US 6631109

I'll ground this in both the patent text and current search results.

US Patent 6,631,109 B2 — Verified Summary

Sourcing note: The bibliographic data below is taken from the authoritative patent text provided (Google Patents, https://patents.google.com/patent/[US6631109](/patent/US6631109)/en) and cross-checked against search results from Google Patents, Justia (https://patents.justia.com/patent/6631109), and the Federal Circuit's Ricoh v. Quanta opinion (http://cafc.uscourts.gov/opinions-orders/07-1567.pdf). I found no CAFC 2026 docket activity for this patent number — see the litigation section below.

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Bibliographic Data

Family: Four continuation applications all claim the same Mar. 3, 2000 priority and share the title "Method for controlling a multi-pulse record waveform at high velocity in a phase change optical medium": US 10/638,500 → US 7,193,950; US 11/000,202 → US 7,206,271; US 11/491,240 → US 7,382,706; US 11/491,241 → US 7,799,181. Foreign counterparts: EP 1130583 A1 and JP 3839635 B2.

Internal inconsistency to flag: The specification's closing paragraph states the invention "is based on Japanese priority application No. 2000-058399, filed on Mar. 3, 2001," while the priority date is everywhere else given as 2000-03-03. The "2001" appears to be a typographical error in the printed patent, but note it literally rather than correcting it.

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Abstract (verbatim substance)

A light source driving power includes mark/space portions, each mark portion having a pulse width that is a multiple of write-clock period T. A multi-pulse waveform per mark has a front-end portion (first pulse width t₁, high-power write level Pw, starting from middle-power erase level Pe), a multi-pulse portion (write pulses of second width t₂ at Pw and third width t₃ at low-power base level Pb, with duty ratio z = t₂/(t₂+t₃)), and a tail-end portion (fourth pulse width t₄ at Pb, ending at Pe). When medium linear velocity is 5 m/s to 28 m/s, the waveform is controlled so t₁ is 0.1T–1T and t₄ is 0.2T–1.3T.

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Plain-Language Overview of the Independent Claims

There are six independent claims (1, 4, 5, 8, 9, 10), arranged in mirrored method / apparatus / medium triplets:

• Claim 1 — Method (generic optical recording medium). Record phase-change marks by driving a laser with a multi-pulse write strategy having the front-end / multi-pulse / tail-end architecture and duty ratio z defined above; set the medium's linear velocity; and, when the velocity is in the 5–28 m/s high-speed range, hold t₁ within 0.1T–1T and t₄ within 0.2T–1.3T. The point of the invention: fixing these two edge-timing parameters keeps mark edges clean and write-signal asymmetry within the CD-RW standard (−15 ≤ asymmetry ≤ 5) at high speed.

• Claim 4 — Method (rewritable medium, PWM). Substantively the same as claim 1, narrowed to a rewritable medium and expressly reciting a pulse width modulation (PWM) write-clock basis. This is effectively a belt-and-suspenders companion to claim 1 (note the asserted claim in the Quanta litigation was claim 1; the district court also invalidated claim 4).

• Claim 5 — Apparatus (generic). A light source driver unit (LDD) applying the driving power; a write power determination unit (WPDU) setting the multi-pulse waveform as defined above; and a controller setting rotational linear velocity — with the controller causing the WPDU to hold t₁ at 0.1T–1T and t₄ at 0.2T–1.3T in the 5–28 m/s range. This maps to FIG. 3's elements 12 (pickup), 13 (LDD), 16 (CTRL/CPU) and 17 (WPDU).

• Claim 8 — Apparatus (rewritable medium, PWM). Same as claim 5, narrowed to a rewritable medium and PWM write clock.

• Claim 9 — Optical storage medium (generic). A medium storing data blocks recorded by the recited method, where each data block carries first information indicative of t₁ of the front-end portion and second information indicative of t₄ of the tail-end portion in the waveform. This is the "media-carries-its-own-write-strategy-parameters" claim (specification describes this information in wobbling grooves and use of a PCA test-write region).

• Claim 10 — Optical storage medium (rewritable). Essentially identical to claim 9; the only material textual difference is the final clause's reference to "the light source driving waveform" rather than "the waveform." Note this near-duplication as written.

Dependent claims: 2 (medium carries t₁/t₄ info) and 3 (test-write to a test-write region, read back, compute optimum t₁/t₄) depend from claim 1; claims 6 and 7 mirror them under claim 5.

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Supporting Specification Details Worth Noting

• Medium design constraints (FIG. 2): the phase-change material should satisfy vo ≥ 0.7·vwh; vo ≤ 3.0·vwl; Δvo/vo < 0.4; 0.1 < R_A/R_B < 0.6; and vwh/vwl ≥ 2.5 (enabling CAV recording of a 120-mm disc).
• Recording layer: AgInSbTe, formula Ag_α I_β Sb_γ Te_δ with 0.1≤α≤3.0, 5.0≤β≤12.0, 60.0≤γ≤72.0, 22.0≤δ≤30.0; thickness 13–17 nm; N doping optional.
• Experimental basis (FIG. 5): CD-RW at 9.6 m/s (≈8×), 780 nm, NA 0.5; t₁ swept over {0.1T, 0.4T, 0.7T, 1.0T} and t₄ over {0.2T, 0.5T, 0.8T, 1.0T, 1.3T}. Cited prior art includes JP 63-29336, JP 63-266632, JP 63-266633, US 5,150,352, EP 0898272, EP 0737962, WO 98/36411.

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Litigation / Docket Check (This Patent Number Only)

• District court suits: W.D. Wis. 3:06-cv-00462; E.D. Tex. 5:04-cv-00104; N.D. Cal. 5:07-cv-01942 and 3:07-cv-01942 (per Unified Patents litigation data linked from the Google Patents page).
• Federal Circuit: The only appellate decision I can authoritatively confirm is Ricoh Co., Ltd. v. Quanta Computer Inc., 550 F.3d 1325 (Fed. Cir. 2008) (appeal no. 2007-1567). There, the Federal Circuit affirmed summary judgment that claims 1 and 4 of the '109 patent were invalid for obviousness over EP '272 and/or EP '962, rejecting Ricoh's teaching-away and unexpected-results rebuttals; the court vacated and remanded only as to the '552 and '755 patents on contributory infringement/inducement.
• CAFC 2026: My searches of Federal Circuit 2026 scheduled cases and opinions returned no 2026 docket involving US 6,631,109. This is consistent with the patent's expiration (adjusted expiration Jan. 2, 2022).

Uncertainty disclosures: (1) I could not independently reproduce a full-text USPTO PatentCenter/Global Dossier record in this session; bibliographic fields above rest on the authoritative patent text plus Google Patents/Justia listings, which agree. (2) The Google Patents "Current Assignee" field is expressly caveated as possibly inaccurate — I have verified only that Ricoh Company, Ltd. was the original assignee via the recorded Mar. 1, 2001 assignment. (3) I cannot confirm any post-2008 reassignment or any 2026 CAFC activity beyond the absence of hits in the sources searched.

I'll research the litigation dockets for US 6,631,109 specifically, focusing on the case numbers identified on the patent record.

Let me verify the remaining dockets and the parties involved.

Let me pin down the E.D. Tex. 2004 docket and check the Unified Patents caselist.

Known Litigation Involving U.S. Patent 6,631,109

Scope note: I searched for the literal number "6631109" / "6,631,109" only and did not substitute similar numbers. The patent issued Oct. 7, 2003, so any pre-issue dispute would concern a pending application, not the patent. I found two confirmed litigations that name the '109 patent and one docket entry of uncertain subject matter that I could not verify. Date convention: the task header says "Current Date: April 26, 2026" while my session metadata reads 2026-09-29 — flagged, not reconciled.

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Confirmed litigation

1. Ricoh Company, Ltd. v. Quanta Computer, Inc., et al. — W.D. Wis.

Outcome / current status — full procedural history:

• Claim construction — May 11, 2007 (571 F. Supp. 2d 929): "pulse width" construed as "the time interval between the beginning and the end of the pulse" (court refused defendants' "edges" formulation); "multi-pulse portion" required no construction.
• Summary judgment — August 21, 2007, reported at 579 F. Supp. 2d 1110 (W.D. Wis. 2007): the court held claims 1 and 4 of the '109 patent invalid as obvious over EP 0 898 272 and/or EP 0 737 962, and granted summary judgment of noninfringement / no contributory infringement on the '552 and '755 patents.
• Federal Circuit — December 23, 2008, appeal no. 2007-1567, reported at 550 F.3d 1325 (Fed. Cir. 2008) (panel: Gajarsa, Linn, Dyk; per curiam with a Gajarsa dissent as to § 271(c)): affirmed the '109 invalidity holding ("[t]he remainder of the decision is affirmed in all respects"), but vacated and remanded the contributory-infringement and inducement rulings on the '552 and '755 patents. Rehearing denied; Supreme Court certiorari denied.
• Remand trial — November 24, 2009: jury returned a verdict for Ricoh against Quanta Storage Inc., judgment entered in the amount of $14,500,000 (Dkt. 510, Nov. 24, 2009).
• Settlement — April 13, 2011: Ricoh and Quanta settled and the action was withdrawn by stipulation (per the Taiwan IPO case study of this litigation). The docket remained open for ancillary/sealing matters, with orders on sealed documents as late as July 31, 2015 and September 23, 2015.
• Net effect on the '109 patent: claims 1 and 4 held invalid, affirmed on appeal — the dispositive result for the '109 patent in this case.

Sources: https://dockets.justia.com/docket/wisconsin/wiwdc/3:2006cv00462/800 ; https://www.wiwd.uscourts.gov/opinions/pdfs/2006-2009/06-C-462-C-05-11-07.PDF ; http://cafc.uscourts.gov/opinions-orders/07-1567.pdf ; https://www.courtlistener.com/opinion/[1819060](/patent/1819060)/ricoh-co-ltd-v-quanta-computer-inc/ ; https://www.govinfo.gov/content/pkg/USCOURTS-wiwd-3_06-cv-00462/ ; Taiwan IPO case study, https://tiponet.tipo.gov.tw/downloads/module030/information_4_2_4.pdf

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2. Asustek Computer Inc. and ASUS Computer International v. Ricoh Company, Ltd. — N.D. Cal.

Outcome / status:

• November 21, 2007 order (Dkt. 58): the court denied Ricoh's motion to stay and held that, under the Wisconsin judgment, Ricoh is collaterally estopped from asserting claims 1 and 4 of the '109 patent. The court refused to dismiss the '109 patent in its entirety, because § 282 presumes each claim valid independently and § 288 permits suit on any remaining valid claims — i.e., the untested claims (e.g., claims 5–10) were not extinguished by the Wisconsin judgment at that stage. The action was a live dispute over the rest of the '109 patent and the other patents until the W.D. Wis. matter was finally resolved.

Important consolidation flag: The Google Patents page lists two California Northern District entries — 5:07-cv-01942 and 3:07-cv-01942. Based on the filings I retrieved, these are the same case, the "5" versus "3" being the San Jose-division versus San Francisco-division prefix on the same docket number as the case was assigned/reassigned. I did not find evidence of two separate lawsuits. Treat them as one.

Sources: https://www.findforms.com/single_form.php/form/[737081](/patent/737081)/... (Nov. 21, 2007 Order, Case 3:07-cv-01942-MHP) ; http://g.casetext.com/case/asustek-computer-inc-v-ricoh-company ; https://www.plainsite.org/attorneys/paul-hastings-llp/shanee-y-w-nelson/

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Docket entry I could NOT verify — flag

E.D. Tex. 5:04-cv-00104 appears on the Google Patents litigation links but I was unable to confirm the parties, the asserted patents, or whether it involves the '109 patent at all. A contemporaneous news account (CNews) describes Ricoh filing two separate suits against Taiwanese companies in 2004 — one in California against CD-media maker CMC Magnetics and one in Texas against an unnamed CD-drive manufacturer — which is consistent with a 2004 E.D. Tex. filing predating the Quanta case, but the news item does not name the patent(s), and the '109 patent issued only in October 2003, so a 2004 suit could but need not involve it. Do not treat 5:04-cv-00104 as a confirmed '109 case. It must be pulled from PACER/Unified Patents and checked against the complaint before it is relied on.

Also flagged as unrelated (do not conflate): the N.D. Cal. case Ricoh Co. v. Aeroflex Inc., et al. (CV 03-04669 MJJ; also involving Synopsys, Matrox, AMI Semiconductor) and the consolidated In re Ricoh Co., Ltd. Patent Litigation concern Ricoh's '432 and '016 patents, not the '109 patent. Likewise, the E.D. Tex. 5:04-cv-00104 must be checked on its own terms, not inferred from these.

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Bottom line

Two litigations are confirmed to involve U.S. 6,631,109:

1. Ricoh v. Quanta Computer et al., W.D. Wis. 3:06-cv-00462-bbc, filed Aug. 24, 2006 — claims 1 and 4 of the '109 patent held invalid for obviousness, affirmed at 550 F.3d 1325 (Fed. Cir. 2008); after remand, a $14.5M jury verdict (Nov. 24, 2009) on the '552/'755 patents, then a 2011 settlement.
2. Asustek v. Ricoh, N.D. Cal. 3:07-cv-01942-MHP, filed April 6, 2007 — declaratory-judgment action in which Ricoh was held collaterally estopped from asserting '109 claims 1 and 4, but not from asserting the remaining claims.

One unverified docket (E.D. Tex. 5:04-cv-00104) is listed on the patent's litigation metadata but could not be confirmed as an '109 case. No PTAB proceeding, ITC investigation, or post-2011 district-court suit naming this patent was found. I did not reach a query on the Unified Patents caselist before exhausting my search budget, so the negative finding rests on the other sources searched, not on that portal specifically.

Uncertainty disclosures: (1) 5:04-cv-00104 unresolved — verify independently. (2) Whether the 5:07 and 3:07 California entries are formally one case or a transfer formally renumbered — I infer same case but did not see the transfer order. (3) Docket sheet details for the N.D. Cal. matter beyond the Nov. 21, 2007 order (e.g., ultimate disposition) were not retrieved. (4) The task header date (April 26, 2026) differs from my session date (2026-09-29); this affects none of the above, as no post-2011 '109 activity was found.

I'll start by searching for any AIA trial proceedings, then cross-check against the Federal Circuit record.

Let me run additional targeted searches to confirm the absence of PTAB proceedings.

Proceedings overview

There are zero AIA trial proceedings on file for US 6,631,109 — the USPTO Open Data Portal block returns no IPR, PGR, or CBM for this patent, and my independent searches (Google Patents, Justia, PTAB decision databases, CourtListener, Federal Circuit docket material) surfaced no petition number, institution decision, or FWD involving the '109 patent. The breakdown is therefore: active 0 / claims invalidated by PTAB 0 / claims sustained by PTAB 0 / settled 0 / institution denied 0.

The bottom-line defensive posture is inverted from the usual IPR story: the patent was never attacked at the Board, but claims 1 and 4 were held invalid for obviousness by a district court and that holding was affirmed by the Federal Circuit in Ricoh Co. v. Quanta Computer Inc., 550 F.3d 1325 (Fed. Cir. 2008) — a judicial invalidity adjudication, not a PTAB cancellation. Separately, the patent expired 2022-01-02, so IPR is now largely a dead letter for a defendant anyway (see the § 315(b)/expiry analysis below). If a demand letter cites claims 1 or 4, the recipient has an unusually strong, already-affirmed invalidity answer; the untested claims (2, 3, 5–10) are the only live exposure, and they are exposed only for pre-2022 past damages.

Flagged contradiction with the earlier section: the previously generated summary is correct that claims 1 and 4 of the '109 patent were invalidated, and correct that the vehicle was CAFC 2007-1567. What it does not say — and what matters here — is that this was not an IPR. No PTAB proceeding ever touched this patent. Any internal work product that describes claims 1/4 as "canceled by the PTAB" would be wrong; they were held invalid by the district court and affirmed on appeal.

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Proceedings on file

None — no AIA trial proceeding exists

• Type: N/A (no Inter Partes Review, Post-Grant Review, or Covered Business Method review was ever filed)
• Filed: N/A
• Status: N/A — the ODP "PTAB proceedings on file" block is empty, and no proceeding number appears in any public source searched.
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A
• Settlement / termination: N/A
• Appeal: N/A (there is no FWD to appeal)
• Defensive value: Do not cite an IPR to a defendant — there isn't one. Cite the Article III adjudication instead, which is stronger: the invalidity of claims 1 and 4 is a judgment, not an administrative holding, and it survived appeal.

Why the Board never saw this patent (and what it means): The AIA trial regime began 2012-09-16. By then the '109 patent was nine years old, its principal assertion campaign (W.D. Wis. 3:06-cv-00462 and the CAFC appeal) had already run its course, and the patent's adjusted expiry was 2022-01-02. The accused-drive defendants of 2004–2008 had no IPR available to them; the accused-drive defendants who would have had IPR available (2012 onward) had no commercial reason to file. So this is not a "hardened patent that survived the Board" — it is a pre-AIA-era, judicially-invalidated patent that simply aged out before the Board was available as a tool.

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The operative record for a defendant: the Article III invalidity judgment

This is not a PTAB proceeding, but it is the dispositive defensive fact and must be stated with claim-level precision.

• Case: Ricoh Co., Ltd. v. Quanta Computer, Inc., W.D. Wis. No. 06-C-462-C (Barbara B. Crabb, J.); summary judgment reported at 579 F. Supp. 2d 1110 (W.D. Wis. 2007).
• Claims at issue on validity: claims 1 and 4 of the '109 patent. Those were the asserted claims.
• Disposition at the district court: claims 1 and 4 obvious. The sole distinction Ricoh conceded over prior art was the "high-speed range from 5 m/s to 28 m/s"; EP '272 and EP '962 disclosed to 5.6 m/s, creating a presumption of obviousness under Ormco Corp. v. Align Tech., Inc., 463 F.3d 1299, 1311 (Fed. Cir. 2006).
• Federal Circuit: appeal no. 2007-1567, decided 2008-12-23, panel Gajarsa, Linn, Dyk (per curiam). Affirmed as to the '109 patent: "[T]he district court's summary judgment dismissing all claims... The remainder of the decision is affirmed in all respects." The court rejected Ricoh's teaching-away argument (EP '272's "recrystallization upper-limit linear speed" is a property of the medium, not a criticism of the write strategy) and rejected the unexpected-results rebuttal.
  • Opinion: http://cafc.uscourts.gov/opinions-orders/07-1567.pdf
  • CourtListener: https://www.courtlistener.com/opinion/[209414](/patent/209414)/ricoh-co-ltd-v-quanta-computer-inc/
• Claim-construction ruling that still matters (W.D. Wis., 2007-05-11, same case): "pulse width" = "the time interval between the beginning and the end of the pulse" (court refused defendants' "edges" framing); "multi-pulse portion" required no construction (the court rejected defendants' argument that the waveform has exactly three portions, holding "includes" is open-ended). Every independent claim in the patent recites "pulse width" and "multi-pulse portion," so this construction governs any residual dispute. Order: https://ipmall.law.unh.edu/sites/default/files/hosted_resources/Markman/pdfFiles/2007.05.11_RICOH_COMPANY_LTD_v._QUANTA_COMPUTER_INC.pdf

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Strategic summary

Canceled vs. sustained vs. untested. No claim of US 6,631,109 is canceled in the technical sense, because cancellation is a PTAB act and no PTAB trial occurred. What exists instead is a judicially adjudicated invalidity of claims 1 and 4 — the two asserted claims, and the same pair the prior-art challenge was aimed at. Claims 2, 3, 5, 6, 7, 8, 9, and 10 were never adjudicated by anyone — not by the W.D. Wis. court, not by the Federal Circuit, and not by the Board. In particular, independent claims 5 and 8 (apparatus) and 9 and 10 (medium) are untested as to validity. Be precise about this: the untested claims are not thereby good; the same EP '272 / EP '962 art maps onto the same waveform architecture in every independent claim, so the Ormco range-overlap logic would apply with equal force in a fresh forum. It simply has not been run to judgment.

Estoppel landscape. The § 315(e)(2) estoppel framework is inapplicable here — it attaches only to a petitioner in an IPR/PGR that reached a final written decision, and there was none. That cuts against a defendant in one narrow respect: no petitioner is estopped, so any ground is theoretically live. But it cuts in the defendant's favor far more strongly in two ways: (a) issue preclusion / collateral estoppel from the affirmed W.D. Wis. judgment is available against Ricoh as to claims 1 and 4, subject to the usual identity-of-patent-and-claim requirements; and (b) the § 315(b) one-year bar and the patent's 2022-01-02 expiry mean an IPR is almost certainly unavailable or pointless to file now. Practically, the defendant's art options are: EP '272, EP '962, and the other of-record references (JP 63-29336, JP 63-266632, JP 63-266633, US 5,150,352, EP 0442566, WO 98/36411, EP 0898272, EP 0737962) — all of which were before the examiner or the court, meaning a § 325(d) discretion problem if anyone tried to re-run them at the Board.

Pattern signals. There is no pattern to report: no repeat petitioner, no joined proceedings, no Director Review, no PTAB appeal by Ricoh, and no defensive aggregator in the chain. The Google Patents page links litigation entries through the Unified Patents Litigation Data and Darts-ip datasets — those links are citations to the litigation datasets themselves, not evidence that Unified Patents filed anything. Do not read them as a Unified IPR. The only Ricoh-side appellate activity I can confirm is the 2007-1567 appeal, where Ricoh was the appellant and lost.

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Recommended next steps

1. If you are a defendant and the assertion rests on claims 1 or 4: you do not need the PTAB at all. Cite the affirmed judgment — Ricoh Co. v. Quanta Computer, Inc., 579 F. Supp. 2d 1110 (W.D. Wis. 2007), aff'd in relevant part, 550 F.3d 1325 (Fed. Cir. 2008) (http://cafc.uscourts.gov/opinions-orders/07-1567.pdf) — and quote the disposition: the district court "ruled that the asserted claims of the '109 patent are obvious," and the Federal Circuit "affirm[ed]... in all respects" as to the '109 patent. Then invoke issue preclusion on claims 1 and 4 against Ricoh (present assignee of record: Ricoh Company, Ltd.).
2. If the assertion reaches claims 5–10 (untested): there is no PTAB win to borrow, so your invalidity case must be built from scratch on EP '272 / EP '962 under Ormco. The '109 specification's own priority document (JP 2000-058399) and the specification's admission that the write strategy is "not limited to use on a particular phase change medium" (quoted by the Federal Circuit) are your best admissions. Budget for the fact that the earlier litigation never reached these claims.
3. If you are considering filing an IPR: check the § 315(b) service date first — if you were served more than one year ago, you are barred. Independently, note that the patent expired 2022-01-02 and is listed by the Office as Expired – Lifetime; an IPR on an expired patent is permissible but construed under Phillips and yields only past-damages leverage. Given the affirmed invalidity of the asserted claims, an IPR is very unlikely to be the efficient path.
4. Do not expect any 2026 PTAB or CAFC activity. With expiry in 2022 and no pending proceeding, the absence of docket activity is expected, not anomalous. If someone tells you there is a 2026 CAFC appeal on this patent, ask for the docket number — I could not find one.

Uncertainty disclosures: (1) I could not query the USPTO PTAB E2E / PTAB API directly in this session; the "no proceedings" conclusion rests on the ODP block plus the absence of any hit across multiple public sources, and I am confident but not infallible on a pre-2018 filing that might be poorly indexed. (2) I found no evidence of an ex parte reexamination and no reexamination certificate; I cannot affirmatively rule one out from the sources searched, but nothing in the record suggests one. (3) I have not verified whether the W.D. Wis. invalidity judgment was entered as a final judgment with full preclusive effect against all of Ricoh's successors or only as to the parties then before the court — a defendant should confirm that before relying on issue preclusion rather than on the patent's expiration. (4) The Google Patents "Current Assignee" field is expressly caveated as possibly inaccurate; I have verified only that Ricoh Company, Ltd. was the original assignee.

I'll attempt to pull the actual USPTO assignment records before writing anything.

Let me probe specifically for assignment-record data and any post-issuance transfers.

Sourcing limitation (read first)

I could not execute a direct query against the USPTO Patent Assignment Center in this session. The Assignment Center (https://assignmentcenter.uspto.gov/ , legacy interface at https://assignment.uspto.gov/patent/index.html ) is an interactive database whose individual records are not indexed by the search engine available to me — my queries for "US 6,631,109" plus reel/frame, and for Ricoh assignment records, returned no reel/frame pages for this patent. Accordingly, I cannot report reel/frame numbers, execution dates, or the correspondent of record for any assignment in this chain. Everything below rests on (a) the legal-events block in the authoritative patent text (https://patents.google.com/patent/US6631109/en), (b) the Federal Circuit record in Ricoh Co. v. Quanta Computer Inc., 550 F.3d 1325 (Fed. Cir. 2008), and (c) court filings. I flag the gaps rather than filling them.

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Inventors

Pattern notes:

• The assignment was executed and recorded on 2001-03-01, the same day the application was filed (application 09/795,436; filing date 2001-03-01). This is the ordinary employee-invention practice (assignment taken contemporaneously with filing), not the pattern of an inventor holding rights and later selling them.
• Not determinable: whether Nakamura left Ricoh, and when. I found no evidence of inventor departure within 12 months of filing, and no evidence of any inventor-held or third-party-held residual interest. There is no co-inventor and therefore no co-ownership fragmentation. A single-inventor, single-employer chain is the cleanest possible ownership record — I saw no fire-sale precursor signal here (I searched for one and found nothing).

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Original assignee

• Entity on the issued patent: Ricoh Company, Ltd. (Tokyo, Japan). Original assignee; the 2001-03-01 assignment was recorded as "ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)" with Ricoh as assignee. Google Patents' "Current Assignee" field also reads Ricoh Co Ltd (that field is expressly caveated as possibly inaccurate; I verified only that Ricoh is the assignee of record from 2001).
• Primary line of business: Ricoh is a large Japanese operating company — office imaging (MFPs/printers), digital services, commercial/industrial printing, thermal media, and precision optical components. Ricoh's own IP page (https://www.ricoh.com/technology/rd/ip) reports 30,667 maintained patents worldwide as of March 31, 2025 (12,903 JP / 17,764 overseas) — an operating company with a very large organic portfolio, not a licensing vehicle.
• Did Ricoh ship products embodying the claims? Yes, materially. The patents-in-suit were directed to optical disc drive and media technology (CD-RW write strategies, disc velocity control, disc formatting). Ricoh was an active CD-R/CD-RW media supplier, and the accused products in the litigation were third-party drives (Quanta Storage models SBW-081, SDW-042, SDW-086, etc.). Ricoh also granted an optical-disc patent license as licensor: Ricoh's Form 20-F disclosed a "Patent licensing agreement relating to optical disc (the Company as the licensor)" with a term of February 22, 2011 to February 22, 2016 — i.e., Ricoh monetized these rights by licensing as owner, not by selling them.
• Current status: Operating, listed company. No Chapter 7/11 proceeding involving Ricoh Company, Ltd. was found. (The bankruptcy in this story runs the other way: Eastman Kodak — a Ricoh counterparty in a separate 2012 licensing dispute — was the Chapter 11 debtor, and Kodak sued Ricoh, not the reverse.)

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Assignment timeline

Chronological list of every ownership-relevant event I could verify:

• 2001-03-01 (executed) / recorded 2001-03-01 — Reel not retrievable in this session

  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNORS INTEREST")
  • Assignor: NAKAMURA, YUKI
  • Assignee: RICOH COMPANY, LTD.
  • Correspondent: not retrievable. Non-authoritative color only: Cooper & Dunham LLP (New York) was Ricoh's counsel of record on the Federal Circuit appeal (Ivan S. Kavrukov, of counsel, per 550 F.3d 1325), and that firm is a long-time Ricoh US patent house — but I have no evidence it was the assignment correspondent, and I am not asserting it as a finding.
  • Context: Acquisition — routine employee-invention assignment to the employer, executed on the filing date.

• No further conveyance of any type is recorded in the patent's legal-events data. After 2001-03-01, the events shown for US 6,631,109 are: application filed by Ricoh (2001-03-01); publication US 2001/0019523 A1 (2001-09-06); priority to four continuations (2003-08-12; 2004-12-01; 2006-07-24 ×2); grant (2003-10-07); adjusted expiration (2022-01-02); status "Expired – Lifetime."

Plain statement of the finding: there is no shell-entity transfer, no security interest, no merger, no change of name, and no transfer to an asserter anywhere in this chain in the sources available to me. The only ownership event in 22 years of patent life is the original employee assignment. As the instructions note, that silence is itself the finding: Ricoh remained the owner of record through expiry. The four US continuations (US 7,193,950; US 7,206,271; US 7,382,706; US 7,799,181) were filed by Ricoh as continuations of the same Mar. 3, 2000 priority — i.e., internal family-building, not conveyances — though I did not independently verify each continuation's assignment record (unverified).

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Timeline diagram

timeline
    title Ownership of US 6631109
    2000 : Japanese priority application filed
    2001 : Nakamura assigns rights to Ricoh
         : Application 09-795-436 filed same day
         : Pre-grant publication issued
    2003 : Patent US 6631109 issues to Ricoh
         : First continuation filed by Ricoh
    2004 : Second continuation filed by Ricoh
    2006 : Ricoh sues Quanta and NU in Wisconsin
    2007 : Claims 1 and 4 held invalid
    2008 : Invalidity affirmed by Federal Circuit
    2022 : Patent reaches adjusted expiration

(Comma-free, paren-free, slash-free event text; stacked 2001 and 2003 events use leading colons.)

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NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. There is no recorded transfer off Ricoh's books at all. No assignee with an "IP / Patents / Licensing / Holdings / Ventures" suffix appears in the legal-events chain; the only assignee in the record is Ricoh Company, Ltd. (2001-03-01). No Delaware or Texas single-purpose LLC shows up.

2. Known asserter in the chain — NOT PRESENT. Ricoh Company, Ltd. appears on none of the NPE lists cited (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Erich Spangenberg entities). To the contrary, Ricoh is the defendant-side counterparty in a 2012–2014 licensing dispute brought by Kodak (S.D.N.Y. 1:12-cv-03109), and a licensor in its own optical-disc license (Ricoh 20-F: licensor, term Feb. 22, 2011 – Feb. 22, 2016). A large operating company with 30,000+ maintained patents and its own licensing arm is the opposite of an NPE.

3. Repeat correspondent across the chain — UNKNOWN / NOT ASSESSABLE. There is exactly one recorded assignment in this chain, so recurrence is impossible to observe on this patent. I could not retrieve the correspondent of record for even that single entry, so I make no finding here. (Caution per the brief: a single correspondent appearance is not a finding anyway, and Cooper & Dunham does substantial operating-company prosecution work.)

4. Cascading transfers — NOT PRESENT. Zero post-2001 transfers means zero chained LLC hops. Nothing in the 2001–2022 window.

5. Pre-litigation transfer — NOT PRESENT (inverse pattern). The first suit naming this patent was filed August 2006 in W.D. Wis. (3:06-cv-00462) against Quanta Computer, Quanta Storage, NU Technology, Asustek and others — approximately 5.5 years after the 2001-03-01 assignment. The patent was asserted by its own long-term owner, not by an entity that acquired it to sue. That is the opposite of the pre-litigation-transfer tell.

6. Bankruptcy fire-sale — NOT PRESENT. No Ricoh bankruptcy. No sale of this patent in any insolvency proceeding (unlike the Kodak, Nortel, Polaroid, Sun-type patterns).

7. Privateering — NOT PRESENT. Ricoh asserted in its own name as plaintiff-appellant (550 F.3d 1325), against actual hardware competitors (Quanta Storage optical drives, Asustek, Philips-affiliated parties as third-party defendants). There is no NPE fronting Ricoh's claims and no evidence of a covert backer.

8. Defensive aggregator — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at Ricoh, then at expiry (adjusted expiration 2022-01-02; status "Expired – Lifetime").

One honest counter-consideration to flag (not a signal score): Ricoh's assertion posture is that of an operating company suing suppliers of competing drives, and Ricoh did not sell CD-RW drives in the US in competition with Quanta at the relevant time as far as this record shows — but Ricoh did supply optical disc media and held the patents as an operating-company asset, licensed them commercially, and its claims were held invalid for obviousness (claims 1 and 4). An invalid patent is commercially unattractive to NPEs, which is consistent with the observed absence of any transfer. Note also claims 5–10 were never adjudicated invalid in that judgment; that residual scope is precisely what an NPE would have wanted, and it nonetheless was never sold — reinforcing the no-transfer finding.

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Verdict

Operating-company assertion — historical, now moot.

The ownership chain consists of a single conveyance: Yuki Nakamura → Ricoh Company, Ltd., executed and recorded 2001-03-01 (reel/frame not retrievable in this session). There is no post-issuance assignment, security interest, merger, name change, or transfer of any kind in the record through the patent's adjusted expiration on 2022-01-02, so no NPE signal in the checklist is present. The patent was asserted by its owner — Ricoh — against actual competitors in W.D. Wis. 3:06-cv-00462 (filed August 2006), where claims 1 and 4 were held invalid for obviousness (Aug. 21, 2007) and that holding was affirmed at 550 F.3d 1325 (Dec. 23, 2008), rehearing denied Feb. 17, 2009; the patent is now expired. Caveat: because I could not open the Assignment Center record itself, the reel/frame, correspondent, and execution-date details for the 2001-03-01 entry remain unverified — verify directly at https://assignmentcenter.uspto.gov/ (and the legacy index at https://assignment.uspto.gov/patent/index.html ) by searching patent number 6631109. If a later conveyance exists that is not reflected in the legal-events data, it would change this verdict; nothing in the sources I could reach suggests one.

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Flagged contradictions / open items carried forward

• JP priority date typo (already flagged upstream): specification closing paragraph says priority JP 2000-058399 was "filed on Mar. 3, 2001," while all bibliographic fields say 2000-03-03. Note it literally; do not auto-correct.
• Unverified litigation dockets: the Google Patents litigation links list E.D. Tex. 5:04-cv-00104 and N.D. Cal. 5:07-cv-01942 / 3:07-cv-01942 in addition to W.D. Wis. 3:06-cv-00462. I could not confirm the parties or which patent(s) each case asserted, and my attempt to resolve 5:04-cv-00104 was cut off. Treat these as unconfirmed — in particular, I have no basis for treating any of them as an NPE-filed case.
• Continuation-family ownership unverified: I infer (but did not verify per-patent) that US 7,193,950 / 7,206,271 / 7,382,706 / 7,799,181 remained with Ricoh.

I'll research US 6,631,109 and each of its cited prior-art references. Note upfront: the task header says "Current Date: April 26, 2026" while my operating context date is 2026-09-28 — I'll flag that discrepancy rather than silently pick one.

Now let me research the remaining cited references, especially US 5,150,352 (which the spec cites for mark-edge control) and the Japanese/Korean/Philips references.

Analyst's note before the analysis

Three framing issues, stated up front rather than silently resolved:

1. Date inconsistency. The task header says "Current Date: April 26, 2026," while my operating context date is 2026-09-28. I flag it and proceed; it does not affect the prior-art analysis below.
2. Patent number. I interpret "6631109" literally as US 6,631,109 B2 (app. 09/795,436), and I did not substitute any similar number.
3. The §102 framing vs. what actually happened. You ask which references "potentially anticipate" under §102. My honest finding is that none of the cited references individually anticipates any of the ten claims; the closest art was adjudicated as a §103 obviousness combination (see the synthesis at the end). I report both, because telling you only what the task's framing invites would misrepresent the record.

Sourcing caveat: I retrieved full/partial text for EP0737962, EP0898272, US5150352 (title check) and the Taiwan IPO case study of the '109 invalidity holding. Four of the cited references (JP 63-29336, JP 63-266632, JP 63-266633, EP0442566, EP0802531, WO98/36411, EP0986054) I could only verify via the citation tables and the patent's own characterization — I mark those explicitly rather than inventing content.

Also note: the Google Patents "Citations (11)" table shows ten entries before the fetched text truncates; the eleventh is cut off. I analyze the ten shown.

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Cited references — consolidated table

Sources: https://patents.google.com/patent/US6631109/en ; https://patents.justia.com/patent/6631109

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Reference-by-reference analysis

1. JP 63-29336 A — "Optical disk," Hitachi Maxell

• Dates: priority 1986-07-22; published 1988-02-08.
• Description: Cited in the '109 specification for the generic concept of recording by applying a light-source driving waveform based on a write-data modulation method. It is background, not a waveform-parameter reference.
• §102 assessment: Discloses none of the claim-1 limitations. No anticipation of any claim.

2. JP 63-266633 A — "Method for recording optical information," Fuji Photo Film

• Dates: priority 1987-04-23; published 1988-11-02.
• Description: Per the '109 specification, discloses applying a driving waveform with a front-end or tail-end portion of increased pulse width (or increased power level) to eliminate mark-edge positional variation and improve jitter. This is the direct ancestor of the '109 front-end/tail-end concept.
• §102 assessment: This is the single most conceptually relevant old reference for the "front-end portion" and "tail-end portion" elements of claims 1/4/5/8. But it does not disclose (a) the three-part front-/multi-/tail architecture with an express duty ratio z = t₂/(t₂+t₃), (b) the numeric windows t₁ = 0.1T–1T and t₄ = 0.2T–1.3T, or (c) the 5–28 m/s velocity condition. No strict anticipation; it is best characterized as §102(b)/§103 art. (I could not retrieve full text this session — characterization rests on the '109 spec's own description and the citation table.)

3. JP 63-266632 A — "Information recording method and device," Hitachi

• Dates: priority 1987-04-24; published 1988-11-02.
• Description: Cited in the '109 specification for using a PWM multi-pulse light-source driving waveform to record a long amorphous mark on a fast-crystallizing phase-change layer.
• §102 assessment: Supplies the "multi-pulse portion" idea but nothing about t₁/t₄ windows or the velocity range. No anticipation; at most §103 art combinable with reference 2. (Full text not retrieved.)

4. EP 0 442 566 A1 — "Information recording device," Koninklijke Philips

• Dates: priority 1990-02-12; published 1991-08-21.
• Description: Examined/listed citation; a recording-device reference. I could not retrieve its substantive text this session, so I decline to characterize its disclosure.
• §102 assessment: Cannot responsibly assess; on the record available, no demonstrated anticipation. (Unresolved — flagged.)

5. US 5,150,352 A — Canon

• Dates: filed 1988-09-27; issued 1992-09-22.
• ⚠ Title/decription mismatch. The '109 specification states that "JP 63-266633 and U.S. Pat. No. 5,150,352 disclose an optical recording method which eliminates positional variations of a mark edge and improves the jitter characteristics." But the actual granted title of US 5,150,352 A, as listed in the '109 citation table and confirmed in the Google Patents G11B 19 sitemap, is "Information recording and reproducing apparatus having an emergency conveying device for moving a carriage member to an ejecting port." That is a disc-loading/transport apparatus, not a mark-edge recording method. I do not auto-correct this; I flag that the specification's characterization of US 5,150,352 is inconsistent with the patent's recorded title, and that the neighboring number US 5,150,351 (Ohno et al., Sept. 22, 1992) is the more plausible intended reference for waveform control. This is a real discrepancy in the record, not a search artifact.
• §102 assessment: On its literal title, US 5,150,352 discloses no recording-waveform limitation and cannot anticipate any claim. If the intended reference was US 5,150,351, the §102 conclusion would need re-evaluation — but that reference is not what the patent cites.

6. EP 0 737 962 A2 — "Data recording/regenerating method, data recording/regenerating apparatus and data recording medium," Ricoh

• Dates: filed 1996-04-12; priority JP 89464/95 (1995-04-14) and three others; published 1996-10-16; granted EP 0 737 962 B1 on 2003-06-04.
• Description (verbatim substance from the abstract): Under PWM recording, the "0" signal (width nT) is a continuous electromagnetic wave at power level e; the "1" signal is a pulse array comprising a pulse section fp (time width x, power level a), a multi-pulse section mp in which low-level pulses (power b) and high-level pulses (power c) alternate at a duty ratio y, and a pulse section op (time width z, power level d) — with 0.5T ≤ x ≤ 2T, 0.4 ≤ y ≤ 0.6, 0.5T ≤ z ≤ 1T and (a and c) > e > (b and d).
• §102 assessment: This is the closest structural antecedent to claim 1's waveform. The fp/mp/op architecture, the duty ratio, and the power ordering map onto the '109 front-end/multi-pulse/tail-end architecture. However, EP'962 does not explicitly disclose (i) the claimed windows t₁ = 0.1T–1T and t₄ = 0.2T–1.3T (its x and z windows differ, and it does not recite the endpoints the '109 claims), (ii) the "starting from erase level Pe / ending at erase level Pe" recitation in the '109 form, or (iii) the 5–28 m/s velocity limitation. It therefore does not, standing alone, anticipate under §102; it is the primary §103 reference. This matches how the courts actually treated it (see synthesis). Sources: https://patents.google.com/patent/EP0737962A2/en ; https://data.epo.org/gpi/EP0737962B1.pdf ; https://www.search-for-intellectual-property.service.gov.uk/EP0737962

7. EP 0 802 531 A2 — "Information recording method and apparatus," Hitachi

• Dates: priority 1996-04-17; published 1997-10-22.
• Description: Recording-method reference listed among the citations. Also appears as a cited reference in the Hitachi 8-16 modulation family (US 7,417,933's references list "EP 802 531").
• §102 assessment: No claim-1-dispositive disclosure demonstrated on the record I retrieved. No anticipation; possible §103 background art. (Full text not retrieved.)

8. WO 98/36411 A2 — "Method and device for writing an optical record carrier," Koninklijke Philips

• Dates: priority 1997-02-14; published 1998-08-20.
• Description: A write-strategy reference for phase-change record carriers.
• §102 assessment: Cannot be shown to disclose the t₁/t₄ windows or the 5–28 m/s condition. No anticipation. (Full text not retrieved.)

9. EP 0 898 272 A2 — "Optical recording medium and recording and reproducing method using the same," Ricoh

• Dates: filed 1998-08-14; priority JP 239557/97 (1997-08-15); published 1999-02-24; granted EP 0 898 272 B1 on 2003-05-21 (now expired).
• Description: A phase-change optical recording medium (first dielectric / recording layer / second dielectric / reflection-and-heat-dissipation layer / overcoat), where the recording layer is an Ag–In–Sb–Te–(N and/or O) material with 0 < α ≤ 6, 3 ≤ β ≤ 15, 50 ≤ γ ≤ 65, 20 ≤ δ ≤ 35, 0 ≤ ε ≤ 5, and having a recrystallization upper-limit linear speed of 2.5–5.0 m/s; the document also proposes recording and reproducing methods using that medium. Note that the '109 specification's own recording-layer formula (Ag_α I_β Sb_γ Te_δ with 0.1≤α≤3.0, 5.0≤β≤12.0, 60.0≤γ≤72.0, 22.0≤δ≤30.0) is a narrower species of the EP'272 genus, and the '109 FIG. 2 "phase-change critical velocity vo" concept is the same family of medium-characterization thinking.
• §102 assessment: EP'272 is a medium-composition + method reference. It does not recite the claim-1 multi-pulse parameter windows or the 5–28 m/s condition, so it does not anticipate claims 1/4/5/8 on its face. Its relevance is strongest against the medium claims (9/10) and as the second §103 reference combined with EP'962. Sources: https://patents.google.com/patent/EP0898272A2/en ; http://data.epo.org/gpi/EP0898272B1-Recording-and-reproducing-methods-using-an-optical-recording-medium.html ; https://www.search-for-intellectual-property.service.gov.uk/EP0898272

10. EP 0 986 054 A1 — Matsushita Electric

• Dates: priority 1998-09-14; published 2000-03-15.
• Description: The fetched citation table truncates the title. I will not guess it.
• §102 assessment: Cannot be assessed on the retrieved record — marked unresolved rather than fabricated.

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Synthesis: which art actually matters, and under which statute

Closest prior art, in order:

1. EP 0 737 962 A2 (Ricoh) — discloses the fp / multi-pulse (with duty ratio) / op waveform architecture in a PWM phase-change system. Closest single reference to the waveform limitations of claims 1, 4, 5, and 8.
2. EP 0 898 272 A2 (Ricoh) — discloses the Ag–In–Sb–Te–(N/O) phase-change medium and its recrystallization upper-limit linear speed; closest to the medium claims 9/10 and the medium-parameter language in the specification.
3. JP 63-266633 A and JP 63-266632 A (both 1988) — together supply the "front/tail edge pulse widening" idea plus "multi-pulse for long marks," i.e., the two halves of the claim-1 waveform architecture, decades earlier.

On §102 strictly: None of the ten cited references, taken alone, discloses every limitation of any independent claim — specifically, none discloses the 5 m/s–28 m/s velocity condition coupled with the t₁ = 0.1T–1T and t₄ = 0.2T–1.3T windows. EP'962 comes closest but recites different windows (x = 0.5T–2T; z = 0.5T–1T) and no velocity limitation. No §102 anticipation is sustainable on this record.

On what was actually decided (§103): This is the real story, and it corroborates the analysis above. In Ricoh Co. v. Quanta Computer Inc., the Federal Circuit (2008) affirmed summary judgment that claims 1 and 4 of the '109 patent are invalid as obvious over EP 0 898 272 ("EP 272") and/or EP 0 737 962 ("EP 962"). A Taiwan IPO case study of the same dispute records the reasoning: "Ricoh had already filed EP 0898272 ('EP 272') and EP 0737962 ('EP 962') in Europe before applying for the '109 patent; either European patent discloses a laser pulse waveform sequence concept similar to the '109 patent, but the range of linear velocity for writing to the disc differs." The differentiator the '109 patent tried to rely on was the 5–28 m/s range, and the courts found that difference insufficient to confer patentability. Source (Chinese-language case study, §4.3 "法院對於'109號專利有效性之認定"): https://tiponet.tipo.gov.tw/downloads/module030/information_4_2_4.pdf

Bottom line for your §102 question: The most relevant prior art to US 6,631,109 is EP 0 737 962 A2 and EP 0 898 272 A2 (both Ricoh's own earlier applications), with JP 63-266633 A and JP 63-266632 A as the older edge-control / multi-pulse ancestors. None of them anticipates under §102; their legal effect on the claims was §103 obviousness. If your analysis requires a §102-only conclusion, the honest answer is that the record supports no anticipation of any claim, and the challenged claims fell on obviousness instead.

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Discrepancies and unresolved items (explicit)

1. US 5,150,352 A title mismatch — the '109 specification describes it as a mark-edge/jitter recording method, but its granted title is a Canon carriage-ejecting apparatus. Flagged, not corrected. Possible intended reference: US 5,150,351.
2. Eleventh citation truncated — the "Citations (11)" table shows only ten entries in the fetched text; the eleventh is unavailable.
3. Prior-priority paragraph — the '109 specification's closing paragraph says the JP priority was "filed on Mar. 3, 2001," while every other field says 2000-03-03. Noted literally (carried forward from the earlier summary section).
4. Not retrieved this session: full texts of JP 63-29336, JP 63-266632, JP 63-266633, EP0442566, EP0802531, WO98/36411, and EP0986054. Their descriptions above rest on the '109 specification's characterization and the citation tables, and are marked accordingly.
5. Date discrepancy between the task header (April 26, 2026) and the operating context (2026-09-28).

I'll ground this analysis in the actual prior-art references of record, so let me pull what's verifiable about the key ones before mapping them onto the claims.

Let me verify two more references of record that matter for the apparatus/medium claims and the t₁/t₄ ranges.

Obviousness Analysis — US 6,631,109 B2 under 35 U.S.C. § 103

Scope note. Claims 1 and 4 of this patent are not merely "at risk" — they were adjudged obvious and that judgment was affirmed on appeal (W.D. Wis. 06-C-462-C, 579 F. Supp. 2d 1110; aff'd, 550 F.3d 1325 (Fed. Cir. 2008)). I will not re-narrate that history (it is covered in the litigation and PTAB sections above). Instead I use it as the anchor and do what those sections did not: an element-by-element § 103 mapping, an articulation of the motivations to combine, and an honest assessment of where the untested independent claims 5–10 stand on the art of record.

Everything below is grounded in (a) the authoritative patent text supplied, (b) the Citations (11) list on the Google Patents page, and (c) the reference texts and court opinions retrieved this session. Where a reference's disclosure is outside what I could verify, I say so.

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1. The legal frame that actually decides this patent

Three doctrines do nearly all the work:

1. Overlapping ranges. "Where a claimed range overlaps with a range disclosed in the prior art, there is a presumption of obviousness." Ormco Corp. v. Align Tech., Inc., 463 F.3d 1299, 1311 (Fed. Cir. 2006) (citing Iron Grip Barbell Co. v. USA Sports, Inc., 392 F.3d 1317, 1322 (Fed. Cir. 2004); In re Geisler, 116 F.3d 1465, 1469 (Fed. Cir. 1997)). The presumption is rebutted only by teaching away or new and unexpected results. Id.
2. Narrower disclosed range inside a broader claim. A prior-art range within the claimed range does not save the claim absent demonstrated criticality. In re Peterson, 315 F.3d 1325, 1330 (Fed. Cir. 2003) (routine optimization of ranges); In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990) (narrower prior-art range; applicant cannot show unexpected results outside the claimed range).
3. KSR. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) — predictable variation, design incentives, and "ordinary creativity" defeat patentability where the only difference is a known, speed-driven parameter selection.

The Federal Circuit applied (1) to this patent and then supplied the KSR gloss in terms that will govern any re-run:

"Ricoh does not dispute that EP '272 discloses every limitation of claims 1 and 4 of the '109 patent other than the aforementioned linear speed range… [T]he mere understanding that the write strategy of the '109 patent and EP '272 is useful in a faster but overlapping linear speed range is not the type of result that can rebut a prima facie case of obviousness arising from the overlapping ranges. Such development of the prior art is the quintessence of 'ordinary skill' or 'ordinary skill and common sense' rather than patentable innovation."
— 550 F.3d 1325, as quoted in the FindLaw/CourtListener text retrieved this session; opinion at http://cafc.uscourts.gov/opinions-orders/07-1567.pdf

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2. Person having ordinary skill in the art (PHOSITA)

A designer of phase-change optical disc drive write-strategy firmware, holding a B.S. in EE/physics or equivalent, with ~2–3 years in CD-RW drive development, familiar with EFM/PWM mark-edge recording, the Orange Book Part III (CD-RW) write strategy, and the front/multi/tail pulse architecture. This framing matters because the § 103 case turns on whether retuning two pulse widths across a speed range the industry had already targeted was within that person's ordinary skill — it was.

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3. Claim 1 — element-by-element mapping

Claim 1's architecture is set out in full in the earlier summary; here I map each element to the art of record. Note the Markman construction of 2007-05-11 in the W.D. Wis. case governs interpretation: "pulse width" = "the time interval between the beginning and the end of the pulse" (the court refused the defendants' "edges" framing), and "multi-pulse portion" required no construction because "includes" is open-ended (rejecting the argument that the waveform has exactly three parts). That construction makes the mapping below easier, not harder, for the challenger.

The overlap is arithmetically real. The claimed range [5, 28] and the disclosed range [2.4, 5.6] share the interval [5.0, 5.6] m/s. That is the entire predicate for the Ormco presumption — and the parties did not dispute it.

Two additional points the earlier sections did not develop:

• The pulse-width ranges themselves are also overlapping/subsumed. EP '962 discloses x ∈ [0.5T, 2T], which overlaps claimed t₁ ∈ [0.1T, 1T] across [0.5T, 1T]; and EP '962 discloses z ∈ [0.5T, 1T], which sits entirely inside claimed t₄ ∈ [0.2T, 1.3T]. So the challenger has two range-overlap presumptions in claim 1 (t₁ and t₄) plus the speed-range overlap — Woodruff/Peterson territory, not just Ormco.
• The claimed speed range is not a discovery; it is the standard. The specification itself states: "The linear velocities 4× to 10× according to the standards (the orange book, part III) range from 5 m/s to 28 m/s" and that "Preparations of high-speed specifications of 4× to 10× linear velocity recording … are now under way." The claimed 5–28 m/s is coextensive with the CD-RW 4×–10× envelope. A claim whose numerical range is dictated by an industry standard under development is the paradigm of a design incentive under KSR, and an admission against the patentee.

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4. Ground 1 (adjudicated): EP '272 or EP '962 alone + overlapping range

This is the ground that killed claims 1 and 4. Its logic, stated cleanly so it can be reused:

1. EP '272 (and, independently, EP '962) discloses every structural limitation of claim 1 except the speed range — conceded by the patentee.
2. The references' disclosed 2.4–5.6 m/s overlaps the claimed 5–28 m/s → presumption of obviousness (Ormco).
3. Patentee's rebuttals fail:
   • Teaching away — rejected. EP '272's statement that a medium with recrystallization upper-limit > 5.0 m/s "cannot assume a complete amorphous state" is a statement about the medium, not about the write strategy. The asserted claims are "write strategies comprising a specified sequence of laser pulses, not limited to use on a particular phase change medium." In re Fulton/Optivus ("criticize, discredit, or otherwise discourage" standard).
   • Unexpected results — rejected. Ricoh "does not argue that the write strategy differs in any way between the two patents"; only the speed changed. Cf. 35 U.S.C. § 100(b) ("process" includes a new use of a known process).
4. Post-KSR overlay: the CAFC expressly invoked KSR to hold this is "ordinary skill and common sense."

Why Ground 1 is fragile as a template for the untested claims: it was single-reference obviousness bootstrapped off the overlap presumption. It works cleanly only because the sole gap was a number. For claims 5–10 the gaps are (i) the speed number (same analysis) and (ii) for 9/10, the on-medium information element (different analysis — below).

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5. Ground 2: EP '272 + EP '962 as a true two-reference combination

Because a court may prefer a two-reference theory over "single reference + overlap," the combination is easy to articulate with a proper motivation. (Note: the parties are the same assignee, Ricoh — common ownership is not itself a motivation, but it evidences a shared technical focus, and it removes the "unrelated fields / different problems" defense that a § 103 challenger normally faces.)

Motivation to combine:

• Same field, same problem, same architecture. Both are Ricoh patents on PWM mark-edge recording of phase-change media (IPC G11B 7/0062, 7/0045, 7/125). EP '962 supplies the pulse-train parameters (x, y, z) and the AgInSbTe medium; EP '272 supplies the medium-composition/recrystallization-limit characterization and, critically, an express teaching that write parameters are speed-dependent.
• EP '272's own claim 10 is a speed-adaptation teaching. EP '272 claim 10 requires that the ratio of erasing power to writing power be different at 2.4–2.8 m/s than at 4.8–5.6 m/s. A POSITA reading that is told, in terms, that the write strategy must be re-tuned as a function of linear velocity — the exact reasoning needed to extend t₁ and t₄ to 5–28 m/s.
• EP '962's own background names the prior art that motivates edge-trimming. EP '962's specification recites: JP 266632/1988 (pulse-array recording of long amorphous marks is effective for PWM on high-crystallization-speed film), and JP 266633/1988 and U.S. Pat. No. 5,150,351 (improve jitter by raising laser energy at the head and end of the pulse array, or lengthening irradiation, to suppress mark-edge positional fluctuation). That is the patentee's own prior art expressly framing t₁ and t₄ as the jitter-control levers.
• Reasonable expectation of success. The waveform is unchanged; only the drive speed is raised. The result (cleaner edges / controlled asymmetry) is precisely the result the references already predict for the same waveform at lower speed. KSR: predictable variation.

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6. Ground 3: Adding the art of record that speaks directly to t₄ and to speed-dependent cooling

This is the ground I would develop for a fresh defense of the untested claims, because it supplies an express why for the specific numerical limitations the adjudicated ground treated as "just a range."

WO 98/36411 (Koninklijke Philips, pub. 1998-08-20) — "Method and device for writing an optical record carrier." Retrieved text is unusually on point:

"the duration of the period during which the second power level is maintained, i.e. the so-called cooling period… If the cooling period is too short, the erasure starts too soon and will erase too much of the just written mark. If, on the other hand, the cooling period is too long, the erasure starts too late and previously written marks… will not be erased. There is an optimum duration of the cooling period when writing at a certain speed. … the duration of the cooling period must be changed in dependence on the writing speed in order to obtain a proper transition from the write operation to the erasure operation."

That is a direct, express teaching that the trailing low-power period (claim 1's tail-end portion, t₄) must be optimized as a function of writing speed — the single most valuable non-adjudicated motivation available. Combined with EP '272/EP '962, it renders the t₄ ∈ [0.2T, 1.3T] at 5–28 m/s limitation obvious rather than merely "overlapping."

JP 63-266633 / U.S. Pat. No. 5,150,352 (cited in the '109 specification as teaching that front-end or tail-end portions with increased pulse width or increased power eliminate mark-edge positional variation and improve jitter). This is the motivation for t₁ (front-end width) as a deliberate control variable, rather than an incidental one.

Flag — citation-table anomaly (interpreted literally, not corrected). The Google Patents Citations (11) table lists US5150352A with the title "Information recording and reproducing apparatus having an emergency conveying device for moving a carriage member to an ejecting port" (Canon, 1988-09-27/1992-09-22). That title does not match the specification's description of US 5,150,352 as "an optical recording method which eliminates positional variations of a mark edge and improves the jitter characteristics." Compounding this, EP '962's own text cites "U.S. Patent No. 5150351" (…351, not …352). I am reporting all three strings as found. A defendant should pull the actual '352 and '351 documents before relying on either — the digit discrepancy could matter to a § 102/§ 103 chart.

JP 63-266632 (Hitachi, 1987) — the specification and EP '962 both describe it as teaching that a long amorphous mark is recorded using a pulse array in PWM recording on high-crystallization-speed film. That is the motivation for the multi-pulse portion itself.

EP 0986054 A1 (Matsushita, 1998) — "Optical data recording method, and data recording medium." Its retrieved text expressly frames the start / middle / end segmentation of the recording pulse for mark-edge recording, citing JP 7-129959 (US 5,490,126 / 5,636,194) for segmenting a mark into "start, middle, and end parts, the start and end parts each having a constant pulse width and the middle containing pulses of a constant period." This is an independent confirmation that the three-section architecture of claim 1 was a recognized, teachable approach by 1998 — useful as a secondary teaching that the architecture itself (independent of the Ricoh patents) was known.

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7. Ground 4: The apparatus claims (5 and 8) and the rewritable/PWM claims (4, 8, 10)

• Claims 4, 8 and 10 narrow to a rewritable medium and a PWM write clock. EP '962 is by definition a PWM phase-change recording method on a rewritable medium, and EP '272 is a rewritable CD-RW phase-change medium. So this narrowing adds nothing beyond the art that already invalidated claim 1 — which is presumably why claim 4 fell with claim 1.
• Claims 5 and 8 (apparatus). The apparatus elements — light source driver unit (LDD), write power determination unit (WPDU), and controller — map to the structure in FIG. 3 (elements 13/17/16). The art of record is adequate on this because each reference is a recording method and apparatus pair: EP '962 is titled "Data recording/regenerating method, data recording/regenerating apparatus…" and EP '272's claim 11 recites a reproduction method with drive-level power control. A POSITA implementing the EP '962/EP '272 write strategy necessarily builds the LDD/WPDU/controller triad — the claim adds only naming labels to the algorithm already held obvious. Expect a strong "recited structure is the conventional means for practicing the recited method" argument. This is the least-defensible category of the untested claims.

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8. Ground 5: Claims 9 and 10 (medium carries t₁/t₄ information), and dependents 2, 3, 6, 7

Claims 9/10 add a genuine element not present in EP '272/EP '962 as such: the medium carries first information indicative of t₁ and second information indicative of t₄. This is the weakest-mapped element in the patent, and I want to be explicit about my confidence level here.

Available art of record:

• EP '272's own claim 3: "said substrate bears an Absolute Time in Pre-groove data (ATIP data) including a predetermined optimum recording power for said optical recording medium." This establishes, in the same assignee's own prior art, the practice of encoding a recommended write parameter in the medium's pre-groove channel. The step from "ATIP carries optimum recording power" to "pre-groove/wobble carries the two pulse widths" is a predictable application of a known data channel to a known class of parameters (KSR: "a court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions"). The '109 specification itself treats this as routine: it says optimum t₁/t₄ "are predetermined. And, wobbling grooves or the like, carrying both the first information and the second information are formed on the medium 1," and adds that it is "preferred to make commercially available" such a medium "for the sake of convenience of the users." That is a convenience/standardization rationale, not a technical advance.
• Claims 3 and 7 (test-write to a test-write region, read back, compute optimum t₁/t₄) map well onto EP 0442566 A1 (Philips, 1990). Its retrieved text describes precisely this: means for generating a test signal, control means for causing test information patterns to be recorded at addressable locations on the record carrier and then read, with the write-intensity setting adapted "in response to the analysis signals obtained during reading of the test-information patterns," and a zone preceding the test zone so address information isn't destroyed. Substitute "optimum t₁/t₄" for "optimum write intensity" and the mechanism is the same. The '109 specification's own reference to a power calibration area (PCA) is the CD-RW implementation of that same idea.

Honest caveat: I could not verify a single reference of record that discloses storing pulse-width (as opposed to power) indicia in the pre-groove channel. So claims 9/10 rest on a combination plus POSITA knowledge of the ATIP/wobble channel, which is a stronger conclusion than a single-reference hit and should be presented as such. Note also that the "information recorded on a carrier" aspect invites a separate printed-matter / non-functional-information challenge (the wobble data is functionally related to the drive's operation, so that challenge is likely to lose — I flag it as an alternative, not a primary, theory).

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9. Secondary considerations — and why every rebuttal fails

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10. Bottom line

1. Claims 1 and 4: obvious as a matter of res judicata. Ground 1 (EP '272 or EP '962 + overlapping speed range, under Ormco) is the adjudicated winner, affirmed at 550 F.3d 1325.
2. Claims 5 and 8 (apparatus): obvious with high confidence. Same art, same gap, plus only conventional structural recitations of the LDD/WPDU/controller triad. The Markman ruling that "multi-pulse portion" is open-ended removes the only claim-differentiation theory I can construct.
3. Claims 4, 8, 10 (rewritable / PWM variants): obvious with high confidence — the narrowing is literally what both references already are.
4. Claims 9 and 10 (medium-carries-t₁/t₄) and claims 2, 6: obvious via EP '272 (ATIP optimum-parameter) + EP '962/EP '272 waveform + POSITA knowledge of the pre-groove/wobble parameter channel, but this is a combination case, not a single-reference one. Medium confidence.
5. Claims 3 and 7 (test-write / PCA): the best-supported of the "extra element" claims, via EP 0442566 (Philips) + EP '272/'962. Medium-high confidence.
6. Most promising plaintiff counter-argument on the untested claims is not the speed range but the level-identity gap: claim 1 requires the front-end portion and each multi-pulse write pulse to be at "the write level Pw" and the tail-end portion at "the base level Pb," whereas EP '962 discloses distinct levels a, c, b, d (subject only to (a and c) > e > (b and d)). If a ≡ c is not literally disclosed in the relied-upon embodiment, a plaintiff could argue the asserted claims are narrower than the reference. I could not resolve this from the retrieved text, and the CAFC's recitation of Ricoh's concession ("discloses every limitation … except the linear speed range") suggests it was not pressed. Verify against the EP '962 figures before relying on either side.

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11. Uncertainty disclosures and anomalies

• I did not auto-correct anything. The anomalies I found are reported as-is: (a) the US 5,150,352 title mismatch in the Citations table and the '351 vs. '352 discrepancy in EP '962; (b) the patent's closing statement that the JP priority application "No. 2000-058399" was "filed on Mar. 3, 2001" versus the everywhere-else 2000-03-03 (already flagged in the summary section — reproduced here only to confirm the contradiction is real).
• Do not conflate this patent with US 5,026,109. Search results surfaced a Finnegan case note about a "U.S. Patent No. 5,026,109" invalidated for obviousness directed to "retractable segmented covering systems" (truck trailers). Different patent, different technology. It is a search artifact, not this patent's family.
• Date inconsistency in my instructions: the task header states "Current Date: April 26, 2026," while this session's metadata says 2026-09-28. Nothing in the § 103 analysis turns on the date (the patent's adjusted expiry is 2022-01-02), but per the operating rules I am not silently reconciling it.
• Unverified: I could not retrieve the full text of EP 0442566 or EP 0802531 or JP 63-29336 / JP 63-266632 / JP 63-266633 in this session; my characterizations of the JP references rest on the '109 specification's and EP '962's descriptions of them (which is itself useful, since it is the patentee's own characterization). I could not verify the Matsushita EP 0986054 disclosure beyond its introductory "Definitions" text. And I explicitly did not use the Matsushita US 2005/0213464 family as prior art, because its priority post-dates the '109 patent's 2000-03-03 priority date.
• Sources: https://patents.google.com/patent/US6631109/en (authoritative text); https://patents.google.com/patent/EP0898272A2/en and http://data.epo.org/gpi/EP0898272B1-…; https://patents.google.com/patent/EP0737962A2/en and http://data.epo.org/publication-server/rest/v1.2/patents/EP0737962NWA3/document.pdf; https://patents.google.com/patent/WO1998036411A2/en; https://patents.google.com/patent/EP0986054A1; http://cafc.uscourts.gov/opinions-orders/07-1567.pdf; https://www.courtlistener.com/opinion/[209414](/patent/209414)/ricoh-co-ltd-v-quanta-computer-inc/.