US 5978560

I'll search for authoritative information on US 5978560, including any litigation activity.

Let me check for any litigation or post-grant proceedings involving this patent.

US Patent 5,978,560 — Summary

Important search caveat: I found no CAFC 2026 docket entry, PTAB proceeding, or district-court litigation naming U.S. Patent No. 5,978,560. The requested "CAFC 2026 docket" search returned no results for this number. Treat the litigation statement below as a negative finding, not proof of non-existence — court dockets are not fully indexed by the search tools available to me.

Bibliographic Data

Note: the Google Patents bibliographic data lists inventors as "Shengkuo Fan," while the EP family publication (EP0917044A3) spells it "Fan, Sheng Kuo." The US record provided uses "Shengkuo Fan." I am flagging the discrepancy rather than correcting either.

Abstract (verbatim)

"A distributed printing system that more optimally distributes job requests within a distributed printing system based on more detailed information about the particular attributes of each output device. In particular, additional printer attributes are used that allow greater utilization of a plurality of attached printers having differing capabilities. These attributes include "max-concurrent-jobs-processing" (MCJP), "number-of-jobs-on-device" (NJOD) and "number-of-cascaded-jobs" (NCJ), and a attribute value "saturated" for the attribute "printer-state". The attribute MCJP is an integer value that is based on the capabilities of the printer. NJOB and NCJ attributes allow monitoring of jobs sent to each printer for supported and unsupported printers. If NJOB or NCJ are greater than MCJP, then the attribute "printer-state" is set to "saturated", prohibiting further spooling of print jobs to that particular printer."

Technology in one paragraph

The patent addresses load balancing across a client/server print network (spooler server 410 + supervisor server 420 + logical printers 412 + physical printers 422). Instead of simple FIFO/round-robin distribution, it introduces four printer attributes:

• max-concurrent-jobs-processing (MCJP) – a static, administrator-entered integer reflecting how many concurrent jobs a device can handle.
• number-of-jobs-on-device (NJOD) – a dynamic value returned by supported printers via status query.
• number-of-cascaded-jobs (NCJ) – a dynamic counter incremented when the system sends a job and decremented on completion; a fallback for "dumb"/foreign printers that cannot report NJOD.
• printer-state "saturated" – a third state (beyond idle and printing) entered when NJOD or NCJ ≥ MCJP, which blocks further job submissions until the load drops below MCJP.

Independent Claim 1 (system) — plain language

A distributed printing system with a printer system, at least one output device, and an attribute database holding:

• "max-concurrent-jobs-processing" assigned a numeric value for how many concurrent print jobs the device can handle;
• "printer-state" having a "saturated" value; and
• at least one of "number-of-jobs-on-device" and "number-of-cascaded-jobs".

NCJ is dynamic and incremented by the printing system when a job is sent to the device; NJOD is dynamic and updated by the output device itself. The "printer-state" attribute is set to "saturated" when NJOD or NCJ ≥ MCJP, and the system is prevented from sending a print job to that device while it is saturated.

Independent Claim 10 (method) — plain language

A load-balancing method: store the same attribute set (MCJP with a numeric job-handling value; a "saturated" printer-state value; and at least one of NCJ or NJOD); receive a print request; generate and queue a print job until it can be sent; compare NJOD or NCJ against MCJP and set "printer-state" to "saturated" when either meets or exceeds MCJP; and send the print job only if "printer-state" is idle or printing.

Dependent claims (brief)

• 2: MCJP, NJOD, NCJ are integer values.
• 3–4: Means for incrementing NCJ on job send and decrementing on reported completion.
• 5–6: Output device may be a printer, fax machine, or pager; two or more devices supported.
• 7: Multiple devices may carry different MCJP values.
• 8: Updating means to refresh NJOD from device query responses.
• 9: System includes a spooler (queues jobs) and a server that reads the attributes and drives job flow.
• 11: Client/spooler/supervisor implementation details.
• 12–13: Increment NCJ on send; decrement on completion.
• 14: Differing MCJP values for devices of differing capability.
• 15: Periodic attribute updates and periodic comparison.
• 16–17: Initializing attributes; manually entering MCJP.
• 18: Setting NJOD to "null" and disregarding it when the device does not support NJOD.

Prior art cited on the face

US 5,179,636 (Canon); US 5,287,194 (Xerox, "Distributed printing"); US 5,630,079 (Xerox); US 5,559,933 (Unisys); US 5,813,348 (Man Roland); US 5,873,659 (Edwards).

Downstream significance

The patent has been cited by later Xerox filings, notably US 8,149,438 ("Distributed printing system with improved load balancing"), which expressly describes US 5,978,560 as an improvement over earlier distribution schemes. Cited-by lists also include Sharp Laboratories' load-balancing family (e.g., US 8,411,298) and EFI's automatic print load balancing (US 7,081,969).

Uncertainties

1. No litigation/CAFC 2026 docket found for 5,978,560 — I cannot confirm or deny that any exists.
2. Inventor name spelling differs between the US and EP records ("Shengkuo Fan" vs. "Sheng Kuo Fan").
3. The patent text itself contains a bracketed editorial artifact in the specification ("[probably not necessary as we are only concerned with the ability to return a NJOD value.]"), which appears in the Google Patents transcription; I am reporting it as-is rather than treating it as authentic claim language.

I'll search for litigation involving US patent 5978560 across litigation databases.

Let me search litigation-specific databases for this patent number.

Let me search more specialized litigation databases directly.

Search Results: Litigation Involving U.S. Patent No. 5,978,560

Bottom line: I found no evidence of any litigation involving U.S. Patent No. 5,978,560.

What I searched

I ran targeted searches designed to surface patent litigation records — including general queries on "5978560" combined with litigation/lawsuit/docket/complaint/case-number terms, plaintiff/defendant-oriented queries ("Xerox"), infringement-suit queries, and site-restricted queries aimed at litigation databases (e.g., Unified Patents portal). I was working within a limited number of search steps and could not exhaustively query PACER, Docket Navigator, or Unified Patents' case lists directly.

What the search actually returned

Every hit referencing the number was a non-litigation source:

1. US5978560A itself — the patent document (Google Patents), "Load balancing of distributed printing systems using enhanced printer attributes," Xerox Corp., filed 1997-11-07, granted 1999-11-02. Its "Cited By" list shows 96+ forward citations and its "Families Citing" list shows follow-on patents — these are patent-office citations, not lawsuits.
2. Prior-art / family references citing US5978560A or its EP family member EP0917044 — e.g., WO2001065352A3 and WO2001031432A1 both list US 5978560 A / EP 0917044 in their search reports. Again, these are IDS/prior-art citations, not enforcement actions.
3. A patent-valuation aggregator (Patent Leaderboard) listing US5978560 among David P. Nesbitt's patents — no litigation data.

I found no complaint, docket entry, case number, PACER record, PTAB proceeding (IPR/PGR/CBM), ITC Section 337 investigation, or CAFC appeal naming U.S. Patent No. 5,978,560 as an asserted patent.

Important caveats

• This is a negative finding, not proof of non-litigation. My searches were constrained and may not have reached every source. A definitive answer would require direct queries to PACER, Docket Navigator, Lex Machina, or Unified Patents' full case list, which I could not complete here.
• Practical context: The patent issued 1999-11-02 and its anticipated expiration was 1997-11-07 + 20 years = 2017-11-07 (per Google Patents, status "Expired - Lifetime"). This means the window for active enforcement has closed. Any past litigation would be historical, not ongoing.
• Do not infer litigation from the "Cited By" lists in the patent record — forward citations reflect later patents referencing it as prior art, not infringement suits.

Identifiers I did NOT search for (to avoid cross-contamination)

Per your instruction, I excluded similar but distinct numbers such as 5,957,856 (Weil), 5,597,656 (Xerox "Unistrokes"), and 5,968,560-family numbers. Those returned results are not relevant to U.S. 5,978,560.

Recommendation

For a definitive litigation history, run a direct query on:

• PACER (all district courts, party = Xerox or any assignee),
• Docket Navigator or Lex Machina (patent → litigation mapping),
• Unified Patents litigation portal (https://portal.unifiedpatents.com/litigation/caselist),
• and the USPTO PTAB for any IPR/PGR involving this patent.

If those return nothing, the correct statement is: No litigation is known involving U.S. Patent No. 5,978,560.

PTAB Proceedings on US 5,978,560

Verification note: I ran targeted web searches (Google Patents, uspto.report, PTAB decision databases, CourtListener-style dockets) for any AIA trial proceeding naming U.S. Patent No. 5,978,560, and I also cross-checked the structured "PTAB proceedings on file" block supplied in the prompt. Both sources agree: no AIA trial proceeding exists or has ever existed for this patent. The discussion below therefore documents that absence and its defensive significance rather than summarizing decisions that do not exist.

Proceedings overview

Total AIA trial proceedings on file: 0. There are no active proceedings, no claims invalidated by the PTAB, no claims sustained in an FWD, no settled proceedings, and no institution denials — because no petition has ever been filed. The bottom line for a defendant is not that "the patent is hardened by survival," but that the patent has been expired since 2017-11-07 and has never been tested at the PTAB; its vulnerability is unproven, not proven, and the practical damages exposure is now largely extinguished by the patent term having run plus the § 286 six-year lookback.

Proceedings

None. There are no proceedings to list. Per the operating rules, I will not invent proceeding numbers to populate this section. If a petition had been filed, it would appear here ordered by impact.

What the absence does and does not tell us

No PTAB activity on file. The USPTO Open Data Portal returns zero AIA trial proceedings for US 5,978,560 as of the most recent ingest, and my web searches surfaced no IPR, PGR, or CBM record, and no Federal Circuit appeal of any PTAB decision on this patent. The pattern signals worth extracting:

• This patent was never asserted in a way that attracted an IPR. Well-asserted patents in high-stakes campaigns reliably draw IPRs or CBM petitions within 1–2 years of a district-court complaint. Zero petitions on a 1997-filed Xerox printing patent strongly suggests it was not a frontline assertion patent. That is a commercial signal, not a legal invalidity signal — the claims have simply never been adjudicated.
• The relevant windows have closed. A PGR petition is only available within 9 months of grant (granted 1999-11-02), and the CBM transitional program sunset in September 2020. Only an IPR remains formally available, and on an expired patent the Board's remedy (canceling claims) is largely moot, so institution would be an uphill and often pointless exercise. Substantively, there is no live PTAB path left worth pursuing.
• No defensive aggregator in the chain. I found no Unified Patents or similar non-practicing-entity challenge linking this patent.

Strategic summary

Claim status. All of claims 1–18 are, in PTAB terms, UNTESTED — none has been canceled by the Board, none has been sustained in an FWD. That is unusual and cuts both ways. The narrowest independent claims the Board would have looked at are claim 1 (system) and claim 10 (method), both of which require the combination of a "max-concurrent-jobs-processing" numeric attribute, a "printer-state" attribute with a "saturated" value, and at least one of the dynamic "number-of-jobs-on-device" / "number-of-cascaded-jobs" attributes, with the saturated state triggered at NJOD-or-NCJ ≥ MCJP. Claims 2–9 depend from claim 1; claims 11–18 depend from claim 10. Because there is no FWD, there is no claim-level disposition to quote and no estoppel-triggering record.

Estoppel landscape. § 315(e)(2) estoppel is a non-issue here: estoppel attaches only to petitioners who obtain a final written decision (or whose proceeding is terminated after institution), and no such proceeding exists. A defendant today faces no estoppel and would be free to raise any § 102/§ 103 ground in district court. The cited-art record you can build on is thin but real: the patent's face cites six references, including US 5,287,194 (Xerox, "Distributed printing"), US 5,559,933 (Unisys, "Distributed enterprise print controller"), US 5,813,348 (Man Roland, "Print job allocation system"), and US 5,873,659 (Edwards, "printer having internal queue job management"). Notably, the EPO search report for the family member EP0917044 rated US 5,559,933 alone as "X" (particularly relevant) against claims 1, 4, 6, 7, and 10 — i.e., the EPO examiner viewed the broadest system and method claims as anticipated by a single pre-1994 reference. That is a strong lead for a § 102 challenge, and it was never litigated or adjudicated on the U.S. side.

Pattern signals. Inventors Shee-Yen Tan, Sheng Kuo Fan, Joseph Z. Fung, and David P. Nesbitt; assignee Xerox Corporation. The patent was swept into Xerox's 2002–2003 bank security-interest assignments (Bank One, JPMorgan Chase) and subsequently released. It has attracted substantial downstream citation (Google Patents lists ~96 citing publications, and ~13 family members citing the family), and subsequent Xerox load-balancing filings (e.g., US 2007/0201078 and US 2007/0201077, "Distributed printing system with improved load balancing") cite this line of work. The patent owner has not pursued any PTAB appeal because there was nothing to appeal.

Recommended next steps

1. If you are asserting or defending a demand that cites this patent, check the term first. US 5,978,560 issued 1999-11-02 from an application filed 1997-11-07 and the ODP record shows "Anticipated expiration" on 2017-11-07 (status: Expired – Lifetime). For any complaint filed after roughly 2023-11-07, the § 286 six-year damages lookback window no longer reaches any period of patent enforceability, so recoverable past damages are effectively zero. That is a threshold, potentially case-dispositive defense; confirm maintenance-fee history and any term adjustments independently before relying on it.
2. There is no FWD to link to and no PTAB decision to quote — I am explicitly telling you this rather than fabricating a disposition. For any proposition about this patent's validity, cite the specification/claims (https://patents.google.com/patent/US5978560/en) or the EPO search report on the family member (https://patents.google.com/patent/EP0917044B1/en), not a PTAB record.
3. If your client genuinely needs a validity opinion (e.g., to support an invalidity contention in a still-live matter), the EPO's "X"-rated US 5,559,933 against claims 1, 4, 6, 7, 10 is the highest-value starting point, followed by US 5,287,194 and US 5,873,659. Because no IPR was ever filed, there is no § 315(e)(2) estoppel and no § 325(d) "substantially the same prior art" exposure from a prior Board proceeding.
4. Treat the zero-PTAB finding as itself the deliverable. The absence of any IPR on a 28-year-old Xerox printing patent means the invalidity story is unexplored territory, not a hardened patent — but it also means the practical leverage lies in the expiration date and damages cutoff, not in a PTAB-based invalidation strategy.

Sources consulted: US5978560 Google Patents record (https://patents.google.com/patent/US5978560/en); uspto.report grant page (https://uspto.report/patent/grant/5978560); EP0917044 European search report (https://patents.google.com/patent/EP0917044B1/en); the structured "PTAB proceedings on file" ODP block supplied in the prompt. No PTAB E2E or CourtListener record for this patent was located.

I'll verify the assignment record using targeted searches before reconstructing the chain.

Let me verify the reel/frame numbers specific to this patent and check the correspondent of record.

Let me pull the Espacenet INPADOC legal-events record specific to this patent and check for any post-issuance assignment beyond the security liens.

Assignment & Ownership Analysis — U.S. Patent No. 5,978,560

Patent: Load balancing of distributed printing systems using enhanced printer attributes
App. No.: 08/966,409 · Filed: 1997-11-07 · Issued: 1999-11-02 · Anticipated expiration: 2017-11-07
Assignee of record (per Google Patents): Xerox Corp · Status: Expired – Lifetime

Sourcing note on reel/frame numbers. The authoritative patent text I was given does not print reel/frame numbers for this patent's events. I cross-checked the parallel INPADOC/legal-events records for sibling Xerox patents recorded under the same omnibus instruments (e.g., US 5,608,023 and US 5,790,146), which expose the reel/frames below. Because the 2002 and 2003 instruments were single portfolio-wide recordings filed once against the entire Xerox patent estate, US 5,978,560 is captured within the same reels/frames. I flag each entry as [confirmed via parallel record] vs. [not confirmed]. I did not fabricate any reel/frame.

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Inventors

Pattern assessment: All four inventors assigned their rights to Xerox Corporation on the filing date (1997-11-07), the standard Xerox practice of securing inventor assignments concurrently with filing. No unusual pattern detected. I could not determine employment end-dates for any inventor from available sources, so I make no claim of a "all inventors departed within 12 months" signal — that would be speculation and is explicitly unsupported. (Note: the litigation section found no suits, so there is no inventor-departure-before-fire-sale narrative to support.)

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Original assignee

Xerox Corporation.

• Product embodying the claims: Yes. This patent claims a distributed print-server architecture (spooler + supervisor, logical/physical printers, job-attribute-driven scheduling). It is the software/firmware control layer of Xerox's networked production and office printing products — the specification expressly names the Xerox 4230 laser printer and the Xerox DocuPrint 4635 NPS. Xerox shipped commercial products in this space (DocuPrint / DocuTech lines and CentreWare print-management software).
• Primary line of business: Document technology and services — printers, MFP hardware, and print-management software.
• Current status: Operated as an ongoing public company (historically NYSE/NASDAQ: XRX; Xerox Holdings Corporation). No bankruptcy. Important context: Xerox did not file for bankruptcy, but it experienced a severe financial crisis around 2000–2002 (accounting restatement, SEC inquiry) and raised secured financing — which is precisely why the 2002/2003 security interests below exist. Xerox is the entity of record on both ends of every lien and release; it never parted with ownership.

Note: I could not verify the most recent (2024–2026) corporate-structure changes to Xerox from authoritative sources within this task; treat the current-entity characterization as of the patent record.

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Assignment timeline

Full recorded history (per the authoritative Google Patents legal-events list for US 5,978,560, with reel/frames cross-referenced as noted):

• 1997-11-07 (executed) / recorded 1997-11-07 — Reel/Frame [not confirmed]

  • Conveyance: Assignment of assignors' interest (original assignment)
  • Assignor: Shee-Yen Tan; Joseph Z. Fung; Sheng Kuo Fan; David Paul Nesbitt
  • Assignee: Xerox Corporation
  • Correspondent: [not confirmed] — the patent-side recording does not expose a correspondent in my sources.
  • Context: Original inventor-to-employer assignment; a clean, ordinary corporate ownership record.

• 2002-06-21 (executed) / recorded 2002-06-28 — Reel 013153/0001 [confirmed via parallel Xerox record]

  • Conveyance: Security Interest (grant of security interest / collateral lien)
  • Assignor: Xerox Corporation
  • Assignee: Bank One, NA, as Administrative Agent (Chicago, IL)
  • Correspondent: [not confirmed for patent-side] — on the trademark counterpart for this same Xerox–Bank One arrangement (TTAB record), the correspondent of record was Jackie Lee, 1773 Western Avenue, Albany, NY 12203, with a recording service ("Access Information Services, Inc.") also named. Flagged as suggestive but from the trademark chain, not the patent chain.
  • Context: Securitization — portfolio-wide pledge of Xerox patents as collateral for the 2002 credit facility; not a transfer of ownership.

• 2003-06-25 (executed) / recorded 2003-10-31 — Reel 015134/0476 [confirmed via parallel Xerox record]

  • Conveyance: Security Agreement
  • Assignor: Xerox Corporation
  • Assignee: JPMorgan Chase Bank, as Collateral Agent (Houston, TX)
  • Correspondent: [not confirmed] (lender-side collateral documentation; the underlying master security agreement was prepared by outside counsel, Davis Polk & Wardwell, per Xerox SEC exhibits — a firm-level attribution, not a named recording correspondent).
  • Context: Securitization — the June 19, 2003 credit agreement collateralized by the same patent estate; again not an ownership transfer.

• 2007-10-30 (recorded) — Reel/Frame [not confirmed]

  • Conveyance: Release by Secured Party
  • Assignor: JPMorgan Chase Bank, NA
  • Assignee: Xerox Corporation
  • Correspondent: [not confirmed]
  • Context: Lien release/repayment — restores unencumbered status to Xerox.

• 2007-11-01 (recorded) — Reel/Frame [not confirmed]

  • Conveyance: Release by Secured Party
  • Assignor: Bank One, NA
  • Assignee: Xerox Corporation
  • Correspondent: [not confirmed]
  • Context: Lien release/repayment.

• 2022-08-22 (effective) / recorded 2022-09-07 — Reel 066728/0193 [confirmed via parallel Xerox record]

  • Conveyance: Release by Secured Party
  • Assignor: JPMorgan Chase Bank, N.A., as successor-in-interest Administrative Agent and Collateral Agent to JPMorgan Chase Bank
  • Assignee: Xerox Corporation
  • Correspondent: [not confirmed]
  • Context: Final recorded lien release; Xerox emerges as the sole unencumbered owner.

• 2017-11-07 — Anticipated expiration (no further ownership events; patent is expired).

Bottom line of the chain: One true ownership assignment (1997, inventors → Xerox) plus a financing-lien cycle (pledge → pledge → release → release → release). Ownership never left Xerox.

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Timeline diagram

timeline
    title Ownership of US 5978560
    1997 : Inventors assign to Xerox Corporation
         : Application filed
    1999 : Patent issued to Xerox
    2002 : Security interest to Bank One
    2003 : Security agreement to JPMorgan Chase
    2007 : Bank One releases its security interest
         : JPMorgan releases its security agreement
    2017 : Patent expires
    2022 : JPMorgan successor releases final lien

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NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. No assignment to any "IP / Patents / Licensing / Holdings / Ventures" entity. The only assignees appearing anywhere in the chain are Xerox Corporation, Bank One, NA, and JPMorgan Chase Bank — a printer manufacturer and two banks. No single-purpose LLC, no registered-agent address, no Delaware/Texas shell.

2. Known asserter in the chain — NOT PRESENT. Assignees/assignors (Xerox, Bank One, JPMorgan) match none of the listed NPE directories (Acacia, Marathon, IV, Wi-LAN, Conversant, Vringo, Pendrell, Round Rock, etc.), and none surfaced via Unified Patents/RPX in the litigation search. Consistent with the parallel finding of no litigation on this patent.

3. Repeat correspondent across the chain — UNCLEAR. I could not confirm a correspondent of record on any patent-side recording for this patent. The only correspondent data I located (Jackie Lee, 1773 Western Ave, Albany, NY) sits on the trademark counterpart record for the same Xerox–Bank One arrangement, so it is suggestive of a recurring Xerox recording contact but is not a confirmed patent-chain recurrence. Marked unclear rather than present.

4. Cascading transfers — NOT PRESENT. Only one ownership assignment (1997); no chained LLC-to-LLC conveyances in under 24 months. The 2002/2003 events are liens, not transfers, and both were released.

5. Pre-litigation transfer — NOT PRESENT. No infringement suit exists (see litigation summary), and no assignment precedes any suit.

6. Bankruptcy fire-sale — NOT PRESENT. Xerox never filed for bankruptcy. The 2002/2003 instruments are secured credit facilities ("securitization"), not Article 9 sales or §363 bankruptcy sales. Every lien was released (2007 and 2022), leaving Xerox as owner — the opposite of a fire-sale disposition.

7. Privateering — NOT PRESENT. No transfer to any licensing vehicle; no operating-company→NPE conveyance of any kind.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at the original operating company, Xerox.

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Verdict

Insufficient data — meaning: for ownership purposes, the record contains only the original 1997 inventor-to-Xerox assignment (reel/frame not confirmed for the original; lien documents at 013153/0001, 015134/0476, and 066728/0193 confirmed via parallel Xerox records). The 2002-06-28 Bank One security interest and the 2003-10-31 JPMorgan security agreement are collateral pledges to lenders, never conveyances of title, and each was affirmatively released (2007-10-30, 2007-11-01, and the 2022-09-07 JPMorgan-successor release at 066728/0193), leaving Xerox Corporation as sole owner through expiration on 2017-11-07. Accordingly, every NPE/privateering/fire-sale signal is absent or unverifiable, and the chain affirmatively shows sustained operating-company ownership — so the honest label is "only the original assignment," not an NPE finding.

Why not "Operating-company assertion"? Xerox does ship products embodying the claims, but there is no assertion activity (no suit), and the patent is expired — so the "assertion" prong fails. Why not "Defensive / non-asserting"? That category requires termination at a defensive aggregator, which did not occur.

Verification links:

• USPTO Assignment Center (search by patent number 5978560): https://assignmentcenter.uspto.gov/
• USPTO Patent Assignment Search (legacy index): https://assignment.uspto.gov/patent/index.html
• Google Patents legal events (source of dates): https://patents.google.com/patent/US5978560/en

Caveats: (i) Patent-side reel/frame numbers and correspondents were not exposed in the authoritative text; the reel/frames cited are corroborated from the identical omnibus Xerox recordings on sibling patents and should be confirmed in Assignment Center before relying on them. (ii) A definitive correspondent audit requires pulling the recorded PDFs from Assignment Center for reels 013153/0001, 015134/0476, and 066728/0193 directly.

I'll research the prior art cited on the face of US 5,978,560 to build an accurate anticipation analysis. Let me search for each reference.

Let me research the remaining cited references.

Prior-Art Analysis — U.S. Patent No. 5,978,560

Note on method: The authoritative full text of US 5,978,560 (Google Patents mirror of the USPTO record, fetched 2026-09-24) was supplied and is the primary source used here. I did not separately reach the USPTO PatentCenter/Public PAIR record in this session, so the "front-page citations" below are taken from the patent text as provided. I interpret all identifiers literally and do not correct them.

Critical framing on § 102 vs. § 103: The task asks which claims each reference "potentially anticipates" under 35 U.S.C. § 102. Applying the legal standard honestly — anticipation requires a single reference disclosing every element of a claim as arranged — none of the six front-page references, alone, discloses the full combination of independent claim 1 or claim 10 (specifically, none discloses the specific attribute triad MCJP / NJOD / NCJ plus the "saturated" printer-state value plus the NCJ-or-NJOD ≥ MCJP triggering comparison). These references are therefore best characterized as § 103 obviousness references (individually or in combination), with the strongest § 102-style overlap discussed per reference below. I flag where a reference is closer to true anticipation of a dependent claim.

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1. The face citations of US 5,978,560

Also considered (EP search-report citation, not a US front-page citation):

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2. Reference-by-reference analysis

Reference 2 — US 5,287,194 (Xerox, Lobiondo), "Distributed printing" — the principal background art for distributed-print load balancing

• Full citation: U.S. Pat. No. 5,287,194, filed 1992-11-25, issued 1994-02-15, assignee Xerox Corp.
• Description: A printshop management scheduling routine that allocates jobs across a network of printers based on printer "capability and availability." It maintains a printer file/database containing printer attributes — "printer type, quality, speed, document size, capability" — and routes a job away from a printer whose queue is backed up ("If the queue is relatively empty… allocate the job to the selected printer… If a large number of jobs… in the selected print queue, the scheduler will prompt the user [to use a different printer]"). It can split a job across parallel printers to meet a deadline.
• Claim mapping vs. US 5,978,560: Teaches the preamble concepts of claim 1 — a printing system receiving jobs, multiple output devices, and an attribute database containing printer attributes. It also teaches a load-based routing decision (queue-length awareness), touching the concept behind claim 10's "comparing… against" step.
• § 102 assessment: Does not anticipate claim 1 or 10. It lacks MCJP (a numeric per-device concurrent-job ceiling), lacks NJOD and NCJ, lacks the "saturated" printer-state value, and lacks the N(C)J/NJOD ≥ MCJP triggering rule. Best used as a § 103 base reference for the distributed-load-balancing environment.

Reference 4 — US 5,559,933 (Unisys, Boswell), "Distributed enterprise print controller" — the closest prior art per the EPO

• Full citation: U.S. Pat. No. 5,559,933, App. No. 08/231,547, filed 1994-04-22, issued 1996-09-24, assignee Unisys Corp.
• Description: A distributed printing control system that "coordinates the distribution of print files across multiple computer systems to attached printers." It stores a file database / file-mask library whose file masks contain "file identification information, transfer attributes, and print attributes," plus a print attribute library and transfer attribute library. It supports "multiple page description languages and multiple printers," and via a graphical user interface lets a user modify print-file attributes to "control when, where and how print files are to be printed on any one of many available printers of different types and capabilities." 42 claims.
• Claim mapping: Strongly teaches claim 1's "printer system that receives print requests," "at least one output device," and "attribute database… containing printer attributes," and claim 1/claim 5–7's notion of multiple printers with different capabilities. It also supports claim 16–17-type initialization/manual-entry concepts (GUI-driven attribute libraries).
• § 102 assessment: Does not anticipate the independent claims, because it contains no MCJP value, no NJOD, no NCJ counter, and no "saturated" state or ≤/≥ comparison. However, the EPO examiner cited it in the EP 0 917 044 A3 search report with Category "X" (relevant to claims 1, 4, 6, 7, 10) — i.e., the closest single reference for the system concept (see the EP search report reproduced at patentimages/EP0917044A3). It is the primary § 103 reference against which the MCJP/NJOD/NCJ/"saturated" features must be weighed. ⚠️ I treat the EPO "X" designation as a relevance indicator, not as an anticipation holding.

Reference 6 — US 5,873,659 (Lexmark, Edwards et al.), "Printer having internal queue job management" — most relevant to the NJOD element

• Full citation: U.S. Pat. No. 5,873,659, filed 1996-04-24, issued 1999-02-23; inventors Steve Michael Edwards, Gail Marie Songer, James Francis Webb; assignee Lexmark.
• Description: A printer with bi-directional communications (Network Printer Alliance Protocol, "NPAP") and memory large enough to hold multiple print jobs in its internal queue. The host can "view" the contents of the printer's internal print queue, count/resident jobs, cancel jobs, and reorder them — i.e., the host can obtain, from the device, how many jobs are queued on it.
• Claim mapping: This is the closest art to (i) claim 1's "number-of-jobs-on-device" dynamic attribute "updated by the at least one output device," and (ii) claim 8 ("updating the 'number-of-jobs-on-device' attribute… based on a query response received from the at least one output device"). Although it issued 1999-02-23 (after the 1997-11-07 filing), it was filed 1996-04-24 and is thus § 102(e) prior art.
• § 102 assessment: Does not anticipate claims 1/10 (no MCJP, no NCJ, no threshold comparison, no "saturated" state). It is a § 103 reference (or a § 102(e) reference as to the isolated NJOD-style query feature) for the "query the device for its job count" teaching.

Reference 5 — US 5,813,348 (Man Roland), "Print job allocation system"

• Full citation: U.S. Pat. No. 5,813,348, filed 1995-06-17, issued 1998-09-29, assignee Man Roland Druckmaschinen.
• Description: A system for allocating print jobs among printing machines/presses. (Man Roland is a web-offset press manufacturer; the reference concerns routing/allocating jobs to multiple production output devices.)
• Claim mapping: Touches the general "job allocation across multiple output devices" concept of claim 10's preamble and the multi-device claims 6–7 (different-capability devices). It does not address digital-printer attribute databases or any of MCJP/NJOD/NCJ/"saturated."
• § 102 assessment: Does not anticipate any claim; weak § 103 reference at best, useful only for the generic "allocate jobs to multiple printers" background.

Reference 3 — US 5,630,079 (Xerox, McLaughlin), "Document job key to tailor multifunctional user interfaces"

• Full citation: U.S. Pat. No. 5,630,079, file-wrapper continuation of App. Ser. No. 08/202,606 filed 1994-02-28, issued 1997-05-13, assignee Xerox Corp.
• Description: A user-interface mechanism ("document job key") that, once a user picks a document source and destination (e.g., a printer), automatically surfaces the relevant transmission/print attributes and hides irrelevant ones.
• Claim mapping: Supports the general idea of a selectable, attribute-driven printer/UI (relevant background to claim 1's "attribute database" and claim 16–17's initialization/manual-entry features), but it is a UI-tailoring reference, not a load-balancing reference.
• § 102 assessment: Anticipates nothing in claims 1–18. § 103 value is marginal (only for the attribute-selection UI concept).

Reference 1 — US 5,179,636 (Canon), "Recording apparatus"

• Full citation: U.S. Pat. No. 5,179,636, prior-art date 1988-03-08, issued 1993-01-12, assignee Canon Kabushiki Kaisha.
• Description: An early "recording apparatus" reference (Canon image-recording hardware). It appears on the face largely as general printing/recording-art background.
• Claim mapping: At most relevant to the generic "output device" environment and possibly to the output-device-type recitation of claim 5.
• § 102 assessment: Anticipates nothing. Minimal § 103 value.

Reference 7 — US 5,715,381 / EP 0 697 648 A (Xerox), "Method of creating and managing packages… in a printing system"

• Full citation: U.S. Pat. No. 5,715,381, filed 1994-08-08, issued 1998-02-03, assignee Xerox Corp.; EP counterpart EP 0 697 648 A (published 1996-02-21). Appears under "Family Cites Families" and was cited in the EP search report as Category "A."
• Description: A network document-device server with multiple queues mapped to multiple document-processing devices via a job-distribution controller; queues are disposable in open/closed states; a UI indicates the number of jobs currently residing in each queue. (Note: US 5,978,559 is a sibling application sharing this background text.)
• Claim mapping: Directly relevant to claim 9 (system with "a spooler that receives print requests and queues received print jobs and a server") and claim 11 (client/spooler/supervisor method), and to the "storing the print job until the print job can be sent" step of claim 10.
• § 102 assessment: Does not anticipate claims 9/10/11 as a whole (it lacks the MCJP/NJOD/NCJ/"saturated" attribute set). It is a § 103 reference for the spooler/queue/job-distribution architecture of the dependent claims.

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3. Synthesis

Claim 1 (system) and claim 10 (method):

• No single front-page reference anticipates. Each is missing at least the MCJP numeric ceiling, NJOD/NCJ dynamic attributes, and the "saturated" value/threshold comparison.
• Best § 103 combination would pair US 5,559,933 (distributed print controller with an attribute/file-mask database, multiple heterogeneous printers, GUI attribute editing) and/or US 5,287,194 (printer-attribute database + availability-based routing) as the primary reference(s), optionally with US 5,873,659 for the query-the-device-for-queued-job-count (NJOD) feature. The patent's own "Description of Related Art" characterizes the field as already having limited load balancing, supporting this obviousness framing.

Dependent-claim hot spots:

• Claim 8 ("updating… 'number-of-jobs-on-device'… based on a query response") and the NJOD concept generally → US 5,873,659 is the most on-point reference (§ 102(e) eligible).
• Claim 9 / claim 11 (spooler + queues + server/supervisor) → US 5,715,381 / EP 0 697 648 A (Category "A" in the EP report).
• Claim 17 (manually entering MCJP) → US 5,559,933 (GUI attribute libraries) as background.
• Claims 5–7, 14 (multiple output devices of different capabilities with differing values) → US 5,287,194 and US 5,559,933 both disclose heterogeneous multi-printer networks.

Net conclusion: For US 5,978,560 the cited art is an obviousness (‑§ 103) landscape, not an anticipation (‑§ 102) landscape for the independent claims. The patent's presumptive point of novelty — the named attribute triple MCJP / NJOD / NCJ combined with the third printer state "saturated" and the "≥ threshold blocks submission" rule — is not disclosed by any one cited reference.

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4. Caveats and flags

1. No true § 102 reference located among the six front-page citations for claims 1 or 10; my characterization above is deliberately conservative against the temptation to over-read "X"-type citations as anticipatory.
2. § 102(e) nuance: US 5,873,659 (issued 1999-02-23), US 5,813,348 (issued 1998-09-29), and US 5,715,381 (issued 1998-02-03) all issued after the 1997-11-07 filing date but were filed earlier, so they qualify only as § 102(e) art, not § 102(a)/(b) printed publications. This distinction matters if any of them is asserted as anticipating.
3. Typographical inconsistency inside the patent (reported as-is, not corrected): the Abstract and parts of the specification use "NJOB" where the claims use "number-of-jobs-on-device" ("NJOD"). The claim term is controlling; "NJOB" appears to be a transcription slip in the abstract. Flagging rather than correcting per the literal-identifier rule.
4. Contradiction/consistency check with earlier generated sections: This analysis is consistent with the prior Patent Summary (which listed the same six front-page citations and the US 5,715,381 family citation). It does not repeat the bibliographic or litigation content; and it confirms the earlier summary's note that the "Cited By" lists are office citations, not enforcement — so they are not treated here as prior art against US 5,978,560.
5. Source limitation: I could not confirm whether the prosecution history (e.g., examiner's own § 102/§ 103 rejections and applicant's distinguishing remarks) matches this analysis, since the file wrapper/Public PAIR was not retrieved in this session. The EPO search report (EP 0 917 044 A3) is the only examiner-side relevance judgment I could ground on, and it scores US 5,559,933 (X) highest.

I'll research the cited prior-art references to ground the obviousness analysis in verifiable content.

Obviousness Analysis of U.S. Patent No. 5,978,560 under 35 U.S.C. § 103

Prepared: April 26, 2026
Patent analyzed: US 5,978,560 (US5978560A), "Load balancing of distributed printing systems using enhanced printer attributes"
Assignee: Xerox Corporation | Filed: 1997-11-07 | Issued: 1999-11-02 | Expired: 2017-11-07
Governing framework: Pre-AIA § 103 (application filed 1997-11-07; pre-AIA §§ 102/103 apply because the application was filed before the AIA's 2013-03-16 first-inventor-to-file date)

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0. Scope, method, and a correction to the earlier sections

Instruction followed: this analysis uses only the references appearing in the "Prior Art" section of the US5978560 Google Patents record — i.e., the six examiner-cited references under "Patent Citations (6)" and the single "Family Cites Families (1)" reference — plus the EPO search report on the family member, which the prior "PTAB challenges" section already flagged.

One refinement to flag (not a contradiction): The earlier PTAB section stated the EPO rated US 5,559,933 as "X" — i.e., anticipated — against claims 1, 4, 6, 7, 10. That is close but slightly over-narrow. Under the EPO's own legend (reproduced verbatim in the search reports found in the search above, e.g. https://patentimages.storage.googleapis.com/69/ea/bc/b469b0250ad076/WO2000068015A3.pdf), "X" means the document is "particularly relevant; the claimed invention cannot be considered novel or cannot be considered to involve an inventive step when the document is taken alone." So the EPO's X rating is a combined novelty/inventive-step signal, not a pure § 102 anticipation holding. I therefore treat US 5,559,933 as the strongest single reference for both § 102 and § 103 purposes, which makes it the centerpiece below.

No new litigation/PTAB record is introduced here. Consistent with the prior sections, I found none, and I do not rely on any adjudicative record. Everything below is a prospective invalidity analysis against the printed prior-art record.

Verification limits (stated up front rather than papered over):

• I independently verified the content of US 5,559,933, US 5,287,194, US 5,873,659, and US 5,813,348 against their full texts/abstracts (Google Patents and the USPTO/EPO PDFs surfaced in the search).
• I could not independently verify the substantive content of US 5,179,636 (Canon) and US 5,630,079 (Xerox) within my search budget. I treat them as secondary/background art and flag where that matters.
• The full text supplied in the prompt is authoritative for the patent's own claims and specification. Where the record and my training data conflict, I follow the record.

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1. Legal standard and the level of ordinary skill

1.1 The § 103 test

Under Graham v. John Deere Co., 383 U.S. 1 (1966), obviousness is assessed against four factual inquiries: (1) the scope and content of the prior art; (2) the differences between the prior art and the claims; (3) the level of ordinary skill in the pertinent art; and (4) objective indicia of non-obviousness. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), a claim is obvious if the improvement is "the predictable use of prior art elements according to their established functions," and the analysis may consider design incentives, market forces, and "the background knowledge, creativity, and common sense of the person of ordinary skill." Critically, the prior art is not limited to references that address the same problem — it extends to any reference "reasonably pertinent to the particular problem with which the inventor is involved" (KSR; In re Icon Health & Fitness).

1.2 Presumed level of ordinary skill (PHOSITA)

Based on the patent's own disclosure and the field as reflected in the cited art, a PHOSITA in November 1997 was:

• A software/systems engineer with a bachelor's degree in computer science or electrical engineering and roughly 2–4 years of experience in network print-server or print-spooler software development;
• Familiar with client/server print architectures, print spoolers and queues, page description languages (PostScript/PCL), and bi-directional printer protocols such as NPAP (Network Printer Alliance Protocol, published in the Lexmark-invented US 5,873,659 as "Specification Level 1, Revision N, dated Feb. 11, 1994");
• Familiar with job-ticket / printer-attribute modeling (the claim's "object … collection of attributes" model mirrors the OS/2-and-POSIX-era printing object models the patent itself describes); and
• Capable of routine programming of counters, thresholds, polling loops, and state machines — none of which requires anything beyond ordinary skill.

This is a low-to-moderate skill level. The invention is a software scheduling heuristic, not an unforeseeable engineering breakthrough.

1.3 Claim construction preliminaries that drive the analysis

1. The attribute names carry little independent patentable weight. "max-concurrent-jobs-processing," "number-of-jobs-on-device," and "number-of-cascaded-jobs" are labels for claimed functions. Under In re Stencel, 828 F.2d 751 (Fed. Cir. 1987), and the general rule that a claim's label does not itself impart patentability, the analysis turns on the function the attribute performs, not its mnemonic. This matters enormously here: the invention cannot be saved merely because no prior-art reference used the exact token "MCJP."
2. Claim 1 and claim 10 recite a Markush-style alternative — "one of 'number-of-jobs-on-device' and 'number-of-cascaded-jobs'" (claim 1) / "at least one of" (claim 10). A single prior-art reference or combination that meets either branch satisfies the limitation. The patentee cannot rely on the combination of both branches unless it amends into a claim requiring both.
3. Internal terminology inconsistency to note: the claims recite "max-concurrent-jobs-processing" (MCJP), while the "Summary of the Invention" paragraph of the same patent recites "maximum-concurrent-job-processing." The claims govern, but the discrepancy is worth capturing in any claim chart. (This is an addition to, not a contradiction of, the prior sections.)
4. The preamble ("A distributed printing system that achieves load balancing…") is a statement of intended use and, absent a clear reliance on the preamble for antecedent basis, is non-limiting. The structural elements in the body carry the weight.

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2. Decomposition of independent claim 1 into limitations

The only limitations with any plausible claim to novelty are 1.4–1.5 (a per-device numeric concurrency cap) and 1.8–1.9 (a threshold comparison that gates submissions via a third "saturated" state). Everything else is conventional print-system machinery.

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3. The prior art of record: scope and content

3.1 Reference-by-reference

US 5,559,933 — Boswell, "Distributed enterprise print controller" (Unisys), filed 1994-04-22, issued 1996-09-24
Status: § 102(b) prior art (issued >1 year before 1997-11-07).
URL: https://patents.google.com/patent/[US5559933A](/patent/US5559933A) ; PDF: https://patentimages.storage.googleapis.com/42/72/06/a0352431ca8b9f/US5559933.pdf

What it teaches, per the text:

• A distributed printing control system that "coordinates the distribution of print files across multiple computer systems to attached printers" in a heterogeneous network — limitation 1.1/1.2.
• "A file database … for storage and retrieval of files, each file containing a file mask consisting of file identification information, transfer attributes, and print attributes" and a "print attribute library" — limitation 1.3 (an attribute database in the printing system).
• Page 1 of the reference (as reproduced on Google Patents) expressly defines the prior-art architecture: "a print queue is a list of print jobs with similar attributes to be printed on a particular physical printer," and "Print attributes may consist of physical printer identifier, print job priority, print disposition, and a print format number." This establishes attribute-driven print-job routing to printers — i.e., the attribute-per-printer/attribute-per-job model.
• It supports multiple printers of different types and capabilities, and multiple PDLs, and includes a job submission channel / job query channel / device query channel-style architecture in the disclosure's figures (visible in the PDF text).
• It is the reference the EPO rated "X" against US 5,978,560's claims 1, 4, 6, 7, and 10 in the family search report (per the earlier section).

Why this matters: US 5,559,933 is the primary reference. It supplies the system, the attribute database, the multi-printer distribution, and attribute-defined print queues. What it does not plainly supply is the per-device numeric concurrency cap (MCJP) and the saturated gating state.

US 5,287,194 — Lobiondo, "Distributed printing" (Xerox), filed 1992-11-25, issued 1994-02-15
Status: § 102(b) prior art.
URL: https://patents.google.com/patent/[US5287194A](/patent/US5287194A)/en

What it teaches:

• A "printshop management scheduling routine … [that] utilizes the total complex of printers available at local areas and/or remote locations to allocate and complete printer jobs based on a plurality of criteria."
• A printer-attribute database: "a printer file … containing information relating to each printer, such as printer type, quality, speed, document size, capability, etc." — direct support for 1.3 and for assigning per-device numeric capability values (1.5).
• Queue-load-based decision-making: "The scheduler 50 examines the print queue of the selected printer. If the queue is relatively empty … the scheduler can allocate the job to the selected printer … If a large number of jobs, or a large single job, are in the selected print queue, the scheduler 50 will prompt the user that the print queue is backed up…" — this is the load-balancing-by-queue-depth core of limitations 1.8–1.9, in nascent form, and it teaches routing away from an overloaded device.
• Availability of printers is separately tracked and used as a scheduling criterion — the conceptual parent of a "saturated"/unavailable state.
• It also teaches periodic/bidirectional communication in scheduling.

Why this matters: US 5,287,194 supplies the motivation and mechanism for using observed job-load/capacity data to decide whether to send another job to a device — i.e., it supplies the reason to gate.

US 5,873,659 — Edwards et al., "Method and apparatus for providing a printer having internal queue job management" (Lexmark), filed 1996-04-24, issued 1999-02-23
Status: § 102(e) prior art (granted U.S. patent, application filed 1996-04-24, before the 1997 priority). It is also on the face of US 5,978,560, so it was before the examiner.
URL: https://patents.google.com/patent/US5873659

What it teaches:

• Printers "which contain sufficient memory to accept multiple print jobs while printing."
• A bi-directional host↔printer communication capability (explicitly NPAP), letting the host "view the contents of a print queue within the printer, in which the queue holds one or more print jobs as these print jobs await printing."
• Print jobs "already accepted into a queue by a printer, but not yet printed, can be manipulated from a host computer."
• This is, in substance, "number-of-jobs-on-device" (NJOD): a supported device that reports/accepts queries about how many jobs are sitting in its internal queue. It also supplies the mechanism for limitation 1.7.

Why this matters: US 5,873,659 is the single best NJOD reference — the device-side dynamic job count. This is one branch of the claim's Markush alternative.

US 5,813,348 — Zingher, "Print job allocation system" (MAN Roland), filed 1996-06-17, issued 1998-09-29
Status: § 102(e) prior art.
URL: https://patents.google.com/patent/US5813348

What it teaches:

• Printing machine control devices transmit to a central print job processor "information about present and future available printing machine capacity, scheduling information including the number of jobs in queue and estimated time of completion of jobs in queue…"
• The processor "compil[es] a print job requirements profile and a printing plants capabilities profile" and matches them to "select … one or more printing machines … which provide for optimum use."
• The information may be "updated continuously or periodically using a data polling method" — directly supporting claim 15's periodic-polling limitation.

Why this matters: US 5,813,348 supplies the system-side monitoring of "number of jobs in queue" (an NCJ-like dynamic count) and the periodic-polling/periodic-comparison behavior, plus capacity-vs.-requirement matching.

US 5,179,636 — Canon, "Recording apparatus," issued 1993-01-12 (§ 102(b)). I could not verify its substantive teaching within my search budget. On its face and title it appears to be recording-apparatus hardware art, i.e., background/structural art with low independent relevance to a load-balancing heuristic. I treat it as a non-load-bearing reference.

US 5,630,079 — Xerox, "Document job key to tailor multifunctional user interfaces," issued 1997-05-13 (§ 102(a)/(e)). Title and the patent's own description indicate it concerns job-key/attribute-driven tailoring of multifunction device behavior. I could not verify its full text; I treat it as secondary art supporting the attribute-based job model (limitation 1.3), not as a primary reference.

US 5,715,381 — Xerox, "Method of creating and managing packages, including multiple documents, in a printing system," filed 1994-08-08, issued 1998-02-03 (§ 102(e); cited in the family annex). General print-job packaging/management background.

3.2 What the prior art does not squarely show on its face

• No single reference of record recites a numeric per-device concurrency cap labeled MCJP compared against a device- or system-reported job count to trigger a third "saturated" printer state that blocks submissions.
• US 5,559,933, though EPO-rated "X," may not, on the record I could verify, expressly teach the concurrency-cap-plus-threshold-gate mechanism. (This is exactly the gap the patentee would argue.)

The entire § 103 case therefore turns on whether the gap between "monitor/compare device capability and device queue load" and "cap concurrency at a numeric threshold and block sends via a saturated state" is a patentable step or a predictable design refinement. As shown below, it is the latter.

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4. Primary obviousness combinations

Combination A (strongest): US 5,559,933 (primary) + US 5,873,659 + US 5,287,194

• US 5,559,933 supplies limitations 1.1–1.3 and the attribute-driven print-job routing to multiple printers of differing capability.
• US 5,873,659 supplies 1.7 (NJOD) — a supported printer that tracks and reports the jobs in its internal queue via bi-directional protocol.
• US 5,287,194 supplies the motivation and the gating logic (1.8–1.9): consult a printer's capability file (speed, capability) and its observed job queue depth, and route away from / warn about / not assign to a printer whose queue is "backed up."

The only remaining element is 1.5 (a numeric MCJP). A numeric concurrency cap is exactly what one obtains by quantifying the qualitative capability data US 5,287,194 already stores (printer speed, document size, capability) and the "backed up" trigger it already applies. Selecting the number is a design choice dictated by the device's memory/speed — the specification itself frames it that way: "Printers also have varying levels of internal memory for handling and queuing jobs. Accordingly … individual printers are assigned a MCJP attribute based on the number of jobs that can be effectively handled concurrently." That is a statement about routine engineering parameterization, not an inventive insight.

Combination B: US 5,287,194 (primary) + US 5,559,933 + US 5,873,659

Same elements, different ringleader. This framing foregrounds the load-balancing problem statement (the patent's stated field: "improved load balancing of distributed printing systems"). US 5,287,194's scheduler that "automatic[ally] optimally schedules the job to one or a plurality of printers based on availability and capability" is the load balancer; US 5,873,659 supplies device-side queue depth; US 5,559,933 supplies the attribute-database/multi-printer distribution fabric. This is the framing most favorable to a § 103 rejection because it avoids any need to stretch the primary reference.

Combination C: US 5,559,933 + US 5,813,348

• US 5,813,348 supplies both the queue-length monitoring ("number of jobs in queue") and the capacity-profile matching ("printing plants capabilities profile"), plus periodic polling. Combined with US 5,559,933's attribute-database-derived print queues, this supplies 1.3, 1.7 (or an NCJ analog), 1.8, 1.9, and claim 15, leaving only the MCJP integer as a design choice.

Why Combination C is attractive: US 5,813,348's core idea is matching a job profile against a capacity profile and allocating to the machine with capacity. Reducing "capacity" to a numeric concurrent-job figure and refusing to allocate beyond it is the predictable use of a known element (a numeric capacity limit) according to its established function (allocation gating). This is the textbook KSR fact pattern.

Single-reference overlay: US 5,559,933 alone (§ 102 / EPO "X")

The EPO rated US 5,559,933 "X" against claims 1, 4, 6, 7, and 10 in the EP 0 917 044 search report. If that mapping is correct (I could not independently re-derive the EPO's element-by-element reasoning), then claims 1, 4, 6, 7, and 10 are arguably anticipated, and the § 103 analysis for those claims is a fortiori satisfied. I flag this as a lead to verify against the actual EP search report text, not as an established fact — the earlier PTAB section reached the same conclusion and I build on it rather than repeating it.

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5. Motivation to combine — why a PHOSITA would have done this

A § 103 rejection requires an articulated reason to combine, not merely a showing that each element exists somewhere. The motivation here is overwhelming and arises from the references themselves and from the patent's own admissions:

(a) Same field of endeavor / reasonably pertinent art.
Every reference is in network/distributed print job scheduling. US 5,559,933 and US 5,287,194 are both distributed printing / print-controller patents (Unisys and Xerox respectively); US 5,873,659 is printer-side queue management; US 5,813,348 is print job allocation. No reference is from an unrelated field. Under KSR and In re Icon, this is squarely analogous art.

(b) The references expressly critique the same deficiency the patent purports to solve.
US 5,559,933's own background states the problem in the prior art: "the model of multiple print queues feeding multiple hard-wired printers from a mainframe computer system no longer adequately matches current computer system architectures" and the older systems were "print then distribute" systems with long delays. US 5,287,194's whole premise is that a single selected printer may be overloaded while others idle. The patent's stated problem — "one particular printer may have a long job queue and long delay times in printing while other networked printers are in an idle state" — is verbatim the problem US 5,287,194 and US 5,559,933 set out to solve. A PHOSITA reading these references is directed to the very improvement claimed.

(c) The specification's own admissions supply the motivation for the "dumb printer" fallback (NCJ).
The patent admits: "some 'dumb' printers or foreign printers (i.e., printers not supported by a particular printing system) may not be capable of returning feedback information useful in determining load balancing." This is an admission of a known problem in the prior art. Given US 5,873,659's device-reported queue depth (NJOD for supported printers) and US 5,813,348's host-side "number of jobs in queue" (a system-maintained count — exactly the NJOD-unsupported fallback), the NCJ branch of the Markush alternative follows directly: if the device won't tell you its queue depth, count the sends yourself. That is the most elementary form of job accounting and requires nothing beyond ordinary skill.

(d) Predictable results / finite number of solutions.
KSR instructs that where there is "a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill has good reason to pursue the known options." Here the known options for deciding whether to send another job to a printer were: (i) round-robin/FIFO (explicitly criticized in the patent's background); (ii) use print speed (ppm); (iii) use queue depth / number of pending jobs; or (iv) use a computed completion time. The references teach (ii) (US 5,287,194's "speed" attribute), (iii) (US 5,287,194, US 5,873,659, US 5,813,348), and (iv) (US 5,287,194's completion-time criteria). Selecting queue depth capped at a device-specific concurrency number is one of a small, finite, identified set, with a predictable result (stop sending when the device is full).

(e) Design choice: choosing the numeric MCJP.
Once the metric (concurrent jobs) and the comparison (current jobs vs. capacity) are selected, the specific integer value is a design choice set by device memory/speed. The patent's own examples ("1" for a desktop, "5" for a production printer, "10" for the high-speed printer) are arbitrary and the specification concedes they "can be arbitrarily changed." An arbitrarily adjustable parameter is the hallmark of a design choice, not an inventive step.

(f) The "saturated" state is a mere automation of what US 5,287,194 already did with a prompt.
US 5,287,194 tells the user when a queue "is backed up" and lets the user route elsewhere. Replacing the human prompt with a machine state ("saturated") that gates the spooler is the automation of a prior-art mental/human step — obvious under the Federal Circuit's automation line (e.g., automating a known manual task does not confer patentability where the automation is routine).

(g) No teaching away.
Nothing in any reference disparages per-device thresholds, queue-depth metrics, or device-reported status. The art moves toward more device telemetry (US 5,873,659's bi-directional NPAP is a pro-capability-reporting development), which reinforces the combination.

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6. Claim 1 — element-by-element mapping (Combination A)

Legend: ✔ = expressly disclosed; ▲ = supplied by the combination/reasoning; — = not needed.

Conclusion on claim 1: Every element is present in the combination of US 5,559,933 + US 5,873,659 + US 5,287,194, and the sole element not literally echoed (the MCJP integer and its use as a saturation threshold) is a design choice / predictable refinement supported by US 5,287,194's per-printer capability data and its "backed-up queue" heuristic. Claim 1 is obvious under § 103, with US 5,559,933 also presenting a serious (EPO-endorsed) § 102 challenge on its own.

6.1 Where the patentee would push back (steelmanning)

1. "No reference teaches a numeric concurrency cap used as a binary gate on submissions mediated by a newly defined third state." The patentee would argue this is a specific, advantageous architecture, not a mere design choice, and would cite the patent's explanation that it establishes "three tiers of printer operation: idle / printing / saturated."
   • Rebuttal: the three-tier characterization is a description of the result of a threshold comparison, not an additional structural element. A comparison against a configurable numeric limit is the epitome of a design choice; the result (stop when full) is not "unexpected."
2. "The NCJ/NJOD dual-path redundancy for supported and foreign printers is not taught." The patentee would argue the fallback architecture solves a problem (foreign printers) the references don't address.
   • Rebuttal: the claim's Markush "one of NJOD and NCJ" means either alone satisfies it, so the redundancy argument is foreclosed at claim 1 (it would only become a distinguishing feature if the patentee amended to require both). Moreover, host-side job counting is elementary, and US 5,813,348's "number of jobs in queue" is a system-side count.
3. "Hindsight." The patentee would argue the combination is only "obvious" because we know the answer.
   • Rebuttal: the motivation is documented in the references themselves (US 5,559,933's critique of static print-queue/distribute-then-print models; US 5,287,194's queue-depth routing) and in the patent's own admitted prior art ("printers … in an idle state"; "dumb" printers can't report status). That defeats hindsight because the problem and its direction were known before the filing date.

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7. Independent claim 10 (method) and the method claims

Claim 10 recites the same nine elements as the method counterpart, plus a "storing/queuing" step. It is coextensive in substance with claim 1 and fails for the same reasons: the method steps are (i) store attributes, (ii) receive a request and queue a job, (iii) compare NJOD/NCJ to MCJP and set "saturated," (iv) send only if idle/printing. Steps (ii)–(iv) are the routine operationalization of claim 1's system, and US 5,559,933 discloses the job-queueing/distribution method while US 5,287,194 discloses the compare-then-route method.

No claim-10-specific limitation saves it. The preamble "method of performing load balancing" adds nothing patentable (KSR; method-of-use preambles are generally non-limiting when they merely state the result).

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8. Dependent claims 2–9 and 11–18

Net: No dependent claim introduces a limitation that is not either (a) an express disclosure of a reference, (b) a routine programming/design choice, or (c) an admitted design parameter of the patent itself (e.g., the arbitrary MCJP values).

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9. Objective indicia (secondary considerations)

Under Graham prong four and WBIP, LLC v. Kohler Co., objective indicia must have a nexus to the claimed invention and be co-extensive with it. Here:

• No evidence of record for any objective indicium. No litigation, no license attributable to the claims, no industry praise, no copying, no long-felt-but-unmet-need evidence appears in the record (consistent with the prior "Litigation summary" and "PTAB challenges" sections, which found zero proceedings).
• The patent expired 2017-11-07, roughly nine years ago. Commercial success, if any, is not tied to an enforceable claim and would lack nexus to the claimed heuristic.
• The patent was never asserted, which undercuts any inference of industry recognition or economic significance attributable to the claims.
• Any "long-felt need" cuts the wrong way: the need (printer overload vs. idle printers) was already articulated in the cited prior art (US 5,559,933 background; US 5,287,194 premise), which shows the problem was known and being worked on — reinforcing obviousness rather than non-obviousness.

Conclusion: There is no objective evidence that would overcome the prima facie § 103 case.

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10. Bottom line

I conclude that claims 1–18 of US 5,978,560 are more likely than not invalid as obvious under pre-AIA § 103.

• The strongest and cleanest combination is US 5,559,933 (primary) + US 5,873,659 + US 5,287,194, optionally adding US 5,813,348 for the periodic-polling and queue-length-monitoring limitations.
• US 5,559,933 alone is the leading § 102 candidate for claims 1, 4, 6, 7, and 10, carrying the EPO's own "X" rating (which, per the EPO legend, means the document alone renders the claims not novel or not inventive).
• The motivation to combine is unusually well documented: the references criticize the exact prior-art shortcomings the patent recites, the patent itself admits the "dumb printer" feedback problem, and the remaining gap (numeric concurrency cap + saturation gate) is a design choice / predictable refinement of the queue-depth-vs.-capability comparison the references already disclose.
• No dependent claim adds patentable weight; several (claim 15's periodic polling, claim 17's GUI entry, claim 8's query-based NJOD update, claim 18's null fallback) map almost verbatim onto US 5,813,348, US 5,559,933, and US 5,873,659.

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11. Caveats, uncertainties, and verification notes

1. Not verified in this pass: the substantive content of US 5,179,636 (Canon) and US 5,630,079 (Xerox) — I ran out of search budget before confirming their disclosures. Neither is load-bearing in my combinations; both are treated as background/secondary. Confirm before relying on them.
2. EPO "X" rating: I rely on the prior section's statement that EP 0 917 044's search report rated US 5,559,933 as "X" against claims 1, 4, 6, 7, 10. I could not independently reproduce the EPO's element-by-element reasoning; treat the single-reference anticipation theory as a lead to confirm, not an established fact. Also note (per § 0 above) that "X" under the EPO legend encompasses lack of inventive step taken alone, not only anticipation.
3. Pre-AIA § 102(e) availability: US 5,873,659 (filed 1996-04-24) and US 5,813,348 (filed 1996-06-17) are relied on as § 102(e)/§ 103 art based on their pre-1997 filing dates and post-filing grants. Confirm the applicant's actual invention date if a § 102(e) date becomes contested (a pre-1996 invention date could remove them as § 102(e) art, though they would remain available for § 103 as "prior art" under § 103(a)'s broader reach only if they also qualify under § 102 — a point to brief).
4. Claim-term inconsistency: the claims recite "max-concurrent-jobs-processing" while the Summary recites "maximum-concurrent-job-processing." The claims control, but capture this in any claim chart.
5. This is a technical invalidity analysis, not a legal opinion or advice. An invalidity contention for litigation or an IPR would require a formal element-by-element claim chart with pin cites to each reference's column/line (or paragraph) numbers, which I have flagged at the reference level but not exhaustively pinned to col./line here.
6. Practical posture reminders (from the prior sections, not repeated here): the patent is expired, no PTAB proceeding ever existed, and there is no § 315(e)(2) estoppel. The invalidity story is therefore unexplored rather than hardened — but its practical leverage is temporal (expiration/damages cutoff), not equitable.

Sources consulted:

• US 5,978,560 Google Patents record and full text (authoritative for the patent): https://patents.google.com/patent/US5978560/en
• US 5,559,933: https://patents.google.com/patent/US5559933A and PDF https://patentimages.storage.googleapis.com/42/72/06/a0352431ca8b9f/US5559933.pdf
• US 5,287,194: https://patents.google.com/patent/US5287194A/en and https://uspto.report/patent/grant/5287194
• US 5,873,659: https://patents.google.com/patent/US5873659
• US 5,813,348: https://patents.google.com/patent/US5813348 and https://patents.searchlight.law/doc/US5813348
• EP 0 917 044 (family) text: https://patentimages.storage.googleapis.com/80/f4/d7/7aa915f9c7377f/EP0917044B1.pdf ; https://patents.google.com/patent/EP0917044B1/en
• EPO "X" document legend (for the correction in § 0): https://patentimages.storage.googleapis.com/69/ea/bc/b469b0250ad076/WO2000068015A3.pdf