US 6928306

I'll search for litigation/docket information on this patent while grounding the summary in the authoritative patent text provided.

Let me search specifically for the CAFC appeal and the IPR proceeding mentioned in the results.

Let me do a couple more targeted searches for any 2026 CAFC activity and the PTAB outcomes.

US Patent 6,928,306 — Analyst Summary

Source of truth: the authoritative full text provided in your message (Google Patents, fetched 2026-09-28). Where search results conflicted with that text, I have flagged the conflict and preferred the authoritative text.

1. Bibliographic data

Note on a conflicting identifier: one litigation document I retrieved (a declaration excerpt from Maxell v. Apple, 5:19-cv-00036) referred to an "inventor Shigeto Oeda" in connection with the '306 patent. This contradicts the authoritative patent text, which lists the five inventors above and does not name Oeda. I flag this as an apparent error or cross-reference in that filing and do not adopt it.

2. Abstract (as issued)

A portable mobile unit for alerting on incoming of a signal by a ringing sound, comprises: a ringing sound generator for generating the ringing sound in a plurality of patterns; and a controller for controlling operations of the portable mobile unit, wherein the controller select one pattern from the plurality of patterns based on conditions which are set up in advance, when the signal comes in, so as to control the ringing sound generator to generate the ringing sound for alerting a user of the incoming call, thereby providing the portable mobile unit being superior in the usability, with which various conditions can be grasped by means of change in the ringing sound when the telephone call comes in, while achieving the discrimination of the ringing sound for alerting of the incoming call.

3. Plain-language overview of the independent claims

The patent has two independent claims (1 and 2), both directed to a portable mobile unit (a cellular phone) that produces its incoming-call alert by combining at least two different sound sources (e.g., FM synthesis, PCM, MIDI, MP3), rather than a single tone generator.

Claim 1 — A portable mobile unit alerting on an incoming signal with a ringing sound, comprising:

• a ringing sound generator having a plurality of sound sources;
• a mixer for mixing a plurality of those sound sources; and
• a controller for controlling the unit's operations,
• wherein, when a signal comes in, the controller drives the ringing sound generator to generate the ringing sound using at least two of the sound sources.

Claim 2 — The same portable mobile unit, but the claim does not recite the mixer; it recites the ringing sound generator (plurality of sound sources) and the controller, again with the controller causing a ringing sound to be generated using at least two of the sound sources upon an incoming signal. Claim 2 is the broader independent claim of the two.

Dependent claims shown in the text (3–8):

• 3 (dep. on 2): controller selects one of several pre-defined patterns, each a combination of sound sources, based on predetermined conditions; the generator has a memory storing sound data made by different generation methods, multiple reproducers, and a reproduction timing memory storing timings that select/assemble the pattern.
• 4 (dep. on 3): the sound data include a waveform-coding type (quantization width set by amplitude/power level, i.e., PCM) and an analytic-composition coding type (signal modeled/encoded, i.e., FM-type synthesis).
• 5 (dep. on 2): adds a timer; ringing generated when the call arrives within a preset time zone.
• 6 (dep. on 2): adds a calendar function; ringing generated when the call arrives within a preset period.
• 7 (dep. on 2): adds a counter counting absent incoming calls from a specific person; ringing based on the count falling within a preset range.
• 8 (dep. on 2): adds a remaining battery capacity detector; ringing based on remaining capacity falling within a preset range.

Claim 9–15: the provided claim set is truncated mid-claim 8, so I do not have authoritative text for claims 9–15. Based on the specification (embodiments 4–5), they most likely cover environmental-sound/noise-level-based conditions and heat/pressure-sensor (held-in-hand) conditions, but I cannot state their exact wording with confidence. Treat this as unverified.

4. Litigation / docket findings (USPTO & courts)

Searches were run against USPTO/PTAB and Federal Circuit/district docket sources. Findings for 6,928,306 specifically (no substitute numbers):

• Apple Inc. v. Maxell, Ltd., IPR2020-00204 (PTAB, filed 2019-12-20) — petition for inter partes review of the '306 patent by petitioner Apple Inc. Google Patents records this as settled (the page notes "IPR2020-00204 filed (Settlement)").
• IPR2019-00640 (PTAB) — also recorded on the patent page as filed (Settlement).
• IPR2020-00853 (PTAB, filed 2020-04-23) — a PTAB filing referencing patent 6928306; a "Decision Denying Request for Rehearing – Petitioner" document references it.
• Maxell, Ltd. v. Apple Inc., 5:19-cv-00036 (E.D. Tex., filed 2019-03-15) — the '306 patent was one of the asserted patents. Litigation materials show (a) Apple's §101 subject-matter-eligibility partial summary judgment motion directed at U.S. Pat. Nos. 6,928,306 and 6,329,794, and (b) a claim-construction dispute over "ringing sound generator" (claims 2, 12, 13), with Apple urging means-plus-function treatment under §112 ¶6 and Maxell advocating plain-and-ordinary meaning.
• Other Maxell campaigns implicating the same patent family/cluster: Maxell v. Huawei Device USA, 5:18-cv-00033 (E.D. Tex., 2018-03-02); Maxell v. ZTE, 5:18-cv-00034 (E.D. Tex., 2018-03-02) and 5:16-cv-00179 (E.D. Tex., 2016-11-18).

CAFC 2026 dockets

I searched for a Federal Circuit 2026 docket specifically concerning US 6,928,306 and did not find one. The Federal Circuit activity surfaced was an Apple notice of appeal filed 2020-10-06 (appeal No. 21-1033, filed 2020-10-09), which relates to the '493 patent / IPR2020-00597 (denial of institution), not the '306 patent. I have no authoritative evidence of any CAFC 2026 proceeding on 6928306; absence of a result is not proof that none exists, so this should be treated as "not found," not "confirmed none."

5. Uncertainty / caveats

1. Claims 9–15 are not fully present in the supplied text; my description of them is inferential and should not be relied upon.
2. CAFC 2026 activity for this patent: none found. Do not assume it exists.
3. Inventor discrepancy: a court filing referenced an "inventor Shigeto Oeda" for the '306 patent, contradicting the authoritative inventor list; I credit the patent's own inventor data.
4. Docket statuses (e.g., "Settlement") are as recorded by third-party aggregators (Google Patents / Unified Patents / Docket Alarm) and are not legal conclusions; the PTAB had instituted IPRs at various points before settlement.

If you want, I can pull the full text of claims 9–15 and the PTAB final written decisions, which would sharpen the independent-claim analysis and confirm the settlement posture.

I'll research litigation involving US patent 6928306 across patent litigation databases and court records.

Let me dig deeper into the specific cases and the Unified Patents litigation portal.

Litigation Involving U.S. Patent No. 6,928,306

Patent: U.S. 6,928,306 ("Portable mobile unit"), filed 2001‑01‑04, granted 2005‑08‑09, priority 2000‑01‑07. Original assignee Hitachi, Ltd.; current assignee Maxell, Ltd. (after chain of assignments through Hitachi Consumer Electronics → Hitachi Maxell → Maxell). Per the Google Patents family/litigation record, the patent family is flagged "Family has litigation."

Below is what the available records show. Note a key caveat up front: 6,928,306 was almost always asserted as one of several patents in broader Maxell campaigns, so cases are often reported at the campaign level rather than patent-by-patent. I have flagged where my confidence about this specific patent's inclusion is lower.

1. Maxell Ltd. v. Apple Inc. (District Court)

Sources: CourtListener docket 14722224; RPX Insight litigation profile (txedce‑188434) noting filed 03/15/2019, closed 04/07/2021; Docket Alarm.

2. Apple Inc. v. Maxell, Ltd. (PTAB — Inter Partes Review)

Sources: Docket Alarm (IPR2020‑00204, "Terminated‑Settled"); Casetext/PTAB Paper No. 32 (Apr. 20, 2021); PTAB decision denying Petitioner's Request for Rehearing of Final Written Decision (referencing IPR2020‑00204).

3. IPR2019‑00640 (PTAB — related proceeding)

The Google Patents family/litigation record lists a second PTAB case, IPR2019‑00640, as filed and closed by settlement:

• https://portal.unifiedpatents.com/ptab/case/IPR2019-00640

I could not independently confirm the petitioner, the challenged claims, or the specific patent link in the records retrieved; treat the petitioner/patent mapping as lower‑confidence. It is a settled PTAB proceeding associated with this patent family.

4. Earlier E.D. Tex. Actions (2018) — patent previously asserted

The Google Patents family record lists two earlier Texas Eastern District Court actions:

• 5:18‑cv‑00033
• 5:18‑cv‑00034

An RPX litigation document in a later Maxell case states that six patents — including U.S. Patent No. 6,928,306 — "were previously asserted in this District against Huawei Device Co., Ltd., Huawei Device USA, Inc., ZTE (USA), Inc., ZTE Corporation, and/or ASUSTeK Computer Inc." A 2018 E.D. Tex. opinion, Maxell Ltd. v. Huawei Device U.S. Inc., 297 F. Supp. 3d 668 (E.D. Tex. 2018), reflects claim‑construction activity in the Huawei litigation.

Confidence note: I can confirm 6,928,306 was previously asserted in E.D. Tex. against the Huawei/ZTE/ASUS group, but I could not definitively map which case number (‑00033 vs ‑00034) corresponds to which defendant. These 2018 cases are the "first worldwide family litigation filings" referenced on the patent page.

Cases that do NOT involve 6,928,306 (do not attribute)

Several high‑profile Maxell cases surfaced in searching but concern different patents and should not be attributed to 6,928,306:

• Maxell Ltd. v. Samsung Electronics (E.D. Tex.) — the May 2025 $111.7M jury verdict and the October 2025 JMOL reversing it concern Maxell's device‑unlock / recording‑location / data‑management patents, not 6,928,306.
• Maxell Ltd. v. Apple Inc., 6:20‑cv‑00646 (W.D. Tex.) — asserted e.g. U.S. Patents 10,129,590 and others, not 6,928,306.
• Multiple later IPRs (e.g., IPR2025‑00392/393/394 against 8,339,493, 9,818,449, 10,199,072, etc.) — different patents.

Summary

Net: The only litigation I can confirm with high confidence as directly involving U.S. 6,928,306 is (1) Maxell Ltd. v. Apple Inc., 5:19‑cv‑00036 (E.D. Tex.), and its companion PTAB review IPR2020‑00204 — both concluded by settlement in 2021. The additional Family‑record PTAB case IPR2019‑00640 and the 2018 Texas cases (5:18‑cv‑00033/‑00034) are associated with this patent but with lower confidence as to party/patent mapping.

If you need the case numbers, petitioners, and docket entries verified to court‑record precision, the authoritative next steps are PACER for 5:19‑cv‑00036 and the PTAB‑E2E / USPTO Patent Trial and Appeal Board End‑to‑End system for IPR2020‑00204 and IPR2019‑00640 — I could not fully authenticate every field from the freely available records retrieved.

I'll research the two IPR proceedings referenced in the patent record and check for any others.

Let me dig into the second IPR (IPR2019-00640) and the Apple appeals.

Let me pin down the petitioner and details for IPR2019-00640.

PTAB Proceedings — US 6,928,306 ("Portable mobile unit")

Sourcing note / discrepancy flag. The structured ODP block in this prompt reports no AIA trial proceedings on file. However, the patent's own Google Patents litigation record (authoritative in this task) affirmatively lists two PTAB cases under "Family has litigation," both marked "filed (Settlement)": IPR2019-00640 and IPR2020-00204. Web search corroborates both. The ODP gap is consistent with its known indexing holes for older, settled, pre-institution cases. I report the two proceedings below and do not invent any others. One additional anomaly is flagged at the end and needs verification.

Proceedings overview

Total AIA trials on US 6,928,306: 2 — both settled; 0 claims canceled, 0 claims sustained by any Final Written Decision, 0 institution denials (one case settled before institution, the other terminated before any FWD). Bottom line: no PTAB merits ruling exists on this patent — every claim of the '306 patent remains legally intact and wholly untested at the Board — but the patent expired 2022-08-02 (adjusted expiration), which is the dominant defensive fact for any defendant today.

IPR2020-00204 — Apple Inc. v. Maxell, Ltd.

• Type: Inter Partes Review
• Patent: U.S. Patent No. 6,928,306
• Filed: 2019-12-20 (Apple's Petition, Paper 1)
• Status: Terminated − Settled (docket termination date 2021-04-20). Plain English: the parties settled and the Board closed the case without ever issuing a Final Written Decision, so no claim was canceled or confirmed.
• Judge panel: John Hudalla, Kevin Trock, Michael Zecher, Minn Chung (per the public Docket Alarm PTAB docket). Tech Center 2600, Art Unit 2684.
• Petition grounds: The petition was filed against the '306 patent while Apple and Maxell were litigating in E.D. Tex. (Maxell, Ltd. v. Apple Inc., No. 5:19-cv-00036-RWS, filed 2019-03-15). Maxell's infringement contentions against Apple's products asserted claims 2, 5–6, and 13–15 of the '306 patent (direct and indirect infringement, aimed at the feature that speaks a caller's name at ring time). Apple's IPR chart in the parallel district case lists IPR2020-00204 against the '306 patent, but the retrieved excerpt of the Miller declaration truncates the specific claims challenged and the art, and no grounds document was retrieved. I could not verify the specific § 102/§ 103 grounds or art from primary sources — treat the challenged-claim list and references as unconfirmed.
• Institution decision: Not confirmed in retrieved sources. Timing is consistent with institution (~mid-2020) followed by termination before the ~June 2021 FWD deadline, but the institution paper was not retrieved; do not assume institution.
• Final Written Decision: None issued. No claim-level verdict exists.
• Settlement / termination: The case terminated as "Terminated-Settled" on 2021-04-20. The settlement agreement itself is not public (settlement papers are typically filed as business-confidential information, and the terms are confidential).
• Appeal: None. A settled, non-FWD IPR is not appealable, and no CAFC appeal of IPR2020-00204 was found.
• Defensive value: No estoppel and no invalidity finding flow from this case. Because it never reached a Final Written Decision, § 315(e)(2) estoppel did not attach to Apple. Practically, the proceeding matters only as context: Maxell's infringement theories against Apple products rode on claims 2, 5–6, and 13–15, which remain live on their face — though the patent's 2022-08-02 expiration now caps any recovery to pre-expiration, within-lookback infringement.

Sources: Docket Alarm PTAB docket — Apple Inc. v. Maxell, Ltd., IPR2020-00204 · Google Patents — US6928306

IPR2019-00640 — Petitioner (unconfirmed) v. Maxell, Ltd.

• Type: Inter Partes Review
• Patent: U.S. Patent No. 6,928,306 (per the patent's Google Patents litigation record)
• Filed: 2019 (IPR2019 series). Exact filing date not confirmed in retrieved sources.
• Status: Terminated − Settled before institution. The docket entry is Paper 9: "Order Granting Joint Motion to Terminate Proceeding Due to Settlement before Institution and Granting Joint Request to Treat Settlement [as Business Confidential Information]." Plain English: the parties settled before the Board ever decided whether to institute, so the merits were never reached.
• Judge panel: The retrieved docket metadata associates this case with APJs Lynne E. Pettigrew and Minn Chung, but I could not confirm the full panel from the decision document text — treat as provisional.
• Petition grounds: Not retrieved. Because the case terminated pre-institution, no institution decision, claim analysis, or ground-by-ground reasoning exists in the public record.
• Institution decision: None — no institution decision was reached. This is a pre-institution termination, not a denial on the merits.
• Final Written Decision: None issued. No claim was canceled or sustained.
• Settlement / termination: Joint motion to terminate granted; the settlement was treated as business-confidential and is not public. Terms confidential.
• Appeal: None possible (no FWD).
• Defensive value: Zero negative estoppel, zero invalidity leverage. This IPR produced no finding a defendant can borrow. Its significance is timing-based: it shows an earlier challenger (2019) settled out before institution, leaving the '306 claims untouched heading into the Apple litigation and the later IPR2020-00204.
• Open item: The petitioner is not confirmed. I could not verify whether this was an Apple filing, a related-defendant filing, or a defensive-aggregator filing from the sources retrieved. Note also that the "Unified Patents" label appearing on the Google Patents litigation block is the data-source attribution for the PTAB dataset, not a petitioner — the confirmed petitioner in IPR2020-00204 is Apple Inc., not Unified Patents.

Source: Google Patents litigation record — US6928306 (lists IPR2019-00640 as filed/settled) · Docket Alarm document index — IPR2019-00640, Paper 9 (termination order title)

Strategic summary

Claim status: everything is UNTESTED; nothing is canceled. Neither IPR produced a Final Written Decision. IPR2019-00640 died pre-institution on settlement, and IPR2020-00204 terminated settled on 2021-04-20 without an FWD. Consequently claims 1–15 of the '306 patent stand exactly as issued — including independent claim 1 (mixer + plurality of sound sources), independent claim 2 (plurality of sound sources), and the asserted independent claim 13 (multiple sound-generation protocols), plus dependent claims 5–6 and 14–15 that Maxell pressed against Apple. There is no cancellation of any claim to cite, so the "claims 1–5 are canceled, the troll has no case" posture is not available here. The strongest defensive fact is not a PTAB outcome at all: the patent expired 2022-08-02, which forecloses prospective infringement and confines any damages to pre-expiration, within-§ 286-lookback conduct.

Estoppel landscape. Because no FWD issued in either case, § 315(e)(2) estoppel never attached to Apple or to the IPR2019-00640 petitioner. For a defendant being asserted today, that cuts both ways: your own prior-art grounds are not estopped (nothing was finally decided), but you also inherit no IPR shield — there is no adjudicated invalidity to ride. Note the separate, non-statutory constraints: a defendant who was a real party in interest or privy to either settled IPR still faces the practical § 315(b) one-year bar to filing its own new IPR (timed from service of the complaint), and district-court estoppel principles may still bar relitigating patents the settling parties resolved — but neither is § 315(e)(2) estoppel.

Pattern signals. The record shows a multi-front Maxell monetization campaign, not a single challenger: earlier district-court suits against Apple (5:18-cv-00033 and 5:18-cv-00034, E.D. Tex., 2018) and 5:19-cv-00036 (E.D. Tex., filed 2019-03-15), a ZTE campaign (5:16-cv-00179; ZTE's IPR2018-00236), and Maxell IPRs by Olympus (IPR2018-00904) and, later, LG and Amperex on other Maxell battery/display patents. On the '306 patent specifically, the pattern is settlement, not adjudication — two IPRs, both settled, none reaching FWD, which is a classic sign a plaintiff prefers to litigate/settle broadly rather than risk a canceling decision on its ringtone claim. No defensive aggregator (e.g., Unified Patents) is confirmed as a petitioner on this patent — the "Unified Patents" string in the Google Patents block is a data-source citation.

Recommended next steps

• Confirm the IPR2019-00640 petitioner and filing date. Pull the case from PTAB E2E / PTAB Center (ptacts.uspto.gov) and read Paper 9 (termination order). The petitioner identity determines whether § 315(b) privity blocks anyone, and whether the pre-institution settlement warrants a district-court estoppel/invalidity carve-out.
• Retrieve the Apple petition and any institution decision in IPR2020-00204. No FWD exists, so there is no FWD link to cite — the only citable records are Apple's Petition (Paper 1), any institution decision, and the termination papers. This is the vehicle to reconstruct the art Apple actually ran (useful as a starting prior-art map if you must file fresh), while remembering Apple is not estopped because no FWD issued.
• Verify the anomaly. A USPTO PTAB public document (Petition download, ID 1557278) surfaced a caption reading "Decision Denying Request for Rehearing – Petitioner … Denying Petitioner's Request for Rehearing of Final Written Decision – 37 CFR 42.71(d)" and references 6928306. If that document is genuinely tied to the '306 patent, it would imply a third, FWD-reaching proceeding not reflected in the Google Patents list — which would contradict the two-settlement picture above. Do not rely on it until confirmed; check PTAB E2E for any additional '306 IPR and for the FWD + rehearing decision.
• If you are a defendant today: the decisive point is expiration (2022-08-02). Because no claim was ever canceled and no FWD was issued, an IPR-based invalidity defense has no pre-built foundation — you would be starting from scratch (subject to § 315(b)/§ 325(d) timing and prior-art constraints). Focus first on the damages window (only pre-expiration, § 286-lookback-eligible infringement is actionable) and on the settled Maxell–Apple resolution, which may contain license/release terms relevant to downstream users of Apple products.
• No active proceedings to calendar. With both IPRs terminated, there is no PTAB institution deadline, oral hearing, or statutory one-year FWD date to track on this patent. Treat it as no active PTAB activity for docketing purposes.

Confidence and limits. Confirmed: IPR2020-00204 petitioner (Apple), filing date (2019-12-20), termination type/date (settled, 2021-04-20), panel names, and the absence of any FWD; IPR2019-00640's pre-institution settlement termination (Paper 9 title); the '306 patent's 2022-08-02 expiration; and the asserted claims 2, 5–6, 13–15 against Apple. Not confirmed (flagged, not fabricated): the IPR2019-00640 petitioner and exact filing date; IPR2020-00204's specific challenged claims and prior art; whether IPR2020-00204 was instituted; and the possible third FWD-reaching '306 proceeding hinted at by the rehearing-decision document.

I'll research the assignment record for US 6928306, starting with the litigation and ownership events already surfaced in the patent record.

Found a chain-of-title statement. Let me verify the reel/frame numbers and correspondents specific to this patent.

Assignment & Ownership Analysis — US 6,928,306 ("Portable mobile unit")

Scope note / source limitation. In this session I could query Google Patents' full legal-events record for US 6,928,306 and open web sources, but I could not execute a live query against USPTO Assignment Center (assignmentcenter.uspto.gov / assignment.uspto.gov). The Google Patents legal-events timeline for this patent does record post-issuance assignments, so I proceed — but reel/frame numbers below are only partly corroborated (see the caveat under the timeline). Where I could not verify a reel/frame, I say so rather than inventing one.

Inventors

The employer attribution rests on a single hard data point: the invention was filed by Hitachi, Ltd. on 2001-01-04 (US09/755,878), and the Google Patents legal record shows an assignment "Assigned to HITACHI, LTD." recorded 2001-04-30, with assignors listed as Shinagawa, Akio; Takada, Chikako; Takizawa, Kazuyuki; Esaki, Tomohiro; Matsuda, Masayuki — i.e., all five inventors conveyed to Hitachi. No record in this session identifies their internal division, and I found no evidence of inventors leaving the assignee within 12 months of filing (the "departure precedes fire-sale" flag is not triggered by anything I could verify). Treat the "Hitachi, Ltd." column as an inference from the assignment instrument, not an independent HR record.

Original assignee

Hitachi, Ltd. (Tokyo, Japan), named on the issued patent (filing 2001-01-04; grant 2005-08-09).

• Primary line of business: diversified industrial/consumer electronics conglomerate — at the relevant time it built and sold mobile phones, consumer electronics, storage media and components. The claimed subject matter (a portable mobile unit that generates its ringing sound by mixing multiple sound sources — FM, PCM, MIDI/MP3) sits in Hitachi's mobile-handset line.
• Product practice: Hitachi was an operating handset maker at filing, but I have no evidence that Hitachi (or any successor) shipped a handset that reads on claims 1–15's multi-sound-source mixer architecture. This matters for the NPE call below: the originating assignee was operating, but practice of these claims is unproven.
• Current status: Hitachi, Ltd. is an operating company in 2026 and remains a prior owner of the asserted patent family (it is listed as "Prior owner of the Asserted Patents" in the Maxell v. Apple discovery disclosures). The patent itself has moved on: Google Patents lists the current assignee as Maxell, Ltd., expired – lifetime, adjusted expiration 2022-08-02.
• Family note: a continuation (US 11/097,653 → US 2005/0181838 A1) was filed 2005-04-01 out of the same disclosure; patents granted off that continuation ride the same assignment chain.

Assignment timeline

Dates below are the Google Patents legal-events dates for US 6,928,306; these correspond to the USPTO recordation dates for the underlying §3.11 filings.

2001-01-04 — application filed by Hitachi, Ltd. (not an assignment; included for chain anchoring). Inventor→assignee paperwork was filed afterward.

• 2001-04-30 (recorded) — Reel 022596/0595? ❌ not verified for this docket

  • Conveyance: Assignment (inventor-to-corporation; "ASSIGNMENT OF ASSIGNORS INTEREST")
  • Assignor: Matsuda, Masayuki; Esaki, Tomohiro; Takizawa, Kazuyuki; Shinagawa, Akio; Takada, Chikako
  • Assignee: HITACHI, LTD.
  • Correspondent: not determinable from the sources available in this session. (The reel 022596/0595 inventor→Hitachi recording I was able to confirm in the wild belongs to an application filed in 2014, not to this 2001 filing, so it must not be cited as this patent's reel.)
  • Context: standard employee invention assignment to the sponsoring corporation — internal, not a market transfer.

• 2013-06-12 (recorded) — Reel 030622/0001 (reel/frame pattern corroborated for the Hitachi portfolio; not verified for this specific patent number)

  • Conveyance: Assignment
  • Assignor: Hitachi, Ltd.
  • Assignee: Hitachi Consumer Electronics Co., Ltd.
  • Correspondent: not confirmed for this recording.
  • Context: internal reorganization — Hitachi carved out its consumer-electronics operations (including the legacy handset/AV patent estate) into a dedicated subsidiary.

• 2014-09-08 (recorded) — Reel 033685/0883 (same caveat as above)

  • Conveyance: Assignment
  • Assignor: Hitachi Consumer Electronics Co., Ltd.
  • Assignee: Hitachi Maxell, Ltd.
  • Correspondent: not confirmed for this recording.
  • Context: internal reorganization / intercompany transfer — the consumer-electronics IP estate folded into Hitachi Maxell.

• 2018-01-25 (recorded) — Reel 045142/0208 (reel/frame independently corroborated — see note — for the Hitachi Maxell→Maxell title transfer; signer of the corroborating §3.73(c) statement was /John R. Mattingly/, dated 2018-07-25)

  • Conveyance: Assignment of assignor's interest
  • Assignor: Hitachi Maxell, Ltd.
  • Assignee: Maxell, Ltd.
  • Correspondent: John R. Mattingly — a Hitachi/Maxell prosecution attorney of record (PatentBots: ~1,882 Hitachi filings and ~601 Maxell filings) who signed the Maxell chain-of-title statement per 37 CFR 3.73(c) in an unrelated Maxell IPR. He appears once in my evidence, on a sibling patent's chain statement — not on any NPE filing, and not (as far as I can verify) on a recorded assignment for this docket. Not counted as a repeat-correspondent finding.
  • Context: change of corporate identity / title cleanup — "Hitachi Maxell" was rebranded to "Maxell, Ltd." This lands ~weeks before Maxell's early-2018 E.D. Tex. assertion campaign (see signals).

• 2021-11-29 (recorded) — Reel not verified (Google Patents records the event, not the reel)

  • Conveyance: Merger
  • Assignor: Maxell, Ltd.
  • Assignee: Maxell Holdings, Ltd.
  • Correspondent: not confirmed.
  • Context: holding-company restructuring — pure corporate reorganization, no change in beneficial ownership.

• 2021-12-03 (recorded) — Reel not verified

  • Conveyance: Change of Name
  • Assignor: Maxell Holdings, Ltd.
  • Assignee: Maxell, Ltd.
  • Correspondent: not confirmed.
  • Context: change of name only — the holding company renamed itself back to Maxell, Ltd.; the operating name and the IP-holding name are again the same entity.

Chain-of-title caveat. The four-step reel sequence inventor→Hitachi→Hitachi Consumer Electronics→Hitachi Maxell→Maxell (022596/0595 → 030622/0001 → 033685/0883 → 045142/0208) comes from a 37 CFR 3.73(c) statement for a different Maxell patent (application 14/478,020) and therefore demonstrates the structure of the Maxell portfolio assignments rather than proving the reels recorded against US 6,928,306. Because these Hitachi→successor assignments were recorded as portfolio-level instruments covering schedules of patents, they very likely sweep in the '306 patent — but I could not confirm that in this session, and none of the reel/frame numbers above should be quoted as verified for US 6,928,306 without a fresh Assignment Center pull (search by patent number at https://assignment.uspto.gov/patent/index.html).

Timeline diagram

timeline
    title Ownership of US 6928306
    2001 : Filed by Hitachi Ltd
         : Inventors assign to Hitachi Ltd
    2005 : Patent issued
    2013 : Transfer to Hitachi Consumer Electronics
    2014 : Transfer to Hitachi Maxell Ltd
    2018 : Rebranded to Maxell Ltd
         : Suits filed against Huawei ZTE ASUS
    2019 : Apple suit filed in EDTX
         : First IPR petition filed
    2021 : Merger into Maxell Holdings Ltd
         : Name restored to Maxell Ltd
    2022 : Patent expires

NPE / troll-pattern signals

1. Shell-entity transfer — not present. Every link is a named Japanese kabushiki kaisha inside the Hitachi/Maxell corporate group: Hitachi, Ltd. → Hitachi Consumer Electronics Co., Ltd. → Hitachi Maxell, Ltd. → Maxell, Ltd. → Maxell Holdings, Ltd. → Maxell, Ltd. No "IP / Patents / Licensing / Ventures" suffix, no Delaware or Texas single-purpose LLC, no registered-agent address appears anywhere in the recorded chain.

2. Known asserter in the chain — not present. Maxell, Ltd. does not appear on the enumerated NPE lists (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities). Maxell is, however, a high-volume plaintiff tracked in the RPX/Unified litigation directories (131 accused products, 10 patents-in-suit in the Apple case alone), which is a frequency signal, not an identity match.

3. Repeat correspondent across the chain — unclear / not established. Only one correspondent name surfaced at all (John R. Mattingly, on the sibling-patent §3.73(c) chain statement and as Maxell's long-running prosecution attorney). One data point is not recurrence; the recorded assignments for 2013, 2014, 2018 and 2021 each have a correspondent of record I could not retrieve in this session. Pull the reel headers in Assignment Center to close this out — this is the single most valuable follow-up on this file.

4. Cascading transfers — not present. The links are spaced ~1 year, ~1 year, ~4 years, ~4 years, days apart. The two 2021 events (11-29 merger, 12-03 change of name) are the only sub-24-month pair, and both are the same holding-company restructuring, not shell cascading.

5. Pre-litigation transfer — present. The 2018-01-25 Hitachi Maxell, Ltd. → Maxell, Ltd. assignment (reel 045142/0208 pattern) precedes Maxell's assertion of this patent in E.D. Tex. cases 5:18-cv-00033 and 5:18-cv-00034 (against Huawei Device Co./Huawei Device USA, ZTE Corp./ZTE (USA), and ASUSTeK) — the family record and the 2019 Apple complaint both confirm the '306 patent was among the patents previously asserted there. Mitigating read: the January 2018 recording looks like a portfolio-wide corporate rebranding (Hitachi Maxell → Maxell), not a targeted transfer into an assertion vehicle, so this is a title-cleanup-before-suit variant of the signal rather than the classic "transfer to a shell to enable standing." (Exact 2018 complaint filing dates were not confirmable here; case numbers are consistent with early-2018 filings, which would put the assignment well inside the 6-month window.)

6. Bankruptcy fire-sale — not present. No Chapter 7/11, no §363 sale, no assignment-for-the-benefit-of-creditors anywhere in the chain. The transfers are all intra-group reorganizations.

7. Privateering — partially present / unclear. The patent originated with a practicing handset maker (Hitachi) and now sits with Maxell, Ltd., an operating household-brand manufacturer (batteries, recording media, projectors, functional materials) that does not make portable mobile units but runs an explicit licensing-and-litigation monetization program — its own Samsung complaint states that "many of the smartphone companies well-known to consumers have already entered into a license agreement with Maxell." That is a legacy Hitachi patent estate being monetized against third-party handset makers rather than practiced. It is not classic privateering (no separate assertion-only subsidiary; Maxell sues in its own name), and the 2017–2018 Hitachi/Maxell separation that drove it was a corporate spin, not a covert proxy arrangement I can document.

8. Defensive aggregator (anti-NPE) — not present as a terminating transfer, but note the inverse activity: the family drew PTAB IPR2019-00640 and IPR2020-00204, both terminated by settlement, each linked in the Google Patents record to the Unified Patents PTAB portal (petitioner not confirmed in the sources available here). A defensive aggregator challenging the patent is contextual evidence the patent was being asserted commercially, and the patent has since expired 2022-08-02, so the assertion window is closed regardless.

Verdict

NPE — moderate confidence.

The chain itself is clean of the classic troll machinery: no shell LLCs, no registered-agent addresses, no newco assignees, no bankruptcy liquidation, and the assignee is a genuine Japanese manufacturer rather than a two-employee licensing vehicle — so signals 1, 2, 4, 6 and 8 are all absent. Confidence is nonetheless dragged up from "insufficient data" by two concrete facts: (i) the 2018-01-25 recorded transfer of the estate to Maxell, Ltd. (reel 045142/0208 pattern) sits within weeks of Maxell's early-2018 E.D. Tex. assertion filings (5:18-cv-00033 / 5:18-cv-00034) that named this patent, and (ii) the current owner does not practice the claimed portable mobile unit, instead monetizing the inherited Hitachi portfolio through licensing and litigation against handset makers (Apple in 5:19-cv-00036, filed 2019-03-15). If the rubric is read strictly as "current assignee ships products embodying the claims," the honest alternative label is Operating-company assertion — Maxell is an operating manufacturer suing actual competitors — but because Maxell's product line does not include the ringing-generation handsets the claims cover, I land on NPE-moderate rather than either of the two stronger verdicts.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ and https://assignment.uspto.gov/patent/index.html (search "6928306"). Priority verification task: pull the reel/frame headers for the 2013, 2014, 2018 and 2021 recordings to confirm the reel sequence and to test signal 3 (repeat correspondent), which is the only open question left on this file.

I'll research US patent 6928306 and its prior art citations. Let me search for authoritative information.

Let me get the detailed cited references list from the patent's USPTO records.

Let me retrieve the complete citation lists from the patent databases.

Prior-Art Analysis — US Patent 6,928,306 B2 ("Portable mobile unit")

1. Confirmed patent identification (matches the requested number exactly)

Two things about the claim set drive the whole prior-art analysis:

• Granted independent claims 1 and 2 both require generating the ring sound using at least two of the plurality of sound sources (claim 1 additionally recites a mixer). The original application (US 2001/0014616 A1) claimed "at least one" sound source. That narrowing amendment is the single most important fact for prior-art mapping: a § 102 reference that anticipates claim 1 must disclose two or more sound sources mixed/combined into the ring tone, not merely a tone generator.
• Dependent claims 3–4 (multi-method sound data: waveform-coding + analytic-composition coding; reproduction-timing memory) and 5–15 (condition-based selection: incoming time zone, calendar, count of unanswered calls, remaining battery, environmental noise, etc.) are where most citations land.

2. Scope note on "citations" (important)

A patent has two distinct citation sets, and they are not the same thing:

• "References Cited" (front page / § 56) — prior art the applicant and Examiner considered during prosecution.
• "Cited By" — later documents that cite 6,928,306 (not prior art at all).

You asked for prior art, so the section below is the References Cited set. The authoritative list is drawn from the patent's own record (Google Patents / USPTO) as mirrored on Justia. I was able to confirm the U.S. patent-document list below, but I could not retrieve the complete foreign-patent-document and non-patent-literature sub-lists for the '306 patent within this session; those should be pulled from the USPTO PatentCenter "References Cited" page for a complete answer. I flag every place where my description is inferred rather than confirmed.

3. Patents cited as references against US 6,928,306

Confirmed citation data (number / date / inventor of record):

Descriptions and § 102 mapping

Because the front-page list above is confirmed but I do not have the full text of each reference loaded, the functional descriptions below are given at the level I can support and are marked accordingly. I recommend verifying each against the reference's own text before relying on a § 102 theory.

1. US 5,563,951 (Wang et al.), 1996‑10‑08. (Inferred) A telephone set/alerting-sound reference from the mid‑1990s. Its date places it squarely before the 2000 priority date, so it is a genuine § 102 candidate on timing. Mapping is only viable against the original "at least one sound source" claim; against granted claims 1–2 it would need to disclose ≥2 sound sources mixed — unlikely. More plausible as § 103 background for the condition-based dependent claims.

2. US 5,771,001 (Cobb), 1998‑06‑23. (Inferred) A programmable alerting/notification-type reference. Relevant, if at all, to claim 7 (count/condition of unanswered or repeated notifications) or to the general "alert the user on an event" preamble. Pre-dates priority; genuine § 102 candidate on timing only.

3. US 5,870,684 (Hoashi et al.), 1999‑02‑09. (Inferred) A radiotelephone reference directed to incoming-call sound/alerting control. This is the class of art most directly aimed at claims 5–6 (changing the alert by time/condition) and potentially claim 3's pattern selection. Stronger as § 103 combined with a multi-sound-source teaching than as a standalone § 102 anticipation of claims 1–2.

4. US 6,175,721 (Hayato), 2001‑01‑16. (Inferred) Assigned-date-wise to the same era; likely directed to a portable communication apparatus with selectable/changeable ring tones. Because it granted after the '306 priority date, only its filing/priority date, not its grant date, determines whether it is prior art. Verify its effective date in PatentCenter; if earlier than 2000‑01‑07 it is a § 102 candidate for the condition-based dependent claims.

5. RE 37,281 (Motegi), 2001‑07‑17. (Inferred) A reissue of an earlier patent in the electronic-musical-tone / sound-generation field (Yamaha-style tone generation). Reissues take the original patent's filing date, so this is likely a genuine pre‑2000 reference. Best mapped to claim 4 (analytic-composition coding / synthesized tone generation) and, in combination, to claim 3. As a single reference it is § 103 material, not a clean § 102 anticipation of claims 1–2.

6. US 6,308,086 (Yoshino), 2001‑10‑23. (Inferred) A mobile-termination / incoming-alert reference. Same caveat as #4 — the grant date is post-priority; use the underlying filing date. Likely § 103 relative to claims 5–10 and to claim 3's pattern memory.

7. US 6,463,278 (Kraft et al.), 2002‑10‑08. (Inferred) A communication-system alerting/distinctive-ring reference. Grant date is well after the '306 priority date, so it is prior art only if its filing date (and any foreign priority) precedes 2000‑01‑07 — verify. If so, it is aimed at the condition-based claims and the ring-generation preamble, i.e., § 103, not § 102 of claims 1–2.

8. US 2001/0051536 A1 (Muramatsu), 2001‑12‑13. (Examiner-cited publication.) Published after the '306 priority date; § 102 status depends entirely on its filing/priority date. Most likely cited as background to claim 3 (pattern/selection of sound data).

9. US 2003/0110928 A1 (Yamaki et al.), 2003‑06‑19. ⚠️ Publication date is more than three years after the '306 priority date (2000‑01‑07). On its face this publication cannot be prior art to '306 unless it carries an earlier priority claim or the citation arose in a later proceeding (e.g., reissue/reexam or an IPR). I would treat this entry with caution — it most likely belongs to the "Cited By" side of the record rather than being a pre-filing reference. This is exactly the kind of item that must be verified directly on the USPTO PatentCenter page before being characterized as prior art.

Bottom line on § 102 vs § 103: None of the references above appears to be a clean, single-reference § 102 anticipation of granted claims 1–2, because those claims require at least two mixed sound sources. The realistic invalidity theory for the '306 patent runs through § 103 combinations against the condition-based dependent claims (3–15), using a multi-sound-source generator reference plus one or more condition/alerting references. That is also consistent with the fact that the patent was granted (the Examiner evidently did not find the "two sound sources" limitation anticipated).

4. Prior art cited in the specification itself (background art)

The '306 specification expressly identifies these as known art — they are the references most probative of the problem the invention addresses, and are typically the first place an invalidity search should begin:

The third of these (Hei 09‑312684) is directly relevant to the condition-based dependent claims (caller-identity selection) and is the closest background art to claims 3 and 5–15.

5. What I could NOT confirm (stated explicitly, per instruction)

• The complete "References Cited" list for 6,928,306 — specifically the Foreign Patent Documents sub-table and the Other Publications sub-table. The list above is the U.S. patent-document set; the foreign/NPL portion was not retrievable in this session.
• The bibliographic titles, exact filing dates, and assignees of references 1–7. The dates shown are the dates of record I could confirm; the functional descriptions are inferred and flagged.
• Whether entries 8 and 9 are truly on the "References Cited" side or the "Cited By" side of the record.
• The IPR2020‑00204 (Apple v. Maxell) petition grounds — this IPR was settled, but its petition exhibits would name the art Apple actually asserted against claim 2 and claims 5–6/13–15 (the claims Maxell asserted against Apple per the Japanese case commentary). That petition is the single best source for "most relevant prior art" as a practical matter and was not available to me here.

To close these gaps, pull the "References Cited" and "Cited By" tables directly from the 6,928,306 document page in USPTO PatentCenter, and pull the IPR2020‑00204 petition from PTAB.

6. Recommended verification sources

• Google Patents: https://patents.google.com/patent/US6928306/en (front-page "References Cited"/"Cited By")
• Justia: https://patents.justia.com/patent/6928306 ("Referenced Cited" U.S. Patent Documents table)
• USPTO PatentCenter record for application 09/755,878 (complete § 56 reference list and any IDS)
• PTAB IPR2020‑00204 docket: https://portal.unifiedpatents.com/ptab/case/IPR2020-00204

Note: I did not auto-correct any identifier. The references are reported exactly as they appear in the record (e.g., "RE 37,281," not "RE37,281," and "US 2003/0110928 A1" as published), and I have flagged items 8–9 whose dates are inconsistent with pre-filing prior-art status rather than silently reclassifying them.

I'll research the prior art references identified in this patent, then build the §103 analysis.

Let me pull the actual references cited on the face of the patent and check the prosecution history.

Obviousness Analysis — U.S. Patent No. 6,928,306 ("Portable mobile unit")

Applies: pre‑AIA 35 U.S.C. § 103(a) (application 09/755,878 filed 2001‑01‑04; priority 2000‑01‑07; issued 2005‑08‑09), analyzed under the Graham v. John Deere framework as refined by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).

Note on scope and ground truth. This analysis relies on the references named in the patent's own Prior Art / Background section and on the art the specification itself admits as known. I was unable to retrieve the complete "References Cited" list printed on the face of US 6,928,306 or the full file wrapper, so this is not a substitute for a full reexamination search. I do not treat the citation list appearing on US 2004/0137969 (a headset patent that cites the '306 patent) as the '306 patent's own references of record — that would be an attribution error. Claims 9–15 are truncated in the supplied text, so those are analyzed only inferentially and flagged.

1. Level of ordinary skill

A POSITA would be a degreed electrical engineer (or equivalent) with ~2–4 years in mobile‑handset design, conversant with (a) cellular telephony and caller‑ID signaling, (b) embedded audio/melody synthesis (FM synthesis, PCM/sampled sound, MIDI/MP3 playback), and (c) conventional audio mixing/DAC/amplifier chains. This mirrors the "engineer implementing a ringer subsystem" skill set, and is the level against which the "predictable combination" inquiry is measured.

2. The prior art of record (as identified in the patent's Prior Art section)

All three JP references published more than one year before the 2000‑01‑07 priority date and thus qualify as prior art under § 102(b); each is analogous art (same field of endeavor — mobile/handset alerting).

Critical admission in the specification. The '306 patent expressly states the design trade‑off that motivates its own invention: FM/analytic synthesis gives rich instrument timbres with small memory but cannot produce vocal sounds; PCM/waveform coding can produce voices/sound effects but consumes too much memory. It further states the solution is to use the FM source for main phrases and the PCM source "in addition thereto." That is an admission that the combination solves a recognized, quantified trade‑off by known means — which cuts strongly toward § 103.

3. Claim‑by‑claim obviousness

Claims 1 and 2 (plural/≥2 heterogeneous sound sources; claim 1 adds a mixer)

No single reference teaches ringing with two sound sources for the same alert. These are therefore combination rejections, and the motivation must be articulated:

Proposed Ground: R1 (user‑captured waveform alert sound stored in memory and played on incoming call) + R2 (band‑limited stored/compressed ringing‑tone (melody) data in a cellular phone with melody generation) + A (known FM and PCM sound sources for ringtones) + conventional mixing.

• Difference over art: the claims require at least two of the generator's sound sources to be used for the ring, and claim 1 a mixer.
• Motivation (rational, articulable, KSR‑sufficient):

1. Known trade‑off, expressly recognized in the art admitted by the applicant — small‑memory FM plus short‑duration PCM for voice. Where the prior art discloses both options and their complementary costs/benefits, combining them to obtain both benefits is the definition of an obvious design choice. KSR, 550 U.S. at 417 ("a finite number of identified, predictable solutions"); In re O'Farrell, 853 F.2d 894 (Fed. Cir. 1988) (express teachings of advantages of each option supply the motivation).
2. Same field, same function, no change in principle of operation — R1 and R2 both store sound data in handset memory and play it as the incoming‑call alert; both are handset alerting subsystems. Combining is not a change of principle. In re Keller; MPEP 2144.03.
3. Persistent user demand for distinctiveness — the '306 background (and R2's download‑melody rationale) shows users wanted more varied, individualized ringtones; adding a second source is an obvious way to increase the variety of an essentially mechanical combination.
4. Mixing is conventional — R1 already terminates in a D/A → amp → speaker chain; summing two audio channels with a mixer/summing junction is routine electrical engineering with a predictable result.

• Reasonable expectation of success: High. FM synthesis, PCM playback, DACs, and mixing amplifiers were all mature, off‑the‑shelf technologies as of the priority date. No new physics or unexpected interaction is required. KSR ("combination of familiar elements according to known methods is likely obvious when it does no more than yield predictable results").

Claim 3 (pattern selection from plural sound‑source combinations via a reproduction‑timing memory)

Proposed Ground: Ground for claims 1–2 + R3 (+ R2's melody data).

• R3 expressly teaches a table in memory mapping a condition (the received caller number) to a pre‑set alert pattern, read out and applied on an incoming call. Substituting "sound‑emission pattern" composed of two sources for R3's single‑medium pattern is an obvious substitution of one known alerting medium for another.
• The "reproduction timing memory" storing when each data item sounds is inherent in any melody/MIDI‑style playback: MIDI is a time‑stamped event protocol, and R2's stored/compressed tone data is played out over time. A lookup of "data number → on/off timing" is the ordinary way to sequence multi‑voice audio (an admitted art).
• Motivation: R3 supplies the caller‑specific alerting rationale and the selection architecture; the desire to make the alert recognizable (so the user can, e.g., screen calls) motivates enriching the selected pattern with more than one source.

Claim 4 (waveform coding + analytic composition coding in the same unit)

Proposed Ground: Ground for claim 3 + R1 (captured‑from‑microphone, digitized stored waveform = a waveform‑coding sound) + A (FM synthesis from a sound database = analytic composition coding).

• The two coding families are each admitted to be known and used for handset alerting; the claim merely places both in one unit. This is the essence of a predictable combination. KSR; Anderson's‑Black Rock, Inc. v. Pavement Salvage Co., 396 U.S. 57 (1969).

Claims 5–6 (timer / calendar condition)

Proposed Ground: Ground for claims 1–2 + R3 (condition→pattern lookup) + the ubiquitous handset clock/calendar.

• R3 provides a generic condition‑indexed alerting table; the conditions of claims 5–6 (time zone; calendar period) are additional table keys. Cellular handsets of this era universally carried real‑time clocks (and increasingly calendars), so the additional element is a known device performing its known function in the combination. MPEP 2144.03 ("arranging or interchanging parts… mere change in form" / use of a known element for its known purpose).
• Motivation: adapting the alert to context (quiet, "refreshing" tone at night vs. louder, conspicuous tone in noisy daytime periods) — a benefit the '306 specification itself asserts, and one a POSITA would predict.
• Caveat: I did not locate a specific time‑based‑ringtone reference in the materials retrieved; this ground rests on the R3 selection architecture plus general‑knowledge/KSR reasoning rather than a squarely on‑point document. A full search (e.g., post‑1997 handset "profile"/"time‑based ringer" art) would be needed to firm this up.

Claim 7 (absent‑incoming‑call counter condition)

Proposed Ground: Ground for claims 1–2 + R3 (captures the caller number) + the conventional missed‑call/absent‑call counter and call log.

• Counting incoming calls from a specific number when unanswered is a trivial bookkeeping step on data R3 already captures; escalating the alert pattern upon the Nth repeat is an obvious application of R3's condition→pattern mapping.
• Motivation: the '306 specification's own stated purpose — to flag urgency/importance (family/relative emergency) and to defeat nuisance/retry calls — is a recognized problem addressed by an obvious algorithmic extension.

Claim 8 (remaining‑battery‑capacity condition)

Proposed Ground: Ground for claims 1–2 + R3 + the conventional battery‑level detector/low‑battery indicator.

• Battery gauges and low‑battery alerts were standard handset features. Feeding a known gauge reading into R3's condition→pattern lookup is a predictable use of known elements. (References such as NEC's portable‑terminal sound‑level control art, US 6,233,462 / US 6,459,911, are of possible relevance but I could not verify their text here and do not rely on them.)

Claims 9–15 (environmental sound / noise level / sensor conditions; multiple sound‑generation protocols)

Only inferential — the claim text is truncated in the supplied materials. From the specification (embodiments 4–5, FIGS. 9–14) and the litigation record:

• The environmental‑sound / ambient‑noise‑level claims use the handset microphone (already present; R1 uses A/D conversion of captured audio) as the sensor and R3's table as the selector. Automatic ringer‑volume adaptation to ambient noise was well known; selecting among pre‑stored patterns (rather than merely scaling volume) is a routine extension of R3. Motivation: unnoticeable‑but‑audible ring in a library vs. conspicuous ring on a noisy street — a recognized context problem.
• The held‑in‑hand / heat / pressure / photo / acceleration sensor claims recite additional transducers whose outputs are routed into the same condition→pattern lookup; each sensor is a known device used for its known function (proximity to body, ambient light, motion).
• Claim 13 reportedly recites generating the ring using multiple sound‑generation protocols — essentially the claim‑4 concept — which is the combination already admitted as known.
• Note: Maxell asserted claims 2, 5–6, 13–15 against Apple (i.e., the two independent claims and the time‑zone and later claims), which is consistent with the above structure but does not itself bear on patentability.

I explicitly decline to state the exact wording or a definitive obviousness conclusion for claims 9–15. Full text must be obtained before a rejection covering them can be considered final.

4. Secondary considerations

On the record I retrieved, no secondary‑consideration evidence (unexpected results, long‑felt need, industry praise, licensing due to the merits, copying) is present or would support non‑obviousness:

• The alleged advantages (variety, caller identification, small memory) are the predictable products of combining two known sources with known characteristics — the memory/voice trade‑off was expressly recognized in the art, so the result is not "unexpected."
• The commercial success of ringtone/melody features is attributable to market forces (Chaku‑Mero services, carrier marketing), not to the claimed combination — the required nexus is absent. In re GPAC.
• The patent expired 2022‑08‑02 and the IPRs (e.g., IPR2020‑00204, recorded as settled) did not produce a final written decision on validity, so there is no adjudicated non‑obviousness determination to weigh.

5. Bottom line

The § 103 case for claims 1–8 is strong: the invention sits squarely in the KSR "combination of familiar elements yielding predictable results" category, where the only non‑trivial feature (two sound sources used for a single ring) is the direct, predictable answer to a trade‑off the specification itself admits was known. Verify claims 9–15 and the printed references of record before relying on this for any formal challenge.

Flagged uncertainty (unchanged from prior sections): (i) claims 9–15 are absent from the supplied text; (ii) the litigation declaration's "Shigeto Oeda" inventor reference conflicts with the patent's own five‑inventor list and should not be adopted; (iii) no CAFC 2026 activity on this patent was found.