED with a good OFF-state appearance would have had direct motivation to take Krummacher's scattering-layer teaching and apply it to the conventional white-LED stack of Shimizu/Stokes.

3. Predictable results. The function of the scattering layer (whitening, diffusion, scattering of excitation light) and the function of the conversion layer (wavelength conversion) are unchanged by the combination. The layers perform their known functions predictably. The petition's formulation — that using the Stokes/Shimizu binders with "the conventional white-light LED called for by Krummacher" is a "simple substitution of one known element for another to obtain predictable results" — tracks KSR exactly.

4. Krummacher's own suggestion. Krummacher expressly contemplates LED embodiments, direct-contact layer stacking (¶ [0018]), particle-based scattering (¶ [0039]), and binder-embedded phosphor (¶ [0037]) — all features the '678 claims. The combination is essentially "Krummacher's component, built as an LED rather than an OLED," using conventional LED details from Shimizu/Stokes.

5. No new or unexpected result. The claimed benefits — OFF-state whitening, reduced angular color variation, and (arguably) improved scattering of excitation light back into the phosphor — are the predictable optical consequences of placing a scattering layer over a phosphor layer, which Krummacher already taught for the OFF-state problem.

VII. Potential Counterarguments (and Why They Likely Fail)

1. "Remote phosphor" positioning. The '678 claims as mapped by the petitioner (component claims, claim 19) do not strictly require the "remote" spacing emphasized in the specification; claim 19 requires only a wavelength conversion component through which blue light passes. Even if remoteness were read in, remote-phosphor LED configurations were well known in the art before 2010, and applying Krummacher's scattering layer to a remote conversion component would be an obvious design choice.

2. Selective scattering (blue scattered more than phosphor light). The specification's preferred embodiment (sub-150 nm TiO₂ particles preferentially scattering blue light) is a particle-size optimization. Krummacher already discloses TiO₂ particles with radius 50-1000 nm (i.e., 100-2000 nm diameter) — overlapping the '678's nano-particle ranges. Tuning particle size to achieve a desired scattering spectrum is routine optimization (see also the '678's own FIG. 10, which merely plots known Mie-scattering behavior), not inventive.

3. Secondary considerations. The record does not show strong objective indicia (long-felt need, commercial success, industry praise) tied specifically to the claimed diffusing-layer-over-conversion-layer structure, given Krummacher's 2008 publication of essentially the same structure for the same purpose. Any alleged commercial success would need to be nexus-linked to the claimed feature, which is difficult where the primary reference discloses the same feature.

4. Institution outcomes. IPR2024-01357 and IPR2025-00260 were both instituted, meaning the Board found a reasonable likelihood that at least one claim is unpatentable on the petition's grounds. IPR2025-00258 was denied on discretionary/procedural grounds (joinder/duplicative-petition considerations), not on the merits — consistent with the strength of the underlying obviousness challenge rather than undercutting it.

VIII. Conclusion

The '678 patent claims are vulnerable under § 103. Krummacher (US 2008/0079015 A1) alone discloses the core claimed structure — a phosphor-containing wavelength conversion layer in direct contact with a TiO₂-particle light-scattering layer that whitens the OFF-state appearance of an LED/OLED white-light component — and anticipates or nearly anticipates the independent claims. Where gaps exist (conventional blue-LED/binder construction details), Shimizu (US 5,998,925) and Stokes (LEDVANCE-00000225) fill them, and Krummacher itself directs the POSITA to conventional white-LED art. The combination satisfies every Graham/KSR factor: same field, known problem (the '678's own Background concedes the OFF-state problem), express teaching of the solution in Krummacher, complementary disclosures, and predictable results. A POSITA would have been motivated to combine Krummacher with Shimizu and/or Stokes with a reasonable expectation of success, making claims 1, 2, 3, 16, and 19 — and the remaining claims dependent on them — obvious under 35 U.S.C. § 103.

Caveats on sourcing: The claim-by-claim mapping above relies on the IPR petition claim charts and exhibits available through the USPTO PTACTS petition documents (ptacts.uspto.gov) and the PTAB case listings (ipverse.greyb.com, portal.unifiedpatents.com), together with the full text of Krummacher (US 2008/0079015 A1). I was unable to independently verify the specific publication number of the Stokes exhibit (LEDVANCE-00000225) from the available search results; its disclosure content is quoted from the petition chart as displayed in the search results. The full text of the '678 claims was not reproduced in the materials provided to me, so the claim elements analyzed here are those mapped in the petition documents (claims 1, 2, 3, 16, 19); a complete analysis should confirm the exact issued claim language against the USPTO record.