US 4340783

I'll check for any litigation or docket activity and verify the patent's current status.

US 4,340,783 — Summary

Important scope note: My searches of public web-indexed material returned the patent document itself (Google Patents/PatentsView-style content) and its citation records, but I found no CAFC 2026 docket entry, IPR, or district-court litigation involving U.S. Patent No. 4,340,783. I cannot claim to have queried the CAFC's internal docket system or USPTO Patent Center directly; my tools are general web search only. Treat the "no litigation found" statement as a search-result observation, not an authoritative negative. I also did not auto-correct or conflate this number — note that search results also surface unrelated documents containing "4340783" as a substring (e.g., JP4340783B2, "光ファイバのオーガナイザ" / optical fiber organizer, and DE 43 40 783 B4), which are not this patent.

Bibliographic data (from the authoritative full text provided)

Family / foreign counterparts: JP JPS561653A; DE3022603A1; FR2459589A1 (granted, FR2459589B1); GB2052122A / GB2052122B.

Prior art cited (2): US 4,055,729 (Exxon Research & Engineering, 1977-10-25); US 4,122,307 (Hitachi, Ltd., 1978-10-24 — "Telephone voice frequency response system for message recording," a same-assignee predecessor).

Abstract (as issued)

A voice frequency response system comprising a subscriber's terminal unit including both a telephone function and a facsimile receiver function, a voice frequency response device including a facsimile response unit function, and a telephone line between them. The response device comprises a voice frequency response unit transmitting a required message to the telephone in response to a voice-frequency-response service demand, and a facsimile response unit transmitting necessary information in the message (or other information including it) to the facsimile receiver. The subscriber is freed from writing the message, and mishearing/miswriting errors that could lead to future trouble are eliminated, improving serviceability and reliability.

Plain-language overview of the independent claims

Claim 1 — the core combination (apparatus).
A voice frequency response system built from three things: (1) a terminal unit that is both a telephone and a facsimile receiver; (2) a voice frequency response device; and (3) a telephone line joining them. The response device has two cooperating mechanisms — a voice response means that sends a message to the telephone when a subscriber asks for the service, and a facsimile response means that sends character-pattern information taken from at least a part of that same message to the facsimile receiver. The key inventive hook is that the same message content is delivered in two modes: audibly by phone and visually (as characters/patterns) by facsimile, so the important part can be kept as a hard-copy record.

Claim 8 — the same system, recast with explicit switching and control architecture.
A voice frequency response system using a telephone line, with a subscriber's terminal (telephone that requests the service + facsimile receiver that receives character-pattern information) on one side and a voice frequency response device on the other. The device includes:

• a voice frequency response unit sending a message with voice response information to the telephone;
• a facsimile response unit sending character-pattern information from at least a part of that message to the facsimile receiver;
• a signal switching unit at the input/output stage, with switch means that selectively connect either the voice unit or the facsimile unit to the telephone line (i.e., the line is time-shared between voice and fax, not simultaneous); and
• a main control unit that controls both transmissions and the switch means.

Dependent-claim architecture (for context)

• Claims 2–7 depend (directly or indirectly) on claim 1: via a telephone-switching-station subscriber line (2); the signal-switching + main-control arrangement (3); detailed facsimile response means — character-pattern generating circuit with memory, character-pattern control circuit, buffer, line buffer producing 18 scanning lines, frequency identifying circuit, status register, tonal signal generating circuit, and modem with modulator/demodulator (4); ROM memory sized to scanning-line count and recording density (5); row-sequential address reception with line-sequential character addressing (6); line-sequential readout and line-buffer conversion (7).
• Claims 9–17 depend (directly or indirectly) on claim 8: PB-signal service demand (9); voice message ending with a "switch to facsimile" manipulation-instructing signal (10); the facsimile receiver's first "ready" signal (11); the second/third/fourth/fifth/sixth handshake signal sequence — GC, CFR, character-pattern data, EOM, MCF (12); the hardware implementing that sequence, including demodulator, frequency identifying circuit, first and second switches, tonal signal generator, and modulator (13); the character-pattern transmitting circuit detail with status-register-driven address handoff (14); ROM sizing (15); row-sequential/line-sequential addressing (16); line-sequential readout into the line buffer (17).

Technical essence (from the specification)

The system is a 1979-era "voice response + fax-back" service: the subscriber presses PB (push-button) keys to request service; a Hitachi voice response device plays an assembled spoken message from a message drum (10), then speaks "PLEASE SWITCH OVER TO FACSIMILE" and flips switch f in the signal switching unit 4. The subscriber presses the fax start button; the fax receiver sends a GI tone (e.g., 1850 Hz); the device answers with a GC tone (2100 Hz); the receiver returns CFR (1650 Hz); the device renders stored 16×16-bit character/pattern ROM data line-by-line, expands it to 18 scanning lines per row via a line buffer, modulates it (AM-PM-VSB in the preferred embodiment), and after all rows sends EOM (1100 Hz), receiving MCF (1650 Hz) to trigger line disconnection. The patent expressly lists alternatives: AM-DBS, AM-BSS, AM-VSB, AM-PM-DSB variants, AFS, and FS, plus non-ROM memory and other cell sizes/scan-line counts.

Uncertainty flags

• Litigation/docket: No CAFC 2026 (or other) proceedings for US 4,340,783 surfaced in my searches. Absence of results is not proof of absence.
• Legal status: The reprint lists "Expired – Lifetime" with a 2000-06-13 anticipated expiration, consistent with a pre-1995-URAA patent having a 17-year term from the 1982-07-20 grant (June 1999 nominal, plus any terminal disclaimer/adjustment). I have not independently verified the exact expiry date against USPTO Patent Center.
• Assignee accuracy: Google Patents notes listed assignees may be inaccurate; I did not verify current ownership via USPTO Assignment records beyond the "Hitachi Ltd" listing.

I'll search for litigation involving US patent 4340783.

Let me search additional litigation-specific sources.

Let me try a few more targeted sources.

Litigation Search Report: US Patent No. 4,340,783

Bottom line

No litigation was found involving U.S. Patent No. 4,340,783. I searched multiple litigation-oriented sources (Google Patents/Patents justia litigation tabs, Unified Patents' litigation portal references, PACER/CAFC-adjacent dockets surfaced via web search, Docket Alarm, CourtListener, and general web queries combining the number with "litigation," "lawsuit," "infringement," and "v."). None returned a district court case, ITC investigation, PTAB proceeding, or CAFC appeal naming this patent.

What I did find (and why it is not litigation of '783)

• US 4,340,783 is cited as prior art by later patents — e.g., U.S. Patent 5,001,744 (Canon) lists "4340783 | July 20, 1982 | Sugiyama et al." in its Referenced Cited section (https://patents.justia.com/patent/5001744). A citation in another patent's specification is prior-art citation, not litigation.
• The "Cited By" list on Google Patents (32 entries such as US 4,812,367, US 4,936,772, US 5,291,302, US 5,517,556, etc.) reflects patents that cite '783 as prior art. These are patent-to-patent citations, not lawsuits asserting '783.
• The "Patent Citations" / "Family Cites Families" entries (e.g., US 4,055,729 to Exxon; US 4,122,307 to Hitachi; GB 1,038,602 to IBM; BE 787,246 to Siemens) are prior art cited during prosecution of '783 — again, not litigation.

Identifiers that are easy to confuse (interpreted literally, not auto-corrected)

• JP4340783B2 — a Japanese patent titled "光ファイバのオーガナイザ" (Optical Fiber Organizer; e.g., https://patents.google.com/patent/JP4340783B2/ja). A different patent, unrelated to the US '783.
• DE 43 40 783 (DE4340783 A1/B4) — a German patent assigned to WEH Verbindungstechnik. A different patent, unrelated.
• Neither of the above constitutes litigation of US 4,340,783.

Patent status context (for the record)

• Patent: US 4,340,783 — "Voice frequency response system"
• Inventors: Tomonori Sugiyama; Akio Suehiro
• Assignee: Hitachi, Ltd.
• Priority date: 1979-06-19 (JP 54-76299 / JPS561653A); Filed: 1980-06-13; Granted/Published: 1982-07-20
• Legal status: Expired – Lifetime (anticipated expiration 2000-06-13)
• Foreign family: DE3022603A1, GB2052122B, FR2459589A1/B1, JPS561653A

The patent has been expired for roughly 25 years and issued to a large operating company (Hitachi) rather than a patent-assertion entity, which is consistent with my finding of no asserted-infringement litigation.

Caveats

• I could not access a fully authoritative, fee-based litigation database (e.g., Docket Navigator or Lexis CourtLink) directly; my conclusions rest on publicly indexed sources reachable by web search. It remains possible that a suit was filed and never surfaced in the indexed sources, or that '783 was asserted in a complaint that is not freely indexed.
• If you need a definitive negative, I'd recommend a direct Docket Navigator / Lexis CourtLink / RPX search, or a PACER docket search on the patent number.

If you'd like, I can run additional targeted searches (e.g., specific courts, or the Japanese family member JPS561653A / the GB or FR counterparts) to look for litigation on the foreign family members.

I'll verify the ODP "no proceedings" result against public sources before writing up.

Let me run two more targeted checks before finalizing.

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding naming US 4,340,783, and my own searching across PTAB public decisions, PTAB E2E/petition document portals, and general web sources surfaced no proceeding number, FWD, or institution decision for this patent (searches for "US4340783 IPR," "Patent No. 4,340,783," and "4340783 PTAB" returned only unrelated patents and third-party dockets). The breakdown is therefore: 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials. There is no litigation-driven invalidation history to hand a defendant — but the more important point is that this patent expired on 2000-06-13, roughly twelve years before the AIA's trial procedures even existed, so the reason there are no PTAB proceedings is not that nobody bothered; it is that by the time PTAB trials were available, US 4,340,783 had already been dead for over a decade. Any demand letter citing it today is not a litigation threat, it is a record-keeping error.

Proceedings overview — why the empty list matters

There are no per-proceeding sections to write, because there are no proceedings. Rather than fabricate entries, here is the doctrinal and factual reason the list is empty, which is what a defendant actually needs:

No proceeding to summarize — the patent was expired before AIA trials existed

• Patent at issue: US 4,340,783 ("Voice frequency response system"), inventors Tomonori Sugiyama and Akio Suehiro, original assignee Hitachi, Ltd.
• Priority date: 1979-06-19 (JP 54-76299, which published as JPS561653A)
• Filing date: 1980-06-13
• Grant date: 1982-07-20
• Statutory term expiry (as recorded in Google Patents' legal-status timeline): 2000-06-13 — the 20-year date measured from the 1980-06-13 filing, consistent with the pre-URAA term rule for applications filed before 1995-06-08. The Google Patents record states "Expired – Lifetime" with the anticipated expiration event on 2000-06-13.
• AIA trial availability: IPR and PGR became available 2012-09-16 (AIA § 6); the transitional CBM program under AIA § 18 ran from 2012-09-16 and was sunset on 2020-09-16 (petitions had to be filed before that date).
• Taxonomy classifications: H04M11/06, G06F3/16, H04N1/32, H04N1/00127, Y10S379/908.

The consequence: every AIA trial vehicle is either unavailable or pointless for this patent. PGR is statutory dead on arrival — 35 U.S.C. § 321(c) limits PGR petitions to patents with a claim having an effective filing date on or after 2012-03-16; this patent's claims are from a 1979/1980 priority chain. CBM review was the only AIA vehicle that reached pre-AIA patents regardless of issue date (AIA § 18(a)(1)(B)), but the program has been repealed since 2020-09-16, and in any event the § 18(d)(1) "financial product or service" hook is a poor fit for a facsimile-plus-voice-response switching system. IPR remains technically available against even an expired patent in narrow circumstances, but no petitioner has used it here, and none has any incentive to: an expired patent cannot support injunctive relief and its damages window closed long ago.

Prior-art and reexamination context (not an AIA proceeding)

Even though there is no PTAB record, a defendant should know what the examiner and the public already looked at, because it shapes any § 282 defense:

• US 4,055,729 (Exxon Research & Engineering, 1976-05-24 / 1977-10-25) — "Apparatus for the direct connection of ancillary equipment to a telephone network." Cited on the face of the patent. This is squarely about hanging non-telephone equipment (e.g., facsimile) off a switched telephone line, and it is the most on-point anticipatory-looking reference in the file.
• US 4,122,307 (Hitachi, Ltd., 1976-08-13 / 1978-10-24) — "Telephone voice frequency response system for message recording." Cited on the face of the patent, and notably assigned to the same company as the patent under challenge — Hitachi's own earlier voice-response patent. It is a sibling of the claimed invention's voice-response half.
• Foreign family-cited art: GB 1,038,602 (IBM, 1964-04-06) and BE 787,246 (Siemens, 1971-08-06), both cited in the family's prosecution history per the Google Patents family citation list.

These two front-page US references together disclose (a) connecting ancillary equipment to a telephone network and (b) a telephone voice response system for message recording — which is most of the two-element combination that the '783 claims pre-date. I have not seen an examiner's reason-for-allowance, so I cannot tell you with high confidence why the claims issued over them; I flag this as a lead for a § 102/§ 103 defense, not as a conclusion.

Strategic summary

Claim status: all 17 claims UNTESTED — but untested because the patent is expired, not because it survived challenge. There is no PTAB or reexamination certificate in the record that cancels or narrows claims 1–17. Claims 1 and 8 are the two independent claims (claim 1 to the system broadly; claim 8 to the system with the signal-switching unit and main control unit); claims 2–7 depend from claim 1 and claims 9–17 depend from claim 8. That structure matters for a defendant only if the patent were live — which it is not. The "untested" label is not a defensive asset.

Estoppel landscape: empty. Section 315(e)(2) estops only a petitioner (and its real parties in interest and privies) that obtained a final written decision in an IPR on this patent. With no petitioner and no FWD, there is no statutory estoppel, no IPR-canceled claim, and no ground that is foreclosed. That cuts both ways: nothing is barred for you, and nothing is foreclosed for the patent owner either. But it is academic — the more fundamental bars are § 286's six-year damages lookback, which ran out in 2006 at the latest against an expired 2000 patent, and the total absence of any enforceable term. See 35 U.S.C. § 271(a) and § 286.

Pattern signals: none. There is no repeated-petitioner pattern (no petitioner at all), no PTAB appeal track record, and no sign of a defensive aggregator such as Unified Patents or RPX challenging this patent — the standard tell for a patent that was ever aggressively asserted. That absence is itself the signal: patents that are actually being asserted in the 2012–2020 AIA window on tech that matters almost always attract at least one petition. US 4,340,783 never did, because it was already expired.

Recommended next steps

If you are a defendant being asserted against and the demand cites US 4,340,783:

1. Lead with expiration, not invalidity. The patent's statutory term expired 2000-06-13 per the recorded legal-status timeline, and the accompanying FR/DE/GB family members (FR2459589B1, DE3022603A1, GB2052122B) are likewise long expired. Check the USPTO Patent Center maintenance-fee record for US 4,340,783; a lapse for nonpayment would independently extinguish enforcement even before 2000-06-13. Any assertion should be answered on this basis first — it is dispositive and cheap to prove.

2. Reject the § 315(b)/§ 311 framing entirely — do not budget for an IPR. There is no AIA proceeding to join, no estoppel to exploit, and no live trial to monitor. No institution-decision deadline, oral-hearing date, or one-year FWD deadline exists for this patent. If opposing counsel suggests a pending PTAB matter on US 4,340,783, ask for the proceeding number — on the available record, none exists, and a proposed number should be treated as fabricated until verified on PTAB E2E.

3. If any residual live claim is somehow asserted (e.g., via a reissue or an uncorrected term theory), build the invalidity case on the front-page art. Pull the examiner's reasons for allowance from the file wrapper in USPTO Patent Center and PTAB E2E, then attack the combination using US 4,055,729 (Exxon — direct connection of ancillary equipment to a telephone network) against the switching/connection limitations of claims 1 and 8, and US 4,122,307 (Hitachi — telephone voice frequency response system for message recording) against the voice-response limitations. The unity-of-invention story in the specification — audible response plus a facsimile record of "necessary information in the message" — is exactly the combination these two references bracket. The obviousness theory under § 103 would be that a POSITA would have combined a known voice-response messaging system with known ancillary-equipment connection techniques to give the subscriber a hard copy.

4. Source documents to pull, with links:

   • Patent text and legal-status timeline: https://patents.google.com/patent/US4340783/en
   • PTAB E2E proceeding search (confirm the null result yourself before relying on it): https://ptacts.uspto.gov/ptabweb
   • USPTO Patent Center (maintenance fee / file wrapper): https://patentcenter.uspto.gov
   • For the two cited references: https://patents.google.com/patent/[US4055729A](/patent/US4055729A)/en and https://patents.google.com/patent/[US4122307A](/patent/US4122307A)/en

Accuracy caveat, stated plainly: I found no PTAB proceeding on US 4,340,783, and I am reporting that as a null result rather than asserting it as a verified negative across all time. My search relied on Google Patents' proceeding data and general web coverage, not a full PTAB E2E docket query, and I could not independently inspect the PTAB E2E database directly. A definitive "zero proceedings" answer requires a PTAB E2E / PTAB API query on the patent number — which the structured ODP block in this prompt already reflects. I did not find, and therefore do not assert, any district court litigation, ex parte reexamination, or Federal Circuit appeal involving this patent; that is a gap in the record I checked rather than a confirmed negative.

I'll research the assignment/ownership record for US 4,340,783 before writing anything.

Let me try to reach the assignment records directly and via aggregators.

Research limitation (read first)

I ran web searches against the USPTO Assignment Center index, uspto.report, Google Patents legal events, and general web indexes. I was unable to retrieve any assignment record for US 4,340,783. I could not query assignmentcenter.uspto.gov or PATENT CENTER directly (my tools are general web search only), so I cannot state authoritatively that no records exist — only that none surfaced. What I can confirm from reproduced sources:

• The published record lists applicant/assignee HITACHI, LTD. and prosecution agent of record Craig and Antonelli (reproduced in a third-party copy of the front-page data for this grant, wenku.baidu.com record).
• Google Patents legal events for this patent show only one event: 1982-07-20 STCF "Information on status: patent grant." No post-issuance assignment, security, merger, or change-of-name event is listed.
• Status: Expired – Lifetime, anticipated expiration 2000-06-13.

I have therefore written the requested sections but substituted "no retrievable record" where the template assumes reel/frame data. I am not going to invent reel/frame numbers.

Inventors

Unusual-pattern check: The pattern here is the opposite of the departing-inventor tell. Two of the same-assignee's own engineers are tracked across a two-patent, same-technology-line Hitachi family (US 4,122,307 → US 4,340,783) spanning 1978–1982. That is consistent with a stable in-house voice-response R&D team, not with inventors exiting within 12 months to enable a portfolio sale. No departure signal found (and none would be expected for a Japanese corporate invention of this vintage, where the JP priority filing was made by Hitachi).

Original assignee

• Entity on the issued patent: Hitachi, Ltd. (the same-assignee predecessor patent US 4,122,307 is also assigned to Hitachi, Ltd.).
• Primary line of business: diversified Japanese industrial/electronics conglomerate — heavy industry, power systems, information/telecommunications equipment, consumer electronics. The voice-frequency-response and facsimile work in this patent sat in its telecom/computer-systems product lines.
• Did they ship a product embodying the claims? Unclear from my sources. Hitachi was demonstrably building this technology (it held the earlier US 4,122,307 on telephone voice frequency response for message recording, cited as prior art against the present patent), which suggests a real product program rather than a paper portfolio. But I found no catalog, 10-K/20-F disclosure, or product literature tying this specific claim set to a shipped Hitachi voice-response-plus-fax service.
• Current status: Operating. Hitachi, Ltd. remains an active global conglomerate (since 2020 reorganized under a Hitachi, Ltd. holding-company structure with operating subsidiaries such as Hitachi Global Life Solutions, Hitachi Energy, Hitachi Vantara, etc.). Hitachi's legacy telecom equipment business was substantially divested/restructured over time (notably the Hitachi–Fujitsu telecom joint venture, subsequently exited), so ownership of any unexpired legacy telecom patents would most likely have moved during those reorganizations — but this patent expired around 1999–2000, well before any of that mattered.

Assignment timeline

No recorded assignment could be retrieved for US 4,340,783. Per the instruction to say so plainly: I found no reel/frame, no conveyance type, no assignor/assignee transfer record, and no assignment correspondent of record in any indexed source I could reach, and Google Patents' legal-events list for this patent contains only the 1982-07-20 grant entry.

Two caveats, so the finding is not over-read:

1. Absence is expected for this filing pattern. A 1980 US application claiming Paris priority to a 1979 Japanese application filed by Hitachi, Ltd. would normally have the inventors' rights assigned to Hitachi in Japan before the US filing; the US case was filed with Hitachi as applicant of record. USPTO assignment records only appear where a separate US recording was made. So "no post-issuance assignment" here most plausibly means Hitachi, Ltd. held the patent for its entire term, not that the record is missing.
2. One attorney-firm lead, prosecution not assignment: Craig and Antonelli appear as the agent of record on the published bibliographic data. This is a Washington, D.C. IP firm historically used by Hitachi. It is not an assignment-record correspondent for this patent as far as I can determine, and I am explicitly not treating it as an NPE-shell-manager tell — one appearance, on a 1980 Hitachi prosecution, is exactly the innocuous pattern the task warns against over-reading.

If you want this nailed down, the authoritative call is a patent-number search at assignmentcenter.uspto.gov (also surfaced at assignment.uspto.gov/patent/index.html) plus the application-level page at patentcenter.uspto.gov/applications/06159223.

Timeline diagram

timeline
    title Ownership of US 4340783
    1979 : JP priority application filed by Hitachi
    1980 : US application filed by Hitachi Ltd
    1982 : Patent granted to Hitachi Ltd
    1999 : Term expired approx
    2000 : Anticipated expiration recorded

NPE / troll-pattern signals

Every item is answered against retrievable evidence, with reel/frame cited where it exists. For this patent, no reel/frame exists in the record I could reach.

Evidence caveat: signals 1, 3, and 8 are reported as "not present" on the basis of a negative search result, which is weaker than the reel/frame-level evidence the template asks for. If the Assignment Center in fact contains recordings I could not index, these three would need re-examination — but nothing in the retrievable record hints at any transfer at all.

Verdict

Insufficient data.

The chain shows a single recorded owner — Hitachi, Ltd. — from filing (1980-06-13) through grant (1982-07-20) to the recorded anticipated expiration (2000-06-13, status "Expired – Lifetime"), with no post-issuance assignment of any kind retrievable and therefore no reel/frame, no conveyance, and no assignment correspondent to analyse. Because I could not query the USPTO Assignment Center directly, I cannot certify that the record is empty; I can only report that nothing surfaced. There is zero evidence of shell-entity transfer, NPE acquisition, repeat NPE-side correspondents, cascading transfers, bankruptcy sale, privateering, or defensive aggregation — and an expired 1999–2000-vintage patent held by a large operating conglomerate has no assertion value in 2026 regardless.

Verification link: assignmentcenter.uspto.gov — search patent number 4340783

Mis-numbered lookalikes I excluded (do not conflate)

Consistent with the "interpret identifiers literally" rule, these surfaced under a bare "4340783" search and are not US 4,340,783:

• JP 4340783 B2 — Japanese grant (optical-fiber organizer / 光ファイバのオーガナイザ class).
• DE 43 40 783 A1 / B4 — WEH Verbindungstechnik (quick-connector / sealing technology), published 1994-06-09.
• Trademark Registration 4,340,783 — "THE BOOKSOURCE" mark, cancelled 2020-01-03.
• Assorted unrelated numeric matches (Kenyan ID numbers, Spanish land-registry parcel coordinates, an INE tender doc ID).

None of these are in this patent's family. The true family is: JP JPS561653A / JPS646584B2; DE 3022603A1; FR 2459589A1 / FR 2459589B1; GB 2052122A / GB 2052122B — all originally held by Hitachi, Ltd.

I'll research the cited prior art references for US 4,340,783. Let me start with the two references cited on the face of the patent, plus context.

I have the two face-cited references. Let me verify details on the "Family Cites Families" references and confirm the exact filing/grant data.

Prior-Art Analysis — US 4,340,783 ("Voice frequency response system")

Scope and verification note

Per the strict rule, I interpreted every alphanumeric identifier literally and did not auto-correct. The patent at issue is U.S. Patent No. 4,340,783 A (Sugiyama & Suehiro, Hitachi, Ltd.), and I confined the search to that number. I did not return JP4340783B2 (optical-fiber organizer), DE 43 40 783 B4, or any other document that merely contains "4340783" as a substring — those are distinct patents, as flagged in the earlier sections.

On sourcing: my tools are general web search, not a direct USPTO API/Patent Center query. The bibliographic and citation data below therefore comes from USPTO-mirroring sources (uspto.report's grant record for 4,340,783, https://uspto.report/patent/grant/4340783) and the Google Patents record of the same number, which reproduces the printed front page. I did not obtain the examiner's search-room classification sheets or a foreign search report for the family, so the citation list may be incomplete.

Reference inventory for US 4,340,783 (as printed on the patent and its family record):

Only A and B are the two references actually cited in the U.S. prosecution of '783 (the front page lists exactly two U.S. patent documents). C and D appear as family-level citations and I could not retrieve their full texts (search budget exhausted), so their characterizations are limited to their titles/dates.

A. US 4,055,729 A — Vandling (Exxon Research & Engineering)

Full citation: U.S. Patent No. 4,055,729, J. M. Vandling, "Apparatus for the direct connection of ancillary equipment to a telephone network," appl. Ser. No. 689,263 filed May 24, 1976; granted Oct. 25, 1977. Assignee: Exxon Research & Engineering Co.
Source text: https://patentimages.storage.googleapis.com/a0/fb/02/d02e20a9869f24/US4055729.pdf

Brief description: A coupling/connection arrangement that directly connects "ancillary equipment" — expressly, a facsimile transceiver with a rotatable drum (item 10/12) — to the telephone network without an acoustic coupler. It includes:

• Transfer means / transfer relay that transfers the primary communication connection of the network between the telephone station set and the ancillary (facsimile) equipment;
• Sensor means (opto-isolator: LED in series with the telephone set plus phototransistor) responsive to the off-hook→on-hook change of the telephone set to transfer the connection back;
• Transfer control means coupled to the ancillary equipment to move the connection in response to the state of that equipment (cover open/closed = inoperable/operable);
• A secondary communication connection allowing the subscriber to monitor a fax transmission through the telephone set; and
• Signal power-level limiting for the fax signals.

Notably, claim 21 of '729 is drawn to "Apparatus for providing a combination voice/facsimile capability over the telephone network," comprising a discrete facsimile unit, a discrete voice communication unit, plug/jack connectors, and transfer means for transferring the primary communication connection … from one to the other of said discrete units in response to the state of the facsimile unit (claims 23–24).

Relation to '783 — potential § 102 anticipation: none, in my assessment.
'729 discloses the terminal-side hardware environment (telephone + fax sharing one line; automatic talk/fax transfer; monitoring), but it contains no central "voice frequency response device," no voice-frequency-response means that edits and transmits a spoken message on demand, and no facsimile response means that transmits character-pattern information taken from that message. Every independent claim of '783 (claims 1 and 8) requires those two cooperating response means. '729 cannot therefore anticipate claim 1 or claim 8, nor any dependent claim adding the response-unit architecture (claims 3–7, 12–17).

What '729 is relevant to:

• Claim 1 (and claim 8), the "terminal unit including both a functional part functioning as a telephone and a functional part functioning as a facsimile" element — '729 expressly discloses such a combined voice/facsimile terminal arrangement. This is a § 102(a)/§ 103 element-level teaching, not full-claim anticipation.
• Claims 3 and 8 (signal-switching means / "switch means by which the voice unit is selectively connected to the line … and by which the facsimile unit is selectively connected") — the transfer-relay concept is the same general mechanism, though '729 places the transfer at the subscriber interface rather than in a central response device's input/output stage.

Net: § 103 (obviousness) art for the switching/terminal elements; not a § 102 anticipation of any claim.

B. US 4,122,307 A — Suehiro (Hitachi) — the closest prior art

Full citation: U.S. Patent No. 4,122,307, "Telephone voice frequency response system for message recording," inventor Akio Suehiro (co-inventor of '783), assignee Hitachi, Ltd., U.S. appl. No. 05/823,427; JP priority 1976-08-13; granted 1978-10-24.
Sources: https://patents.google.com/patent/US4122307 ; https://patentimages.storage.googleapis.com/b1/c6/41/5ec4bd5a325115/US4122307.pdf ; https://uspto.report/patent/grant/4122307

Brief description: A voice frequency response system of a central voice frequency response device + terminal unit. The central device confirms a specific code allotted to the terminal unit. Its memory (message drum 16) stores, in addition to voice information, an actuating signal of voice frequency band. The central device selectively reads out that actuating signal and sends it to the terminal prior to transmitting the required voice information, upon confirming the terminal's code. The terminal detects the actuating signal and automatically starts its recorder (TPR); the central device detects commencement of the recorder's operation, and only then transmits the voice information. Architecture includes a main control unit 11, status registering unit 12, automatic calling unit 13, incoming signal intake unit 14, message editing unit 15, message drum 16, PB signal receiving unit 17, and trunk 18.

Its specification even states the same motivation as '783 — that voice-only service risks mishearing or miswriting and can be "the source of future trouble," especially for money information.

Relation to '783 — potential § 102 anticipation: no full-claim anticipation, but the strongest single reference; near-complete teaching of everything except the fax/character-pattern feature.

Element mapping against '783:

Consequently:

• Claims 1 and 8 are not anticipated: the "functional part functioning as a facsimile receiver" and "facsimile response means / character-pattern information" limitations are absent. '4122307 discloses a recorder, not a facsimile receiver.
• Claims 3, 4, 8, 13 (main-control-controls-everything; status register; message editing) have close counterparts in '4122307's main control unit 11 / status registering unit 12 / message editing unit 15 — again § 103 territory, element-level disclosure rather than anticipation.
• Claims 10 and 11 (manipulation-instructing signal at the end of the voice message telling the subscriber to switch the line to the facsimile receiver; the receiver then emitting a "ready" signal) are the clearest conceptual overlap: '4122307 teaches the analogous "tone instructs the terminal to activate its device, device signals start" loop — with a recorder instead of a fax.

Net: the single most relevant prior art; realistically a § 103 primary reference (optionally combined with '729 or another fax reference) rather than a § 102 anticipation of any claim as issued. The same-inventor/same-assignee relationship is worth noting for the prosecution history: Hitachi effectively built '783 by adding a facsimile branch to the system already claimed in '4122307.

C. GB 1,038,602 A — IBM, "Data processing system"

Citation: GB 1,038,602 A, IBM; filed 1964-04-06; published 1966-08-10 (family-level citation, "Family Cites Families").
Description: Not retrievable within my search budget; the title and assignee indicate a general-purpose data-processing system, i.e., memory/address handling and addressing art.
Potential § 102 anticipation of '783: none that I can substantiate. Its only plausible role would be as background for memory/address-control limitations (e.g., the address-information/buffer/status-register mechanics of claims 4 and 14). Because I could not read it, I will not assert an element mapping — flag: unverified.

D. BE 787,246 A — Siemens AG

Citation: BE 787,246 A, Siemens AG; filed 1971-08-06; published 1973-02-05 (family-level citation). Title: "Assembly for telephone systems with additional exchange of information between the different subscriber stations and a central information processing installation."
Description: From the title, this is a telephone system in which exchange of information occurs between subscriber stations and a central information-processing installation — thematically the same "subscriber terminals talk to a central processor over the telephone network" genus as '783's central voice frequency response device.
Potential § 102 anticipation of '783: cannot be asserted. It predates '783 (1973 < 1979 priority), so it is available as prior art on its face, and the title suggests relevance to claim 1's overall system topology; but without its text I cannot match limitations. Flag: unverified — contents not retrieved. If it is the central-station/system-architecture reference, it would be § 103 material at most, since nothing in the title suggests character-pattern (facsimile) transmission.

What is NOT prior art to '783 (to avoid a common error)

• The 32 "Cited By" entries (e.g., US 4,552,941; US 4,812,367; US 4,826,559; US 4,936,772; US 5,291,302; US 5,517,556; the Parus Holdings and Audiofax families) are later patents that cite '783 — they post-date '783 and cannot be prior art against it. '783 cannot be anticipated by documents that came after it.
• The "Patents Citing '783" I found elsewhere (e.g., US 5,001,744, Canon, listing Sugiyama et al. in its "References Cited") are likewise downstream citations, not prior art to '783.
• US 4,131,926 and US 4,130,840 surfaced during searching (both Exxon-linked facsimile direct-coupling art citing the same copending Ser. No. 689,263 as '729). They are analogous art in the fax-over-telephone-line area but were not cited against '783; if you want a broader § 103 picture, US 4,130,840 (FM facsimile signaling and direct coupling) is worth pulling, but it is outside the two-reference face of '783.

Bottom-line § 102 answer

No reference cited against — or found for — US 4,340,783 discloses the full combination of every limitation of claims 1 or 8, specifically the pairing of a central voice-frequency-response device with facsimile response means that transmit character-pattern information derived from the spoken message. US 4,122,307 (Hitachi, same inventor/assignee) is the most relevant prior art, missing only the facsimile/character-pattern branch, and US 4,055,729 (Exxon) is the most relevant art for the combined telephone/facsimile terminal and the line-switching mechanism. Both are properly § 103 (obviousness) references rather than § 102 anticipations.

Caveats and gaps

1. Incomplete citation capture. I could not verify whether any foreign search reports (the DE 3022603, GB 2052122, FR 2459589 counterparts) cite additional references beyond US 4,055,729 and US 4,122,307; my retrieval of a GB2052122 search report failed (search budget exhausted). If completeness matters, the GB/DE/FR prosecution files should be checked directly.
2. Unverified family cites. GB 1,038,602 A (IBM) and BE 787,246 A (Siemens) are listed as family-level citations in the Google Patents record; I could not retrieve their texts, so I have deliberately not asserted any limitation-by-limitation mapping for them. Treat C and D as leads, not findings.
3. '4122307 filing date. I confirmed the JP priority (1976-08-13) and grant date (1978-10-24) and the U.S. application number (05/823,427); I did not confirm the exact U.S. filing date from an authoritative source in this pass.
4. Database access. The conclusions rest on publicly indexed/mirrored USPTO data reachable by web search, not a direct USPTO Patent Center or examiner's search-history query. "No additional cited reference found" is a search observation, not an authoritative negative.

If you'd like, I can next (a) pull the full text of US 4,130,840 and the other Exxon copending-application art as secondary § 103 references, or (b) attempt targeted retrieval of GB 1,038,602 A and BE 787,246 A to close out gaps C and D.

I'll pull the prior-art references that appear on this patent's page so I can ground the § 103 analysis in what those references actually disclose.

Let me check the two additional prior-art references listed in the "Family Cites Families" section of this page.

Obviousness Analysis — U.S. Pat. No. 4,340,783 under 35 U.S.C. § 103

Note on scope/inputs. Per the instruction, this analysis is built on the prior-art references that actually appear in the Prior Art / Citations sections of the US4340783A page (https://patents.google.com/patent/[US4340783](/patent/US4340783)/en): the two examiner-cited U.S. references and the two "Family Cites Families" references. I build on — and do not repeat — the earlier Patent summary, Litigation summary, and Claim architecture sections. One flag: the task header gives the current date as April 26, 2026, while my operating parameters give 2026-09-25; I note the discrepancy rather than resolving it.

1. The prior-art arsenal (as disclosed on the page)

Key refinement to the earlier summary (not a contradiction): the earlier Patent summary correctly called US 4,122,307 a "same-assignee predecessor." It did not note that Akio Suehiro is a named inventor on both US 4,122,307 and US 4,340,783 (the '783 lists Sugiyama and Suehiro). That fact materially strengthens the motivation-to-combine analysis in §4 below.

2. Person of ordinary skill and claim construction

POSITA (as of the 1979-06-19 priority date): a telephone-systems engineer with working knowledge of (a) PB/multifrequency signaling, (b) central audio-response units using a message drum/memory (the Hitachi/Nakata line of art — e.g., the JNR seat-reservation audio response work of Kimura et al., which even describes the subscriber "hear[ing] this audio reply, takes necessary notes"), (c) facsimile terminals and their line-control signaling, and (d) digital character generators (ROM font stores + raster/scan-line conversion) as used in CRT terminals and fax.

Two claim-construction points that matter for § 103:

1. Claim 1 is narrower than the specification/abstract. Claim 1 requires the facsimile means to transmit "character-pattern information in at least a part of said message." The abstract/description broaden this to "necessary information in the message or other information including the necessary information." The claim therefore must be read as the same-message-content-both-modes combination.
2. Claim 8's switching element is located at the service-provider end ("said voice frequency response device including … a signal switching unit functioning as an input/output stage"). That differs from US 4,055,729, whose transfer means sits at the subscriber's premises. This is the single most useful non-obviousness lever for the patent owner — and §5 explains why it is weak.

3. The core combination: US 4,122,307 + US 4,055,729 against claims 1 and 8

Claim 1

Claim 8

Claim 8's added architecture — voice frequency response unit, facsimile response unit, signal switching unit with switch means selectively connecting either unit to the line, and a main control unit controlling both — maps onto '729's transfer means + its control responsive to equipment state, plus '307's main control unit 11 / status registering unit 12 supervisory structure. The only real delta is where the switch sits (central vs. premises) and that '783's fax unit generates rather than merely passes through the document. Neither is a difference in kind.

4. Motivation to combine (KSR-compliant rationales)

1. The problem the '783 asserts it solves is stated verbatim in the prior art. '783's background is entirely about "mishearing or miswriting… a source of future trouble." '307 says the identical thing and is even more pointed: "mishearing of a received message or miswriting of the record… especially important in a system which deals with money information." '783's own background use cases (train/airplane seat reservation, bank balance confirmation) are the same use cases '307 and the contemporaneous JNR audio-response literature describe. This is the classic "known problem, known solution" situation.
2. '729's express purpose is the very combination claimed. Claims 21–31 are literally titled/worded as "combination voice/facsimile capability over the telephone network." A reference whose stated object is the claimed combination is not hindsight—it is the applicant's own framing. That the later US 4,341,926 patent incorporates '729 by reference to implement voice/fax line sharing confirms the art treated '729 as the standard teaching for this.
3. Common inventor and common assignee. '307 (Suehiro/Hitachi) → '783 (Sugiyama + Suehiro/Hitachi). The asserted invention is the same team's follow-on to its own voice-response patent. A POSA of ordinary creativity at that team, having just built an audio response unit with a message drum and a terminal-side automatically-started machine, would naturally ask "what if the terminal-side machine were a facsimile receiver instead of a recorder?"
4. Predictable result / design incentive. Adding a fax-back of the same message text is a straightforward substitution of one output transducer (a hard-copy character-pattern receiver) for another (the voice recorder of '307) while keeping the voice path — with the added benefit (expressly recited by '783) of a preservable record. § 103 does not require that the substituted element operate identically, only that the substitution be within the skill of the art and produce a predictable improvement.
5. The '307 sentinel-signal architecture already anticipates the "switch to facsimile" step. '307 reads an actuating signal of voice frequency band from the same memory drum, sends it to the terminal before the message, causes the terminal machine to start automatically, and waits for confirmation that it started. Map that onto '783 claim 10's "manipulation instructing signal" and the claim 11–12 handshake, and the delta collapses to "swap the terminal machine and its signal set."

5. Claim-by-claim § 103 disposition (with the references that get you there)

6. Anticipated rebuttals, and why they are weak

• "'307 has no facsimile; '729 has no central message generator → improper hindsight."
  Rebuttal: the combination does not require either reference alone to have both. '307 supplies a central, memory-driven message source with a terminal-side automatically-started machine and a confirmation protocol; '729 supplies fax-over-the-same-telephone-line to a dual telephone/fax terminal and expressly names that combination as its objective. The only remaining step — converting the stored message text into character patterns — is the routine character-generator operation, not an inventive leap. A POSA would do this for a predictable benefit (a permanent, accurate record).
• "'729's switch is at the subscriber's premises; claim 8 requires it in the response device."
  Rebuttal: (i) the function (time-sharing one subscriber line between voice and fax under a controller) is identical; (ii) once the service provider houses both a voice unit and a fax unit on a single line, a switching stage at the provider's end is the necessary and obvious consequence; the claimed location is a design choice, not an advance in the art. Expect this to be the patent owner's best argument, and expect it to fail absent evidence of unexpected results.
• "The examiner considered '729 and '307 and still allowed."
  Rebuttal: while examiner allowance over cited art is some evidence of validity, it is not controlling. Note that in the earlier-generated analysis of this same page I catalogued no litigation and no PTAB proceeding in which validity was ever tested — so there is no adjudicated presumption and no secondary-considerations record to weigh.
• Teaching away? '307's tone-triggered automatic-start scheme is tailored to a simple voice recorder; one could argue it would not work with a protocol-bearing fax machine. Rebuttal: '729 is precisely the art that teaches fax operation on the telephone line, so the "adaptation" the '307 scheme supposedly cannot make is the very thing '729 supplies. No teaching away.

7. Secondary considerations

None are apparent from the record available on this page. The extensive "Cited By" list (AudioFAX, Brooktrout, Radish, VMX, Comverse, etc.) shows '783 became a frequently-cited reference — evidence of technical significance in the art, which is not the same as non-obviousness, and citation frequency cuts both ways (a broadly claimed, foundational-seeming arrangement often does). The patent has been expired since the 2000-06-13 anticipated expiration, so commercial-success/nexus evidence is unlikely to exist for the relevant window. Caveat: I have not searched for secondary-considerations evidence (e.g., Hitachi product literature claiming unexpected results); my statement is limited to what this page shows.

8. Bottom line

• Claims 1 and 8 are prima facie obvious over US 4,122,307 in view of US 4,055,729: same technical field (H04M 11/06), the '307 reference articulates the exact mishearing/miswriting problem '783 claims to solve (indeed with the same "money information"/bank-balance use case), and '729 expressly claims the voice/facsimile-over-one-telephone-line combination with a dual telephone/facsimile terminal and transfer means. Motivation is supplied by '307's own stated problem, by '729's stated purpose, and by the common inventor (Suehiro) and assignee (Hitachi).
• Claims 9, 10, 11, 12 carry the highest invalidity risk among the dependents — 9 and 10 are essentially '307's PB-demand and message-resident instructing-signal features, and 11 and 12 recite the standard CCITT T.30 GI/GC/CFR/EOM/MCF handshake, i.e., a design dictated by interoperability.
• Claims 5 and 15 are the weakest claims in the set on their own (memory-capacity/scan-line sizing = routine optimization).
• Claims 4, 6, 7, 13, 14, 16, 17 sit in the middle: a competent invalidity case should add a third reference (or POSITA knowledge) for the ROM character-pattern generator + line buffer + scanning-line conversion blocks; the page's listed background references (GB 1 038 602 (IBM) and BE 787246 (Siemens)) are candidates for the data-processing/buffering and subscriber-station↔central-processing aspects, but I could not verify their specifications from search and therefore do not rely on them as disclosures.
• Strongest (though still probably losing) patent-owner argument: the location of the signal-switching unit in the response device (claim 8) versus the premises-side transfer means of '729, plus the fact that the examiner allowed over both '307 and '729.

Confidence: High on claims 1, 9, 10, 12 (grounded directly in the two verified references plus the standardized fax handshake). Moderate on claims 3, 4, 6, 7, 11, 13, 14, 16, 17. Lower/conditional on claims 2, 5, 15. I flag that a complete § 103 record would require the actual text of GB 1 038 602 and BE 787246 (unverified here) and ideally a dedicated ROM-character-generator reference, and that any live IPR would be moot because the patent has been expired since 2000.