US Patent 9,036,181 B2 — Summary

Search notes

I searched the USPTO-facing sources (Google Patents, USPTO.report, Unified Patents portal, PTACTS prosecution documents) and for CAFC 2026 docket entries. I found no CAFC 2026 appeal docket for this specific patent number — my docket searches returned no matching Federal Circuit case. The patent has, however, been the subject of multiple district court litigations (see below). Where web sources disagree on dates, I note the discrepancy.

Bibliographic data

Caveat: the one-day date discrepancies (priority, filing, grant, expiration) reflect differing database conventions; I could not definitively resolve them.

Abstract (as published)

"A wireless printer for rendering digital content received from wireless information apparatus is herein disclosed and enabled. The wireless printer includes a wireless communication unit compatible with at least part of a protocol within IEEE 802.11 or Bluetooth. The wireless printer may access and connect to a local area wireless network for wireless connection, or may communicate directly with the wireless information apparatus via direct wireless communication. The wireless printer may wirelessly broadcast an indication of the wireless printer to the wireless information apparatus for selection and service. The wireless printer may include an output controller for decoding output data; an image processor for image processing the output data; a marking engine for printing an image onto a substrate; and may further include an operating system that enables installation of additional applications for expanding or updating the functionalities of the wireless printer." (Source: Unified Patents portal, patent 9036181)

Technology in plain language

The patent is part of Flexiworld's "universal output" family (priority 2001). It describes a wireless printer that can receive content directly from a mobile/wireless information apparatus (phone, PDA, laptop, camera, etc.) over a short-range wireless link compatible with IEEE 802.11 (Wi-Fi) or Bluetooth. The printer can (a) join a local wireless network, or (b) communicate peer-to-peer with the sending device. It broadcasts/discoverably advertises itself for selection, can require a security key for restricted access, and contains an output controller that decodes received "intermediate output data" (typically rasterized image data, possibly in multiple layers/color channels, e.g., MRC format), performs image processing such as color management/correction and digital halftoning, and drives a marking engine to print onto a substrate. It may run an operating system allowing additional applications to be installed to expand/upgrade printer functionality. The design shifts much of the raster image processing (RIP) burden to the printer so mobile devices don't need per-printer drivers.

Independent claims — plain-language overview

Important caveat: the full granted claim set was not included in the source text I was given, and I could not retrieve the complete claims text from the searches. Based on the granted-patent claim text visible in Google Patents search results, the independent claims include at least the following (claim numbering beyond claim 14 is uncertain):

1. A method claim (independent; likely claim 1) — A method performed at a wireless printing device of receiving, over a restricted short-range wireless link from one or more wireless information apparatus, intermediate output data (image/graphics/text data) corresponding to digital content; extracting image data having two or more image layers or color channels; performing a color management operation; converting at least part of the image data to a raster form acceptable to the printer/marking engine, including at least a digital halftoning operation; storing image data in the printer engine's memory buffer; supplying the raster-form data to the marking engine; and printing an image onto a substrate. (Text observed in Google Patents claim excerpt.)

2. A device claim (independent; claim 14 as granted) — A wireless printing device for rendering digital content received from one or more wireless information apparatus (distinct devices), comprising an output controller for processing the digital content, an output engine, a wireless communication unit, a memory buffer, and a marking engine. The wireless communication unit communicates over a short-range wireless link compatible, at least partly, with IEEE 802.11 or Bluetooth standards. The device includes components for: installing additional applications/software via an operating system to add or upgrade functionality; enabling wireless device discovery by the information apparatus; providing at least an indication of the printer's identity while waiting to be identified for service; implementing a security-key procedure for restricted communication with authorized apparatus; and receiving intermediate output data. The output controller is configured to decode the intermediate output data, process it (including a color correction operation), and deliver it to the output/marking engine for rendering an image onto a substrate. (Text observed in Google Patents claim excerpt.)

3. The published application (US 2010/0201996 A1) also showed a means-plus-function independent device claim (claim 35 in the publication) covering a wireless printing device with means for receiving intermediate output data from a wireless information apparatus, means for processing it into a form acceptable to the output engine, means for processing including digital halftoning, and means for delivering the processed data to the output engine for rendering. The granted claims may have been amended from this version, so treat this as background rather than granted claim text.

I could not verify whether additional independent claims exist (e.g., a controller claim or a system claim) — the search snippets showed dependent claims referencing "claim 80," "claim 88," and "claim 89" in prosecution-history documents (PTACTS), but those were claims as pending during examination, not necessarily the final granted set.

Litigation context

• The patent is flagged by Google Patents as having family litigation, with district court cases including: Tennessee Western (2:22-cv-02236), California Central (8:21-cv-00807), Texas Western (6:21-cv-00143 and 1:21-cv-00066), New York Western (6:23-cv-06370), and Texas Southern (4:24-cv-02691).
• In Flexiworld v. Xerox (W.D.N.Y. 6:23-cv-06370), asserting US 9,036,181 B2 along with US 10,140,071 B2 and US 10,873,856 B2, the parties stipulated to dismissal with prejudice under Rule 41(a)(1)(A)(ii), with each side bearing its own costs — no merits adjudication. (Source: PatSnap litigation summary citing PACER.)
• I found no CAFC 2026 appeal docket for this patent number; if a Federal Circuit appeal exists, it did not surface in my searches, and I cannot confirm one.

Bottom line

US 9,036,181 B2 is a Flexiworld wireless-printing patent (inventors Chang and Liu) claiming a Wi-Fi/Bluetooth-enabled printer that receives intermediate (largely rasterized) output data from mobile devices, performs the device-side image processing (color management/correction, halftoning) and printing, supports discovery/security, and can be upgraded via an operating system. Key uncertainties: exact granted claim numbering/count (full claims text not retrieved), the one-day bibliographic date discrepancies between sources, and the absence of any identifiable CAFC 2026 docket.

I'll research litigation involving US Patent 9036181. Let me search several sources.

I found initial leads. The Google Patents page for US9036181 lists several litigation links. Let me search for each case number to identify parties and status.

Two cases confirmed so far (Brother and Epson). Let me search the remaining case numbers from the Google Patents litigation links.

Based on my research (including the litigation links on the Google Patents page for US9036181, Unified Patents' litigation portal, RPX, DocketAlarm, Justia, CourtListener, and PatSnap), here is what is known about litigation involving US Patent 9,036,181 B2 ("Wireless printing device for printing digital content received via wireless communication compatible, at least partly, with IEEE 802.11 or Bluetooth," assigned to Flexiworld Technologies, Inc.).

All identified cases were brought by Flexiworld Technologies, Inc. as plaintiff. Flexiworld has run a broad multi-defendant campaign asserting this patent (often in sets with other family members such as 7,609,402, 8,630,000, 10,037,178, 10,140,071/073, 10,481,846/847, etc.).

Confirmed cases involving US 9,036,181

1. Flexiworld Technologies, Inc. v. Epson America, Inc.

• Case No.: 8:21-cv-00807
• Jurisdiction: U.S. District Court, Central District of California (Santa Ana)
• Filing date: April 29, 2021
• Patents: The '181 patent was expressly named among the 14 "Patents-in-Suit" in Epson's answer (7,609,402; 8,630,000; 9,036,181; 10,037,178; 10,140,071; 10,140,073; 10,481,846; 10,481,847; 10,642,576; 10,740,066; 10,761,791; 10,768,871; 10,846,031; 10,873,856)
• Judge: Andre Birotte Jr.; Magistrate Judge Douglas F. McCormick
• Status: Closed. The docket reflects a "REPORT ON THE DETERMINATION OF AN ACTION... (Closing)" with an Order Dismissing Civil Action entered February 2, 2022 (i.e., dismissed; the with/without-prejudice terms were not confirmed in my search).
• Sources: https://portal.unifiedpatents.com/litigation/California%20Central%20District%20Court/case/8%3A21-cv-00807 ; https://www.action-intell.com/wp-content/uploads/2021/08/Epson-answers-to-Flexiworld-lawsuit.pdf

2. Flexiworld Technologies, Inc. v. Canon, Inc. and Canon Solutions America, Inc.

• Case No.: 6:21-cv-00143
• Jurisdiction: U.S. District Court, Western District of Texas (Waco Division), Judge Alan D. Albright
• Filing date: February 11, 2021
• Patents: RPX described the Canon complaint as asserting patents "generally related to short range wireless communications or wireless printing"; Google Patents' litigation list ties this case to US9036181.
• Status: Closed — voluntary dismissal with prejudice (Rule 41(a)(1)(A)(i)) filed August 26, 2021, before Canon answered.
• Sources: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A21-cv-00143 ; https://www.action-intell.com/wp-content/uploads/2021/08/Flexiworld-v-Canon-notice-of-dismissal.pdf ; https://litigation.rpxcorp.com/news/65373

3. Flexiworld Technologies, Inc. v. Brother Industries (U.S.A.), Inc.

• Case No.: 2:22-cv-02236 (consolidated/related with 2:22-cv-02237, 2:22-cv-02250, 2:22-cv-02251, all against Brother)
• Jurisdiction: U.S. District Court, Western District of Tennessee (Memphis Division), Judge Jon Phipps McCalla
• Filing date: April 15, 2022
• Status: Dismissed with prejudice (settlement). Joint Motion to Dismiss with Prejudice filed March 10, 2023; case terminated March 13, 2023. Each party to bear its own costs/fees.
• Sources: https://portal.unifiedpatents.com/litigation/Tennessee%20Western%20District%20Court/case/2%3A22-cv-02236 ; https://www.action-intell.com/wp-content/uploads/2023/03/Flexiworld-motion-to-dismiss-Brother-lawsuits.pdf ; https://www.docketalarm.com/cases/Tennessee_Western_District_Court/2--22-cv-02236/

4. Flexiworld Technologies, Inc. v. Xerox Corporation

• Case No.: 6:23-cv-06370
• Jurisdiction: U.S. District Court, Western District of New York
• Filing date: 2023 (exact date not confirmed in my search)
• Patents: US10140071B2, US10873856B2, and US9036181B2 (per PatSnap's PACER-based analysis)
• Status: Dismissed with prejudice via stipulated dismissal under Rule 41(a)(1)(A)(ii) — all pending claims and counterclaims extinguished with prejudice, each party bearing its own costs. No merits adjudication.
• Sources: https://portal.unifiedpatents.com/litigation/New%20York%20Western%20District%20Court/case/6%3A23-cv-06370 ; https://www.patsnap.com/de/resources/blog/litigation/flexiworld-v-xerox-wireless-printing-patent-dispute-dismissed-patsnap/

Cases linked to US 9,036,181 on Google Patents but not fully verified in my search

5. Case 1:21-cv-00066 — Western District of Texas

• Listed on the Google Patents litigation tab for US9036181 (W.D. Tex., filed January 2021). I was unable to confirm the defendant or status within my search limits. Given Flexiworld's W.D. Tex. campaign in that period (Amazon, Roku, Canon, HP), it may be another Flexiworld infringement action, but I cannot state the parties with confidence.

6. Case 4:24-cv-02691 — Southern District of Texas

• Listed on the Google Patents litigation tab for US9036181 (S.D. Tex., filed 2024). I was unable to confirm the parties or status. It may be a later Flexiworld action, but I cannot verify it from the sources I reached.

Caveats

• The Google Patents page for US9036181 lists exactly six district-court litigation links; four are confirmed above (Brother, Epson, Canon, Xerox) and two (1:21-cv-00066, 4:24-cv-02691) I could not verify as to parties/status before exhausting my search budget.
• Related Flexiworld matters I found (e.g., the 2025 Amazon subpoena matter 2:25-mc-00018 in W.D. Wash., and the 2025 LG suit in E.D. Tex.) do not assert US9036181 — the LG suit involves patents 9,042,811; 9,836,259; 9,965,233; 10,140,072; 10,162,596; and 10,037,178 — so I have excluded them.
• All confirmed cases were dismissed (voluntarily or by settlement) — no merits judgment on US9036181 was identified in these sources.

If you want, I can run a follow-up search specifically on docket numbers 1:21-cv-00066 and 4:24-cv-02691 (and confirm the exact filing/dismissal dates for the Xerox case) to complete the picture.

The first search surfaced a PGR on a different Flexiworld patent (US11029903, PGR2021-00112 — Roku v. Flexiworld), not US9036181. Let me search more specifically for proceedings on the '181 patent.

The searches are surfacing IPRs on other Flexiworld patents (IPR2022-00775 on US9836257; PGR2021-00112 on US11029903). I need to check specifically whether any AIA proceeding targeted US9036181. Let me query the PTAB proceeding search directly and check Unified Patents' portal page.

I've hit the search-step limit, but I have enough to answer. Here's what the record shows.

Proceedings overview

No AIA trial proceedings (IPR/PGR/CBM) are on file for US9036181. The USPTO ODP structured data reports zero proceedings, and my web searches surfaced no PTAB petition, institution decision, or Final Written Decision directed to this patent — the IPRs/PGRs that exist in this family (e.g., IPR2022-00775 and IPR2022-01267 on US9836257; PGR2021-00112 on US11029903) all challenge different Flexiworld patents, not the '181. The bottom-line defensive posture: this patent expired in January 2022 and has never been through an AIA trial — the strongest defenses are expiration (no post-2022-01-18 liability at all) and the absence of any PTAB estoppel constraints on prior-art grounds a defendant may raise in district court.

PTAB proceedings

There are no proceedings to report for US9036181. The structured "PTAB proceedings on file" block is empty, and independent web searching did not surface any petition, institution decision, FWD, settlement, or CAFC appeal naming U.S. Patent 9,036,181 as the challenged patent.

What the searches did surface — and why it's not on point:

• PGR2021-00112 — Roku, Inc. v. Flexiworld Technologies, Inc. challenges US11029903 (a different Flexiworld patent in the same pervasive-output family), on written-description and § 101 grounds. Not the '181.
• IPR2022-00775 — Unified Patents, LLC v. Flexiworld Technologies, Inc. challenges US9836257; the PTAB's Final Written Decision (2023-11-01) determined no challenged claims unpatentable and dismissed Flexiworld's revised motion to amend (panel: APJs McMillin, Ogden, Dougal). Not the '181, but a useful signal that Flexiworld has successfully defended sibling patents at the Board.
• IPR2022-01267 — Roku, Inc. v. Flexiworld Technologies, Inc. also challenges US9836257 (filed 2022-07-29). Not the '181.

Family litigation context (district court, not PTAB): Google Patents flags family-level litigation including W.D. Tenn. 2:22-cv-02236; C.D. Cal. 8:21-cv-00807; W.D. Tex. 6:21-cv-00143 and 1:21-cv-00066; and S.D. Tex. 4:24-cv-02691. The one case I can confirm at the patent level is Flexiworld v. Xerox, 6:23-cv-06370 (W.D.N.Y.), where Flexiworld asserted US9036181 alongside US10140071 and US10873856 — resolved by a Rule 41(a)(1)(A)(ii) stipulated dismissal with prejudice (each party bearing its own costs), i.e., no merits adjudication. Note also that the '181's own Google Patents record lists status: "Expired - Fee Related" with anticipated expiration 2022-01-18 (Unified Patents' portal lists expiration 2022-01-17 and $0 lifetime renewal fees tracked), and the asserted-family cases have been resolving without merits wins for Flexiworld.

• Type: N/A — no proceeding filed
• Filed: N/A
• Status: No AIA trial proceeding on file (ODP ingest) and none found via web search
• Defensive value: There is no PTAB estoppel bar here, so a defendant facing assertion today is free to raise every available § 102/§ 103/§ 101/§ 112 ground in district court. And because the patent expired 2022-01-18, any infringement theory is limited to pre-expiration conduct within § 286's six-year damages window — a demand letter premised on ongoing or post-2022 infringement has no statutory basis.

Strategic summary

Claim status: CANCELED vs. SUSTAINED vs. UNTESTED. No claim of US9036181 has ever been canceled or sustained by the PTAB, because no AIA proceeding was ever filed against it. All claims (1–N, as granted) remain formally "untested" at the Board. That is a double-edged fact: there is no IPR-based prior-art win to lean on, but equally no estoppel and no adverse claim construction from a FWD.

Estoppel landscape. § 315(e)(2) estoppel simply does not apply — no petitioner exists, no grounds were raised or "reasonably could have been raised" in a trial, because there was no trial. For a defendant currently being asserted against, every prior-art ground remains available: the full universe of § 102/§ 103 art (including art the family's challengers used against sibling patents, such as Olgaard, Moghadam, Acharya, Griffiths, and the Newton OS reference from IPR2022-00775), plus § 101 eligibility and § 112 written-description arguments (mirroring Roku's PGR2021-00112 theories). You are not boxed in by anyone else's PTAB strategy.

Pattern signals. Flexiworld has faced repeated PTAB challenges on sibling patents — Unified Patents (a defensive aggregator with 3,000+ members, including Roku as a beneficiary) and Roku itself are the repeat petitioners — and Flexiworld has defended those aggressively (e.g., the 2023-11-01 FWD in IPR2022-00775 upholding US9836257's claims and Flexiworld's motion-to-amend practice). The absence of any IPR on the '181 is itself notable: it is the oldest anchor patent in the asserted wireless-printing cluster (priority 2001-01-19), yet no challenger bothered to run an IPR against it — most likely because it expired in January 2022, making PTAB review of an expired patent (with only pre-expiration damages at stake) poor economics. Meanwhile, the Xerox case — the only confirmed '181-specific assertion — ended in a with-prejudice dismissal on mutually agreed terms, not a merits win.

Recommended next steps

1. Lead with expiration. This patent's statutory term ended 2022-01-18 (Google Patents: "Anticipated expiration 2022-01-18," status "Expired - Fee Related"). If your accused activity post-dates that date, there is no infringement as a matter of law — no injunction, no ongoing royalty, no post-expiration damages. Only pre-2022-01-18 conduct within the § 286 six-year lookback is even theoretically in play, and any demand based on current products should be rejected in writing on this ground alone.
2. Confirm the exact expiration/lapse record. Pull the USPTO Patent Center / Assignment record for 12/764,015 to confirm whether the "Expired - Fee Related" status reflects a maintenance-fee lapse or term expiration, and verify the precise expiration date (Google Patents says 2022-01-18; Unified Patents' portal says 2022-01-17). This determines the last possible date of infringing conduct for damages purposes.
3. Do not rely on PTAB — but know you're unconstrained. There is no FWD to cite because there is no proceeding. In district court, you are free to run every § 102/§ 103 ground, plus § 101 (Alice) and § 112 written-description challenges, with no § 315(e)(2) estoppel. The art and theories that worked procedurally against sibling patents (Unified's obviousness combinations in IPR2022-00775; Roku's written-description/§ 101 attack in PGR2021-00112) are all available to you, adapted to the '181's claims.
4. If you want a PTAB record anyway, check timing. An IPR on this expired patent is technically possible (the Board regularly reviews expired patents), but it is almost certainly not worth it: estoppel would run against you (§ 315(e)(2)), the economics are poor given expiration, and Flexiworld has shown it will fight hard (see the US9836257 FWD). The more efficient path is an early summary-judgment motion on expiration and/or § 101.
5. Watch the docket for the pending family cases (e.g., S.D. Tex. 4:24-cv-02691) — Flexiworld's claim constructions and any § 101 rulings there may be persuasive (though not binding) in your case, and the Xerox dismissal shows Flexiworld will settle for a walk-away when the merits look weak.

Caveat on sourcing: The ODP structured block is the canonical source and reports no proceedings; my web searches (limited in number) corroborated that finding but could not exhaustively rule out a very recently filed petition the ODP has not yet indexed. If you want belt-and-suspenders confirmation, run a fresh PTAB proceeding search on 9036181 at PTAB E2E / the USPTO PTAB proceeding search before filing anything. Do not cite any of the sibling-patent proceedings (IPR2022-00775, IPR2022-01267, PGR2021-00112) as if they involved the '181 — they did not.

Ownership Chain Reconstruction — US Patent 9,036,181 B2

Data-access caveat up front: I could not directly query the USPTO Assignment Center (assignmentcenter.uspto.gov) from my search environment, and my searches did not surface a reel/frame number or correspondent-of-record specifically for the '181 patent's recorded assignment. The assignment event described below comes from the Google Patents legal-events tab for US9036181. I have flagged everything that is verified vs. unverified and have not fabricated reel/frame numbers. For context I did find verified reel/frame citations for sibling Flexiworld patents in litigation pleadings (e.g., '402 patent at Reel/Frame 028733/0064; '072, '178, '031 patents at 042385/0202; '596 at 039816/0200; '871 at 046519/0534; '856 at 043675/0454 — all from Flexiworld complaints/Epson's answer), but none of those reels is verified to cover the '181 patent, so I do not attribute them to it.

Inventors

Unusual pattern? No inventor-departure pattern. Unlike a typical fire-sale setup (inventors leave the assignee and the portfolio is sold), Chang and Liu are the principals of the assignee and remain associated with it through the 2021–2024 assertion campaign. The inventors and the asserting entity are effectively the same people — a founder-operated licensing company, not a departed-inventor transfer.

Original assignee

• Entity named on the issued patent: Flexiworld Technologies, Inc. (also indexed as "Flexiworld Tech Inc" in USPTO/Unified Patents data).
• Primary line of business: Development and licensing of "universal output" / wireless-printing technology. PatSnap's litigation summary describes Flexiworld as a "Wireless printing technology licensor — holder of US10140071B2, US10873856B2, and US9036181B2." I found no evidence that Flexiworld shipped a printer or any product embodying the '181 claims.
• Current status: Operating as a patent-assertion/licensing entity. It was the plaintiff in every identified case on this patent (Epson, Canon, Brother, Xerox, HP) and has active suits in its family through 2024–2025 (e.g., S.D. Tex. 4:24-cv-02691 against HP remains open per Unified Patents). No bankruptcy or dissolution found.

Assignment timeline

Based on Google Patents' legal-events tab for US9036181, exactly one assignment-related event is recorded for this patent. I could not retrieve the reel/frame, execution date, or correspondent from my search tools; the USPTO Assignment Center should be consulted to confirm.

• Executed: not retrieved / recorded 2012-10-11 — Reel not retrieved (Google Patents legal event; USPTO Assignment Center not directly accessible in my search)
  • Conveyance: Assignment of Assignors' Interest
  • Assignor: William Ho Chang; Christina Ying Liu
  • Assignee: Flexiworld Technologies, Inc.
  • Correspondent: not retrieved
  • Context: Late recordation of the original inventors→company assignment, filed ~2.5 years after the 2010-04-20 filing of application 12/764,015 and ~11 years after the 2001 priority date. This is a routine (if delayed) chain-of-title clean-up, consistent with Flexiworld's practice of recording assignments across its continuation family; it is not a transfer to a third party.

No post-issuance assignment, security agreement, merger, or name change was surfaced. The patent issued to Flexiworld (2015-05-19) and has remained with Flexiworld through the 2021–2024 litigations — every complaint's standing allegations run from Flexiworld as assignee. If the Assignment Center shows additional records (e.g., liens or security interests), they did not appear in my search results; the absence of post-issuance transfers is itself a finding: the original assignee still owns the patent.

Timeline diagram

timeline
    title Ownership of US 9036181
    2001 : Priority date filed
    2010 : Application 12 slash 764015 filed
    2012 : Inventors assign to Flexiworld
         : Assignment recorded Oct 2012
    2015 : Patent granted to Flexiworld
    2021 : First infringement suits filed
    2024 : HP suit filed in Texas

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The patent never moved from an operating company to a licensing-only LLC; it issued to Flexiworld Technologies, Inc. and stayed there. The only recorded conveyance is the inventors→Flexiworld recordation (recorded 2012-10-11). Note: Flexiworld itself behaves as a licensing entity, but the signal as defined (transfer into a shell) did not occur.

2. Known asserter in the chain — Present (strong). Flexiworld Technologies, Inc. is both the current assignee and a high-frequency plaintiff asserting this exact patent in at least five district-court cases: Epson (C.D. Cal. 8:21-cv-00807), Canon (W.D. Tex. 6:21-cv-00143), Brother (W.D. Tenn. 2:22-cv-02236), Xerox (W.D.N.Y. 6:23-cv-06370), and HP (S.D. Tex. 4:24-cv-02691). Unified Patents' portal for patent 9036181 lists these related cases and classifies Flexiworld as "NPE (Small Company)" in the HP case. PatSnap independently characterizes Flexiworld as a licensor rather than a product company.

3. Repeat correspondent across the chain — Unclear. I could not retrieve the correspondent of record for the 2012-10-11 recordation, so I cannot assess recurrence. (The correspondents on the litigation side are the Flexiworld trial firms, but that is not assignment-correspondent data.)

4. Cascading transfers — Not present. Only one assignment event was identified; there are no chained LLC transfers, no shared registered-agent addresses, and no 24-month transfer cascade.

5. Pre-litigation transfer — Not present. The recorded assignment (2012-10-11) predates the first infringement suits (2021) by roughly nine years. The late recordation (~11 years after priority) is notable but does not fall within the six-month pre-suit window and was recorded long before any case.

6. Bankruptcy fire-sale — Not present. No Chapter 7/11 proceedings or court-supervised patent sale involving Flexiworld was found.

7. Privateering — Not present. No operating company transferred the patent to an NPE for assertion against its competitors; the original assignee itself is the assertor.

8. Defensive aggregator (anti-NPE) — Not present. The chain terminates at the asserting entity. No RPX, AST, LOT Network, Unified Patents, or OIN involvement; the patent remains an active enforcement asset (PatSnap notes it "remains enforceable" after the Xerox dismissal).

Verdict

NPE — moderate confidence.

The assignment record itself is clean and short — one inventors→company recordation (recorded 2012-10-11) and no post-issuance transfers — so the classic shell-transfer and cascading-transfer tells are absent. The single strong signal is the chain's terminus: Flexiworld Technologies, Inc., a licensing-only entity that Unified Patents classifies as an NPE (Small Company) and that has asserted this patent against Epson, Canon, Brother, Xerox, and HP (8:21-cv-00807, 6:21-cv-00143, 2:22-cv-02236, 6:23-cv-06370, 4:24-cv-02691). Under the rubric, one strong signal (known asserter/NPE classification) with no second corroborating strong signal from the assignment record supports moderate, not high, confidence.

Verification link: https://assignmentcenter.uspto.gov/ (patent-number search "9036181"; legacy mirror at https://assignment.uspto.gov/patent/index.html) — confirm the reel/frame and correspondent for the 2012-10-11 recordation and check for any liens or security agreements not surfaced in my search.

I'll research the prior art cited against US Patent 9,036,181 B2. Let me start by locating the official USPTO records and the citations listed on the patent.

Let me dig into the citations section of the patent record on Google Patents and the USPTO.

The Limestone validity report gives a useful starting list of prior art. Now I need the exact "Patent Citations" (References Cited) listed on the granted US9036181 patent itself. Let me try to pull the citation list from the USPTO full-text record and the published application.

I've reached the limit of my search budget for this session, so I'll answer based on the sources I could retrieve. Here is my prior-art analysis with full transparency about what I could and could not verify.

Prior Art Analysis — US Patent 9,036,181 B2

Methodological note (read this first)

• I was not able to pull the complete official "References Cited" (front-page citations) section from the USPTO full-text HTML or from Google Patents in this session — the patent page renders the citations in a section that did not fully surface in my searches, and I was cut off before I could fetch it directly.
• The most reliable artifact I located that is specific to this exact patent number is a Limestone IP validity report for US-9036181-B2 (limestoneip.com). Its "Preview Results" list is a prior-art search result set generated against this patent. I am using that list as the basis for this analysis, supplemented by my knowledge of the Flexiworld patent family. It is a good proxy for "most relevant prior art," but it may not be identical to the examiner's final "References Cited" list on the face of the patent — I flag this rather than pretending otherwise.
• Because the application (12/764,015) was filed April 20, 2010 (before the AIA's March 16, 2013 effective date), pre-AIA 35 U.S.C. §§ 102/103 govern. The patent's priority date is January 19, 2001, so any reference with an effective prior-art date before that is § 102 prior art.
• I do not have the full granted claim text (noted as an open item in the earlier summary). The claim-level anticipation assessments below are mapped against the two independent claims as reconstructed from the published claim excerpts (a method claim, likely claim 1, and a device claim, likely claim 14). Treat the claim mappings as plausible/high-level, not element-by-element findings.

Prior-art references identified for US 9,036,181 B2

A. U.S. patents and published applications

1. US 6,980,319 B2 — Ricoh Company, Ltd.

• Title: "System and method of selectively printing at remote printers via portable digital device"
• Priority: March 10, 2000 · Published/granted: December 27, 2005
• Description: A portable digital device (PDA/handheld) selects and prints to remote printers; covers printer selection/discovery, transmitting a document/print job from the portable device over a network, and rendering at a remote printer.
• § 102 relevance: Strongly relevant to the method and device claims (receiving output/print data from a wireless/portable information apparatus; printer selection/discovery; rendering at the printer). Potentially anticipates claim 1 elements (receiving data from a wireless information apparatus; printing at a wireless printing device) and claim 14 elements (wireless printing device; output controller; discovery/identity indication for selection). Effective date (2000-03-10) precedes the 2001-01-19 priority date.

2. US 7,016,061 B1 — Hewlett-Packard Development Co., LP

• Title: "Load balancing for raster image processing across a printing system"
• Priority: October 25, 2000 · Published/granted: March 21, 2006
• Description: Distributes raster image processing (RIP) tasks across a printing system — precisely the "shared RIP" architecture that is the core inventive concept of the '181 patent (information apparatus performs part of the RIP, the printer/output controller performs the rest, e.g., color conversion and halftoning).
• § 102 relevance: Potentially anticipates the method claim (claim 1) and device claim (claim 14) insofar as they require performing image processing (color management/correction, halftoning) at the printing device rather than the source. Effective date (2000-10-25) precedes the priority date.

3. US 6,529,522 B1 — Canon Kabushiki Kaisha

• Title: "Communication apparatus with digital interface"
• Priority: March 12, 1997 · Published/granted: March 4, 2003
• Description: A communication apparatus (e.g., a printer/camera/PC) with a digital interface enabling direct device-to-device communication of image data — relevant to the direct wireless communication between an information apparatus and a printing device.
• § 102 relevance: Relevant to the communication/structure elements of claim 14 (wireless communication unit; receiving digital content from an information apparatus). Effective date (1997) is well before the priority date.

4. US 2002/0075508 A1 — Hewlett-Packard (application publication)

• Title: "Notification of print job status over a wireless link"
• Priority: December 20, 2000 · Published: June 20, 2002
• Description: A printing system in which a wireless device submits a print job and the printer/print system returns status notifications (e.g., job completion, error) over a wireless link.
• § 102 relevance: Relevant to the communication/interaction between a wireless information apparatus and a wireless printing device, and to status/identity signaling elements of claim 14 (e.g., the printer providing indications while awaiting service). Effective date (2000-12-20) precedes the priority date.

5. US 7,587,468 B2 — Electronics for Imaging, Inc.

• Title: "Methods and systems for the provision of printing services"
• Priority: October 16, 2000 · Published/granted: September 8, 2009
• Description: Provision of printing services over a network, including driverless/universal printing architectures in which the client need not install device-specific drivers — highly relevant to the '181 patent's "universal output without per-device drivers" feature.
• § 102 relevance: Potentially anticipates claim 1 (universal intermediate output data method) and claim 14 (output controller decoding intermediate output data; no dedicated driver needed at the source). Effective date (2000-10-16) precedes the priority date.

6. US 7,019,061 — already covered as item 2 above (duplicate in the search output; no separate treatment needed).

B. European patent documents (as cited/identified)

7. EP 1 211 593 A2 — Ricoh Company, Ltd.

• Title: "Apparatus method and system for printing from a wireless mobile device over the internet"
• Priority: November 30, 2000 · Published: June 5, 2002
• Description: Printing from a wireless mobile device (e.g., WAP phone) over the Internet to a printer via a server; the server performs document conversion so the mobile device does not need a printer driver.
• § 102 relevance: Relevant to claim 1 (receiving intermediate/printable data corresponding to digital content from a wireless apparatus and printing it) and to the "driverless" aspect of claim 14. Effective date (2000-11-30) precedes the priority date.

8. EP 1 217 824 A2 — Ricoh Company, Ltd.

• Title: "Printing interface with payment component for wireless devices"
• Priority: December 22, 2000 · Published: June 26, 2002
• Description: A printing interface for wireless devices that includes a payment/authentication component — relevant to the security/restricted-access and authorization features of the '181 claims (e.g., security-key procedure).
• § 102 relevance: Potentially anticipates the security-key/restricted-communication element of claim 14. Effective date (2000-12-22) precedes the priority date.

9. EP 1 328 859 A2 — Electronics for Imaging, Inc.

• Title: "Print driver apparatus and methods for forwarding a print job over a network"
• Priority: October 16, 2000 · Published: July 23, 2003
• Description: Print driver apparatus and methods for forwarding print jobs over a network — relevant to how print data is generated at the client and forwarded to a network printer.
• § 102 relevance: Relevant to claim 1 (generating/transmitting output data) and claim 14 (receiving output data at the printing device). Effective date (2000-10-16) precedes the priority date.

10. EP 1 328 860 A2 — Electronics for Imaging, Inc.

• Title: "Printer polling apparatus and methods for requesting and receiving print jobs over a network"
• Priority: October 16, 2000 · Published: July 23, 2003
• Description: A printer polls/requests print jobs over a network — relevant to the printer-side discovery, identification, and job-acquisition behavior of the '181 patent.
• § 102 relevance: Potentially anticipates the discovery/identification/waiting-for-service elements of claim 14. Effective date (2000-10-16) precedes the priority date.

11. EP 1 328 858 A1 — Electronics for Imaging, Inc.

• Title: "Spooling server apparatus and methods for receiving, storing and forwarding a print job over a network"
• Priority: October 16, 2000 · Published: July 23, 2003
• Description: A spooling server receives, stores, and forwards print jobs — relevant to intermediate handling of print data between a source and a printer.
• § 102 relevance: Relevant to the output-data handling/processing elements of claim 1 and claim 14. Effective date (2000-10-16) precedes the priority date.

12. EP 1 327 187 A2 — Electronics for Imaging, Inc.

• Title: "Methods and systems for the provision of printing services"
• Priority: October 16, 2000 · Published: July 16, 2003
• Description: Counterpart of US 7,587,468 (item 5); provision of printing services, including driverless printing over networks.
• § 102 relevance: Same as item 5 — potentially anticipates the driverless/universal output method (claim 1) and output-controller device (claim 14). Effective date (2000-10-16) precedes the priority date.

13. EP 1 120 701 B1 — SafeCom A/S

• Title: "System and method for ensuring secure transfer of a document from a client of a network to a printer"
• Priority: January 28, 2000 · Published (grant): September 26, 2007
• Description: Secure transfer of documents from a network client to a printer, including authentication/security mechanisms — relevant to the restricted-access/security-key features of the '181 patent.
• § 102 relevance: Potentially anticipates the security-key/restricted-communication element of claim 14. Effective date (2000-01-28) precedes the priority date.

14. EP 1 058 211 A1 — Agfa Corporation

• Title: "Method and apparatus for modifying raster data"
• Priority: May 28, 1999 · Published: December 6, 2000
• Description: Modifying raster data (image processing at the raster level) — relevant to the printer-side image-processing elements (color management, halftoning, raster conversion) of the claims.
• § 102 relevance: Potentially anticipates the image-processing steps of claim 1 (color management, halftoning) and the output-controller image processor of claim 14. Effective date (1999) precedes the priority date.

15. EP 0 893 754 A1 — Seiko Epson Corporation

• Title: "Print system, printing method and printer"
• Priority: 1998 (July 1998 filing per family records) · Published: January 27, 1999
• Description: A print system and printing method in which a printer receives print data and performs printing; a foundational printing-system reference.
• § 102 relevance: Relevant to the basic printer-side receiving/rendering elements of claim 1 and claim 14 (receiving data, memory buffer, marking engine, printing onto substrate). Effective date (1998/1999) precedes the priority date.

16. EP 1 076 311 B1 — Seiko Epson Corporation

• Title: "Printer with bookbinding function for binding printed matter"
• Priority: August 12, 1999 · Published (grant): October 18, 2006
• Description: A printer with a bookbinding/finishing function. Least relevant of the set to the wireless-communication and shared-RIP claims; it concerns printer mechanics/finishing rather than wireless data reception.
• § 102 relevance: Marginal; at most relevant to generic printer-structure elements of claim 14 (printer with marking engine/substrate output). Effective date (1999-08-12) precedes the priority date.

Ranked most relevant prior art (for § 102 anticipation)

1. US 7,016,061 B1 (HP, "Load balancing for raster image processing across a printing system") — closest to the '181 patent's central innovation: splitting RIP between the source and the printer-side system (including halftoning/color operations at the printer). Most likely primary § 102 reference against the method claim (claim 1) and the output-controller device claim (claim 14).
2. US 6,980,319 B2 (Ricoh, remote printing via portable digital device) — closest on the "wireless/portable information apparatus printing at a selected remote printer" combination, including device selection/discovery.
3. US 7,587,468 B2 / EP 1 327 187 A2 (EFI, provision of printing services) — closest on driverless/universal printing (no per-device driver at the client), matching the '181 patent's universal-output goal.
4. EP 1 211 593 A2 (Ricoh, printing from a wireless mobile device over the internet) — closest on the specific "wireless mobile device sends printable content; server/device converts; printer prints" flow.
5. EP 1 120 701 B1 (SafeCom, secure transfer to printer) and EP 1 217 824 A2 (Ricoh, printing interface with payment component) — closest on the security-key/restricted-access element of claim 14.

Important caveats (do not treat these as settled findings)

• Unverified official citation list: I could not confirm that the Limestone report list exactly matches the examiner's "References Cited" on the face of US 9,036,181 B2. The examiner of record is Marcus T. Riley; a definitive list requires pulling the USPTO full-text front page or the PTACTS file history.
• No full claim text: My § 102 mappings are against reconstructed claim summaries, not the granted claim language. An actual anticipation analysis requires element-by-element comparison against the final claims (and the file history for amendments during prosecution, e.g., the means-plus-function claim 35 of the published application that may have been amended).
• Pre-AIA law: Because the application predates March 16, 2013, anticipation analysis is under pre-AIA § 102 (and obviousness under pre-AIA § 103), so I used the 2001-01-19 priority date as the § 102 threshold. Note that if any claim is not entitled to the 2001 priority date (e.g., new matter added in the 2010 continuation), later-dated references could also qualify as prior art — that is a claim-by-claim priority analysis I did not perform.
• Two unverified district-court cases (1:21-cv-00066 W.D. Tex. and 4:24-cv-02691 S.D. Tex.) remain open items from the earlier litigation summary; they are unrelated to prior art but worth closing out if this analysis feeds into a validity/claim-construction project.

If you want, the next step would be to pull the official USPTO "References Cited" page and the full granted claims (both retrievable via USPTO Patent Center / Global Dossier for 12/764,015), then re-run this mapping element-by-element against the actual claim language.

The initial searches didn't surface the actual cited prior art (backward citations) for the '181 patent. Let me dig for the prosecution citations and any PTAB/litigation invalidity positions.

I've reached my search budget. Before giving the § 103 analysis, let me be transparent about what the "Prior Art section" yielded and what remains unverified, because the analysis's reliability depends on it.

Materials and verification status

What I could retrieve (the Prior Art section of the face-of-patent record):

• The uspto.report page for US9036181 (which mirrors the U.S. patent citations printed on the granted patent) surfaced a partial, number-ascending list of cited U.S. patents — spanning 5,287,194 (Feb. 1994) through 5,826,244 (Oct. 1998) — before my search budget ran out. The list is truncated; the full citation set (including any 1998–2010 references, non-patent literature, and foreign references) was not retrieved.
• I could not retrieve the complete granted claim text of the '181 patent. The element mapping below therefore relies on the claim overview in the earlier summary (independent method claim; independent device claim 14), not on verbatim claim language. A full § 103 chart would require the complete claims.
• I found no IPR/PGR petition directed to US9036181 itself. (The PTAB petition that surfaced, PGR2021-00112, is against a different family member, US 11,029,903, and concerns written description/§ 101, not § 103 on this patent.) The district-court cases (Epson, Canon, Brother, Xerox) were all dismissed without merits rulings, so no court has adjudicated obviousness of the '181 claims. One case remains open per Unified Patents: 4:24-cv-02691, Flexiworld v. Hewlett-Packard Co., S.D. Tex., filed 2024-07-18 — its invalidity contentions are not public in my search. I also note a minor docket discrepancy: Unified lists Brother case 2:22-cv-02236 under "Tennessee Eastern," while DocketAlarm/earlier research listed W.D. Tenn.; this does not affect the obviousness analysis.

Integrity rule applied below: For face-of-patent citations, I only assert patent numbers, dates, and inventor surnames (as printed on the face and shown in the uspto.report snippet). I do not assert titles/contents of those specific numbers except where noted, because I could not verify them. For the technical landscape, I rely on well-documented, high-confidence prior art (standards, products, and architectures that a POSITA in 2001 would know), clearly labeled as such.

1. Legal framework

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 (Graham v. John Deere, 383 U.S. 1 (1966): scope/content of prior art, differences, level of ordinary skill, secondary considerations). Post-KSR v. Teleflex (2007), obviousness does not require a rigid teaching-suggestion-motivation test; it can rest on common sense, predictable solutions to known problems, design incentives, and marketplace pressure, provided the combination is not the product of impermissible hindsight.

POSITA profile (circa Jan. 2001): A person with a B.S. in electrical engineering/computer science (or equivalent), 2–4 years' experience in one or more of: printer architecture and raster image processing (RIP, halftoning, color management), embedded systems, and short-range wireless networking (Bluetooth, IEEE 802.11, IrDA); familiarity with printer drivers, PDLs (PostScript/PCL), print servers, and host-based (GDI) printing.

2. Claim elements at issue (from the summary's claim overview)

3. The prior art landscape

3.1 Face-of-patent U.S. citations (verified as printed; partial list)

From the uspto.report snippet — all cited on the face of the '181 patent (numbers, dates, inventors as printed):

5,287,194 (Lobiondo 2/1994); 5,303,342 (Edge 4/1994); 5,319,711 (Servi 6/1994); 5,337,258 (Dennis 8/1994); 5,353,388 (Motoyama 10/1994); 5,404,433 (Hosugai 4/1995); 5,412,798 (Garney 5/1995); 5,467,434 (Hower, Jr. 11/1995); 5,475,507 (Suzuki 12/1995); 5,479,206 (Ueno 12/1995); 5,485,634 (Weiser 1/1996); 5,490,287 (Itoh 2/1996); 5,515,480 (Frazier 5/1996); 5,519,641 (Beers 5/1996); 5,524,185 (Na 6/1996); 5,537,107 (Funado 7/1996); 5,537,517 (Wakabayashi 7/1996); 5,546,079 (Wagner 8/1996); 5,564,109 (Snyder 10/1996); 5,566,278 (Patel 10/1996); 5,568,595 (Yosefi 10/1996); 5,580,177 (Gase 12/1996); 5,589,889 (Kawaoka 12/1996); 5,596,697 (Foster 1/1997); 5,604,843 (Shaw 2/1997); 5,613,123 (Tsang 3/1997); 5,613,124 (Atkinson 3/1997); 5,619,257 (Reele 4/1997); 5,619,649 (Kovnat 4/1997); 5,625,757 (Kageyama 4/1997); 5,636,211 (Newlin 6/1997); 5,644,662 (Vuylsteke 7/1997); 5,664,243 (Okada 9/1997); 5,675,717 (Yamamoto 10/1997); 5,687,332 (Kurahashi 11/1997); 5,699,495 (Snipp 12/1997); 5,710,557 (Schuette 1/1998); 5,717,742 (Hyde-Thomson 2/1998); 5,724,106 (Autry 3/1998); 5,737,501 (Tsunekawa 4/1998); 5,739,928 (Scott 4/1998); 5,748,859 (Takayanagi 5/1998); 5,754,655 (Hughes 5/1998); 5,757,952 (Buytaert 5/1998); 5,761,480 (Fukada 6/1998); 5,802,314 (Tullis 9/1998); 5,822,230 (Kikinis 10/1998); 5,826,244 (10/1998)…

Verification caveat: I could not verify the titles or teachings of these individual references (with one notable exception — 5,485,634 (Weiser et al.), the Xerox PARC "ubiquitous computing" patent concerning dynamic selection/allocation/arbitration of control between devices within a region, which I know with high confidence). The density of 1994–1998 printer/imaging/wireless patents is itself consistent with the examiner citing the core fields the claims draw on: host/device printing, RIP/halftoning, image encoding, and device communication. I will not attribute specific teachings to the unverified numbers; where used below, they are cited as "face-of-patent references in the printing/imaging/wireless space" rather than for pin-point disclosures.

3.2 Well-documented state of the art (pre-2001; high-confidence background, not verified as face-of-patent citations)

A POSITA in January 2001 would know:

1. Wireless printing was a mature, actively-commercialized problem space:
   • IEEE 802.11b (Wi-Fi) ratified 1999; wireless print servers shipping by 2000 (e.g., HP JetDirect 802.11b cards; Apple AirPort base station, July 1999, with a printer port).
   • Bluetooth v1.0 (1999) with service discovery (SDP) and PIN-pairing security; Bluetooth printing demos/profiles by 2000–2001 (Ericsson/HP); the Bluetooth Basic Printing Profile was in development in this exact window.
   • IrDA printing — e.g., IrTran-P (1998) for printing from digital cameras; HP CapShare 920 (1999) handheld scanner printing over IR; Palm + PalmPrint (Stevens Creek, ~1999) printing from a PDA over IR. The '181's own background concedes wireless connection "using, for example, radio communication or infrared communication" was known.
2. Host-based ("GDI") printing — by the late 1990s, low-cost printers (e.g., HP LaserJet 1100-class, Canon GDI engines) had no PDL controller: the host rasterizes to a device-ready bitmap ("intermediate output data" in substance), and the printer engine marks. The '181's Figure 4B/1B dichotomy (RIP at host vs. RIP at PDL controller) is the textbook split that GDI printers and PostScript/PCL controllers already embodied.
3. RIP at the printer — PostScript Level 2 (1990)/Level 3 (1997) and PCL controllers performing interpretation, color space conversion, color matching, and digital halftoning in the printer; error diffusion and screening were standard.
4. Multi-layer / multi-channel image encoding — Mixed Raster Content (MRC), standardized in ITU-T T.44 (2000) and promoted by Adobe, uses a background layer, foreground layer, and selector layer with different resolutions/compression; color printing inherently separates into CMYK color channels; JPEG 2000 (published Dec. 2000) used multi-component/layered encoding.
5. Service discovery and security — SLP (RFC 2608, 1999), UPnP (2000), Bluetooth SDP, AppleTalk NBP; WEP (1999) and Bluetooth PIN pairing for restricted access; network printers with PIN/secure-print features (1990s).
6. Embedded OS/applications in printers — printers shipped with embedded RTOSes (VxWorks, pSOS, Windows CE); HP's embedded Web server in JetDirect/printers (~1997–2000) and HP Chai (embedded Java for printers, ~1999) allowed remote management and installing/updating applications in the printer; network firmware-upgrade capability was standard.

4. Obviousness combinations

Combination 1 — Wireless printer + host-rasterized "intermediate output data" (elements A, B, D, F, G)

Primary references: Wireless print-server art (802.11b print servers, Apple AirPort, Bluetooth/IrDA printing, HP CapShare/Palm IR printing) + host-based GDI printing art (host rasterization to a device-ready bitmap) + the face-of-patent printing/wireless references (e.g., 5,564,109 Snyder; 5,580,177 Gase; 5,737,501 Tsunekawa; 5,748,859 Takayanagi; 5,802,314 Tullis; 5,822,230 Kikinis — numbers verified as cited, teachings not individually verified).

Element mapping: A wireless adapter/radio on a printer (802.11b/Bluetooth) was already sold as a print-server add-on; replacing the parallel/USB input of a host-based GDI printer with a wireless input is the routine substitution of one standard I/O for another. The "intermediate output data" is precisely what a host-based GDI pipeline sends to the printer: a rasterized image that the printer decodes and marks. Memory buffer + marking engine are the standard anatomy of every printer engine (the '181's own Figs. 4A/4B describe exactly this).

Motivation: The known problem the '181's background itself recites — a mobile user "walk[ing] up to a nearby printer" without carrying a cable — was the raison d'être of IrDA/Bluetooth/802.11 printing products already on the market in 1999–2000. The known problem for mobile devices (limited CPU/RAM; PDL files too large; per-printer drivers) was the raison d'être of host-based printing. A POSITA combining a wireless adapter with a host-based printer has a predictable result: a wireless printer receiving raster data. This is a classic KSR "combination of familiar elements according to known methods" with predictable results, driven by marketplace pressure (every printer OEM was adding wireless).

Combination 2 — Split RIP: host rasterizes, printer color-manages and halftones (elements B, C, D, E, F)

Primary references: Host-based GDI printing (host does rasterization; printer receives bitmaps) + PostScript/PCL controller art (printer performs color space conversion, color matching, halftoning) + MRC/color-separation art (two or more layers/color channels: ITU-T T.44/MRC; CMYK separation) + face-of-patent imaging references (e.g., 5,303,342 Edge; 5,644,662 Vuylsteke; 5,664,243 Okada; 5,687,332 Kurahashi; 5,757,952 Buytaert — numbers verified, teachings not individually verified).

Element mapping: (C) is satisfied by color printing's inherent CMYK channel separation or MRC's layered format; (E) color management/correction and (F) halftoning were standard printer-controller functions (PostScript Level 2/3); (D) decoding a received bitmap is the core function of any GDI printer engine controller.

Motivation: The '181's own background identifies the two known drawbacks it "solves": (i) doing full RIP on the host strains mobile devices; (ii) sending PDL creates large files and bandwidth demands. The known middle path — rasterize at the host into a compact intermediate bitmap, and push device-dependent operations (color, halftone) into the printer — was already the engineering answer embodied in host-based printers and in controller-based printers with color management. A POSITA has a strong design incentive to shift computationally intensive halftoning/color into the device with a power supply and more processing headroom. Reasonable expectation of success is high because both halves existed in shipping products. This combination maps onto the method claim's core (receive intermediate data → extract layers/channels → color-manage → halftone → buffer → mark).

Combination 3 — Discovery/broadcast + security key (elements H, I)

Primary references: Service discovery art (Bluetooth SDP; SLP RFC 2608; UPnP; IrDA discovery; AppleTalk NBP) + Weiser 5,485,634 (verified face-of-patent citation; dynamic selection/allocation/arbitration of control between devices in a region — i.e., a device advertising itself and being selected for service) + wireless security art (WEP; Bluetooth PIN pairing; secure/PIN printing).

Element mapping: A wireless printer broadcasting an indication of its identity for selection by a nearby device is SDP/beacon behavior; restricting access via a security key is WEP-key/PIN-pairing behavior. Both were inseparable from the Bluetooth and 802.11 standards themselves (a device implementing Bluetooth SDP and pairing necessarily does H and I).

Motivation: No wireless protocol of the era functioned without device discovery; no secure wireless link functioned without key-based access control. Adding both to a wireless printer is the standard implementation of the chosen radio standard, not a design choice requiring invention. Obviousness here is at its strongest: element H and I are dictated by Bluetooth/802.11 compliance.

Combination 4 — Embedded OS with installable applications (element J)

Primary references: Embedded-OS-in-printer art (printers with VxWorks/Windows CE; HP embedded Web server; HP Chai embedded Java for printers; remote firmware/application update over the network).

Element mapping: An operating system enabling installation of additional applications to expand/upgrade printer functionality is the ordinary function of every embedded OS and of the web-server/Java environments that printer OEMs shipped in 1999–2000.

Motivation: Printer vendors' known need to add features (new PDLs, workflow apps) and fix bugs post-sale drove embedded OSes with downloadable applications. A POSITA combining an embedded OS (already in printers) with the wireless printer of Combination 1 does nothing more than keep the existing OS when adding the wireless interface.

Combination 5 — (Fallback) Two or more image layers or channels (element C)

If claim 1's "two or more image layers or color channels" is treated as a separate inventive point, MRC (ITU-T T.44, 2000; Adobe) and standard CMYK separation provide it. MRC's express purpose — better compression and image quality for mixed text/graphics/image content destined for fax or print — is the same purpose the '181 specification attributes to its layered intermediate output data. Motivation: use the known MRC format in the known host-to-printer data path to reduce file size and bandwidth, with predictable results.

5. Why a POSITA would combine (aggregate motivation)

• Same field / analogous art: Every reference category (wireless printing, host-based RIP, printer controllers, MRC, discovery/security, embedded printer OS) is in the printer or short-range wireless field — the field of the invention.
• Known problems with known solutions: The '181's own Background section identifies (a) driver-installation burden, (b) mobile-device resource limits, (c) PDL file size/bandwidth. Each was a published problem with a published solution by 2000 (driverless/Point-and-Print; host-based printing; compressed/layered raster formats; printer-side RIP).
• Design incentives and marketplace pressure: By 2000, every major OEM (HP, Canon, Epson, Xerox, Brother) was shipping wireless or network printing in some form; the KSR "marketplace pressure" rationale directly applies.
• Predictability: Each combination is the union of components that already worked together in shipping systems (wireless adapter + printer; host RIP + printer halftone; SDP + PIN; OS + apps).
• No inventive "ordered combination" is apparent from the claim overview: the claimed sequence (receive → decode → color-manage → halftone → buffer → mark) is the ordinary pipeline of a controller-based printer with a wireless front end.

6. Counterarguments Flexiworld would press (and their weaknesses here)

1. "Universal/driverless output" as a paradigm shift — Flexiworld would argue the claims are directed to a driverless universal output architecture. But the individual building blocks (host rasterization, printer-side halftoning, wireless reception, discovery, security, embedded OS) all existed; KSR bars reliance on the mere novelty of the combination if the combination is predictable.
2. Discovery + security + OS as a non-obvious cluster — each element is standard for the chosen wireless standard or printer platform; no synergy beyond predictable aggregation is apparent from the claim overview.
3. Secondary considerations — I found no evidence of long-felt need, copying, or commercial success in the record I retrieved; all litigations settled/dismissed without merits findings, and the patent expired in 2022 for non-payment of maintenance fees. No court has credited non-obviousness.
4. Claim-construction uncertainty — a genuine caveat: because I lack the full granted claim text and the parties never litigated to a claim-construction order, the mapping above is provisional. If, e.g., "intermediate output data" is construed narrowly to require MRC-encoded, device-independent raster data with host-side segmentation, Combination 2/5 would need the MRC references to be robustly mapped; if "operating system" is construed to require a general-purpose, third-party-app-capable OS (rather than a vendor RTOS), Combination 4 is weaker and the examiner's allowance may be attributable to that limitation.

7. Bottom line

On the record available, the claims of US 9,036,181 as summarized would most likely have been obvious under § 103 over combinations of:

1. Wireless print-server/Bluetooth/802.11 art + host-based (GDI) printing art (elements A, B, D, G) — strongest, given shipping 1999–2000 products;
2. Printer-controller RIP art (color management + halftoning) + host-rasterization art + MRC/color-channel art (elements C, D, E, F) — strong, given PostScript Level 2/3 and GDI printers;
3. Bluetooth SDP/802.11 beacon + WEP/PIN security (elements H, I) — strongest, effectively dictated by the standards;
4. Embedded printer OS/web-server art (element J) — moderate-to-strong, depending on claim construction.

The principal uncertainties are (i) the full granted claim text, (ii) the unverified teachings of the individual face-of-patent citations, and (iii) the absence of any merits adjudication or PTAB review of this patent — meaning no tribunal has yet tested these combinations. The pending Flexiworld v. HP (S.D. Tex. 4:24-cv-02691) is the most likely venue where these arguments will be developed and where a complete claim chart and the full cited-reference list (including post-1998 citations I could not retrieve) should be obtained for a definitive analysis.