US 6091507

I'll search for authoritative information on US patent 6091507, including any litigation/docket activity.

Let me run additional targeted searches for litigation and docket records.

US Patent 6,091,507 — Analyst Summary

Search scope note / uncertainty flag: I searched for USPTO and CAFC 2026 docket material specific to patent number 6091507 (and the "6,091,507" formatting). I found no CAFC 2026 docket entry, no PTAB proceeding, and no district-court litigation record naming U.S. Patent 6,091,507. The only third-party citations I surfaced were prior-art citations of the patent in later documents (e.g., GB 2 396 235 A and WO 2001/058138 A1 both list "US 6091507 A" in their search reports / citation tables), not litigation. I would not represent that the patent is litigation-free — only that my searches found no docket record. Treat the bibliographic data below as sourced from the patent's own front-page record; treat the absence of litigation as "not found," not as "confirmed none."

Bibliographic data

Abstract (as published)

A network protocol, transmission format, and hardware interface facilitating high-speed transmission of raster data from a host computer having a raster image processor to a printer. The protocol and hardware interface minimize memory-to-memory transfers of raster data by defining data transfers directly from local memory of network hardware to memory associated with a raster connection management module. The transmission format minimizes handshaking by sending a large number of data packets between acknowledgements. The invention also allows a host computer to request printer profile information and process raster data based on that profile information.

Technology in one paragraph

The patent addresses the bottleneck created when a host computer "RIPs" (raster image processes) a page description language document into a full-page bitmap and then must push that multi-megabyte bitmap across an Ethernet network to a printer. Its solution is a dedicated raster network bus running a custom high-speed protocol alongside the conventional network, with a "raster connection management" module and a "raster network intervention module" that inspect packets in the network card's local RAM and DMA only the needed bytes directly to the raster management module — bypassing the repeated memory copies of the ISO-OSI stack. The protocol uses directed/broadcast/multicast addressing, connected vs. connectionless command packets, burst transmission with large end-sequence numbers, out-of-order/go-back-N style early retransmission requests, probe/keepalive commands, and open/close virtual-connection handshakes. A second theme is printer profile feedback: the host RIP queries the printer for media and ink profile data (media thickness, transparency, reflectivity, size; ink lot number, color, chromatic characteristics) and corrects the raster data accordingly.

Independent claims in plain language

There are seven independent claims: 1, 8, 12, 13, 14, 15, and 16. All recite the same core architecture — a RIP and a printer connected by both a common network bus and a distinct dedicated raster network bus.

Claim 1 — the "profile-corrected printing" method. RIP the PDL instructions at the host to make a raster image; open a high-speed virtual connection to the printer on the dedicated raster bus; transmit the raster image over that connection; print it; close the connection; then, via a "raster connection management portion," request and receive a profile information set from a memory structure coupled to the printer, where the profile relates to physical characteristics of the print media as those characteristics relate to the printer's ink-based marking material; and process the raster image based on that profile so a corrected raster image data set is produced that differs from the uncorrected image.

Claim 8 — the "printer-side correction" variant. Substantially the same pipeline, but (a) the printer is recited as containing "circuitry means for receiving a plurality of high-speed raster protocol instructions," and (b) the profile set relates to characteristics of the printing ink installed and available, with the corrected (second) raster image being generated by the printer and differing from the first due to the profile.

Claim 12 — the "printer discovery" variant. The RIP/print/close pipeline, plus: the network has multiple printers; the system broadcasts a network entity ID request on both buses, receives a printer entity ID response from each responding printer, and selects a printer from the responses.

Claim 13 — the "connection negotiation" variant. The pipeline, plus a specific open-connection handshake: the host issues an open connection request containing its network address and a maximum data transmit block size; the printer returns an open connection response (on either bus) containing a maximum data receive block size, establishing the connection.

Claim 14 — the "burst flow-control" variant. The pipeline, plus block-based transfer where the raster image is N blocks of M packets each: job information command → confirmation → repeated request/acknowledge commands carrying a current sequence number and an end sequence number, with the host transmitting L packets per burst where L = end sequence number − current sequence number.

Claim 15 — the "print-multiple-copies" variant. The pipeline, plus inspecting a first portion of the raster image data and, only if it contains the specific packet addressing codes for a given printer, storing the image in that printer's memory and printing multiple copies from stored memory (avoiding re-RIP and retransmission).

Claim 16 — the "discovery" variant of claim 8. The claim-8 pipeline (high-speed raster protocol instruction receiving means; ink profile correction), plus broadcasting a network entity ID request on both buses, receiving responses containing a data string identifying printers capable of accepting high-speed raster protocol instructions, and selecting a printer based on that data string.

All other claims (2–7, 9–11) are dependent claims adding details such as broadcast/multicast discovery (claim 2), ink lot number plus two chromatic characteristics (claim 3), connection handshake details (claim 4), block/packet sequencing (claim 5), packet-address inspection and multi-copy printing (claim 6), and the raster connection management module being distinct from the raster image processor (claims 7 and 11).

Observations worth flagging

• Drafting artifacts. The granted text contains apparent typographical errors that a court would have to construe around — e.g., claim 1 recites "closing the high-speed virtual connection on the dedicated rarer network bus," and claim 8 recites "differing from the first raster image due to he at least one profile information set." These are in the authoritative text; I have not auto-corrected them.
• Claim/specification tension on ordering. The specification describes the profile exchange as occurring before transmission ("After a printer is selected, the selected printer provides media and ink information… Media/ink correction module 134 uses… to produce corrected raster image data"), whereas claims 1 and 8 recite closing the virtual connection before requesting the profile set. That sequencing mismatch is a point a validity or infringement analysis would likely probe.
• Family-member overlap. US 6,348,973 is a divisional in the same family; US 5,577,172 is a continuation-in-part sharing the 1994-07-01 priority date and is directed to the packet protocol itself rather than printing per se. If you need claim-level coverage of the protocol independent of the printing context, the '172 patent is the more direct target.

Bottom line on your specific request: I could confirm the patent's bibliographic, abstract, and claim content from the patent record, but I could not confirm any USPTO post-grant proceeding or CAFC 2026 docket activity for 6091507. If you need a definitive litigation check, it should be run against a paid docket database (e.g., Docket Navigator, LexisNexis IP, or PACER/PTAB APIs) using both the patent number and the party names ColorSpan / MacDermid Acumen / Hewlett-Packard Development.

I'll research litigation involving US Patent 6091507 specifically. Let me search multiple sources.

Initial results didn't surface litigation. Let me search more targeted litigation databases.

Let me check specific litigation databases and the Unified Patents portal.

Summary: No litigation found involving U.S. Patent 6,091,507

Based on my searches, I was unable to identify any known litigation (district court, ITC § 337, CAFC appeal, or PTAB proceeding) specifically involving U.S. Patent No. 6,091,507. I want to be explicit and honest about this rather than manufacture case citations: every result returned for the number "6091507" was either (a) the patent's own bibliographic record, (b) the same number appearing coincidentally in unrelated documents, or (c) the patent being cited as prior art in other applications/proceedings — none of which is litigation against or asserting the '507 patent.

What the searches did and did not show

What was confirmed about the patent (from the Google Patents record):

• Patent No.: US 6,091,507 — "Method and apparatus for printing a document over a network"
• Application No.: 08/270,046; Priority/filing date: 1994-07-01; Granted: 2000-07-18
• Inventors: Danny James Vatland; Jeff David Pagel
• Original assignee: Colorspan Corp (with assignments recorded to Lasermaster Technologies, Inc. / Lasermaster Corporation)
• Later assignments: MacDermid Acumen, Inc. (2007) → Hewlett-Packard Development Company, L.P. (2008)
• Related family members: US 5,577,172 (continuation-in-part, "High-capacity protocol for packet-based networks"); US 6,348,973 (divisional, "Apparatus for printing a document over a network"); WO 96/001449 A1; AU 2955895 A
• Legal status: Expired – Lifetime (anticipated expiration recorded 2017-07-18)

What appeared in search results — and why none of it is litigation:

1. The number "6091507" appeared as an unrelated registry/notice number in a Lithuanian and a Brazilian document — not the patent.
2. The number appeared inside the phrase "MDL 1507" (a Wyeth/Prempro multi-district litigation) in a Nebraska docket — a different identifier entirely.
3. GB 2 396 235 A and other applications cite US 6,091,507 as prior art ("Documents Cited by ISA") — citation, not litigation.
4. EP 0 930 563 and WO 01/058138 list the '507 patent only as a family member / cited reference.

Important caveats

• I could not complete direct queries against the live Unified Patents litigation portal, Docket Alarm, PACER, or the CAFC docket because my search access did not return litigation records for this specific number; their absence from my results is not proof of absence from those databases.
• Given the patent expired on 2017-07-18, any assertion litigation would necessarily predate expiration (i.e., filed roughly 2000–2017). It is plausible that litigation over this patent exists but is not indexed in the sources my searches reached.
• I am also not aware, with high confidence, of any decision — CAFC or district court — naming this patent.

Recommended next steps for authoritative confirmation

To verify definitively, these sources should be queried directly (I could not fully reach them):

• Unified Patents litigation portal: https://portal.unifiedpatents.com/litigation/caselist
• PTAB / IPR records: https://ptacts.uspto.gov (search patent number, not party)
• FreeLaw / CourtListener RECAP: https://www.courtlistener.com (docket search by patent number)
• Justia Dockets: https://dockets.justia.com (patent search)
• USPTO Patent Center / Assignment records: for the assignment chain noted above
• Westlaw / LexisNexis / Docket Navigator: for any settled or dismissed suits that may predate electronic indexing

If you'd like, I can run targeted searches against one of those specific databases (e.g., CourtListener or the Unified Patents portal) if you can confirm which is accessible, or I can search for litigation involving the closely related family members (US 5,577,172 and US 6,348,973), which may reveal activity that also implicates the '507 patent.

Bottom line: No litigation involving US 6,091,507 was located in the sources searched. I cannot confirm any plaintiff, defendant, jurisdiction, case number, filing date, or outcome for such a case, and I will not fabricate them.

I'll start by checking for any PTAB activity on this patent, given the ODP indicates none.

Let me run more targeted searches to confirm the absence of PTAB activity and check related litigation.

Let me do a couple final confirmatory searches on litigation history and the patent family.

PTAB Proceedings Analysis — US 6,091,507 ("Method and apparatus for printing a document over a network")

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding for US 6,091,507, and my independent web verification (PTAB petition/decision repositories, litigation docket aggregators, and patent-family records) surfaced no petition number, institution decision, Final Written Decision, or Federal Circuit appeal attributable to this patent. The genuine count is therefore zero active, zero claims invalidated, zero claims sustained, zero settled, and zero institution denied — there is simply no PTAB record to report at any status.

Bottom line for a defendant: the patent was never PTAB-tested, but that absence carries almost no defensive risk here because the patent is expired. US 6,091,507 issued 2000-07-18 and reached anticipated expiration on 2017-07-18 (Google Patents legal status: "Expired – Lifetime"). An expired patent cannot ground a forward-looking infringement claim, and any damages theory for pre-expiration conduct is subject to the six-year recovery bar of 35 U.S.C. § 286 — i.e., conduct before 2017-07-18 would have needed suit by roughly 2023 to keep a recovery alive. The "no IPRs" signal that would normally be worrying (a well-asserted, live patent eventually attracts petitions) does not apply to a patent that drew no AIA challenges during its entire enforceable life.

Proceeding entries

None — no AIA trial proceeding on file

• Type: N/A
• Filed: N/A — no petition exists to date (earliest possible AIA petition date would have been 2012-09-16, well after issuance)
• Status: No proceeding on file (USPTO ODP), corroborated by web search
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A
• Settlement / termination: N/A
• Appeal: No CAFC appeal identified
• Defensive value: Because the patent expired 2017-07-18, the relevant defensive posture is expiry, not invalidity. A demand letter citing this patent on post-2017-07-18 products is facially meritless (no enforceable right). For pre-expiration conduct, § 286's six-year lookback bars recovery as of 2023, and laches/estoppel analysis under the pre-SCA Hygiene framework may also apply. An IPR is likely unavailable in any event: PGR is time-barred (9-month window long closed), CBM is inapplicable (this is a printing/network protocol patent, not a "financial product or service" method, and CBM sunset in 2020), and any IPR would be of limited value against a patent with no live damages exposure.

Strategic summary

Claim status — untested, not invalidated. None of claims 1–16 of US 6,091,507 has been canceled, confirmed, or even challenged in an AIA trial. Claims 1 and 8 are the independent method claims; claims 2–7, 9–11, 12–15, and 16 are dependents/independent variants directed to the printer-ID-call/response selection, media/ink profile retrieval, burst-negotiation (open-connection request/response with max transmit/receive block sizes), request/acknowledge sequencing (current/end sequence numbers), and stored-image multi-copy printing features. This matters legally but is largely academic commercially: there is no surviving-but-live claim to design around, because the exclusivity term ran out on 2017-07-18.

Estoppel landscape — § 315(e)(2). Because no IPR was ever instituted, no statutory estoppel attaches to anyone. Any party could theoretically still rely on any art (including the 25 examiner-cited references) in a district court action, free of § 315(e)(2) estoppel — but this is a Pyrrhic point given the patent's expired status and the § 286 damages bar. Conversely, there is also no IPR record to borrow for an invalidity defense; a defendant in any older case that is still somehow breathing would need to build its own prior-art record from scratch rather than cite a PTAB cancellation.

Pattern signals. No repeat-petitioner pattern (no petitioners at all). No patent-owner PTAB-appeal history attributable to this patent. No defensive-aggregator (e.g., Unified Patents) involvement — the patent predates the modern CBM/Unified ecosystem and expired before the AIA trial regime matured. Ownership history is notable but litigation-neutral for our purposes: originally assigned to LaserMaster Technologies (1994), renamed ColorSpan Corporation (1998), then to MacDermid Acumen (2007), and finally to Hewlett-Packard Development Company (2008) — meaning any residual rights sit with a large operating company, not an NPE. Related family members worth flagging if you encounter parallel assertions: US 5,577,172 ("High-capacity protocol for packet-based networks," CIP of the same 1994-07-01 priority family) and US 6,348,973 (division, "Apparatus for printing a document over a network"). Any challenge strategy should treat the family collectively, since the '172 patent covers the protocol art and the '973 covers the apparatus claims.

Recommended next steps

• If you received a demand or complaint citing US 6,091,507: lead with expiration. The patent's term ended 2017-07-18; there is no actionable post-expiration infringement, and pre-expiration theories are barred by the § 286 six-year recovery window (closed since approximately 2023-07-18). Request the specific accused conduct date and the asserted claims.
• If the demand cites claims 1 or 8 specifically: note that neither claim has ever been adjudicated invalid — so do not cite a nonexistent FWD. The correct defense is temporal (expiry), not a PTAB disposition. I found no FWD, no institution decision, and no appeal to link; do not let opposing counsel assert a "hardened" or "invalidated" status that does not exist.
• Check the companions before settling on strategy: confirm whether the assertion actually rests on US 5,577,172 or US 6,348,973 (also expired — same 1994-07-01 priority family), because those are the family members a licensor might pivot to if the '507 patent's expiry is raised. Cross-check their expiry dates and any post-issuance activity before responding.
• Since there is no PTAB activity, say so plainly in any invalidity/validity memo. The absence is a factual finding from the ODP structured block, confirmed by search; do not manufacture proceeding numbers, panels, or ground-level findings to fill the template. If you want a definitive primary-source check, query USPTO PTAB E2E (https://ptacts.uspto.gov) and USPTO PatentCenter for US 08/270,046 directly, plus the patent's Google Patents page (https://patents.google.com/patent/US6091507/en) for assignment and legal-status history.

Sourcing note: the "no proceedings" conclusion rests on (1) the authoritative ODP structured block in the prompt, and (2) web searches of PTAB petition/decision repositories (ptacts.uspto.gov) and docket aggregators that returned no hit for US 6,091,507. I did not locate, and have deliberately not invented, a proceeding number, judge panel, or FWD for this patent. Litigation-history specifics involving ColorSpan/LaserMaster from the 1990s–2000s are outside what I could verify here and should be confirmed on PACER/Docket Alarm before being relied upon.

I'll research the assignment chain for US 6091507 from available sources before writing anything.

Good leads. Let me verify the specific reel/frame records and check for any litigation.

I hit my search budget mid-verification, so I'll be explicit below about what is confirmed versus inferred.

Data-integrity note up front. The authoritative patent text I was given (Google Patents for US6091507) reproduces USPTO legal events for this patent without reel/frame numbers and without correspondent-of-record fields. I could not open USPTO Assignment Center directly with the tools available, and my search budget was exhausted before I could retrieve the underlying assignment PDFs for this specific patent. I will therefore not invent reel/frame numbers for US 6091507. Where I cite reel/frame values below, they come from the INPADOC legal-status record of a sibling patent in the same corporate portfolio (US5369429) and are labelled as such — they are indicative, not verified for this patent.

Inventors

Both inventors executed assignments on the filing date (1994-07-01) and again on a second 1994 record (recorded 1994-10-11), both naming them as assignors. There is no evidence of inventors departing the assignee within 12 months of filing, and no third-party inventor scramble — this is a normal employee-assignment pattern, not a pre-fire-sale exodus. (I have no reliable public record of either inventor's later employment; I will not guess.)

Note the US 08/299,010 continuation-in-part ("High-capacity protocol for packet-based networks," issued as US5577172A) shares the same 1994-07-01 priority and the same inventorship lineage, which is why the packet-protocol claims in US6091507 read on the earlier LaserMaster work.

Original assignee

• Entity named on the issued patent (issued 2000-07-18): ColorSpan Corporation, Minnetonka, MN — listed on Google Patents as "Original Assignee: Colorspan Corp."
• Lineage: Founded 1985 as LaserMaster Corporation; renamed ColorSpan Corporation in 1997 to reflect its pivot to wide-format inkjet. Per PCMag/Computer Language: "In 2000, ColorSpan was acquired by MacDermid, Inc. and operated as MacDermid ColorSpan, Inc., a wholly-owned subsidiary. In late 2007, the division was acquired by HP."
• Did they ship a product embodying the claims? Yes. ColorSpan/MacDermid ColorSpan sold the DisplayMaker wide-format inkjet printer line (e.g., DisplayMaker 72sR, 5400uv, 9840uv) — precisely the inkjet, large-format use case the specification describes (the spec's discussion of 54×54-inch, ~125 MB raster files and ink-dry "banding" is a description of this product class). The host-RIP + high-speed raster link described in the claims is the architecture those products used.
• Current status: Not operating as an independent entity. The business was absorbed into HP's Imaging and Printing Group; the ColorSpan product line was rebranded HP Designjet H35000/H45000 and HP Scitex FB910 (HP press release, 2008-02-01).
• Unverified data point, flagged rather than relied on: an OCR'd Minnesota business-profile book snippet describes ColorSpan as a "subsidiary of VirtualFund.com, Inc. (formerly LaserMaster, Inc.)." I could not corroborate this holding-company name and treat it as unclear; it does not change the assignment chain below.

Assignment timeline

Records are the five assignment events exposed in the Google Patents legal-events table for US6091507. Reel/frame and correspondent are not present in that source and are marked "not verified."

1. 1994-07-01 (executed) / recorded 1994-07-01 — Reel not verified for this patent

   • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
   • Assignor: Danny James Vatland; Jeff David Pagel (inventors)
   • Assignee: LASERMASTER TECHNOLOGIES, INC.
   • Correspondent: not disclosed in source
   • Context: Initial employment assignment, executed on the filing date.

2. 1994-10-11 (recorded) — Reel not verified for this patent

   • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
   • Assignor: Danny James Vatland; Jeff David Pagel (inventors)
   • Assignee: LASERMASTER CORPORATION
   • Correspondent: not disclosed in source
   • Context: Corporate entity/name true-up within the LaserMaster organization (second record from the same inventors); nature of the entity change is unclear from the legal-events data alone.

3. 1998-03-18 (recorded) — Reel not verified for this patent; sibling record points to 009046/0219

   • Conveyance: Change of Name (no change in beneficial ownership)
   • Assignor: LaserMaster Corporation
   • Assignee: COLORSPAN CORPORATION
   • Correspondent: not disclosed in source
   • Context: Pure name change (LaserMaster Corporation → ColorSpan Corporation, effective 1997-08-27 per the sibling INPADOC entry).

4. 2007-08-27 (recorded) — Reel not verified for this patent

   • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
   • Assignor: ColorSpan Corporation
   • Assignee: MACDERMID ACUMEN, INC.
   • Correspondent: not disclosed in source. Possible repeat correspondent, unverified: a MacDermid-era recording for a sibling patent (US 6,789,876) was filed by Linda M. Freed, Carmody & Torrance LLP, 50 Leavenworth Street, Waterbury, CT (legacy-assignments.uspto.gov assignment PDF, REEL 019991 / FRAME 0954, recorded 2007-10-22). That recording is for a different patent and a different conveyance, so it is only a lead for the MacDermid correspondent, not a finding for this chain.
   • Context: Internal IP consolidation inside MacDermid, executed weeks before the HP deal was announced (2007-09-13). Note a date discrepancy to resolve: the sibling INPADOC record shows a Colorspan → MacDermid Acumen assignment at REEL/FRAME 010942/0194, effective 2000-06-13, recorded 2000-07-03 — i.e., a different recording on a different date. Either US6091507 was moved later than the sibling patents, or the 2007 entry is a confirmatory re-recording. I could not resolve this without the Assignment Center record.

5. 2007-11-01 (effective) / recorded 2008-01-28 — sibling record: REEL/FRAME 020417/0607 (not verified for this patent)

   • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
   • Assignor: MACDERMID ACUMEN, INC.
   • Assignee: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P. (Texas)
   • Correspondent: not disclosed in source
   • Context: M&A closing — HP's acquisition of the MacDermid ColorSpan business (announced 2007-09-13, portfolio integration completed 2008-02-01). This is the terminal link in the chain; HP remains assignee of record today and the patent expired 2017-07-18 ("Expired – Lifetime").

Family/related filings worth tracking for the same chain: US6348973B1 (division, filed 2000-07-18), US5577172A (CIP), WO1996001449A1, AU2955895A. Any of these should carry the same Lasermaster → ColorSpan → MacDermid → HP chain; checking one sibling reel set (e.g., 020417/0607) against US6091507 is the cheapest way to close the reel/frame gaps above.

Timeline diagram

timeline
    title Ownership of US 6091507
    1994 : Inventors assign to LaserMaster Technologies
         : Reassignment to LaserMaster Corporation
    1998 : Name change to ColorSpan Corporation
    2000 : ColorSpan bought by MacDermid
    2007 : Assigned to MacDermid Acumen Inc
         : HP announces ColorSpan purchase
    2008 : Assigned to Hewlett Packard Development Co
    2017 : Patent expires

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No assignee in the chain is an "IP / Holdings / Licensing / Ventures" entity. The 2007 links run between operating companies: ColorSpan (printer manufacturer) → MacDermid Acumen, Inc. (IP-holding subsidiary of MacDermid, Inc., a specialty-chemicals operating company) → Hewlett-Packard Development Company, L.P. (HP's operating IP holder). MacDermid Acumen is a corporate subsidiary of a manufacturer, not a licensing-only shell; no registered-agent address, no single-purpose Delaware/Texas LLC appears.

2. Known asserter in the chain — not present. The chain contains none of Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity. Terminal assignee is HP.

3. Repeat correspondent across the chain — unclear / not established. The legal-events data for US6091507 exposes no correspondent field, so I cannot test recurrence on this chain. The only correspondent I recovered is Linda M. Freed of Carmody & Torrance LLP (Waterbury, CT) on REEL 019991 / FRAME 0954 — a MacDermid-era recording for US 6,789,876, a different patent. One appearance on an unrelated property is explicitly not a finding under your own rule; I'm reporting it only because it identifies the likely correspondent for MacDermid-era recordings in this portfolio, which should be checked against reel 010942/0194 and 020417/0607.

4. Cascading transfers — not present as an NPE pattern. There are two transfers inside ~5 months (2007-08-27 ColorSpan → MacDermid Acumen; 2007-11-01 MacDermid Acumen → HP), but both are dated to, and explained by, a single public M&A event (HP's announced 2007-09-13 purchase of MacDermid ColorSpan). No chain of unaffiliated LLCs, no shared correspondents, no common principals.

5. Pre-litigation transfer — not present. I found no infringement suit asserting US6091507 by any of HP, MacDermid, or ColorSpan. The 2007–2008 transfers are dated to a purchase agreement, not to a complaint.

6. Bankruptcy fire-sale — not present. No Chapter 7/11 record for LaserMaster, ColorSpan, MacDermid ColorSpan, or MacDermid Acumen in the chain. The 2000 and 2007 transactions were going-concern acquisitions (MacDermid acquiring ColorSpan; HP acquiring the MacDermid ColorSpan division).

7. Privateering — not present. No operating company transferred to an asserting entity; HP is the acquirer and the ultimate beneficiary and is not asserting through an intermediary.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at an operating printer manufacturer.

Verdict

Operating-company assertion — with an express caveat on the litigation prong.

Justification: The chain runs inventors → LaserMaster Technologies (1994-07-01) → LaserMaster Corporation (1994-10-11) → ColorSpan Corporation by change of name (1998-03-18) → MacDermid Acumen, Inc. (2007-08-27) → Hewlett-Packard Development Company, L.P. (effective 2007-11-01, recorded 2008-01-28), and it terminates at a large operating company that actually commercializes the claimed subject matter — HP rebranded the ColorSpan line as HP Designjet H35000/H45000 and HP Scitex FB910 (HP press release, 2008-02-01). Zero NPE signals are present: there is no shell LLC, no listed asserter, no bankruptcy, no privateering, no defensive aggregator, and the patent expired 2017-07-18. The caveat: I found no evidence of HP filing suit on US6091507, so read this as "operating-company ownership of a product-embodying patent," not a confirmed assertion campaign.

Two open verification items (please confirm at the Assignment Center before relying on this for anything dispositive): (a) the actual reel/frame numbers for the five events above for US6091507, and (b) the discrepancy between the 2007-08-27 MacDermid Acumen record surfaced by Google Patents and the 2000-06-13 / reel 010942/0194 assignment shown by INPADOC for sibling patent US5369429.

Verify at: USPTO Assignment Center and USPTO Patent Assignment Search — search by patent number 6091507. Patent copy: https://patents.google.com/patent/US6091507/en

I'll verify the patent record and the cited prior-art references via search before building the analysis.

Good grounding. Let me verify the remaining key protocol and print-architecture references.

Prior-Art Analysis — U.S. Patent No. 6,091,507

A note on method and a flagged inconsistency. Before the analysis: (1) the task states "Current Date: April 26, 2026," while the authoritative patent fetch in this record is timestamped 2026-09-27 — I flag the discrepancy and proceed on the merits. (2) I ran live searches against the patent record and several cited references, but the search tool cut me off mid-verification. Verified live: the '507 / '973 family record, US 5,113,494 A, US 5,220,674 A, US 5,321,813 A, and US 5,084,877 A. Characterized from the patent's own front‑page citation record (authoritative) plus established knowledge, but not individually re‑verified live: the remaining references. I say so explicitly rather than implying uniform verification.

1. The patent's own prior-art statement (most important single reference)

The '507 specification does not merely list references — it names its closest prior art in the Background:

"This problem is addressed in U.S. Pat. No. 5,113,494 to Menendez et al., which discloses a high speed raster image processor that RIPs PDL instructions fast enough to minimize the idle time of a laser printer's print engine. The RIP disclosed by Menendez et al. resides in a common printer node with the print engine, and specifies a dedicated connection between the RIP and the print engine."

That is a § 102/§ 103 starting point and a subject-matter admission. The specification also admits as prior art the two architectures the claims are built against: (a) printer‑resident RIP fed PDL over a network, and (b) host‑resident RIP sending a raster image over the network. Those admissions matter because independent claims 1 and 8 recite the host‑RIP‑to‑network‑printer pipeline as their preamble.

2. The cited references, one by one

The front page lists 26 citation rows (25 unique; US 5,231,634 A and US 5,231,634 B1 are the same reference as originally filed and as reexamined/dedicated). All were cited by the examiner. I organize by theme. "Anticipation" is assessed under pre‑AIA 35 U.S.C. § 102, which requires a single reference disclosing every limitation as arranged in the claim.

A. RIP / image-processing references

B. Network printing / print-server architecture references

C. Protocol / transport references (relevant to claims 5, 13, 14 and to discovery claims 2, 9, 12, 16)

D. Cross-check: art that cites '507 (not prior art to '507)

The front page's "Cited By (26)" table (e.g., US 6,348,973 B1, US 2002/0042884 A1, GB 2 396 235 A, US 6,829,833 B1, etc.) is later art citing '507; it cannot anticipate '507 and should not be confused with the examiner-cited list above.

3. Bottom-line anticipation assessment

No single cited reference anticipates any claim of US 6,091,507. Every independent claim (1, 8, 12, 13, 14, 15, 16) requires the concurrence of at least three elements that no cited reference supplies together:

1. a raster image processor at the host that RIPs PDL instructions into a raster image;
2. an open high-speed virtual connection on a dedicated raster network bus, with the RIP and printer also connected by a distinct common network bus; and
3. for claims 1, 8, 10, 16, printer-profile-based correction (media characteristics as they relate to the ink-based marking material, or ink lot/chromatic/manufacturing characteristics) producing a "corrected raster image data set."

Reading the record:

• Element 1 is disclosed by US 5,113,494 (and is admitted prior art in the '507 Background) — but '494 keeps the RIP in the printer node with a dedicated RIP-to-print-engine connection, exactly the architecture the '507 claims distinguish.
• Element 2 is not disclosed by any of the cited references. The closest are EP 0 545 261 (network of image processors + print engines) and US 5,084,877 (high-speed transport) — neither teaches a dedicated raster bus distinct from a common bus.
• Element 3 is approached only tangentially by US 5,220,674 (server requests/obtains resources on the printer's behalf) — but '674 requests fonts/forms resources, not media/ink profiles, and never corrects a raster image with them.

Where the cited art is genuinely powerful (for § 103, not § 102):

4. Caveats and one family note

• Family, not prior art. US 5,577,172 ("High-capacity protocol for packet-based networks") is a continuation-in-part by the same inventors, filed 1994‑08‑31, claiming the same 1994‑07‑01 priority, and US 6,348,973 is a division of '507. Neither can be § 102 prior art against '507. If you need claim coverage of the protocol independent of the printing context, the '172 patent is the more direct target (as flagged in the earlier summary section).
• Statutory posture. '507's term expired 2017‑07‑18. Any § 102 analysis is therefore now a historical/validity exercise (e.g., for a later-filed family member or a defensive challenge), not an infringement-validity fight over a live patent.
• Verification limits. I confirmed live: '507's record, US 5,113,494, US 5,220,674, US 5,321,813, and US 5,084,877. I hit the tool's step ceiling before individually re-pulling the remaining ~20 references; those rows rest on the patent's own authoritative citation table plus my knowledge. No claim of a definitive litigation or PTAB record is made here — consistent with the earlier sections, none was found.

If you want, I can next (a) re-pull the unverified rows individually against the USPTO/Google Patents record, or (b) run a formal single-reference § 102 chart for the two strongest references (US 5,084,877 against claims 5/14; US 5,113,494 against the claims 1/8 preamble).

I'll ground this obviousness analysis in the actual references cited on the face of US 6,091,507. Let me pull details on the most relevant prior-art references.

I have solid grounding on the protocol and print-server references. Let me now target the two elements that are hardest to map — printer/media/ink profile feedback and printer discovery — plus the two remaining cited references I want to characterize.

Obviousness Analysis — U.S. Patent No. 6,091,507 under 35 U.S.C. § 103

Patent: US 6,091,507 A, "Method and apparatus for printing a document over a network"
Appl. No.: 08/270,046 | Priority/filing: 1994-07-01 | Granted: 2000-07-18
Governing law: Pre-AIA 35 U.S.C. § 103(a) (priority before 2013 AIA change)
Prior-art cutoff: the 1994-07-01 priority date (note: the sibling CIP US 5,577,172, filed 1994-08-31, is therefore not available as prior art against the '507 patent — same family, later filing; flagging this because it is an easy self-collision error).

Scope/uncertainty note (please read first). The analysis below is built from the references listed in the "Citations"/"Patent Citations" section of the Google Patents record for US 6,091,507, together with the '507 specification's own admitted-prior-art background. I retrieved and read full text of four key references (US 5,113,494; US 5,220,674; US 5,260,933; US 5,084,877). I could not retrieve full text of several other cited references before my search budget was exhausted (e.g., US 5,012,973, US 5,018,138, US 5,077,875, US 4,993,025, SG 50544 A1). For those I rely on their front-page titles and general field knowledge and I have tagged them as lower-confidence. Where the strongest limitation of a claim is not clearly met by the art I actually read, I say so plainly rather than papering over it.

1. Legal framework applied

• Graham v. John Deere Co., 383 U.S. 1 (1966) — scope/content of prior art; differences between prior art and claims; level of ordinary skill; secondary considerations.
• KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) — a claimed combination is obvious when the improvement is a predictable use of prior-art elements according to their established functions; a "problem known in the field" supplies the motivation; the analysis requires an articulated reasoning with a rational underpinning, not a mere showing that elements exist somewhere (In re Kahn).
• MPEP § 2143 — exemplary rationales: combining prior-art elements by known methods to yield predictable results; simple substitution of one known element for another; use of a known technique to improve similar devices in the same way; "obvious to try" where the field presents a finite number of identified, predictable solutions.

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

Given a 1994 priority date and the subject matter (host-based raster image processing, network transport protocols, and printer control), a PHOSITA would be a person with a B.S. in electrical engineering or computer science plus about 2–4 years of experience in networked printing / raster imaging and/or data-communications protocol design, or equivalent. This is the level at which the following references are combined. (No secondary-considerations evidence — unexpected results, commercial success, licensing, copying — was located; Graham factor four is therefore neutral/unsupported, which weakens non-obviousness but does not by itself defeat it.)

3. Key claim terms (construction matters to the § 103 result)

Drafting artifacts flagged earlier remain operative: claim 1's "dedicated rarer network bus" and claim 8's "due to he at least one profile information set" would be construed as obvious typographical errors, not claim scope.

4. The prior art and what each reference teaches

A. US 5,113,494 (Menendez et al., Eastman Kodak; issued 1992-05-12) — admitted background AND cited of record.
Discloses a pipelined RIP that drives a print engine at high rate using multiple parallel image-processing components interconnected by a bus (and a second bus), an arbiter establishing data paths directly between components, an image buffer, a scaler, and a printer interface. It expressly shows producing the raster image "in a selected media" and printing "said raster image a specified number of times in said selected media." Critically, the '507 specification itself cites and distinguishes Menendez, stating it "resides in a common printer node with the print engine, and specifies a dedicated connection between the RIP and the print engine." That characterization is an admission of what Menendez teaches: a dedicated RIP-to-engine data path solving the RIP/engine throughput mismatch.
Source: https://patentimages.storage.googleapis.com/6a/19/2b/1738933804a88a/US5113494.pdf

B. US 5,220,674 (Digital Equipment Corp.; issued 1993-06-15).
Local-area print server managing print jobs across a LAN to one or more printers. Teaches: a logical CONNECT message to establish a connection to the server before data is sent; DATA, CONTROL, END-OF-JOB, STATUS and RESOURCE-FAULT message types; a printing system that "notifies the other network components … the type of services, including fonts, it has available"; multi-printer selection based on the "printer ready message most recently received from that printer"; and printers whose capabilities vary by media trays, paper sizes, and (foreseeably) color. This is the strongest single reference for networked, managed print-data distribution with connection setup and printer-capability feedback.
Source: https://patentimages.storage.googleapis.com/d7/7a/22/808af4c2e27efa/US5220674.pdf

C. US 5,084,877 (AT&T Bell Laboratories; issued 1992-01-28).
High-speed transport protocol explicitly motivated by the fact that "protocol processing" and per-packet acknowledgement limit throughput. Teaches transmission in blocks of packets, each block carrying a sequence number; block-level acknowledgement (the receiver acknowledges blocks, not individual packets); selective/partial retransmission ("the entire block, but only that block, is retransmitted"); and two independent windows — a network window and a receiver flow-control window.
Sources: https://patentimages.storage.googleapis.com/ec/55/b3/9c11e40cc4bb06/US5084877.pdf ; https://SumoBrain.com/patents/us/High-speed-transport-protocol/[5084877](/patent/5084877).html

D. US 5,260,933 (Rouse, IBM; issued 1993-11-09).
Acknowledgement protocol with frame sequence counts, out-of-order delivery, a CREDIT_CNT/MAX_CREDIT field representing the number of buffers available at the recipient (i.e., how many frames the recipient can take before needing an acknowledgement), and an acknowledgement-frame control bit indicating the transmission status of all prior acknowledgements (cumulative acknowledgement). Directly relevant to the '507 claim 14 "current sequence number"/"end sequence number" and claim 13 "maximum receive block size."
Sources: https://uspto.report/patent/grant/[5260933](/patent/5260933) ; http://www.everypatent.com/comp/pat5260933.html

E. US 5,018,138 (Echelon Systems) and US 5,319,641 (Echelon) — LOWER CONFIDENCE (full text not retrieved).
Titles indicate a protocol for a network having a plurality of intelligent cells and a multiaccess protocol with priority messages — i.e., broadcast/multicast messaging and node addressing in a multi-node control network. Used only as supporting art for the discovery claims.

F. US 5,012,973 (Oce-Nederland) — LOWER CONFIDENCE (full text not retrieved).
Title: "Front-end system for a raster output scanner." By title and field, a front-end that feeds raster data to a scanner/output engine — supporting art for separating raster-data handling from the output engine.

G. US 5,903,716 / SG 50544 A1 (Dataproducts, "Virtual printer"; priority 1992-12-18).
Listed in the '507 record as a family-cited reference. Teaches virtual printers that abstract and store a physical printer's configuration/context, with print jobs directed to a virtual printer by address, and configuration restored for reuse. Relevant to claims 6/15 (storing a raster image at a printer and printing multiple copies) and to the general concept of printer-profile/config abstraction.
Source: https://FreePatentsOnline.com/[5903716](/patent/5903716).html

H. The '507 specification's own admitted prior art.
The background admits as known: (i) host-based RIP sending raster images to a printer; (ii) that a full-page 4 MB color raster is impractical over IEEE 802.3 Ethernet at print-engine rates; and (iii) that "a user must preset parameters of the RIP based on media information of the printer" because the host RIP "may not have information about the printer's media and ink colors." Admissions in the specification are usable as prior art (MPEP § 2129) and are powerful here because they establish both the problem and the motivation.

5. Element-by-element mapping (independent claim 1 as representative)

Claims 8–11 add (a) means-plus-function "circuitry means for receiving high-speed raster protocol instructions" — met by any raster network interface (see § 8's FIG. 8 module) — and (b) generation of the corrected image at the printer, which is a straightforward relocation of the correction step already taught/known.

6. The obviousness combinations and the motivation to combine

Combination I — Claim 1 (and 8): Dual-bus host-RIP architecture with printer-profile correction

References: Menendez '494 + DEC '674 + the '507 admitted prior art (+ optional AT&T '877).

Why a PHOSITA would combine:

1. A problem known in the field. The '507 background itself states the central problem: host-based RIP produces a multi-megabyte raster that IEEE 802.3 Ethernet "cannot transfer to printer fast enough to feed a moderately fast print engine." Providing more bandwidth on a dedicated path is the routine, expected engineering response. Menendez '494 already teaches the premise that the RIP↔engine link is the throughput-critical path and provides a dedicated, parallel high-speed data path for it.
2. Known technique, same way, same result (KSR). Moving the RIP off the printer and giving raster data its own channel are two known techniques applied to their established functions — offloading compute and isolating high-bandwidth traffic. That yields the predictable result of higher effective throughput.
3. The profile-correction element is supplied by the admitted art and by DEC '674. The '507 background concedes host RIPs lacked media/ink information and were configured by preset parameters from printer media data; DEC '674 teaches the network protocol carrying printer capability/status information. Applying DEC's protocol to fetch the printer's media/ink data and correct the raster is a predictable use of a known query mechanism.

Rationale in one sentence: Given Menendez's teaching of a dedicated high-speed RIP-to-engine path and DEC '674's networked print server with printer-capability messaging, and given the admitted problem that general-purpose LAN bandwidth and printer-specific media/ink data were the two obstacles to host-based RIP, it would have been obvious to give the host RIP a dedicated raster channel and to query the printer for media/ink profile data to correct the raster before/at printing.

Combination II — Claims 5 and 14: Burst/block transfer with current- and end-sequence numbers

References: AT&T '877 + IBM '933 (with DEC '674 for the job-information command/confirmation exchange).

Why: AT&T '877 and IBM '933 were both expressly directed at the same problem the '507 addresses — that per-packet handshaking throttles throughput on high-speed links. AT&T '877 teaches blocks with sequence numbers, block-level acknowledgement, selective block retransmission, and windowing; IBM '933 teaches a creditable sequence count ("current sequence number") plus a cumulative status bit ("end sequence number") that acknowledges all prior frames. Combining block-based transmission with a cumulative sequence scheme to compute how many packets to send in the next burst (the '507's "L = end sequence number − current sequence number") is the predictable result of combining two known flow-control schemes, both of which already disclose exactly those two operands. This is KSR's paradigm case.

Combination III — Claims 4 and 13: Connection negotiation of transmit/receive block sizes

References: IBM '933 (MAX_CREDIT / credit count = recipient buffer availability) + AT&T '877 (two-window flow control) + DEC '674 (CONNECT handshake).

Why: Negotiating the sender's maximum burst against the receiver's available buffers is the known, standard way to size a window; IBM '933 literally reports the number of buffers available at the recipient, and AT&T '877 sets windows to the bandwidth-delay product and to receiver capacity. The '507's "maximum data transmit block size" and "maximum data receive block size" are the two sides of this known credit/window exchange.

Combination IV — Claims 2, 12, and 16: Broadcast discovery and printer selection

References: DEC '674 (multi-printer selection based on the most-recent "printer ready" message; protocol that advertises available services) + Echelon '138 (broadcast/multi-node protocol) [lower confidence].

Why: DEC '674 already teaches choosing among multiple printers and advertising printer services over the protocol; adding a broadcast/multicast ID request to enumerate responding printers is the routine use of a known broadcast mechanism (Echelon) in the known print-server context. Selecting a printer by a returned data string is ordinary address/capability matching.

Combination V — Claims 6 and 15: Address-filtered storage and multiple-copy printing

References: Menendez '494 (storing the bit-mapped image and producing it "a specified number of times in said selected media") + Dataproducts '716/SG 50544 ("virtual printer," directed-by-address jobs, stored configuration) + DEC '674 (directed printer messages) + any network address-filtering art.

Why: Inspecting packet address fields to decide whether to accept data is inherent in every addressed network (directed/multicast/broadcast). Storing the image in the printer's buffer and printing multiple copies follows directly from Menendez's "specified number of times" teaching and from the admitted need to avoid re-RIP and retransmission.

Combination VI — Dependent claims 3, 7, 9, 10, 11

• Claims 7 and 11 (raster connection management module "distinct from the raster image processor"): a routine design/partitioning choice; the '507 specification describes the module as a discrete block, and separating protocol/connection management from the RIP is conventional layering.
• Claim 9 (response with a "data string" identifying high-speed-raster-capable printers): capability-string matching, routine in the art (DEC '674 advertises available services/fonts).
• Claims 3 and 10 (ink lot number / manufacturing characteristic plus two chromatic characteristics): see the caution below.

7. Weak points — where obviousness is genuinely contestable

I want to be candid rather than manufacture certainty:

1. The media/ink profile-correction limitation (claims 1, 3, 8, 9, 10, 16) is the hardest to invalidate on this record. The cited references I read establish (a) that printer-capability/status data traveled on the network (DEC '674) and (b) that host RIPs were preset with printer media parameters (admitted art). But I did not find, in the references on this record, an express teaching of querying the printer for ink-characterization data (lot number, chromatic characteristics) and algorithmically correcting a host-rip'd raster based on it. A petitioner would need an additional reference or expert testimony on then-existing device-dependent color-management practice to close this gap. Absent that, claims 1/8 (and their profile-dependent dependents) are the best non-obviousness candidates — though the specification's own admission that this was a known problem materially helps the challenger.
2. The "dedicated raster network bus distinct from the common bus" limitation is strong for the FIG. 4 embodiment, but the '507 FIG. 5 embodiment has the two "networks" share the same physical media — a reminder that the claim's "distinct bus" boundary is narrow. If the two-bus limitation is read structurally, Menendez's dedicated RIP↔engine path is the key teaching; if read only functionally, the case is even stronger.
3. Claim 3's "lot number … and at least two chromatic characteristics" may read on a specific data content rather than a technical advance; expect an argument that the selection of which ink parameters to transmit is a non-obvious choice rather than a predictable one. This is arguable both ways.
4. Secondary considerations: none found (no long-felt-need/unexpected-results/copying evidence located, and § 5 of the earlier litigation summary found no asserting litigation that would have generated a nexus record). This does not help the patent, but the absence is "not found," not "confirmed none."
5. Claim-construction tension already flagged: claims 1/8 recite closing the virtual connection before requesting the profile set, while the specification describes the profile exchange before transmission. A court construing the claims to require the spec's ordering could narrow them; either reading leaves the core architecture (Combination I) exposed to art.

8. Claim-by-claim bottom line

9. Caveats and verification status

• Confirmed from primary text: US 5,113,494, US 5,220,674, US 5,260,933, US 5,084,877.
• Lower-confidence (title/field only; full text not retrieved due to search limits): US 5,012,973, US 5,018,138, US 5,319,641, US 4,993,025, US 5,077,875, SG 50544 A1. Verify each before relying on it in a formal validity opinion or IPR petition.
• All references identified as prior art predate the 1994-07-01 priority date (latest cited filings are 1992-12-31 for US 5,379,296 and 1992-05-15 for US 5,260,933), so Barton/102(e)-type date issues do not appear to defeat them. The sibling CIP US 5,577,172 is excluded as non-prior art (later same-family filing).
• This is a retrospective analysis. The '507 patent expired 2017-07-18, so validity would matter only in a past-damages/backward-looking posture; the strongest claims to attack are the protocol/architecture claims (4, 5, 7, 11, 13, 14), and the profile-correction claims (1, 3, 8, 10) are where a challenger should expect the real fight.

Bottom line: Claims 4, 5, 7, 11, 13 and 14 look clearly obvious over AT&T '877 + IBM '933 (+ DEC '674). Independent claims 1 and 8 (and profile-bearing dependents 3, 10) are obvious only if a reference or expert testimony establishes the then-known practice of querying printer ink/media characterization data to correct a host-rip'd raster — that element is the pivot on which the patent's defensibility turns, and it is not fully closed by the references I was able to read on the face of the patent.