US 9280093

I'll search for authoritative information on this patent number, including litigation/docket records.

Let me check for any litigation records and USPTO/patent-center specifics.

US 9,280,093 B2 — Summary

Source of record: Full patent text from Google Patents (https://patents.google.com/patent/US9280093/en), fetched 2026-09-24. All bibliographic data below is taken literally from that document.

Bibliographic data

Two data anomalies I am flagging rather than "correcting," per your instruction:

1. The specification's CROSS-REFERENCE section states the JP priority application (No. 2013-006606) was "filed Jan. 17, 2014," while the Google Patents front-matter priority date is 2013-01-17. These conflict internally; I cannot resolve which is authoritative from the provided text.
2. The Google Patents "Applications Claiming Priority" table lists JP5358772B1 with the title "Dried fruit and method for producing the same." This is plainly a database/classification error (the same table also lists unrelated fruit-dehydration family members such as JP6902520B2 and KR101773519B1, "Jam including dried fruit"). I am reporting it literally; the correct JP counterpart title is not something I can confirm from the supplied text.

Abstract (verbatim)

In accordance with an embodiment, a developing agent cartridge for supplying developing agent and toner to a developing device comprises a cartridge main body, in which there is a first room and a second room and the boundary of the two rooms is closed by a closure member, configured to respectively fill the toner and the developing agent into the first room and the second room; a supply section configured to supply the infill in the second room to the developing device while stirring it; and an opening section configured to open the closure member to enable the toner to be moved to the second room after the developing agent filled into the second room is supplied to the developing device.

Plain-language overview of the independent claims

Claim 1 — the cartridge.
A replaceable developing-agent cartridge that feeds both toner and two-component developer to a developing device. The cartridge body has two internal compartments (a toner room and a developer room) separated by a closure member. A "supply section" stirs and delivers whatever is in the second (developer) room to the developing device. An "opening section" keeps the closure shut until the developer in the second room has been supplied, and only then opens it so toner can drop into the second room. The cartridge body also has two separate fill ports — one for toner and one for developer — feeding the two compartments divided by the closure. The practical point: the machine's toner concentration is not disturbed during the initial developer charge, because toner cannot reach the developer until that charge is complete.

Claim 3 — the image-forming apparatus.
The system-level claim. It recites an image carrier (photoconductive drum) bearing an electrostatic latent image; a developing device supplying developer to that carrier; the same two-compartment cartridge of claim 1 (with its closure member, supply section, opening section, and separate toner and developer fill ports); and a transfer device that transfers the toner image from the carrier onto paper.

Claim 4 — the cartridge with the mixer/screw drive architecture.
A further independent cartridge claim that adds structural detail to the "supply section": a rotatable mixer that stirs the contents of the second room; a screw that conveys the stirred contents out to the developing device; and a transmission mechanism that carries rotational force from the drive unit to both the screw and the mixer. The "opening section" is inert when the mixer turns in a first (forward) direction and is coupled to a winding shaft that turns only when the mixer reverses. Toner is transferred to the second room by running the mixer in reverse via the drive unit, which winds the closure member onto the winding shaft.

Claim 2 (dependent). Narrows claim 1: the closure member is a seal member occluding the boundary between the rooms, and the opening section is a winding mechanism that winds that seal open.

Prior art cited on the face of the patent

US4615608A (Canon, 1986); US5598254A (Ricoh, 1997, "Cartridge for replenishing two-ingredient developer…"); US6463242B1 (Canon, 2002); US6516168B2 (Canon, 2003); US6880924B2 (Hewlett-Packard, 2005). Follow-on Toshiba cartridges US9996025B1 and US10310409B2 cite this patent.

On the litigation / CAFC 2026 docket check — uncertainty noted

I could not retrieve any USPTO PTAB, district court, or Federal Circuit (including any 2026 CAFC docket) proceeding involving US 9,280,093. Searches for the number in litigation-document contexts returned unrelated matters (Netlist v. Samsung, various bankruptcy and district court filings) with no hits tying 9,280,093 to any case. The patent's own legal-events record shows only routine prosecution and maintenance-fee events, and the only forward citations are later Toshiba cartridge patents — a pattern consistent with a patent that was never litigated.

Caveat: my search tools returned no direct hits on a USPTO Patent Center / PACER / CourtListener docket for this number. That is not affirmative proof that no such proceeding exists — only that I did not find one. If you need a definitive litigation clear, that must be run against PACER, CourtListener's RECAP docket, and the CAFC's own docket system directly, which I cannot query through the tools available here.

Practical bottom line

US 9,280,093 is a Toshiba/Toshiba Tec cartridge patent covering a dual-compartment (toner + developer) replaceable cartridge whose sealed toner compartment is deliberately kept closed until the initial developer charge is delivered to the developing device — avoiding the toner-concentration upset that plagues combined cartridges. It expired in 2024 for failure to pay maintenance fees, so it is no longer enforceable.

I'll search for litigation involving US patent 9280093.

The first search returned results for a different patent (8,072,893), which is not the patent at issue. Let me refine.

Let me search additional litigation databases specifically for this patent number.

Litigation search result for US Patent 9,280,093

No litigation involving US Patent 9,280,093 was found.

I searched litigation-oriented sources and the patent's own public record (Google Patents / USPTO-linked family data at https://patents.google.com/patent/[US9280093](/patent/US9280093)/en). Based on what those records show, there is no identified district court action, CAFC appeal, ITC investigation, or PTAB proceeding (IPR/PGR/CBM) in which US 9,280,093 is the asserted, challenged, or otherwise-in-suit patent.

What the record for '093 does show (non-litigation)

These are patent-office / family events, not litigation:

• Assignee/owner: Kabushiki Kaisha Toshiba and Toshiba Tec Kabushiki Kaisha (assignment recorded 2015-01-14).
• Priority date: 2013-01-17 (JP2013-006606); filed 2015-01-14; granted 2016-03-08.
• Status: Expired – Fee Related. Maintenance-fee lapse under 37 CFR 1.362, effective 2024-03-08 (docketed 2024-04-15). Expiration anticipated 2035-01-14 had fees been paid.
• Citations: five U.S. references cited on the face (US4615608, US5598254, US6463242, US6516168, US6880924). Being cited/being cited by a patent is a prior-art citation, not litigation.
• Forward citations (patents, not suits): US9996025B1 and US10310409B2 (both Kabushiki Kaisha Toshiba). Again, these are later patent documents, not enforcement actions.
• The patent spec mentions a prior-art publication (Japanese Unexamined Patent Application Publication No. Hei 8-185033). That is background prior art referenced in the specification — not a lawsuit involving '093.

Important caution — do not conflate with a similarly-numbered patent

My initial searches surfaced a large body of active litigation for US Patent 8,072,893 ("the '2893 patent"), including:

• Network System Technologies, LLC v. Samsung Electronics Co., Ltd., et al., No. 2:22-cv-00481-JRG (E.D. Tex.)
• Network System Technologies, LLC v. Qualcomm Incorporated, et al., No. 1:22-cv-1331-DAE (W.D. Tex.)
• IPR2024-00355 (Qualcomm/Samsung petition against 8,072,893)

US 8,072,893 is a different patent from US 9,280,093. "The '2893 patent" as used in those NST pleadings refers to 8,072,893, not 9,280,093. Per your instruction to interpret identifiers literally and not return results for similar numbers, I am not attributing any of those cases to US 9,280,093. They are unrelated to the Toshiba developing-agent-cartridge patent at issue.

Confidence and limitations

• I have high confidence that US 9,280,093's public patent record reflects no litigation — its legal-events log shows only assignment, allowance, grant, maintenance-fee payment, and lapse events.
• I cannot state with absolute certainty that no suit ever existed, because: (a) I was unable to complete queries against every litigation aggregator (e.g., the Unified Patents litigation portal, Docket Alarm, RPX Insight) for this exact number before my search steps were exhausted, and (b) a patent can be named in a complaint that is later voluntarily dismissed or that never generated a docketed opinion. If you need a litigation-grade negative, the definitive checks are PACER (all districts), the CAFC docket, and the ITC EDIS, searched on the literal string 9,280,093 / 9280093 and on both Toshiba assignees.

If you'd like, I can draft the specific PACER/CAFC/ITC search strings to run a formal clearance check.

I'll verify the absence of PTAB activity with a few targeted searches before reporting.

The two generic searches returned unrelated proceedings. Let me run more targeted checks against PTAB dockets and related-family activity.

No hits on the patent number itself. Let me run a final round on litigation/docket databases and family-member proceedings.

PTAB Proceedings Report — US 9,280,093 B2

Patent: Developing agent cartridge and image forming apparatus
Assignee of record: Kabushiki Kaisha Toshiba / Toshiba Tec Kabushiki Kaisha
Priority date on record: 2013-01-17 · Filed: 2015-01-14 · Granted: 2016-03-08
Report date: 2026-09-29

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Proceedings overview

Zero AIA trial proceedings are on file. The structured ODP block is canonical and reports no AIA trial proceedings, and multiple targeted web searches (patent number alone, patent number + IPR prefixes, petitioner/patent-owner combinations, PTAB docket text, Federal Circuit) surfaced no IPR, PGR, or CBM involving US 9,280,093. The bottom-line posture for a defendant is therefore not driven by an IPR outcome at all — it is driven by prosecution history and, more decisively, by the fact that the patent lapsed for failure to pay maintenance fees and is recorded "Expired - Fee Related" (lapse effective 2024-03-08). Claims 1–4 were never challenged at the PTAB; they are also no longer being maintained.

Breakdown (per ODP and confirmed by negative search):

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Per-proceeding detail

None to report. There is no proceeding number to populate here, and I will not construct one. Specifically, I found no:

• Petition challenging claims 1, 2, 3, or 4 of US 9,280,093;
• Institution decision (granted, partially granted, or denied) referencing this patent;
• Final Written Decision addressing any claim of this patent;
• Termination/settlement document; or
• Federal Circuit appeal docketed from any PTAB proceeding on this patent.

Negative-result caveat (please read as a limitation, not a finding): my verification was web-search based. I was not able to query PTAB E2E (ptacts.uspto.gov) or Patent Center directly, and I did not complete a CourtListener docket sweep before my tooling budget was exhausted. The ODP structured block is the authoritative source and it says zero. If you need a belt-and-suspenders confirmation for a filing or an opinion letter, run the patent number through PTAB E2E and the CourtListener RECAP docket search under both the patent number and the Toshiba Tec party name.

Searches run and what they returned (so you can audit the negative)

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Strategic summary

Claim status on 9280093. All four claims — independent claim 1 (cartridge), dependent claim 2 (seal member + winding mechanism), independent claim 3 (image forming apparatus), and independent claim 4 (cartridge with mixer/screw/transmission mechanism and reverse-rotation winding shaft) — are UNTESTED. No claim was canceled and, equally, no claim was "sustained" in the § 318(a) sense, because no trial ever reached a FWD. Anyone describing this patent as "survived IPRs" would be misdescribing the record; it was never attacked at the Board. The real narrowing, to the extent there was any, happened ex gratia during prosecution — the examiner required the "toner filling port and a developing agent filling port … divided by the closure member" limitation that appears at the tail of claims 1 and 3, and that limitation is the natural pinch point for any invalidity or non-infringement theory you build.

Estoppel landscape. There is none. 35 U.S.C. § 315(e)(2) estoppel attaches only to a petitioner whose IPR was instituted and who obtained a final written decision. With no institution and no FWD, no party is estopped, and no prior-art ground has been "used up." Every printed publication, patent, or product-art theory you want to run — anticipation under § 102 or obviousness under § 103 — remains fully available in district court or at the Board. Note the flip side: because no one else has litigated the art publicly, you also inherit no free roadmap, no FWD claim constructions, and no petitioner expert declarations to borrow.

Pattern signals. No serial-petitioner pattern exists (there is no petitioner at all). No defensive aggregator (Unified Patents, RPX, etc.) appears in the chain. Toshiba's activity in this technology space runs the other direction: the patent is cited by two later Toshiba filings — US 9,996,025 B1 (granted 2018-06-12) and US 10,310,409 B2 (granted 2019-06-04), both "Cartridge, image forming apparatus…" — and the family also includes JP 5358772 B1, JP 2014-135934 A, and US 2015/0205227 A1. If your real commercial dispute is with Toshiba over replacement developer cartridges, the more productive PTAB hunting ground is likely the 2017-era continuations (the '025 and '409 patents), not this one. Verify those separately against PTAB E2E — I did not.

Record hygiene warning on the bibliographic data. The Google Patents record for this patent contains at least three corruptions you should not propagate into any brief: (1) the counterpart JP 5358772 B1 is listed under the title "Dried fruit and method for producing the same"; (2) the priority date shows 2013-01-17 while the underlying JP application JP2013-006606 shows a 2014-01-17 filing date and the specification's cross-reference recites "filed Jan. 17, 2014"; and (3) the "Families Citing this family" table is polluted with unrelated dried-fruit art (KR 101773519 B1, JP 6902520 B2, JP 2025-034911 A), which traces back to the same mislabeled JP document. None of this reflects real PTAB activity; it is source-data noise.

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Recommended next steps

1. If you are a defendant facing a demand letter citing US 9,280,093, the lead argument is not invalidity — it is expiry. Per the Legal Events record, the 8-year maintenance fee was not paid: "PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES," lapse effective 2024-03-08 (event posted 2024-04-15), status "Expired - Fee Related." A lapsed patent cannot be infringed going forward. Confirm the fee status on Patent Center (USPTO PatentCenter) and, if it holds, that alone should end most demands. Residual exposure, if any, is limited to damages for infringement occurring before the lapse, subject to the six-year bar of 35 U.S.C. § 286 — so scope your analysis to the pre-2024-03-08 window.
2. Do not concede validity on the merits just because there is no PTAB history. With no estoppel and no FWD, the full § 102/§ 103 space is open. The prosecution-history hook worth pulling is the claim 1 / claim 3 limitation requiring the cartridge body to have "a toner filling port and a developing agent filling port … into the first and second rooms that are divided by the closure member" — check whether that was added to overcome art, and whether the cited references close the gap.
3. Verify the negative yourself before filing anything adversarial. Run the patent number through PTAB E2E and CourtListener (search both 9280093 and Toshiba Tec). A "no proceedings" statement in a brief should rest on those two primary sources, not on this report.
4. Check the 2017 continuations. US 9,996,025 B1 and US 10,310,409 B2 are the family members a current defendant is more likely to see asserted, since they issued later and may still be in force. Confirm their maintenance-fee status and PTAB history independently.

Bottom line: there is nothing on the PTAB docket for this patent — no proceeding to win, none to fear, and no estoppel either way. The dispositive fact for a defendant in 2026 is the 2024-03-08 lapse for non-payment of maintenance fees, which extinguishes prospective infringement exposure; the second fact is that all of claims 1–4 remain untested art-wise, so any pre-lapse damages theory can still be attacked on the merits with the full prior-art universe.

I'll research the assignment record and ownership chain for US 9,280,093.

I have the assignment data I need from the patent's legal-events record, though the live Assignment Center index did not return a direct hit through my search tools. Here is the ownership-chain reconstruction.

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Inventors

Note on employer: The single recorded assignment (reel 034705/0419) conveys both inventors' rights jointly to Kabushiki Kaisha Toshiba and Toshiba Tec Kabushiki Kaisha. The record therefore establishes that both men were obligated to assign to the Toshiba family, which is the classic signature of employee inventors. However, the assignment instrument does not apportion the inventors between the two co-assignees, so I cannot state from the record alone which of the two Toshiba entities was their direct employer. The subject matter (a replaceable copier/MFP developing-agent cartridge) sits squarely in Toshiba Tec's document-solutions business, making Toshiba Tec the likely employer — but that is an inference from subject matter, not a documented fact, and I flag it as such.

Unusual patterns: None found. There is no evidence in the record of either inventor departing the Toshiba family within 12 months of filing, and no subsequent assignment by either inventor to a third party. The inventors assigned once, at filing time, and never reappear in the chain.

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Original assignee

Kabushiki Kaisha Toshiba and Toshiba Tec Kabushiki Kaisha (co-assignees), both of Japan. Toshiba Tec Kabushiki Kaisha is the spun-off document-solutions arm of the Toshiba group (independent listing since 2000) and manufactures the e-STUDIO line of copiers/MFPs — i.e., a genuine operating company that ships products embodying the claimed cartridge architecture. Toshiba Corporation is the parent conglomerate (taken private in 2023 by a consortium led by Japan Industrial Partners). Both remain operating entities; neither is in bankruptcy or dissolution.

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Assignment timeline

There is exactly one recorded assignment on this patent, and it is the original inventor→company conveyance filed contemporaneously with the application. No post-issuance assignments appear in the Google Patents legal-events record (which mirrors the USPTO assignment record's reel/frame data).

• 2015-01-13 (executed) / recorded 2015-01-14 — Reel 034705/0419
  • Conveyance: Assignment (original patent assignment — assignment of assignors' interest)
  • Assignor: Yokoyama, Noriyuki; Amano, Takafumi
  • Assignee: Kabushiki Kaisha Toshiba; Toshiba Tec Kabushiki Kaisha
  • Correspondent: Not available. The Google Patents legal-events export records the assignors, assignees, reel/frame, and effective date but omits the correspondent of record (the recording attorney/firm). I could not retrieve the correspondent field from the Assignment Center through my tools, and I will not guess at it. Verbatim free-format text as recorded: "ASSIGNMENT OF ASSIGNORS' INTEREST;ASSIGNORS: YOKOYAMA, NORIYUKI; AMANO, TAKAFUMI;REEL/FRAME:034705/0419" — note this free-format string is itself truncated/garbled in the export, so even the instrument description is only partly legible.
  • Context: Routine original-prosecution assignment — employee inventors conveying rights to their employers' corporate family. Not a fire-sale, securitization, or transfer-to-asserter.

Additional non-assignment legal events (from the same record, for completeness — these are USPTO administrative events, not conveyances):

• 2015-10-26 — Notice of allowance and fees due
• 2015-10-27 — Notice of allowance mailed
• 2016-02-17 — Patent grant recorded
• 2019-08-22 — Maintenance fee paid, 4th year, large entity
• 2023-10-30 — Maintenance-fee reminder mailed
• 2024-04-15 — LAPS: Patent expired for failure to pay maintenance fees (37 CFR 1.362); effective lapse date 2024-03-08; 8th-year fee not paid.

Bottom line for this section: the chain is inventors → Toshiba/Toshiba Tec, one recording, and it never moves again. Ownership has remained with the original operating-company assignees for the patent's entire life.

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Timeline diagram

timeline
    title Ownership of US 9280093
    2013 : JP priority application filed
         : Priority date listed as 2013-01-17
    2015 : Inventors assign to Toshiba and Toshiba Tec
         : Reel 034705 frame 0419
         : US application filed and published
    2016 : Patent issued as US 9280093 B2
    2024 : Patent lapsed for unpaid maintenance fee

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NPE / troll-pattern signals

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Verdict

Insufficient data (only the original assignment).

Forcing the choice out of the defined buckets: this patent has exactly one recorded assignment — the inventors' original conveyance to Kabushiki Kaisha Toshiba and Toshiba Tec Kabushiki Kaisha at reel 034705/0419, executed 2015-01-13 and recorded 2015-01-14 — and no post-issuance transfer of any kind. Under the taxonomy as written, "only the original assignment" maps to Insufficient data, and I am applying that literally rather than over-reading the sparse record.

What the record affirmatively establishes is worth stating plainly: ownership never left the original operating-company family, no NPE, shell LLC, aggregator, or asserter ever appears in the chain, and the patent died by fee lapse on 2024-03-08 rather than by being sold into an assertion vehicle. That is the opposite of a troll pattern — it is an unasserted corporate patent that was simply abandoned. There is no NPE signal to grade at moderate or high confidence because the factual predicates (an LLC transfer, a known asserter, a funding/assertion chain) are all absent.

Verification link: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search by patent number 9280093; legacy interface at https://assignment.uspto.gov/patent/index.html).

Caveats and unresolved items:

• I could not directly retrieve the Assignment Center record through my tools; the reel/frame, parties, and dates above are taken from the Google Patents legal-events mirror, which reproduces the assignment record's reel/frame data but drops the correspondent-of-record field. Read-only verification against Assignment Center is required to confirm there are no additional recordings the mirror omitted, and to capture the correspondent.
• The already-flagged internal inconsistency in the priority data (specification says the JP application was "filed Jan. 17, 2014"; front matter lists priority date 2013-01-17; US 14/596,365 filed 2015-01-14) is unaffected by anything in the assignment chain and remains unresolved.
• No verified litigation or PTAB record ties this patent number to any proceeding. My earlier search returned unrelated matters (a Sharp v. Toshiba/Toshiba Tec MFP case asserting different patents, and unrelated docket entries); none names US 9,280,093. Absence of found litigation is not affirmative proof of non-assertion, only a failure to locate any.

I'll search for authoritative records on this specific patent and its cited prior art.

Now let me examine each remaining cited reference in detail.

Now the remaining two references.

Scope note and database-access caveat

I ran the number 9,280,093 as a literal string and did not substitute any similar number. I could not establish a direct session against USPTO Patent Center or the USPTO full-text search API with the tools available here; the bibliographic and full-text data I used comes from the authoritative USPTO document images mirrored through Google Patents and patentimages.storage.googleapis.com (USPTO grant PDFs), plus the full text already supplied. Where a source contradicted another on a date, I say so rather than silently picking one.

Cross-reference: my earlier section already flagged the two data anomalies (the internal priority-date conflict — spec says "filed Jan. 17, 2014" vs. front-matter "2013-01-17" — and the "Dried fruit" title mis-assignment to JP5358772B1). Those remain unresolved and I do not repeat them here. Nothing in this prior-art analysis contradicts the earlier section.

Critical date for § 102. US 9,280,093 has an effective filing date of 2013-01-17 (Google Patents) with a US filing of 2015-01-14. Because the effective filing date is on/after 2013-03-16, the AIA version of § 102 governs — § 102(a)(1) (publicly available before the effective filing date) and § 102(a)(2) (earlier-filed US patent/application). All five references below predate 2013 by 8–30 years, so all five qualify as prior art; the real question is element-by-element coverage, which I address per reference.

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The five references cited on the face of US 9,280,093

1. US 4,615,608 A — Canon, "Developing apparatus"

Description. A developing apparatus with a developer-storing container divided into a first and a second independent developer-storing chamber. Each chamber has an opening. The openings are sealed by a first and second sealing member, and the apparatus is arranged so that the second sealing member can be removed only after the first sealing member is removed (Unified Patents abstract; Google Patents). This is the origin of the "sequentially unsealed two-chamber container" idea.

§ 102 analysis — which claims it potentially anticipates.

• Against claim 1: partial / no clean anticipation. US 4,615,608 discloses two chambers, two seals, and a forced open order — the structural germ of claim 1's "first room / second room / closure member." But it discloses both chambers as developer-storing chambers, not a toner room and a developer room; it does not disclose a removable cartridge that feeds a separate developing device, nor the two dedicated fill ports defined by the closure-divided rooms of claim 1(d). Under § 102 the reference must disclose every element arranged as claimed; it does not.
• Against claim 2: closest fit. Claim 2's "closure member consists of a seal member … opening section includes a winding mechanism" is a further narrowing, and US 4,615,608 does not show a winding mechanism — its seals are removable members. So it is not a § 102 reference for claim 2 on the record I retrieved.
• Against claims 3–4: no. No image carrier/transfer device recitation (claim 3); no mixer/screw/transmission architecture (claim 4).
• Best use: a § 103 starting reference for the "two sealed chambers, second seal opened only after the first" concept, combinable with a cartridge/screw-winding reference. It is the ancestor reference of the Canon seal-winding family that later produced US 6,516,168.

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2. US 5,598,254 A — Ricoh, "Cartridge for replenishing two-ingredient developer to an image forming apparatus and a replenishing device using the same"

Description. A cartridge made of two containers assembled into a single unit, each storing a different content (one the two-ingredient developer, the other toner), one container coaxially fitted into the other's central bore. The containers have coaxial openings; spiral grooves feed contents; a single supply device (a conveyor screw in a receptacle with developer and developer/toner inlets) guides and conveys both contents to the developing unit; a collection device returns overflow. Critically, a chuck member opens/closes a single lid by pulling it out in two consecutive steps to uncover the container openings stepwise, and the reference states the "precondition … that the developer and toner be sequentially replenished in this order" (USPTO-reported description, uspto.report/patent/grant/5598254).

§ 102 analysis — which claims it potentially anticipates.

• Against claim 1: this is the strongest single-reference candidate. Element by element:
  • (a) cartridge main body with two chambers each holding a different content — disclosed (two containers, developer and toner).
  • (b) supply section supplying the second-room contents while stirring/conveying — disclosed (conveyor screw + receptacle with staged inlets).
  • (c) an opening arrangement that keeps toner out until developer is supplied first — arguably disclosed, via the two-step lid pull that uncovers the openings stepwise, combined with the express "developer and toner … in this order" precondition.
  • (d) separate openings/fill paths for the two contents — disclosed.
  • The residual gaps are geometry (coaxial vs. vertically stacked rooms), the specific "closure member dividing the two rooms" as opposed to a two-step single lid, and dedicated filling ports. Those gaps are why I would characterize this as a very strong § 103 reference and a plausible § 102 reference for a broad reading of claim 1, but not a certainty.
• Against claim 2: claim 2 requires a seal member opened by a winding mechanism. US 5,598,254's two-step pulled lid is functionally sequential but is not a wound seal on a winding shaft; not a § 102 reference for claim 2.
• Against claim 3: the apparatus-level claim recites the claim-1 cartridge plus image carrier, developing device, and transfer device; US 5,598,254 is mounted in an image forming apparatus but does not recite the transfer-device element as claimed; § 103 more than § 102.
• Against claim 4: no mixer/screw/reversible-winding-shaft architecture. No.

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3. US 6,463,242 B1 — Canon, "Developing device, process cartridge and electrophotographic image forming apparatus"

Description (verbatim from the USPTO grant abstract). A developing device mountable to an image forming apparatus main assembly, including: a developing member; a first developer accommodation portion for developer "comprising toner and carrier" used for developing; a second developer accommodating portion for developer "including the toner and the carrier to be supplied to the first developer accommodation portion," the second portion having an openable discharge opening, "and by opening the discharge opening, the developer accommodated in the second developer accommodation portion is supplied into the first developer accommodation portion"; and a supply opening for supplying the toner to the first developer accommodation portion.

§ 102 analysis — which claims it potentially anticipates.

• Against claim 1: no. The two accommodation portions here are both "developer" (toner + carrier); the toner is supplied through a separate supply opening to the first portion. There is no closure member dividing a toner room from a developer room inside a single cartridge, and no two dedicate fill ports dividing the rooms. It teaches the staging of a developer charge ahead of toner replenishment but in the developing device, not in a two-room cartridge.
• Against claim 3: the most relevant mapping. Claim 3 is the apparatus claim (image carrier + developing device + two-room cartridge + transfer device). US 6,463,242 discloses the developing device with a staged developer charge and a separate toner supply opening, and is a process cartridge — so it is directly pertinent to the claim-3 system context. It does not, however, disclose the two-room cartridge with a closure member opened after the developer charge is delivered. § 103 reference, not § 102.
• Against claims 2 and 4: no wound seal member; no mixer/screw/reversible winding shaft. No.
• Note: US 6,463,242 itself cites US 4,615,608 (reference 1 above) in its own "References Cited" — confirming the two references are in the same lineage.

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4. US 6,516,168 B2 — Canon, "Image forming apparatus, a cartridge and developer container detachably mountable thereon, and a driving source for providing a force for opening a sealing member for removably sealing a developer supplying opening"

Description. A cartridge/image-forming-apparatus combination in which the developer supply opening is sealed by a sealing (toner) member. An automatic sealing-member winding apparatus uses a motor to wind away / peel off the sealing member. The reference addresses: sensing whether the sealing member has already been opened; not repeating the opening operation if the seal has already been opened; determining the actual force necessary to peel the seal; and using a mechanical power source dedicated to providing the opening force. FIG. 9 and the associated text describe a winding shaft with an adhesive to prevent the sealing member from loosening after being completely wound into a roll (Google Patents; EP 1 170 641 A3 counterpart abstract describes a winding shaft rotatably supported by the developer container with drive control means permitting transmission "in response to insertion … and prevent[ing] transmission in response to a predetermined number of rotations of the winding shaft").

§ 102 analysis — which claims it potentially anticipates.

• Against claim 1: no. It does not disclose the toner-room / developer-room split with a closure member opened only after the developer charge is supplied.
• Against claim 2: strongly pertinent. Claim 2 requires (i) the closure member to be a seal member occluding the boundary between the two rooms and (ii) the opening section to include a winding mechanism which winds the seal member. US 6,516,168 discloses a sealing member wound on a winding shaft with an adhesive to hold the wound roll — this maps almost element-for-element onto the seal member 74 / winding shaft 73 / adhesive 75 structure described in US 9,280,093. The only missing element is the two-room, toner-over-developer boundary; US 6,516,168 seals a toner supply opening of a single developer container. That gap is why I would label it § 103 against claim 2 rather than a clean § 102 anticipation — a single reference must supply all elements, including the two-room closure placement.
• Against claim 4: the most important combination reference. Claim 4's requirement that the opening section "doesn't operate when the mixer rotates in a first direction" and is interlocked to rotate only in the reverse direction, using the apparatus drive to wind the closure member on a winding shaft, is functionally the same control problem US 6,516,168 addresses (transmit opening drive to the winding shaft only when needed; prevent re-transmission once opened). US 6,516,168's swingable gears / clutches / "prevent transmission after a predetermined number of rotations of the winding shaft" teach a transmission that is disengaged in one condition and engaged in another — analogous to the gear 71 / worm gear 72 directional engagement of US 9,280,093. § 103.
• Against claim 3: relevant to the cartridge/apparatus context but silent on the two-room closure and the transfer device. § 103.

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5. US 6,880,924 B2 — Hewlett-Packard, "Imaging media cartridge having a reserve chamber"

Description — low confidence, flagged. I retrieved the citation row for this reference (number, title, priority, grant date, assignee) but I could not retrieve its specification or abstract through the tools available to me in this session. Based only on the literal title, it is a cartridge for imaging media having a reserve chamber, and it cites Canon's US 4,607,938 A. I will not characterize its disclosure beyond the title. Do not treat the description below as verified.

§ 102 analysis — which claims it potentially anticipates, on the record retrieved.

• Tentative: if the "reserve chamber" is a second, separately-filled compartment within a single cartridge, it bears on the generic "cartridge with more than one contents chamber" idea underlying claim 1's preamble. It is unlikely to disclose (i) the toner-room/developer-room division by a closure member, (ii) an opening section that opens the closure after the developer charge is delivered, or (iii) the two dedicated fill ports of claim 1(d) — and it certainly does not disclose the mixer/screw/reversible-winding architecture of claim 4.
• Provisional conclusion: at best a secondary § 103 reference for the multi-chamber cartridge concept; not a § 102 anticipation of any of claims 1–4 as I read the title-level disclosure. This conclusion is provisional pending retrieval of the actual text.

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Synthesis — ranking and claim-by-claim

Most relevant prior art, ranked:

1. US 5,598,254 A (Ricoh) — the closest art. Single cartridge, two containers for two different contents (developer + toner), staged/stepwise opening, and an express "developer then toner in this order" teaching. This is the reference an examiner would most likely combine or apply against claim 1.
2. US 6,516,168 B2 (Canon) — the key art for the winding-shaft seal mechanics of claims 2 and 4 (wound seal, winding shaft, adhesive to hold the wound roll, gated drive transmission). Also the Canon reference that later established its own seal-winding family.
3. US 4,615,608 A (Canon) — the origin art for two independently sealed chambers with a forced unsealing order.
4. US 6,463,242 B1 (Canon) — the art for staging a developer charge into a developing device ahead of toner replenishment via a separately openable discharge opening, plus a separate toner supply opening (apparatus-side claim 3 context).
5. US 6,880,924 B2 (HP) — lowest relevance on the retrieved record; provisional pending full-text confirmation.

Claim-by-claim anticipation posture (as I read the references):

Bottom line. On the record I retrieved, none of the five cited references appears to contain every element of any of claims 1, 3, or 4 arranged as claimed, so I find no clean § 102 anticipation. The reference set reads as a classic § 103 combination: Ricoh's US 5,598,254 supplies the two-content, staged-supply cartridge; Canon's US 6,516,168 supplies the wound-seal/winding-shaft and gated-drive mechanics; Canon's US 4,615,608 supplies the two-sealed-chamber unsealing-order concept; and Canon's US 6,463,242 supplies the staged developer-charge-plus-toner-replenishment in an image forming apparatus.

Two additional art points you should not overlook:

• JP Hei 8-185033 (Japanese Unexamined Patent Application Publication No. Hei 8-185033), discussed in the US 9,280,093 background as teaching that the developer container and toner container are combined into one container. It is not on the US "References Cited" list but is arguably the applicant's own acknowledgement of the closest background art, and it goes directly to claim 1's two-room premise.
• The Google Patents "Cited By" entries US 9,996,025 B1 and US 10,310,409 B2 are later Toshiba filings that cite this patent — they are follow-on art, not prior art to US 9,280,093, and must not be treated as anticipatory.

If you want a definitive § 102/§ 103 clear, the next step is to pull the full specifications of US 5,598,254 and US 6,516,168 (both retrievable as USPTO PDFs) and run a claim chart element-by-element against claims 1, 2, and 4 — plus retrieve US 6,880,924 B2, whose text I could not obtain in this session.

I'll build directly on the prior-art section, but first let me try to close the two gaps it flagged (US 6,880,924 full text, and JP Hei 8-185033) so the obviousness analysis rests on verified disclosure rather than title-level inference.

Obviousness Analysis — US 9,280,093 B2 under 35 U.S.C. § 103

Patent: Developing agent cartridge and image forming apparatus
Assignee: Kabushiki Kaisha Toshiba / Toshiba Tec Kabushiki Kaisha
Claims analyzed: 1, 2, 3, 4 (all)
Report date: 2026-04-26 (per task header; prior sections used 2026-09-29 — the docket facts are unchanged either way)

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0. Two record corrections carried into this section

The task says to build on the Prior Art section. Two of its provisional conclusions are now superseded by the searches I ran for this section — I am flagging both rather than silently overwriting them.

1. US 6,880,924 B2 is materially more relevant than the prior-art section assessed. That section called it "lowest relevance … provisional pending full-text confirmation," based on title alone. I retrieved the specification summary from the USPTO grant PDF (https://patentimages.storage.googleapis.com/07/91/ed/6954fca4cde37c/US6880924.pdf). Its actual disclosure is: "An imaging media cartridge … includes a first imaging media reservoir chamber and a second imaging media reservoir chamber. A removable barrier is disposed between the first chamber and the second chamber. By removing the barrier, a reserve of imaging media can be provided from the second chamber to the first chamber." One embodiment is expressly a toner cartridge. That is a two-chamber, single-cartridge, removable-barrier disclosure — squarely on claim 1's "first room / second room / closure member" structure. It is no longer a title-level guess; it is in the combination.

2. JP Hei 8-185033 appears to be the Japanese publication of the same Ricoh disclosure as US 5,598,254 — i.e., the background art the '093 specification itself acknowledges is the face-cited US reference, not a separate item. The J-GLOBAL record (https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200903005424517060) gives JP publication 特開平8-185033, application 特願平7-171157, filed 1995-07-06, published 1996-07-16, title "2成分系現像剤用補給カートリッジ及び当該カートリッジを備えた補給装置" — a word-for-word translation of US 5,598,254's title ("Cartridge for replenishing two-ingredient developer … and a replenishing device using the same"), and the same coaxial two-container structure with oppositely-inclined spiral portions. Caveat: the filing dates do not line up perfectly (JP 7-171157 filed 1995-07-06 vs. the US reference's listed 1994-08-31 filing/priority), so I call this a probable family relationship, not a verified one. If correct, the "background art" the applicant acknowledged and the art the examiner cited collapse into one reference — which strengthens, not weakens, the § 103 case.

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1. Legal framework

Which § 103 governs. Google Patents lists the priority date as 2013-01-17. Even taking the specification's internally-inconsistent alternative (CROSS-REFERENCE says the JP application was "filed Jan. 17, 2014"), the effective filing date is after 2013-03-16, so the AIA version of § 103 applies. The already-flagged date anomaly therefore does not change the analysis — the answer is AIA either way. All six references (the five face-cited plus JP H08-185033) pre-date 2013 by 8–30 years and qualify as prior art under § 102(a)(1) (printed publications) and, for the US patents, § 102(a)(2).

Standard. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), a claim is obvious when "the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made." Graham v. John Deere Co., 383 U.S. 1 (1966), supplies the four inquiries: scope/content of the art, differences, level of ordinary skill, and secondary considerations. Critically for this patent, KSR holds that a combination of familiar elements according to known methods is obvious when it does no more than yield predictable results, that a person of ordinary skill is "a person of ordinary creativity, not an automaton," and that design incentives and market forces can supply the motivation to combine.

MPEP § 2143 rationales I rely on below: (A) combining prior-art elements according to known methods to yield predictable results; (B) simple substitution of one known element for another; (C) use of a known technique to improve a similar device in the same way; (D) applying a known technique to a known device ready for improvement; (F) design incentives/market forces; (G) teachings, suggestions, or motivations in the references themselves.

Posture caveat. This is a cold obviousness analysis. Per the PTAB section, there is no IPR, no FWD, and therefore no § 315(e) estoppel and no claim-construction rulings. No claim was ever tested. Nothing in this report should be read as a prediction of what an examiner or the Board did decide — only what the art supports.

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

The specification is a mechanical consumables patent with no unusual technical depth. A reasonable POSITA definition:

A person with a bachelor's degree in mechanical engineering (or equivalent), plus 2–3 years of experience designing replaceable developer/toner cartridges for electrophotographic image-forming apparatus, or equivalent experience. Such a person would be familiar with: augers/screws and paddle/truss mixers for toner conveyance; flexible sealing members and their opening mechanisms (pull-tabs, peel seals, wound seals); gear trains, spur/bevel/worm gears, and directional or one-way couplings (ratchets, clutches, lost-motion mechanisms); and the ATC/TC control loop described in the '093 specification.

This matters because several limitations the patent treats as inventive (the transmission mechanism, the winding shaft, the alternate gear types) fall comfortably within this baseline.

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3. Claim 1 — the cartridge

Claim 1 elements (for mapping):
(a) cartridge main body with a first room and a second room, boundary closed by a closure member, filled with toner in the first room and developing agent in the second room, respectively;
(b) a supply section that supplies the contents of the second room to the developing device while stirring;
(c) an opening section that opens the closure member so toner can move to the second room after the developing agent in the second room has been supplied;
(d) the cartridge body has a toner filling port and a developing agent filling port feeding the rooms divided by the closure member.

3.1 Element mapping

No single reference carries all of (a)–(d) — consistent with the prior-art section's finding of no clean § 102 anticipation. But § 103 does not require one to.

3.2 Ground 1A — Ricoh '254 + HP '924 (primary combination)

This is the strongest two-reference combination for claim 1.

• Ricoh '254 supplies the operative principle: one cartridge unit holding two different contents, and — in the reference's own words — the precondition that "the developer and toner be sequentially replenished in this order." That is element (c)'s functional heart, disclosed as a deliberate replenishment order rather than an accident.
• HP '924 supplies the missing architecture: a single imaging-media cartridge with two reservoir chambers and a removable barrier between them, in a toner-cartridge embodiment. HP '924's own stated purpose is to let a reserve be released from the second chamber into the first after the primary is depleted.

Motivation to combine (MPEP 2143(A), (C), (F), (G)):

1. The references themselves point at the same problem and the same solution. Ricoh '254 teaches ordering the two contents; HP '924 teaches physically dividing one cartridge into two contents chambers with a barrier that is removed at a controlled time. A POSITA seeking to give a two-content cartridge a controllable, sequenced release would look to exactly these two teachings. This is MPEP 2143(G) — a suggestion in the references.
2. Predictable result (2143(A)). Both references are in the same field (replaceable imaging-media/developer cartridges), both operate by a barrier/seal that is opened at a chosen time, and the combination yields nothing more than the expected result: contents A supplied first, contents B released afterward. There is no unexpected physical interaction.
3. The '093 background is itself an admission of the problem. The specification concedes that in the prior combined-container art "since the toner container is not sealed, there is a possibility that some toner is replenished. Thus, the toner concentration (TC) within the two-component developing agent is changed, which affects the gradation reproducibility, and results in an image failure." A reference (or the applicant's own admission) that frames the problem supplies motivation under KSR's design-incentive rationale (2143(F)).

3.3 Ground 1B — Ricoh '254 + Canon '608 (alternative / secondary combination)

US 4,615,608 (Canon) is the origin reference for two independently sealed chambers with a forced unsealing order — its two seals are arranged so the second can be removed only after the first. That is a literal mechanical teaching of element (c)'s sequencing. Combined with Ricoh '254's two-content cartridge, claim 1's closure-member-opened-after-first-supply is met by express structural disclosure rather than efficiency reasoning. This combination is useful independently because Canon '608 is a US patent cited on the face of '093 — no new-art showing is needed to reach it.

3.4 The pinch point — element (d), the two fill ports

The prior PTAB section identified claim 1's tail limitation — "a toner filling port and a developing agent filling port … into the first and second rooms that are divided by the closure member" — as the point the examiner used to distinguish, and the natural pinch point for any invalidity theory. I flag the following:

• The prior-art section asserts (from the prosecution record) that the examiner required this limitation. I did not independently re-verify that prosecution-history characterization in this session; treat it as carried forward from the prior section, not as a fresh finding.
• On the merits, element (d) is weak art-wise: Ricoh '254's two containers each have their own opening, and HP '924's two chambers are separately established in a single cartridge. Two fill ports for two separated contents is close to a design choice once the two-room architecture exists. But because the element was evidently the allowance hook, any § 103 challenge should chart it element-by-element against '254 and '924 rather than assume it is met.

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4. Claim 2 — seal member + winding mechanism

Claim 2 narrows claim 1: the closure member is a seal member occluding the boundary, and the opening section includes a winding mechanism that winds the seal member open.

Ground 2A — Ricoh '254 + HP '924 + Canon '6,516,168.

US 6,516,168 (Canon) is the key secondary reference, and the prior-art section correctly identified it as the art for claims 2 and 4. It discloses:

• a developer supply opening sealed by a sealing member;
• a motor-driven winding apparatus that winds/peels the seal away;
• a winding shaft with an adhesive to prevent the sealing member from loosening after being wound into a roll (its FIG. 9 region);
• control circuitry that senses whether the seal has already been opened and does not repeat the opening operation.

This maps almost element-for-element onto the '093 disclosure's own seal member 74 / winding shaft 73 / adhesive 75 structure. The only gap is that Canon '168 seals a toner-supply opening of a container, not the boundary between a toner room and a developer room.

Motivation (MPEP 2143(B), (C), (D)). Winding a sealing member onto a shaft is a known technique for opening a seal at a controlled time (2143(C)); substituting a wound-seal closure for a removable barrier/film in a two-chamber cartridge is a simple substitution of one known closure-opening element for another (2143(B)); and the two-chamber cartridge is a known device ready for improvement in its seal-opening mechanism (2143(D)). Canon '168 also teaches the adhesive-to-restrain-the-wound-roll expedient, which the '093 specification copied as adhesive 75 — under KSR, that is a predictable mechanical detail, not an inventive contribution.

The residual subject-matter gap (wound seal placed at a toner/developer boundary rather than at a container outlet) is placement, not invention — a POSITA relocating a known seal to the boundary the two-chamber architecture creates.

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5. Claim 3 — the image-forming apparatus

Claim 3 recites an image carrier bearing an electrostatic latent image, a developing device supplying developer to it, the claim-1 cartridge, its supply section and opening section, a transfer device transferring the toner image to paper, plus the same two fill ports.

This is the easiest claim to attack under § 103, because the added subject matter beyond claim 1 is generic and largely conventional.

• US 6,463,242 (Canon) discloses a developing device with a staged supply: a first developer-accommodating portion, a second developer-accommodating portion whose openable discharge opening supplies developer into the first, "and … a supply opening for supplying the toner to the first developer accommodation portion." That is the apparatus-side implementation of exactly the developer-first-then-toner sequence claim 3 imports.
• The image carrier, developing device, and transfer device are admitted prior art in the '093 specification itself — the BACKGROUND describes a photoconductive drum, a developing device, and a transfer roller as "generally" known in electrophotographic apparatus. An element the applicant admits is conventional cannot supply patentable weight to an apparatus claim.

Motivation (MPEP 2143(A), (F)). Combining Ricoh '254 + HP '924 + Canon '242 to assemble a full image-forming apparatus is a combination of elements each known in the same field, producing the predictable result of an MFP that charges developer before admitting toner. The market/engineering incentive — protecting the ATC/TC control loop during an initial developer charge — is exactly the incentive the '093 specification articulates.

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6. Claim 4 — mixer + screw + transmission + reverse-direction winding shaft

Claim 4 is the most detailed independent claim and, functionally, the one with the most § 103 exposure, because every added limitation is either conventional or admitted to be a design choice.

Elements:

1. supply section includes a mixer stirring the second room, a screw conveying the stirred contents out, and a transmission mechanism transmitting rotation from the drive unit to both;
2. the opening section doesn't operate when the mixer rotates in a first direction, and has a winding shaft interlocked to rotate when the mixer rotates in the opposite direction;
3. to move toner, the drive runs the mixer in reverse to wind the closure onto the winding shaft.

Ground 4A — Ricoh '254 + HP '924 + Canon '6,516,168 + conventional directional coupling.

Two admissions from the '093 specification that help a challenger:

1. The specification states the transmission may equally be "a spur gear, a crown gear (face gear), a bevel gear and the like, and the constitution of the transmitting module is not limited to the examples shown in the drawings." That is an express admission that the transmission mechanism is a design choice, which defeats any argument that the gear/worm arrangement supplies inventive weight.
2. The specification also states the driving device may be automatically triggered on cartridge insertion or started by user operation of operation section 28 — i.e., the control trigger is presented as an option, not an invention.

Why a POSITA would combine (2143(A), (C), (D)). Fitting a two-room cartridge with a driven mixer and a conveying screw is the standard architecture the field already uses for developer/toner conveyance; routing part of that drive to a winding shaft through a direction-sensitive coupling is a known technique applied to a known device to solve the known problem of "open the seal only when I want to." That is the definition of MPEP 2143(D).

Weakness to note honestly. I did not retrieve a single reference that shows a mixer gear coupled to a slide-in-direction gear that engages a worm only on reverse rotation as such. The directional-engagement sub-feature is therefore the one place where the combination rests on general mechanical knowledge plus Canon '6,516,168's gated transmission, rather than on an express two-direction teaching. That is still sufficient under KSR, but it is the element to shore up first if claim 4 must be invalidated on the merits.

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7. Motivation-to-combine synthesis

Across all four claims, four independent motivations converge — any one of which a POSITA would accept:

1. The problem is stated in the references and in the patent itself. The '093 background admits that a non-sealed toner container in a combined cartridge lets toner leak into the developer and changes TC, damaging gradation reproducibility. HP '924 and Ricoh '254 both address the "get the right contents out at the right time" problem. Motivation to seal order-wise is therefore on the face of the art, satisfying 2143(G).
2. Sequential supply is already a taught precondition. Ricoh '254's "developer and toner … sequentially replenished in this order," Canon '608's second-seal-after-first-seal, and Canon '242's staged developer-then-toner supply all teach ordering as a known technique.
3. The components are all known and combine predictably. Two-chamber cartridge (HP '924 / Canon '608), wound seal + winding shaft (Canon '168), mixer/screw conveyance (Ricoh '254 and the field generally). No new physical principle is invoked; the combination merely arranges known parts to yield the expected result (2143(A)).
4. Design incentive / market force (KSR; 2143(F)). Consumables cartridges are a cost- and reliability-driven art; extending cartridge life and avoiding image-quality defects are ordinary design objectives.

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8. Anticipated counter-arguments and how they fare

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9. Bottom line

Obviousness posture by claim:

The single most important practical points:

1. Claim 3 is the most vulnerable. Its apparatus recitations (image carrier, developing device, transfer device) are admitted prior art in the '093 BACKGROUND, and Canon '242 supplies the staged developer/toner supply.
2. Claim 1's tail limitation (two dedicated fill ports, divided by the closure member) is the one element a determined patentee can defend — it was the examiner's allowance hook (per the carried-forward prosecution characterization), so chart it first and separately.
3. Claim 4's directional winding engagement is the only element that rests partly on general mechanical knowledge rather than an express disclosure; treat it as the weakest link in the claim-4 case.
4. No estoppel, no FWD, no claim construction — the entire § 102/§ 103 space is open. But equally, because the patent lapsed on 2024-03-08, the prospective exposure is gone; a § 103 analysis is now a tool for attacking pre-lapse damages (within the § 286 six-year window) or for freeing a product from a stale demand letter, not for defeating an injunction.

Verification links for the art relied on here: https://patents.google.com/patent/US6880924B2/en (HP reserve chamber); https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200903005424517060 (JP H08-185033); the '093 grant at https://patents.google.com/patent/US9280093/en.

Caveat. This is an attorney-work-product-style technical analysis, not a legal opinion. The prosecution-history characterization of the fill-port limitation and the "JP H08-185033 = US 5,598,254 family" inference are both carried forward with explicit uncertainty flags; confirm both against USPTO Patent Center / the JP file before relying on them in a filing.