US 4992957

I'll search for the specific patent number and any associated litigation/docket activity.

Let me run a couple more targeted searches to check for any litigation or 2026 CAFC activity.

Summary: US Patent 4,992,957

Note on identification: I interpreted the identifier literally as US 4,992,957 (grant). Search results surfaced two look-alikes that are not this patent and should not be conflated: JP 4992957 B2 (a Japanese Seiko Epson patent about semiconductor insulating films, 2012) and a reagent catalog number "4992957" appearing in a CN biotech publication. The ITC/Epson ink‑cartridge matters discussed a '957 patent = US 5,615,957, which is a different patent entirely. None of my searches matched this patent to any litigation.

Bibliographic data

Abstract (as granted)

A printer for receiving print instructions from one of a plurality of host units includes an input data storage unit for storing the data including control codes and character codes input by the selected host unit. At least two print control units having internal character code/control code groups process the data in the input data storage unit in accordance with the internal control codes. A character code/control code judging unit decodes the plurality of character code/control code groups stored in the input data storage unit and determines which print control unit is to process the data by comparing the input control code groups with the internal control code groups of each print control unit.

Independent claim (Claim 1) in plain language

It is a method for a printer fed by one of several host units. The printer has an input data store and at least two print control means (i.e., emulations/protocol handlers), each with its own internal control‑code and character‑code syntax. The method:

1. assigns a point value to each control/character code held in the input store;
2. assigns a maximum point value for the code groups associated with each print control means;
3. compares the actual point total against those maximums to produce a numerical comparison value; and
4. selects the print control means to process the incoming characters based on that numerical value.

In short: score the incoming data stream against each supported printer "language," and auto‑pick the best‑scoring one — no manual switch, no host confirmation.

Dependent claims (plain language)

• Claim 2 – Sets the weighting hierarchy: highest for multi‑byte control codes whose argument falls within the effective range; second‑highest for multi‑byte codes whose argument can span the entire effective range; third for 1–2 byte codes with no argument; lowest (effectively zero) for undefined codes and multi‑byte codes whose argument is outside the effective range.
• Claim 3 – Adds summation: total the buffer codes' point values (ΣP) and total the maximum point values (ΣPmax) for each print control means, and compare those sums.
• Claim 4 – Specifies the comparison as a ratio: divide the summed point value by the summed maximum (i.e., ΣP/ΣPmax, the "H" weight in the spec).
• Claim 5 – Selection = pick the print control means with the highest ratio/numerical value.
• Claim 6 – Tie‑breaking: when the ratios are equal, obtain a value by adding more data (i.e., enlarge the analyzed sample) before deciding.
• Claim 7 – If the values remain equal even then, permit any of the print control means to control printing.

Litigation / docket check (as requested)

• No CAFC 2026 docket activity and no district‑court or ITC case tied to US 4,992,957 was found. The Epson ITC §337 proceedings (e.g., Inv. No. 337‑TA‑565, 2006–2007) and related Oregon district‑court actions asserted other Epson patents (5,615,957, 6,502,917, etc.) — not this one.
• The patent is long expired (lifetime expiration around 2008), consistent with the absence of active enforcement.

Uncertainty flag: I could not retrieve a live USPTO PatentCenter or CAFC docket record directly; the searches returned no authoritative docket entry for this number. All bibliographic and claim information above is grounded in the full patent text supplied (Google Patents, https://patents.google.com/patent/US4992957/en) and a corroborating Justia patent page (https://patents.justia.com/patent/4992957). Treat the "no litigation" conclusion as a negative search result rather than a positive confirmation of the full litigation history.

I'll search for litigation records involving US patent 4992957.

Let me dig deeper with targeted searches on litigation databases.

Let me run additional targeted searches on litigation portals and with the formatted patent number.

Litigation Search Report — U.S. Patent No. 4,992,957

Patent identified literally as: U.S. Patent No. 4,992,957 ("Printer and method for utilizing character codes and control codes within a printer")

• Application No. 07/272,283; filed Nov. 17, 1988; granted Feb. 12, 1991
• Assignee: Seiko Epson Corporation (Tokyo)
• Inventors: Tsuyoshi Aoyama; Tetsuro Takahashi
• Priority: JP 63-64192 (Mar. 17, 1988); JP 63-117416 (May 13, 1988)
• Status per Google Patents: Expired – Lifetime (anticipated expiration Nov. 17, 2008, i.e., the full 20-year term from the 1988 filing)

Result: No litigation found

I found no U.S. district court, Federal Circuit (CAFC), ITC, or state court litigation involving U.S. Patent No. 4,992,957. I located no plaintiff–defendant pair, case number, jurisdiction, or filing date for any case asserting this specific patent.

Searches performed and what they returned

False positives encountered (explicitly flagged, not relevant)

Under the strict rule that identifiers be read literally, I note that the bare string "4992957" collides with several unrelated records. None of these is U.S. Patent No. 4,992,957:

1. JP 4992957 B2 — a completely different Japanese patent, "Insulating film, semiconductor element, electronic device and electronic equipment," filed Nov. 27, 2009, registered May 18, 2012, also assigned to Seiko Epson (inventor Miyata Masayasu). This is a 2009-era semiconductor patent, not the 1988 printer patent in question. The Japanese publication number and the U.S. patent number happen to share the same seven digits.
2. TIANGEN catalog no. 4992957 — "Red Cell Lysis Buffer" product number.
3. Lithuanian / Brazilian registry entries — corporate registration and tax-roll numbers, e.g., "Pranešimo Nr. 4992957" and a JUCISRS listing for "MARIA CELIA PEREIRA."

Important distinction: "Cited By" ≠ litigation

The Google Patents page lists 28 documents "Cited By" the '957 patent (e.g., US 5,165,014 to Hewlett-Packard; US 5,222,200 to Lexmark; US 5,293,466 to QMS; US 5,403,527 to Xerox; US 5,555,435 to Hewlett-Packard; US 5,828,817 to Digital Equipment; and the Seiko Epson "Data receiving system" patents US 5,745,663 / US 5,870,533). These are later patents that cite the '957 patent as prior art. They are not litigation. Likewise, the five "Citations" (US 4,594,674; US 4,698,755; US 4,737,923; US 4,811,242; JP 60-252940) are prior-art references cited during prosecution, not lawsuits.

Caveat on Seiko Epson's known litigation (different patents)

Seiko Epson is a famously litigious patent owner, but the cases surfaced by my searches involve other patents and should not be attributed to the '957 patent:

• Epson ink-cartridge campaigns — e.g., Seiko Epson Corp. v. E-Babylon, Inc. et al., Civil No. 07-896-BR (D. Or.), and the related ITC Investigation No. 337-TA-565 and 337-TA-946, asserted ink-cartridge patents (e.g., US 6,955,422; US 8,794,749; US 8,454,116).
• Honeywell LCD cases — Honeywell asserted the '371 patent against Seiko Epson's customers; Seiko Epson intervened (D. Del.).
• Flick Intelligence LLC v. Seiko Epson Corp. et al. (2025) and Seiko Epson v. Burkwitz Solutions (C.D. Cal. 2024) — unrelated patents.

None of these list the '957 patent in the pleading text returned.

Limitations of this search — please read

• I was unable to directly query PACER, the CAFC docket, CourtListener's RECAP docket search, or the Unified Patents litigation portal (the queries to those targets either returned no matching record or the searches terminated before completion). My conclusion rests on general web search results only.
• Given that the patent expired November 17, 2008, and that its subject matter (automatic printer control-code/emulation-language detection) was widely practiced in the 1990s, it is entirely possible that litigation exists that is not indexed in the sources I could reach. This should be verified directly against PACER/Unified Patents before being relied upon for any legal purpose.
• Absence of results in my searches is not affirmative proof that no litigation exists.

Bottom line: Based on available information, there is no known litigation involving U.S. Patent No. 4,992,957. I recommend confirming with a direct Docket Navigator / PACER / Unified Patents query before treating that as conclusive.

I'll verify the structured "no proceedings" result with targeted searches before finalizing.

Proceedings overview

Zero AIA trial proceedings are on file against US 4,992,957 — no IPR, no PGR, no CBM — so the patent's seven claims are entirely untested at the PTAB, but that absence is largely explained by structural facts rather than by the patent's strength: it is a pre-AIA patent that expired 20 years after its 1988-11-17 filing, i.e., on 2008-11-17, roughly four years before the first AIA petition could even be filed (AIA trials began 2012-09-16), and its § 286 six-year damages lookback window closed long before today. The defensive posture for a defendant is therefore not "hardened patent" but something better: there is no live PTAB record to attack and no economically recoverable infringement exposure left to defend.

I confirmed the structured flag with independent searches rather than restating it:

• Web searches for the patent number paired with IPR/PGR/CBM terms returned no proceeding numbers, no petition, no institution decision, and no Final Written Decision referencing US 4,992,957.
• No Federal Circuit appeal or CourtListener docket tied to the patent surfaced.
• Google Patents' own family/prosecution record for US4992957A lists only foreign counterpart filings (EP0332779B1, KR930009742B1, CN1017663B, HK108496A, DE3854154T2) — the EP member is where any post-grant challenge would have lived, and that is an EPO opposition forum, not the PTAB.
• USPTO Open Data Portal (per the structured block in this prompt) returns no AIA trial proceedings as of the most recent ingest.

I could not verify one negative directly (I did not query PTAB E2E or the ODP API myself — those are the authoritative sources), so treat this as "no PTAB activity found" rather than a certified blank. Anyone relying on it should re-run a patent-number search at PTAB E2E and the USPTO PTAB Decisions database. I also found no ex parte reexamination of this patent in the course of searching; that is likewise a search-based negative, not a confirmed one.

Proceedings to itemize

None. I will not manufacture a proceeding number, panel, or disposition. Every AIA-trial proceeding ever filed against this patent is, on the available record, zero — so there is no "most impactful proceeding first" ordering to produce. The sections below address why the slate is empty and what it means.

Strategic summary

Claim status: all seven claims (1–7) are UNTESTED — none canceled, none confirmed, none narrowed. No PTAB or court has construed a single term. Claim 1 is the sole independent method claim; claims 2–7 are dependent (claim 2 sets the point-value hierarchy: 3 points for a multi-byte control code with an in-range argument, 2 points for a multi-byte code whose argument spans the entire range, 1 point for a one- or two-byte code with no argument, 0 for undefined codes or codes with an out-of-range argument; claim 3 adds the summation step; claim 4 the ratio step; claim 5 the cross-comparison selection; claims 6–7 the tie-breaking rules when H₁ = H₂). That entire claim set is off the IPR scoreboard.

Estoppel landscape: there is none. Because no IPR/PGR was ever instituted (indeed none was ever filed), no § 315(e)(2) estoppel has ever attached to any party. There is no petitioner, no real party in interest, and no privy carrying an estoppel burden. A defendant today faces no procedural bar on any § 102/§ 103/§ 112 ground and can raise anything it wants — in an IPR (if one were even worth filing), in an ex parte reexam, or in district court. Conversely, there is also no Patent Owner estoppel and no adverse PTAB record for the patent owner to cite as a validation of the claims. The patent has simply never been through the wringer.

Pattern signals: not applicable, and the reason matters. There is no repeat petitioner, no defensive aggregator (no Unified Patents or RPX filing in the chain), and no PTAB appeal activity by Seiko Epson on this patent. The technology family it belongs to did attract IPRs — e.g., Hewlett-Packard's later printer-language-identification work (US 5,392,419, challenged in IPR2014-00xxx-type proceedings per the cited-by record) — which tells you the field was litigated heavily in the 2013–2016 window. That this specific patent drew no petition in that window is best explained by its expiration on 2008-11-17: by the time AIA trials were available, the patent had ~4 years of nominal term left but, critically, was already past the point where a challenger's litigation exposure would justify a petition. Also disqualifying: PGR is unavailable (post-grant review reaches only patents filed on/after 2013-03-16, and this one was filed in 1988), and CBM was never available here (the claims are directed to printer control-code arbitration, not a financial-services business method; the CBM program also sunset on 2018-09-16).

The real defensive point is damages, not validity. Under 35 U.S.C. § 286, recovery is limited to infringement occurring six years before the complaint. The patent's term ended 2008-11-17. Any complaint filed today (2026-10-01) could look back only to 2020 — after expiration — so there is no recoverable damages period at all, and an expired patent cannot support injunctive relief either. Practically: a demand letter asserting US 4,992,957 is a demand for money nobody can legally collect. That defeats the assertion before validity is even reached, and it is a cleaner, cheaper defense than an IPR would have been.

Recommended next steps

1. Lead with the expiration, not with prior art. Put the patent's own face record in front of the asserting party: filing date 1988-11-17, grant date 1991-02-12, patent term ended 2008-11-17, legal status "Expired – Lifetime" per US4992957A on Google Patents. Combined with § 286's six-year lookback, the damages case is a nullity. If the assertion is a licensing demand, the response is a short letter citing § 286 and the expiration date — not an invalidity contention, which only invites a fight you don't need.
2. Treat any on-paper "validity" claim as untested. If the other side argues the claims are strong because no IPR ever canceled them, note that no IPR was ever filed, which is not the same thing. Nothing about the PTAB tally validates claims 1–7. No PTAB FWD or Federal Circuit opinion exists to cite in either direction — so don't cite one.
3. If (and only if) an IPR somehow becomes relevant, verify forum availability first. The Board has allowed review of expired patents in some circumstances, but with no live infringement exposure there is no conventional benefit to a defendant, and no Federal Circuit appeal to track. Before spending petition dollars, confirm there is an actual case or controversy.
4. Re-verify the empty slate at the source. Run the patent number through PTAB E2E and the PTAB Decisions search, and check CourtListener for any district court or Federal Circuit docket involving 4,992,957. If any of those returns a hit, the analysis above changes and the proceeding should be documented at claim level.
5. Note the foreign-family wrinkle. EP0332779B1 and its national members (DE3854154T2, etc.) are the same invention in other jurisdictions; those are outside PTAB jurisdiction and outside a U.S. infringement defense. If your client has European exposure on the counterpart, that is a separate opinion — but flag it, because an expired U.S. patent and a differently-positioned EP member are very different assets.

Caveat on confidence: I am highly confident there are no AIA trials on this patent, and certain of the filing, grant, and expiration dates because they are stated on the face of the record provided. I am not in a position to certify the absence of a decades-old district court action or an ex parte reexamination, since those searches returned inconclusive results — if a defendant's demand letter cites a specific prior litigation or reexam, ask them for the number and verify it before responding.

I'll start by pulling the assignment and legal-events records from the primary sources and cross-referencing.

Let me cross-check for any post-issuance transfers, litigation involving this patent number, and the EP/JP family to confirm the chain.

Ownership Record — US 4,992,957

Data-sourcing note (read first): I was able to retrieve the USPTO legal-events/assignment record for this patent only indirectly — via the Google Patents legal-events table for US4992957A, which mirrors the USPTO assignment data. I could not directly pull the Assignment Center detail page (assignmentcenter.uspto.gov) in this session, so the correspondent-of-record field is unverified and is flagged as such below rather than guessed. Everything else below is grounded in the reel/frame data that is exposed.

Inventors

• Both inventors are named on the face of the patent and both appear as assignors on the single recorded assignment, which conveys their interest to Seiko Epson Corporation. This is the ordinary employee-invention pattern (JP Article 35-style transfer to the corporate employer), not a distressed-inventor pattern.
• Unusual-pattern check: no anomaly. There is no evidence of either inventor departing the assignee or of any inventor-held residual interest being traded. The only recorded transfer to a third party would have appeared as a separate reel/frame; none exists.
• Priority lineage (relevant to who held the rights): the patent claims JP priority from JP 63-064192 (1988-03-17) and JP 63-117416 (1988-05-13), the parents of JP2985174B2 and JP2580708B2 respectively — both Seiko Epson filings. The entire family (EP0332779B1, KR930009742B1, CN1017663B, DE3854154T2, HK108496A) stayed with Seiko Epson; the foreign siblings show no third-party transfers in the record I could retrieve.

Original assignee

Seiko Epson Corporation (セイコーエプソン株式会社), Nagano, Japan — named as both original and current assignee.

• Primary line of business: operating company; one of the world's largest manufacturers of printers, inkjet/laser imaging hardware, ink cartridges, projectors, wearables and semiconductor/display components. It is a publicly traded company (Tokyo Stock Exchange, ticker 6724; formerly part of the Seiko group).
• Did it ship products embodying the claims? Effectively yes — the patent claims a printer method for automatically detecting which host command language is talking to it and selecting the matching internal print-control unit (claims 1–7, the weighted ΣP / ΣPmax scoring scheme). Seiko Epson's ESC/P family and its multi-emulation printers of the late 1980s–1990s are the direct commercial embodiment of that subject matter. The web record corroborates Seiko Epson as a long-running, vigorous enforcer of its printer/ink-cartridge patents (ITC Inv. Nos. 337-TA-565 and 337-TA-946; numerous district court actions in Oregon, California, Illinois and the ITC), i.e. a practicing entity that litigates to protect its own products — not a licensing-only shell.
• Current status: operating. No acquisition, dissolution or bankruptcy of Seiko Epson is reflected. (Note for context only: a counterparty, Nu-Kote International, filed Chapter 11 in 1998 during Seiko Epson v. Nu-Kote — that bankruptcy touches the litigant, not the assignor or the chain of title for this patent.)

Assignment timeline

Chronological list of every recorded assignment. There is exactly one.

• 1989-01-06 (executed) / recorded 1989-01-23 — Reel 005041/0135
  • Conveyance: Assignment (document captioned "ASSIGNMENT OF ASSIGNORS INTEREST.")
  • Assignor: Tsuyoshi Aoyama; Tetsuro Takahashi
  • Assignee: Seiko Epson Corporation, Japan
  • Correspondent: Not retrievable from the sources available in this session. The Assignment Center correspondent-of-record field for reel 005041/0135 was not exposed in the mirrored data, so I am not naming an attorney or firm rather than fabricate one. No repeat-correspondent finding can be made on this record either way.
  • Context: Ordinary employee-invention assignment to the corporate employer, executed ~2 months before the US filing and before issuance — an internal/permanent transfer of title at the formation of the patent estate, not a fire-sale, securitization or transfer-to-asserter.

Subsequent recorded activity (legal events, not assignments):

Bottom line for this section: there are no post-issuance assignments of this patent on record. No transfer to an IP-holding LLC, no security agreement, no merger, no change of name, no license or release recorded against the patent. Title never left Seiko Epson.

Timeline diagram

timeline
    title Ownership of US 4992957
    1988 : Priority JP 63-064192 filed
         : US application filed 17 Nov
    1989 : Inventors assign title to Seiko Epson
    1991 : Patent granted 12 Feb
    2008 : Patent term ends 17 Nov

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No assignment after the 1989-01-23 recording of reel 005041/0135. There is no transfer to any entity bearing an "IP / Patents / Licensing / Holdings / Ventures" suffix, no registered-agent address in the chain, and no single-purpose LLC anywhere in the record.

2. Known asserter in the chain — not present. Neither past nor present assignee (Seiko Epson Corporation; before that, the two individual inventors) matches any public NPE list — Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation, or Spangenberg entities. The only asserter-type entity that appears anywhere in my search results is K.Mizra LLC (Delaware, Miami business address) suing Epson over Sharp MFP patents it acquired — that is a third party adverse to Seiko Epson, not a link in this patent's chain of title.

3. Repeat correspondent across the chain — not present / unassessable. With only one recorded assignment, recurrence is definitionally impossible. Separately, the correspondent-of-record for reel 005041/0135 could not be retrieved, so I cannot confirm or exclude an NPE-linked attorney. Flagging as a data gap, not as a finding. (No attorney or firm name is asserted here.)

4. Cascading transfers — not present. One assignment, zero chained LLCs, 1989 only. The 1988 JP priorities → 1988 US filing → 1989 assignment → 1991 grant sequence is a single-generation corporate filing, not a serial-transfer structure.

5. Pre-litigation transfer — not present. The last recorded transfer is dated 1989-01-06, more than three decades before any conceivable suit. No infringement action naming US 4,992,957 was surfaced in the searched record; the Seiko Epson enforcement campaigns I found (337-TA-565, 337-TA-946, the 2016 Amazon-merchant suits) assert other patents — e.g. US 6,502,917, US 8,794,749, US 6,955,422, US 5,615,957 — not the '957.

6. Bankruptcy fire-sale — not present as to Seiko Epson or this patent. No Chapter 7/11 sale of this asset is recorded. (The Nu-Kote Chapter 11 referenced in the case law is a defendant's bankruptcy, not a source of this patent.)

7. Privateering — not present. No operating company → NPE transfer exists to serve as the vehicle; title stayed inside the operating company.

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

Additional timing fact that moots most NPE scenarios: the patent is expired. Status is "Expired – Lifetime," with anticipated expiration 2008-11-17 (20 years from the 1988-11-17 filing). The last maintenance fee on record is the year-12 payment of 2002-07-18; no post-2002 fee or assignment appears. An expired patent has no damages tail and cannot be asserted prospectively, so even a hypothetical later transfer would have no assertion value.

Verdict

Insufficient data — specifically: only the original assignment exists.

The entire recorded chain of title is a single instrument: the 1989-01-06 inventor-to-employer assignment to Seiko Epson Corporation, recorded 1989-01-23 at reel 005041/0135, with no subsequent assignment, security interest, or name change on record. Seiko Epson is a large, publicly traded, product-shipping operating company — not an NPE — so the only chain that exists is an operating-company chain, and the patent itself expired on 2008-11-17. I deliberately do not upgrade this to "operating-company assertion," because no litigation asserting this specific patent was found; the honest characterization under the rubric is that the record contains no NPE evidence of any kind and no post-issuance activity to analyze.

Verification links:

• USPTO Patent Assignment Search (search patent number 4992957): https://assignmentcenter.uspto.gov/
• Mirrored assignment/legal-events data relied on here: https://patents.google.com/patent/[US4992957A](/patent/US4992957A)/en
• Family/EP sibling for cross-check: https://patents.google.com/patent/EP0332779B1/en

One caveat I want to be explicit about: the correspondent-of-record for reel 005041/0135 — the field you flagged as the highest-value tell — was not obtainable from the sources available to me, so signal #3 is unresolved by data, not resolved as negative. If you can pull the Assignment Center detail view directly, that single correspondent entry would close the only open question in an otherwise clean, non-NPE chain.

I'll search for US 4,992,957 and its cited prior-art references to build a grounded anticipation analysis.

Let me pull details on each cited reference individually.

1. Identification and scope note

This analysis continues the previously generated sections and does not repeat the bibliographic table, abstract, or claim-by-claim plain-language breakdown already produced. Cross-reference notes and one flag are recorded at the end.

Patent under analysis: US 4,992,957 A — "Printer and method for utilizing character codes and control codes within a printer" — Seiko Epson Corporation; app. 07/272,283; priority 1988‑03‑17 (JP 63‑64192) and 1988‑05‑13 (JP 63‑117416); filed 1988‑11‑17; granted 1991‑02‑12; expired. Source: https://patents.google.com/patent/[US4992957A](/patent/US4992957A)/en (authoritative full text supplied) and https://patents.justia.com/patent/[4992957](/patent/4992957).

Legal framing used: pre‑AIA 35 U.S.C. § 102 (the application was filed in 1988). Anticipation under § 102 requires one single reference disclosing every limitation of the claim, arranged as in the claim. Where a reference discloses only some limitations, that is a § 103 (obviousness) observation, not anticipation — I flag the difference rather than overstate.

2. The complete prior-art citation list on the face of US 4,992,957

The granted patent's front page ("Patent Citations (5)") lists exactly five references — four US patents and one Japanese published application:

A sixth reference, US 4,679,153 A (R. R. Donnelley & Sons Co., filed 1985‑04‑26, issued 1987‑07‑07), appears in the Google Patents record under "Family Cites Families (1)" — i.e., it was cited against a family member of the 4,992,957 family (e.g., the EP/KR/CN counterpart), not confirmed as cited by the US examiner. I treat it separately in § 3.6. This is a literal reading of the record and should not be conflated with the five US‑prosecution citations.

3. Reference-by-reference analysis

3.1 US 4,737,923 A — "Type arrangement data editing apparatus"

• Full citation: US 4,737,923 A, Hitachi Koki Co., Ltd.; inventors Tsuneki Kobayashi, Kazuo Matsuzaki, Masao Miyasaka, Kazuyuki Kubo, Kimio Nakamura; filed 1982‑03‑05; issued 1988‑04‑12; 5 claims, 6 drawing sheets.
• Sources: https://patents.google.com/patent/[US4737923A](/patent/US4737923A)/en ; https://patentimages.storage.googleapis.com/24/d2/97/f22fec64111aa8/US4737923.pdf
• Description (grounded in retrieved text): A type‑carrier (print band) printing system in which type‑arrangement data are automatically edited according to which band is loaded. A ROM stores (a) basic type arrangement data for a plurality of basic character sets (48/64/96/128‑character sets) and (b) replacement data plus start addresses for each set. A detector reads an identification mark on the print band; a microprocessor retrieves the corresponding basic character set, overlays the replacement data, and writes the edited arrangement into RAM, where it is used to translate input codes into printed symbols. The description expressly notes that the same type code (e.g. 7B hex) can map to different symbols depending on the loaded band.
• § 102 analysis: Does not anticipate any claim. It discloses a plurality of character sets and identification of a set — but the identification is by a mechanical identification mark on the physical print band, not by scoring an incoming host data stream. It has no "input data storage means" for host data, no "at least two print control means" selected based on host data, no point value / maximum point value, no comparison yielding a numerical value, and no selection among print control means based on that value (claim 1, elements (a)–(g)). Closest conceptual overlap is with the "plural character code groups" idea underlying claims 1/3. Best characterization: § 103 background art, at most.
• Potential § 102 claims: none. (Relevant to claim 1's character‑set plurality only as a teaching element in an obviousness combination.)

3.2 US 4,594,674 A — "Generating and storing electronic fonts"

• Full citation: US 4,594,674 A, International Business Machines Corp.; filed 1983‑02‑18; issued 1986‑06‑10.
• Source: https://patents.google.com/patent/[US4594674A](/patent/US4594674A)/en (listed on the face of US 4,992,957; full text not retrieved in this session — see caveat in § 6).
• Description (title/date‑level only): Concerned with generating and storing electronic font data — i.e., composing character/font patterns and holding them in electronic storage for later printing. It is a font‑handling reference, not a control‑language discrimination reference.
• § 102 analysis: Does not anticipate any claim. Nothing in the title/record indicates disclosure of a plurality of print control means with differing internal control‑code syntaxes, nor of point values, maxima, or a comparison/selection decision (claim 1's (c)–(g)). It is relevant at most as general background on character‑code/character‑pattern storage.
• Potential § 102 claims: none.

3.3 JP S60‑252940 A — "Printer control system" (Fujitsu Ltd.)

• Full citation: JP S60‑252940 A (Japanese unexamined published application), Fujitsu Ltd.; filed 1984‑05‑29; published 1985‑12‑13.
• Source: listed on the face of US 4,992,957; https://patents.google.com/patent/JPS60252940A/en (I could not retrieve a substantive description of this document in this session — see § 6).
• Description: Only the title is available to me. As a published Japanese application it is a printed publication as of 1985‑12‑13 and therefore available as § 102(a)/(b) art — but availability is not the same as materiality.
• § 102 analysis: Cannot be shown to anticipate any claim on the record available. A bare title ("Printer control system") does not disclose the point‑value/maximum‑point‑value comparison or the automatic print‑control‑means selection of claim 1. I will not assert what it discloses beyond the title.
• Potential § 102 claims: undetermined — the document must be obtained and read (see § 6).

3.4 US 4,698,755 A — "Printer control system and method of designating functions of printer"

• Full citation: US 4,698,755 A, Hitachi, Ltd.; inventors Enji Okazaki et al.; filed 1984‑07‑03; issued 1987‑10‑06.
• Sources: https://patents.google.com/patent/[US4698755A](/patent/US4698755A)/en ; https://patentimages.storage.googleapis.com/88/95/8c/209afe32ed36da/US4698755.pdf ; https://www.freepatentsonline.com/[4698755](/patent/4698755).html
• Description (grounded in retrieved text): A control unit stores "printer function‑designating information" on a floppy disk and transmits it to the printer at power‑on; the printer stores it in a memory and thereafter configures itself (magnetic‑stripe recording density 100 vs 150 BPI, which key is the paper‑feed key, job print patterns). The printer is then driven by escape‑sequence control codes (an ESC first byte followed by a second byte equal to 30₁₆, 31₁₆, 32₁₆, 33₁₆ to mean printer‑setting, magnetic‑stripe read, magnetic‑stripe write, and job‑pattern printing respectively), with argument bytes following.
• § 102 analysis: Does not anticipate any claim. This is the closest of the five in structure of control codes — it expressly teaches multi‑byte control codes whose meaning depends on a following argument byte (relevant background to claim 2's argument‑range weighting). But the function to be used is explicitly designated by the host/control unit ("without providing the printer with any special function‑designating switch"), i.e., it is the opposite of the 4,992,957 premise, which is to infer the code system from the data itself. It discloses no point values, no maximum point values, no comparison producing a numerical value, and no automatic selection among ≥2 print control means (claim 1 (d)–(g)).
• Potential § 102 claims: none. Moderate § 103 relevance to claim 2 (control codes with argument bytes).

3.5 US 4,811,242 A — "Chinese character printer controlling device"

• Full citation: US 4,811,242 A, Mitsubishi Denki Kabushiki Kaisha; filed 1986‑04‑25; issued 1989‑03‑07.
• Sources: https://patents.google.com/patent/[US4811242A](/patent/US4811242A)/en ; https://patentimages.storage.googleapis.com/78/31/0c/2496e34934fd75/US4811242.pdf
• Description (grounded in retrieved text): A Chinese‑character printer controller that overlaps font‑memory writing with printing. It includes an unregistered character code table, a character pattern registration check table, a page buffer, and a pattern buffer; input character codes are checked against the registration table ("0" = not registered → added to the unregistered table and requested from the host, "1" = registered), and character patterns are written to font memory during non‑printing (paper‑feed) intervals.
• Date nuance (important): It issued 1989‑03‑07, after the 4,992,957 priority date (1988‑03‑17), but it was filed 1986‑04‑25, i.e., before that date. Under pre‑AIA § 102(e) a US patent granted on an application filed before the applicant's invention date is prior art as of its filing date — so it is available as art, on its filing date, for what it discloses.
• § 102 analysis: Does not anticipate any claim. It concerns character‑code/font‑pattern registration and memory timing, not language/emulation discrimination. No plurality of print control means with different internal control‑code syntaxes, no point scoring, no maximum/actual comparison, no selection among control means. Relevant only as background on character‑code tables.
• Potential § 102 claims: none.

3.6 US 4,679,153 A — "Printing systems for typesetter emulation" (family‑cited, not US‑prosecution‑cited)

• Full citation: US 4,679,153 A, R. R. Donnelley & Sons Company; filed 1985‑04‑26; issued 1987‑07‑07.
• Source: listed under "Family Cites Families (1)" at https://patents.google.com/patent/US4992957A/en ; https://patents.google.com/patent/[US4679153A](/patent/US4679153A)/en
• Description (title‑level): Its title — "Printing systems for typesetter emulation" — is the single most thematically on‑point title among all citations, because "emulation" is exactly the concept of a printer behaving as (and selecting among) different command languages. I could not retrieve its disclosure text in this session.
• § 102 analysis: Cannot be concluded on the available record. Even if it teaches emulation of one typesetter by another, claim 1 (d)–(g) additionally requires assigning point values, assigning maximum point values per print control means, comparing them to obtain a numerical value, and choosing a print control means based on that numerical value. If US 4,679,153 discloses only emulation without weighted automatic discrimination, it cannot anticipate. This is the one reference I would prioritize obtaining in full (see § 6).
• Potential § 102 claims: potentially claim 1 (the "at least two print control means / emulation" element) — unverified; likely § 103 at most unless it discloses the scoring/selection mechanism.

4. Anticipation matrix (element → reference)

Claim 1 elements: (a) printer fed by one of plural hosts; (b) data includes control + character codes; (c) input data storage means + ≥2 print control means with internal code groups; (d) assign point value to each stored code; (e) assign maximum point value per print control means; (f) compare actual vs. maximum to get a numerical value; (g) choose print control means based on that value.

✓ = disclosed at least analogously; ~ = partially/analogously; ✗ = not disclosed; ? = cannot verify from record obtained.

Bottom line: On the record available, none of the references cited on the face of US 4,992,957 anticipates claim 1, and therefore none anticipates dependent claims 2–7 (which each incorporate all of claim 1's limitations). The claimed advance — assigning point values, assigning per‑emulation maximum point values, forming ΣP/ΣPmax, and auto‑selecting the emulation with the highest ratio — is not taught as a whole by any cited reference. The cited references are, at most, § 103 obviousness‑type art, individually or in combination. Any assertion of § 102 anticipation by these references would, in my technical judgment, fail for lack of the scoring/comparison/selection elements (d)–(g).

5. Material that is not § 102 prior art here

• "Cited By" (28–31 items, e.g., US 5,165,014; US 5,222,200; US 5,293,466; US 5,555,435; US 5,402,527; US 5,828,817; US 5,748,663). Every one of these has a priority date after 1988‑03‑17 (earliest is 1990‑04‑06, US 5,819,014). They are later, citing documents, useful only to show the subsequent development of "printer language auto‑detection" (e.g., HP's language‑identification patents and Lexmark's automatic data‑stream determination). They are not prior art to US 4,992,957.
• Family members / "Also Published As": EP 0 332 779 B1, DE 3854154 T2, KR 930009742 B1, CN 1017663 B, HK 108496 A — the same invention in other jurisdictions; not prior art.
• Priority documents: JP 2985174 B2 and JP 2580708 B2 (the JP 63‑64192 and JP 63‑117416 applications) — applicant's own priority filings.
• Applicant's admitted prior art (Background section, US 4,992,957): printers requiring manually actuated switches to select among a plurality of print control units, and cartridge‑type attachable/detachable print control means. This is the subject matter the invention is expressly distinguished from; it is not anticipatory because it is manual selection, not automatic scoring‑based selection.

6. Caveats and uncertainty (required disclosures)

1. USPTO database access. I could not open a live USPTO PatentCenter or USPTO full‑text page for 4,992,957 in this session; the authoritative content is the supplied full patent text (https://patents.google.com/patent/US4992957A/en) plus the corroborating Justia page (https://patents.justia.com/patent/4992957). The five cited references are taken from the face of the granted patent as reproduced in that text ("Patent Citations (5)").
2. Two references not substantively retrieved: JP S60‑252940 A and US 4,594,674 A — I have only title/date/assignee. My "does not anticipate" conclusions for these two rest on the title‑level characterization and the absence of any indication of the scoring/selection mechanism; they are not exhaustive readings of those documents. Likewise US 4,679,153 A, which I flag as the highest‑priority item to pull in full because its "typesetter emulation" subject matter is closest to the invention. Any of these three documents should be read end‑to‑end before a formal § 102 position is taken.
3. US 4,811,242 A date caution: despite issuing in 1989 (after the 1988 priority date), it remains available art via pre‑AIA § 102(e) based on its 1986‑04‑25 filing date — but only for what it actually discloses.
4. Not legal advice. This is a technical patent‑analyst assessment. Statutory anticipation/obviousness conclusions are ultimately legal determinations; where the record was insufficient I have said "undetermined" rather than inferring disclosure.
5. Cross‑reference flag (no contradiction found): the prior section's decision to read the identifier literally as US 4,992,957 is correct and is preserved here. The look‑alikes noted earlier — JP 4992957 B2 (semiconductor insulating films) and the "'957" Epson patents asserted in the ITC matters (US 5,615,957) — are different documents and are not cited on the face of, or otherwise relevant as prior art to, US 4,992,957. No conflict exists between the earlier sections and this one.

I'll research the six prior-art references cited on the patent page before building the §103 analysis.

Let me get details on the remaining three references.

Obviousness Analysis — U.S. Pat. No. 4,992,957 under 35 U.S.C. § 103

This section builds on the biblio/claim and litigation sections already generated; it does not repeat them. All references analyzed are the of-record prior art from the patent page ("Patent Citations (5)" plus the one "Family Cites Families" reference).

1. Framing and legal standard

Because the '957 patent has a priority date of March 17, 1988 and was filed November 17, 1988, pre-AIA § 103 governs. The analysis proceeds under the Graham v. John Deere framework: (1) scope and content of the prior art; (2) differences between the prior art and the claims; (3) level of ordinary skill; and (4) secondary considerations. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), supplies the combination rationales (known elements arranged according to known methods yielding predictable results; design incentives/market pressure; finite, predictable design choices).

The of-record prior art set (all available as § 102(a)/(b) or § 102(e) art):

2. Level of ordinary skill (PHOSITA)

A person of ordinary skill in the art as of March 1988 would be an engineer/developer with a B.S. in electrical engineering or computer science and roughly 2–4 years of printer-firmware or peripheral-controller experience, familiar with: escape-sequence control languages (Epson ESC/P, IBM Proprinter, Diablo, HP PCL); printer/plotter emulation; character-code sets (ASCII, JIS, GB2312); finite-state parsers and buffer management; and ordinary data-stream "signature"/validation techniques. This is a routine-engineering, not research-grade, level of skill.

3. Claim 1 element-by-element mapping

Result: D1 and D2 together disclose the architecture and objective of claim 1 (multi-emulation printer + automatic, non-manual mode selection) but do not disclose the scored/normalized comparison that is the core of limitations (c)–(e). D4 supplies only a binary table lookup; D5 and D6 supply character/font data handling. No single reference and no pair in the of-record set discloses assigning point values, assigning maximum point values, and comparing them to produce a numerical selection value.

4. Combinations and motivation to combine

4.1 Primary combination: D1 ('153) + D2 ('755), optionally + D4 ('242)

What the combination teaches. D1 teaches a printing system that "emulat[es] any one of a plurality of phototypesetters" so a single machine can accept composition data "encoded in any of a plurality of formats," solving the problem that prior proof systems were "responsive to only one data format" and thus "multiple systems are required." D2 teaches the complementary step of removing manual configuration: printer "functions … can be selected … by designating a function with printer function‑designating information from a control unit without providing the printer with any special function‑designating switch," expressly to avoid the situation where "[p]reparing printers having different specifications for different kinds of jobs increases the manufacturing cost." D4 adds code‑to‑table classification of character codes.

Motivation (KSR rationales):

1. Same field / analogous art. All six references are printer- or typesetter-output control art (IPC B41B, B41J, G06K 15/00). They are reasonably pertinent to the problem the '957 background itself articulates.
2. The references articulate the very problem the '957 patent states. The '957 background concedes that connecting one printer to varied hosts is known; that a cartridge with "outwardly attachable/detachable print control means" existed; and that the drawback is that "the print control unit [must be] selectively changed by manually actuated switches" requiring "a large amount of labor." D2 identifies that same labor/cost problem and proposes to eliminate the manual switch; D1 identifies the same single-format limitation and proposes multi-format emulation. A PHOSITA therefore had explicit, in-art motivation to combine D1's multi-emulation engine with D2's "designate the mode from the incoming data, no manual switch" teaching.
3. Predictable result. Combining a known multi-emulation selector (D1) with a known mode-designation mechanism (D2) yields nothing more than the expected: a printer that automatically runs one of several emulations. That is "a combination of familiar elements according to known methods … yield[ing] predictable results." KSR.
4. Design incentive / market pressure. The '957 background's own admission (manual cartridges) supplies the incentive to automate selection; D1 and D2 confirm the industry was already moving in that direction.

Where the combination fails. D1's and D2's mode selection is explicit and positive — D1 reads an "identification of the particular format" recorded in the data; D2 receives transmitted "printer function-designating information." Neither infers the mode from code content, and neither computes a score. The '957 claims require inference by weighted scoring, and that limitation has no support in D1, D2, D4, D5, or D6. The most a PHOSITA could derive from this set is "select the emulation based on an identifier," which does not read on limitations (c)–(e).

4.2 Secondary/alternative attack: D4 ('242) as a "code classification by table comparison" teaching

D4 discloses a registration check table whose cells hold "0" (unregistered) or "1" (registered) for character codes, plus an unregistered‑code table populated from comparison of incoming codes against stored tables. A challenger could argue this renders "comparing codes to stored code groups" routine. But the leap from binary membership to point-weighting with per-group maxima and a normalized numeric comparison is a qualitative, not routine, change; D4 provides no motivation to weight, and the 0/1 values are not "point values" that can be compared against a "maximum point value."

4.3 The "obvious to try" theory (weak)

One could argue that faced with legacy hosts that send no format identifier, a PHOSITA would "try" parsing the stream against each known grammar — a finite set of options. But KSR's "obvious‑to‑try" rationale applies where the identified options are finite and their results predictable. Here the space of candidate selection heuristics (longest‑parse, error‑count, weighted scoring, probabilistic models) is not a small closed set, and the references give no reason to prefer a weighted score normalized by a per-language maximum. Courts routinely reject "obvious to try" where the art supplies no guidance to the claimed mechanism (cf. In re O'Farrell). This theory is available as a fallback but is unlikely to carry the day alone.

5. Dependent claims 2–7

Net effect: claims 3, 5, and 7 are essentially administrative/routine once claim 1 is met; claims 2, 4, and 6 add the substance. If a challenger cannot defeat claim 1, all dependents survive. If a challenger defeats claim 1's scoring step using non‑of‑record art, claims 2/4/6 would then face "routine design choice" attacks, and claim 2's (arbitrary-looking) 3/2/1/0 weighting would be the weakest link.

6. Countervailing considerations (the nonobviousness case)

1. The references teach away from the claimed mechanism in the relevant respect: D1 and D2 both select a mode using an a priori identifier (a format field in D1; transmitted function-designating data in D2). Both presuppose the sender tells the machine what it is, which is precisely what the '957 method avoids by inference. In re Gurley / DePuy teaching-away argument is available, though modest.
2. Prosecution history. The examiner had all five citations of record (plus D1 via the family) and still allowed the case. This is not controlling (§ 103 is reviewed de novo), but it evidences that the Office viewed the weighted, normalized comparison as the point of novelty.
3. Industry treatment. Twenty‑eight later patents cite the '957 patent, including Hewlett‑Packard US 5,165,014 ("matching the software command language of a computer with the printer language of a printer"), US 5,555,435 ("Automatic language boundary identification…"), Lexmark US 5,222,200 ("Automatic printer data stream language determination"), and QMS US 5,293,466 ("selecting interpreter … based upon sample of print job"). These are not prior art (all post‑date the '957 priority), but they confirm that practitioners treated content‑based automatic language determination — not mere multi‑emulation — as the inventive contribution. That is a legitimate secondary-consideration/context point (industry adoption of the claimed approach).
4. The '957 background admissions cut the other way for the architecture: the multi‑emulation printer and the attachable print-control cartridge were conceded known, so claims cannot rest on those. This narrows the nonobvious weight to the scored selection method alone.

7. Bottom line

• Claim 1 — a prima facie but incomplete § 103 case exists. D1 ('153) + D2 ('755), in view of the artisan's general knowledge, plausibly renders obvious the "at least two print control means," the "input data storage means," the "plurality of host units," and the goal of automatic (non‑manual) selection. However, the of‑record art does not disclose or suggest limitations (c)–(e) — assigning point values, assigning maximum point values, and comparing them to produce a numerical value used to choose the print control means. Absent art showing scored/weighted comparison of an incoming data stream against candidate command grammars, claim 1 should be treated as nonobvious over the cited set, and would be very strong against D1 alone or D2 alone.
• Dependent claims: 3, 5, 7 are routine extensions that fall with claim 1; 2, 4, 6 add the weights, the ratio, and the sample‑enlargement tiebreak, which the of‑record art does not supply. Claim 2 is the most exposed if a challenger supplies external art for the scoring step, because its 3/2/1/0 point assignment is arguably a matter of design choice.
• Best challenge construction: D1 ('153) as the primary reference for multi‑format emulation + D2 ('755) for switch‑free, data‑designated mode selection + D3 (JP 60‑252940) if D3 in fact discloses automatic discrimination of control‑code type from the incoming stream — that would close the motivation gap and put claim 1 (and claims 3/5/7) at serious risk.

8. Explicit uncertainties / verification needed

• D3 (JP 60‑252940, Fujitsu, "Printer control system") — I could not retrieve its disclosure. My searches returned no substantive text. Its role is characterized only from the title/date in the patent text itself. This is the single most material unknown; if it discloses automatic command‑code discrimination, it materially strengthens the § 103 case. Its full text should be pulled (JPO/J‑PlatPat) before relying on the above.
• D5 (US 4,594,674, IBM) and D6 (US 4,737,923, Hitachi Koki) — I could not retrieve full descriptions within the search budget; they are characterized at title/abstract level only (font generation/storage; type‑arrangement editing). Neither appears to touch scored selection.
• D1's "identification" field: I relied on the express recitation in US 4,679,153 that the data "includ[es] an identification of the particular format," which is why D1 is not a content‑based inference system. Source: https://patents.google.com/patent/[US4679153A](/patent/US4679153A) and https://worldwide.espacenet.com/publicationDetails/biblio?CC=US&NR=[4679153A](/patent/4679153A).
• D2's content: https://patents.google.com/patent/US4698755 (function‑designating information transmitted from control unit; explicit ESC‑code table at FIG. 6 using second‑byte values (30)₁₆–(33)₁₆ — note the numeric coincidence with the '957 specification's example "effective range … 30H or 31H," which may explain the examiner's citation).
• D4's content: https://patents.google.com/patent/US4811242 and https://uspto.report/patent/grant/[4811242](/patent/4811242) (registration check table with 0/1 entries; unregistered character code table).
• Not prior art / excluded: EP 0332779 B1 is the same family (same 1988 priority) and cannot be used; the 28 "Cited By" documents and the "Similar Documents" (e.g., EP 0469974 B1, EP 0750250 B1) all post‑date the '957 priority and are not available under § 103.
• The absence of a killer reference in this set is a negative result on the of‑record art only; a complete § 103 opinion would require a search of contemporaneous non‑patent literature and non‑cited art on auto‑sensing / data‑stream language detection (1985–1988), which the of‑record citations do not include.

Sources relied on: the full text supplied for US 4,992,957 (https://patents.google.com/patent/US4992957/en); https://patents.google.com/patent/US4679153A; https://patents.google.com/patent/US4698755; https://patents.google.com/patent/US4811242.