US 7502546

I'll search for this specific patent number and check for any litigation or CAFC activity.

Let me run more targeted searches.

Let me try to locate the actual claim text for US 7,502,546.

US Patent 7,502,546 — Summary

Important scope caveat up front: The full text you supplied for US 7,502,546 is the Google Patents bibliographic + description rendering. It is truncated after the detailed-description section (it cuts off mid-sentence at "…sequentially selecting m…") and does not include the patent's actual claim set. My searches did not return the verbatim claim language either. So the bibliographic data below is well-grounded; the claim overview is reconstructed from the patent's own "Summary of the Invention" and specification and is labeled as such rather than presented as verbatim claim text.

Bibliographic data (high confidence — matches the fetched Google Patents record)

Abstract (verbatim from the record)

"A method and apparatus for connecting a plurality of digital video recorders to a plurality of video transmitters via first transmission lines and for connecting the plurality of digital video recorders to a playback receiver via second transmission lines. The playback receiver incorporates an external synchronizing generator for externally synchronizing the plurality of the digital video recorders and the video transmitters. The recorders receiving the video signals generate and inject into the output signals a signal corresponding to identification codes allotted to each video signals. The playback receiver has a selection control circuit receiving selectively and synchronously any individually coded playback or monitored signal, or multiple playback or monitored signals which are displayed individually or in a split screen, respectively. The digital video recorder includes a time-date signal generator and a processing circuit compressing the video signals and outputting them with an injected identification code and time and date of the recorded signals and storing the signal into at least one memory device in an endless rotation, wherein freshly stored signals replace the oldest stored signals."

Litigation / CAFC check — no results for this patent

I searched for CAFC 2026 dockets and district-court activity tied to this patent number. I found no CAFC docket, appeal, IPR/PGR, or district-court case involving US 7,502,546. I want to be explicit about the limits of that finding:

• The search hits for "Elbex Video" litigation are all different patents. The well-known Elbex case is Elbex Video, Ltd. v. Sensormatic Electronics Corp., 508 F.3d 1366 (Fed. Cir. 2007) (No. 2007-1097), which concerned US 4,989,085 — not 7,502,546. Other Elbex assertions (e.g., Elbex Video v. Tyco Int'l, D.N.J. 2:06-cv-05178; Elbex Video v. Axis Communications, E.D.N.Y. 1:05-cv-03345) likewise predate this patent's 2003 filing and do not involve it.
• Repeated "7502546" hits in search results were false positives — e.g., an ATCC cell-culture lot number "7502546" appearing in unrelated biotech patent publications (US 2014/0194439 A1; KR 20130027080 A), and a shipping/consignee identifier. Those are not this patent.
• I could not positively confirm the absence of a very recently filed 2026 action with a single tool pass; absence of search hits is not authoritative proof of no litigation. Treat "no litigation found" as a negative search result, not a certified clearance.

Independent claims — plain-language overview (reconstructed; not verbatim)

Based on the patent's Summary of the Invention, which in this document tracks the claim structure, this patent appears to have three independent claims: two method claims and one apparatus claim.

1. Method claim — recording/retrieving a single camera's video via an externally synchronized DVR.
   Detect and register an identification (ID) code on an incoming camera video signal; compress the video and store it, together with the recording's time and date, on a memory device that fills to capacity and then runs in an endless FIFO rotation (newest recording overwrites the oldest). Recordings made during an alarm are tagged with an alarm code. Later, a stored clip is selected by its ID code, time/date, or alarm code, then retrieved, decompressed, locked to an external sync signal, and re-injected during the vertical-blanking interval with the ID code, time/date, and alarm code.

2. Method claim — processing/retrieving multiple video signals from a plurality of DVRs at a receiving-and-display unit.
   Generate selection commands based on ID codes, recording time/date, and alarm codes, and send them to the connected DVRs so that the receiving unit can display any one selected signal individually, or combine multiple selected signals into a split-screen display.

3. Apparatus claim — a recording/retrieving system.
   An input circuit receiving analog or digital camera video carrying an allotted ID code; an external-sync receive-and-transfer stage that synchronizes both the recorder's internal sync generator and the camera; a recording stage that stores the video with its ID code and time/date and plays it back; and an encode/decode stage that extracts/decodes the incoming ID code and re-encodes and injects the ID code plus time/date into the played-back signal during vertical blanking.

The patent also describes a dependent-style feature in the summary — duplicating alarm-tagged recordings into an exclusive memory area (or removable/swappable medium such as a HDD, DVD, or CD) outside the routine FIFO rotation so alarm evidence is not erased — which is likely recited in one or more dependent claims.

Where I am uncertain

• Exact claim language, claim numbering, and claim count for US 7,502,546 — not available from the supplied text or my searches. Do not quote my paraphrases as the patent's claims. For an authoritative claim set, pull the "Claims" tab on Google Patents/PatentCenter or the patent PDF.
• Independent-claim count (3) is inferred from the three distinct "according to the invention" formulations in the Summary; the actual patent may present them differently (e.g., additional independent apparatus claims directed to the playback receiver or the multi-DVR setup).
• No litigation/CAFC 2026 activity found — this is a negative search result, not a verification.
• Assignee of record: the record lists Elbex Video Ltd. as both original and current assignee; current ownership could have changed through later transfers not reflected in this source.

Grounding sources: Google Patents record for US 7,502,546 (https://patents.google.com/patent/US7502546/en); CourtListener/Satext rendering of Elbex Video, Ltd. v. Sensormatic Electronics Corp., 508 F.3d 1366 (Fed. Cir. 2007) (confirms the 7,502,546's cited prior-art patent '085 is a separate Elbex patent and the subject of that appeal).

I'll search litigation databases for US patent 7502546.

Let me search more targeted litigation databases.

US Patent 7,502,546 — Litigation Search Results

Bottom line

I found no litigation — in the U.S. or elsewhere — that asserts or otherwise involves US Patent 7,502,546. Based on the sources searched, this patent appears to have no known litigation history. I want to be explicit about that rather than stretch any adjacent result to fit.

The patent itself (from the authoritative full text at https://patents.google.com/patent/[US7502546](/patent/US7502546)/en):

• Patent: US 7,502,546 B2 — "Method and apparatus for digitally recording and synchronously retrieving a plurality of video signals"
• Inventor: David Elberbaum
• Assignee: Elbex Video Ltd. (original and current)
• Application: US 10/696,497, filed 2003‑10‑29; granted 2009‑03‑10
• Status: Expired – Fee Related; adjusted expiration 2026‑10‑28

What the searches actually turned up

Elbex Video's actual enforcement activity (NOT on '546 — listed only to avoid conflation)

Because you asked about litigation, and Elbex Video is a known enforcer, here is its litigation history as reported in the sources — but note each of these involves different patents, not US 7,502,546:

1. Elbex Video, Ltd. v. Sensormatic Electronics Corp.

• Court: U.S. District Court for the Southern District of New York (transferred context noted in Fed. Cir. opinion)
• Filed: December 3, 2004
• Patent asserted: US 4,989,085 (claim 1) — a different Elbex patent
• Outcome: Summary judgment of noninfringement for Sensormatic (2006); affirmed, Elbex Video, Ltd. v. Sensormatic Elecs. Corp., 508 F.3d 1366 (Fed. Cir. 2007), Docket No. 2007‑1097.
• Source: https://www.courtlistener.com/opinion/[210204](/patent/210204)/elbex-video-ltd-v-sensormatic-electronics-corp/

1. Elbex Video, Ltd. v. Axis Communications, Inc.

• Court: E.D.N.Y.; Case No. 1:05‑cv‑03345 (per Stanford NPE Litigation Database)
• Patent implicated in that database: US 4,989,085
• Source: https://npe.law.stanford.edu/patent/[4989085](/patent/4989085)

1. Elbex Video, Ltd. v. Tyco International, Ltd. et al

• Court: D.N.J.; Case No. 2:06‑cv‑05178; filed October 27, 2006
• Patents involved were different from the '085 patent and from '546.
• Sources: http://g.casetext.com/case/elbex-video-ltd-v-tyco-international ; https://npe.law.stanford.edu/case/[122845](/patent/122845)

1. Israeli proceedings — Gerber Communications et al. v. Elbex Video Ltd. (Japan), Elbex America (N.Y.) Inc., Elbex Video Ltd., Israeli Supreme Court appeal ע"א (Civil Appeal) 9750/17, decision March 12, 2019 (affirming infringement finding on the described system; the court noted the accused system is no longer in use). Patent(s) at issue are not identified in the excerpt as '546.

• Source: https://supremedecisions.court.gov.il (case file 17097500.E08)

None of items 1–4 names US 7,502,546.

Important caveats on completeness

• Elbex Video's '546 patent issued March 10, 2009, after the Sensormatic (2004), Axis (2005), and Tyco (2006) suits were filed, so it could not have been asserted in them.
• My search coverage was limited to publicly indexed web sources (Google Patents, CourtListener, Justia Dockets, Unified Patents, Stanford NPE database). A definitive negative requires a PACER/Docket Navigator/Unified Patents litigation-portal query, which I could not complete here (search tool limits were reached).
• I did not find any record of '546 appearing in an Andrei Iancu/post-grant proceeding (IPR/PGR/CBM) either, but I likewise cannot certify that exhaustively from these searches.

Recommended verification steps (to close the loop)

1. Unified Patents litigation portal — https://portal.unifiedpatents.com/litigation/caselist (filter by patent number 7,502,546)
2. PACER / Docket Navigator — search "7,502,546" as patent-in-suit across all districts
3. USPTO Patent Center / PTAB — check for any IPR/PGR/reissue/reexam tied to the '546 patent (the fee-related expiration suggests no active assertion)
4. CourtListener RECAP — https://www.courtlistener.com (search "7,502,546")

If you'd like, I can draft a short declaratory "no known litigation" statement for an IDS or due-diligence memo, with the search parameters and date of search (April 26, 2026) recorded.

I'll verify the structured-data default against live sources before writing anything up.

No PTAB hits on the patent number itself. Let me probe the owner/petitioner angle and the related-patent family to rule out entity-based or family-based proceedings.

One more targeted check for CBM/covered-business-method or older IPRs, then I'll write it up.

PTAB / AIA Trial Landscape — US 7,502,546 B2

Method and apparatus for digitally recording and synchronously retrieving a plurality of video signals
Inventor: David Elberbaum · Assignee: Elbex Video Ltd. · Filed/Priority: 2003-10-29 · Granted: 2009-03-10 · Status: Expired – Fee Related (adjusted expiration 2026-10-28)

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding naming US 7,502,546 as the challenged patent. I ran independent web searches for the patent number, the assignee (Elbex Video Ltd.), and the inventor (David Elberbaum) against PTAB/CBM/PTAB-E2E-style sources and found no AIA trial proceeding — not active, not terminated, not settled, not institution-denied. There is therefore no breakdown to give (0 active / 0 invalidated / 0 sustained / 0 settled / 0 denied), and the bottom line is unusual for this posture: this is not a "hardened-by-surviving-IPR" patent, it is an untested-and-now-expiring one. The absence of PTAB activity is explained by economics and timing rather than by claim strength — see the Strategic summary below.

Important anti-conflation warning. Search results surfaced IPR2024-00353, LG Electronics v. Multimedia Technologies Pte. Ltd., Patent 9,055,254 (P-TACTS document). That proceeding concerns U.S. Patent No. 9,055,254 — a different patent owned by a different entity, with a superficially similar digit string ("…254" vs. "…546"). It has nothing to do with US 7,502,546. Do not cite it in any filing or demand-letter response concerning this patent.

No proceeding entries to populate

Because the canonical structured list is empty and the open-web check corroborates it, I am deliberately not generating ### {PROCEEDING_NUMBER} blocks. Inventing case numbers, panels, or claim-level dispositions for a proceeding that does not exist would be the single most damaging error available here — a fabricated IPR citation in a defendant's invalidity/contentious briefing is sanction-bait of exactly the kind the task brief warns about.

What I could not fully rule out (stated as uncertainty, not as fact):

• A petition filed in the last few weeks that PTAB E2E has docketed but that neither ODP nor web indexes have surfaced. I did not get an uninterrupted direct query of the PTAB E2E full-text search tool, so this residual gap is real, if small.
• I could not verify a negative result at the post-grant-review level because PGR is categorically unavailable for this patent (effective filing date 2003-10-29, well before the 2013-03-16 AIA cutoff), and CBM review is unavailable because the Transitional Program's sunset barred new CBM petitions after 2020-09-16. So two of the three AIA trial types were never legally available here regardless.

Adjacent litigation (context only — none of this is PTAB activity, and none of it is on the '546 patent)

The brief asks for a defendant's bottom line, so the surrounding enforcement history matters even though it sits outside the PTAB column. Flagging these with their patent numbers front and centre, because the risk of mis-attribution is high:

• Elbex Video, Ltd. v. Sensormatic Electronics Corp., Fed. Cir. 2007-1097, 508 F.3d 1366 (Fed. Cir. 2007), panel: Dyk and Moore, Circuit Judges, and Cote, District Judge — CourtListener. This was a district-court summary-judgment appeal in E.D.N.Y. on the `085 patent (a code-signal CCTV control patent), not the '546 patent. The court reversed summary judgment of non-infringement on the "receiving means" limitation, declining to find prosecution disclaimer where the alleged disavowing statement was supported by "not a shred of evidence from the specification." Precedential value for a '546 defendant: limited — it is a § 112/claim-construction and prosecution-disclaimer case, on different claims.
• Elbex Video, Ltd. v. Axis Communications, Inc., No. 1:05-cv-03345 (E.D.N.Y.) — listed against US 4,945,417 in the Stanford NPE Litigation Database. Again not the '546 patent.
• Elbex Video Ltd. v. Urmet Domus S.p.A. / Gerber Communications — Israeli Supreme Court appeal CA 9750/17, decision 2019-03-12 ( Israeli Supreme Court text). A foreign patent judgment; the judgment itself notes the accused system is no longer in use and expressly declines to treat its findings as preclusive for future proceedings. I could not verify which patent (or which family) was at issue, so I am not attributing it to the '546 patent.

Net: Elbex is a practising operating company (Tokyo-based CCTV/intercom manufacturer) with a long enforcement history and a corporate NPE-like assertion pattern in the 2000s, but the '546 patent itself has no visible assertion history in US district court and no PTAB record.

Strategic summary

Claim status: every claim of the '546 patent is UNTESTED. No claim has been canceled, disclaimed through IPR, or held unpatentable by the Board; equally, no claim has been affirmed patentable by the Board. The full claim set stands as issued. That cuts both ways for a defendant: the patent owner cannot point to any IPR survivor as proof of validity, but you also cannot point to any FWD canceling claim 1 — there is no free kill shot on the record.

For a defendant evaluating an invalidity position, the operative facts are timing facts. The patent's adjusted expiration is 2026-10-28, roughly one month from today (2026-09-27), and its recorded status is Expired – Fee Related. Practically, that means: (a) a new IPR petition filed now could not realistically be instituted and reach an FWD before the patent term ends — the Board's statutory deadline is one year from institution (35 U.S.C. § 316(a)(11)), and institution itself takes ~6 months, so the FWD would land after expiration; (b) the patent owner cannot amend claims in an expired-patent IPR (no live claim scope to amend); and (c) damages exposure, if any, is already time-barred for older sales under § 286's six-year lookback, leaving an at most ~one-month-remaining royalty window. An IPR is the wrong tool here. The right tool is a § 282 defense in whatever forum you are in, plus a § 286 damages-limitation argument.

Estoppel landscape. Because no IPR was ever instituted, § 315(e)(2) estoppel does not attach to anyone — no petitioner, no privy, no real party in interest. Every prior-art ground is still fully available to every defendant: § 102 anticipation, § 103 obviousness, § 112 enablement/written-description/definiteness, and the § 282(2) prior-art and public-use/on-sale defenses. There is no estoppel trap and no "reasonably could have raised" shadow over the art. If you are an accused infringer, that is the one genuinely favourable dimension of this file.

Pattern signals. No repeat-petitioner pattern (there are no petitioners at all). No PTAB appeal history. No defensive aggregator (Unified Patents or similar) appears anywhere in the chain — the only entities in the record are Elbex Video Ltd. and its inventor-licensee-adjacent Elbex America (N.Y.) Inc. The absence of any IPR is itself a signal, but here it is a low-value-patent signal rather than a strong-patent signal: the '546 patent was granted 2009-03-10, has been in force for its full ~17-year adjusted term, and — despite Elbex's otherwise active assertion history on older CCTV coding patents — attracted no third-party AIA challenge. Patents that generate real revenue or real litigation expense eventually attract IPRs. This one did not.

Recommended next steps

1. Do not characterize the '546 patent as PTAB-hardened or PTAB-invalidated. If opposing counsel or a demand letter implies either, the correct response is: no AIA trial proceeding against US 7,502,546 has ever been filed; the patent has never been tested at the Board. Say it plainly and put the burden on them.
2. Check the live docket yourself before relying on this memo. PTAB E2E's full-text search and the ODP "proceedings" endpoint are the authoritative sources; re-run both, plus a Patent Center transaction-history pull for the '546 file, and specifically confirm no Reexamination (which is not an AIA trial and would not appear in an AIA-trials query) has been filed. Reexamination records live in the patent's file wrapper, not the AIA trial list — that is the most plausible blind spot in this report.
3. If a demand letter cites claims of the '546 patent today, the dispositive dates are: priority 2003-10-29, grant 2009-03-10, adjusted expiration 2026-10-28. Anchor your damages position on § 286 (six-year lookback) and the near-zero remaining term, and consider whether the matter is practically moot. Ask whether the asserted claim is even within the remaining term at the date of the alleged infringement.
4. Preserve your invalidity grounds without a § 315(e)(2) constraint. No estoppel exists, so you may plead § 102/§ 103/§ 112 freely in litigation and still file an IPR later if — contrary to the above — the patent term is extended or a continuation is asserted. Note the file's own prior-art statements: the '546 specification expressly incorporates US 4,603,352, US 5,267,039, US 4,943,864 (identification-code-in-vertical-blanking), US 4,989,085, and US 5,335,014, and Elbex's own US 5,592,321 (Elberbaum) teaches the same external-sync-injected-on-the-video-line architecture. Those are obvious starting points for a § 102/§ 103 mapping against independent claim 1.
5. No appeal to track and no trial-stage milestones to monitor — there is no institution deadline, no oral hearing, and no FWD due date, because there is no proceeding. If the search gap in point 2 discloses a recently filed petition, the milestone to calendar will be the § 314(b) three-month institution deadline from the Notice of Filing Date Accorded.

Verification note: this conclusion rests on (i) the structured ODP block stating no AIA trial proceedings are on file, and (ii) independent web searches for the patent number and the Elbex/Elberbaum entities, which returned no PTAB matter. Where I could not verify a fact — the patent at issue in the 2019 Israeli appeal, and any petition filed within the last few weeks — I have said so rather than filling the gap.

I'll research this patent's assignment record and litigation history before assembling the analysis.

Let me dig deeper into the specific assignment record and any litigation asserting this patent.

Inventors

Single-inventor patent. No unusual departure pattern: Elberbaum did not leave the assignee, and continues to appear as sole inventor on Elbex Video Ltd. filings well after this patent — e.g., US 10,797,476 (granted 2020‑10‑06) and US 10,225,005 (granted 2019‑03‑05), both Elbex Video Ltd. / Elberbaum per onscope's owner listing (onscope – Elbex Video Ltd.). There is therefore no inventor‑exit signal preceding any portfolio sale.

Original assignee

Elbex Video Ltd. — Tokyo, Japan (1‑11, Nishi‑gotanda 8‑chome, Shinagawa‑ku, Tokyo 141‑0031, per WIPO records). A Japanese closed‑circuit television / surveillance equipment manufacturer (cameras, camera housings, monitors, DVRs, video intercoms and, later, building‑automation and AC‑outlet products). It has a US distribution subsidiary, Elbex America (NY), Inc. (Blauvelt, NY) (WIPO PCT section, applicant listing).

• Ships products embodying the field of the claims: yes — the patent is directed to CCTV DVR recording/synchronous retrieval, squarely within Elbex's commercial product line (the '546 family DVR/surveillance gear).
• Primary line of business: CCTV / security surveillance hardware and systems; the company is a legacy operating manufacturer, not a licensing vehicle.
• Current status: operating — still filing and receiving US patents through at least 2020 (Elbex Video Ltd. as owner/applicant). No bankruptcy, dissolution, or assignment‑out is on record. Notably, the US patent here is listed by Google Patents as "Expired – Fee Related, expires 2026‑10‑28", i.e., maintenance fees were not kept current, which itself argues against an active assertion program on this specific patent.

Assignment timeline

⚠️ Data caveat: The authoritative record for this patent is the inventor→company assignment recorded at the USPTO on 2004‑02‑18, as reflected in the Google Patents legal‑events block for US 7,502,546. That rendering does not expose the reel/frame numbers, the correspondent of record, or the exact execution date, and I was unable to retrieve the Assignment Center reel/frame detail page before running out of retrieval steps. I therefore report the event as recorded, flag the missing fields as unknown, and do not invent reel/frame values. This is a genuine gap in my sourcing, not a statement that the records are absent.

2004‑02‑18 (recorded) — Reel/Frame: not exposed in the fetched record

• Conveyance: Assignment (Assignment of Assignors' Interest — "SEE DOCUMENT FOR DETAILS")
• Assignor: David Elberbaum (sole inventor)
• Assignee: Elbex Video Ltd.
• Correspondent: not exposed in the fetched record (Elbex's US prosecution/recording counsel historically has been Katten Muchin Rosenman and, on later Elbex filings, Shakir Law PLLC — but I can only confirm those as prosecution counsel of record, not as the correspondent on this specific recording, so I do not attribute it here).
• Context: Founder‑to‑company assignment of the inventor's rights to his own operating company — a standard original‑ownership assignment, not a transfer to a third party.

No post‑issuance assignment is recorded. There is no assignment from Elbex Video Ltd. to any other entity, no security agreement, no merger, no change of name, and no release on record for US 7,502,546. On the record available, Elbex Video Ltd. remains the owner (subject to the fee‑related expiry noted above).

(Note: the related patent US 4,943,864, which the '546 specification incorporates by reference and which Elbex asserted against Sensormatic/Axis/Tyco, shows the same clean single‑assignee pattern in the Stanford NPE database — the owner is classified there as a "Product company," not an NPE.) (Stanford NPE Litigation Database – Elbex Video, Ltd.)

Timeline diagram

timeline
    title Ownership of US 7502546
    2003 : Application filed by Elbex Video Ltd
    2004 : Inventor assigns rights to Elbex Video Ltd
    2009 : Patent issued to Elbex Video Ltd
    2026 : Patent lapses fee related

NPE / troll-pattern signals

1. Shell‑entity transfer — not present. No transfer to any "IP / Holdings / Licensing / Ventures" entity exists on record. The only assignment runs inventor → his own operating company (recorded 2004‑02‑18).

2. Known asserter in the chain — not present. Neither Elbex Video Ltd. nor any listed assignee appears on public NPE lists (Acacia, Marathon, IV, IPNav, Wi‑LAN/Mosaid, Vringo, Pendrell, Round Rock, etc.). Elbex is affirmatively classified as a "Product company" in the Stanford NPE database.

3. Repeat correspondent across the chain — unclear / not assessable. The chain has only one recorded assignment, and its correspondent field was not exposed in the fetched record, so recurrence within the chain cannot be tested. No correspondent name is attributed to avoid fabrication.

4. Cascading transfers — not present. One assignment over the entire 20‑year life; no chained LLC hops.

5. Pre‑litigation transfer — not present. There is no assignment dated near any infringement suit on this patent. Elbex's documented suits (Sensormatic, 2004/2006; Axis; Tyco) were filed by the owner itself on sibling patents, with no last‑minute chain assembly.

6. Bankruptcy fire‑sale — not present. No Chapter 7/11 or §363 sale; Elbex Video Ltd. is a going concern that continued patenting into 2020.

7. Privateering — not present. Elbex litigates in its own name as a product company; there is no operating‑company‑to‑NPE back‑assertion arrangement on record.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. (Inverse of a neutralization finding.)

Verdict

Operating-company assertion.

The assignment record for US 7,502,546 contains only the original founder‑to‑company assignment (recorded 2004‑02‑18, David Elberbaum → Elbex Video Ltd.), with no subsequent transfer to any NPE, shell LLC, or aggregator. Elbex Video Ltd. is a genuine operating CCTV/DVR manufacturer that asserts its patents in its own name against actual competitors — e.g., Elbex Video, Ltd. v. Sensormatic Electronics Corp., 508 F.3d 1366 (Fed. Cir. 2007), and the Axis and Tyco actions — and it is classified as a "Product company," not an NPE, in the Stanford database. Caveat: I could not confirm that US 7,502,546 specifically has been asserted (Elbex's documented suits concern sibling patents such as the '085 and '864), and the patent is now flagged fee‑related expired, so the assertion finding is at the company level while the chain itself shows a clean, single‑owner, non‑NPE pattern.

Verify at: USPTO Assignment Center and the Patent Assignment Search — search patent number 7502546 to retrieve the reel/frame and correspondent fields that were not exposed in my fetched sources.

I'll search for US 7,502,546's citation records and the prior-art references it identifies.

Let me pull the patent's front-page citation data and the related Elberbaum application.

I hit the tool step limit before I could pull the patent's front-page "References Cited" table directly, so I'll be explicit about what is and isn't grounded. Below I separate what I confirmed from what remains provisional.

Prior Art Analysis — US 7,502,546 B2

0. Scope / limitation statement (read first)

• The patent is confirmed: US 7,502,546 B2, Method and apparatus for digitally recording and synchronously retrieving a plurality of video signals, App. No. 10/696,497, filed 2003-10-29, issued 2009-03-10, inventor David Elberbaum, assignee Elbex Video Ltd. — pulled verbatim from Google Patents (https://patents.google.com/patent/US7502546/en).
• What I could NOT retrieve: the formal front-page "References Cited" list (applicant- and examiner-cited patents) and the "Cited By" list. The Google Patents rendering supplied in the source text is truncated after the detailed description and omits those tables, and my searches returned the specification's in-text citations rather than the front-page table. Treat the set below as the references cited within the patent document itself, not as a certified front-page citation list.
• No claim set available (as flagged in the previously generated summary). Because § 102 anticipation must be assessed claim-by-claim on the verbatim claim language, the "which claims" column below is mapped to the three reconstructed independent claims (method-single-camera-DVR; method-multi-DVR/split-screen; apparatus). This is provisional. For an enforceable § 102 opinion you must pull the actual claim set from PatentCenter/Google Patents' "Claims" tab.

Reminder of the reconstructed independent claims used as the mapping targets:

• Claim A (method 1): detect/register ID code; compress + store with time/date; endless FIFO rotation; alarm-code tagging; retrieve by ID/time-date/alarm code; decompress; lock to external sync; re-inject ID/time-date/alarm into vertical blanking.
• Claim B (method 2): generate selection commands from ID/time-date/alarm codes; feed to a plurality of DVRs; display individually or combine into split screen.
• Claim C (apparatus): input circuit (analog/digital video with allotted ID); external-sync receive-and-transfer stage; recording stage (store with ID + time/date, play back); encode/decode stage (extract/decode ID; re-encode/inject ID + time/date in vertical blanking).

1. References cited in the specification of US 7,502,546

1.1 — U.S. Pat. No. 4,603,352

Brief description: External-sync generator injects a synchronizing pulse (level higher than the white level of the composite video, within the vertical blanking interval) onto the video transmission line toward the cameras; each camera has a comparator/coupling circuit that detects the injected pulse and locks its internal sync generator to it. The sync pulse is propagated over the same line as the video, in the reverse direction to video propagation.

§ 102 relevance: This is the closest single reference for the “external synchronizing receiving and transfer means” and the “inject sync onto the transmission line / comparator in camera” elements of Claim C. It does not disclose DVR, compression, FIFO endless rotation, alarm coding, time/date indexing, or digital ID extraction/decode. So it can, at most, anticipate a claim that reads only on the sync transfer architecture, and it cannot anticipate Claims A or B as reconstructed.

1.2 — U.S. Pat. No. 5,267,039 ✅ (dates confirmed)

Brief description: CCTV apparatus with a plurality of transmitters each having a TV camera with an allotted identification code, a code-signal generator, and a circuit superposing the code into the composite video; a receiving means extracts the ID codes and has a selective-output circuit that outputs a transmitter’s signal when the selective code matches the extracted ID; an external synchronizing generator injects a pulse (higher than max video level) into the transmission lines, and comparator circuits in the cameras separate the pulse to synchronize the cameras. Also claims a video recorder for recording the sequence and regenerating/retrieving by decoded ID, and a memory circuit storing ≥1 vertical scanning period.

§ 102 relevance — HIGH:

• Claim C (apparatus): elements input circuit receiving camera video carrying an allotted ID code + external-sync receive/transfer + encode/decode extracting ID are all disclosed. This reference is a serious § 102 challenge to a Claim C that does not require digital compression / HDD-FIFO / alarm coding. (It is the same inventor’s own prior patent — relevant under § 102(a)/(b) as of the 2003 filing.)
• Claim A: discloses ID decode, selective retrieval, and external-sync locking, but not compression, endless FIFO rotation, alarm coding, or vertical-blanking re-injection of time/date — so it cannot anticipate Claim A as reconstructed.
• Claim B: no plurality-of-DVR / split-screen-combining teaching → does not anticipate.

1.3 — U.S. Pat. No. 4,943,864 ✅ (issue date confirmed)

Brief description: Plural transmitting means each with a TV camera allotted a specific code, a code-signal generator, and a circuit that injects the code into the video signal; receiving means extracts the code and generates a display signal identifying that camera; a counter counts horizontal scanning lines each field/frame and the code is generated at a predetermined count (i.e., during a chosen horizontal line); a level sensor reproduces the code; a memory stores per-camera display data read out on the basis of the extracted code.

§ 102 relevance — HIGH for the ID-code inject/extract sub-features:

• Anticipates claims reciting the code-generator + horizontal-line-gated injection + level-sensor extraction mechanism (feeds the “encode/decode means” element of Claim C, and the “detect and register an identification code” steps of Claim A).
• Does not disclose digital recording, compression, or FIFO → cannot anticipate the whole of Claims A/B.

1.4 — U.S. Pat. No. 4,989,085

Brief description (per the citing text): a mixer circuit in which the code signals are mixed and injected into the video signal. It is cited as the enabling reference for the code-adding/mixer circuit (15 / 98).

§ 102 relevance — MODERATE, narrow: relevant only to claims reciting the code-injection/mixer structure; it is a supporting reference, unlikely to anticipate any full independent claim on its own. Note a potential contradiction to flag: the previously generated summary associated US 4,989,085 with the Elbex v. Sensormatic appeal; I could not re-verify that association here, so treat that link as unconfirmed. (The confirmed Sensormatic-era Elbex patents in the earlier work were 4,989,085-related assertions and the ’864/’039 family — but the ’085↔Sensormatic link needs a fresh check.)

1.5 — U.S. Pat. No. 5,335,014

Brief description: Synchronous-switching apparatus with externally-synchronized transmitters; each transmitter decodes an ID code, compares it to its allotted code, and gates its video output on/off on match; external sync generator injects a pulse higher than the max video level onto the transmission line, and level-comparator circuits in the transmitters regenerate the sync; includes counters counting horizontal lines to decode the ID at a predetermined line; supports vertical-sync-based switching timing.

§ 102 relevance — MODERATE/HIGH for sync + ID-decode + gating:

• Reinforces anticipation of claims reciting the injected-sync/comparator transfer and horizontal-line-gated ID decode (elements of Claim C, and steps of Claim A).
• Does not disclose DVR compression/FIFO/alarm → cannot anticipate the digital-recording claims.

1.6 — U.S. application Ser. No. 09/818,243 → US 2002/0141731 A1

Brief description: The same-inventor sibling application: a multiplexer/recording receiver connecting multiple cameras (with ID codes) sequentially to a digital recorder; processor-and-compress circuit (JPEG/MPEG classes) feeding compressed signals to the digital recorder with time/date and ID numbers; FIFO HDD rotation with alarm-state transfer to removable media; code-extractor (horizontal-line gate + level sensor); ID and T/D decode/encode.

§ 102 relevance — VERY HIGH (this is the closest art):

• Under § 102(a)/(e) (pre-AIA), this Elberbaum application, filed 2001-03-27 and published 2002, predates the 2003 filing of ’546 and discloses substantially the compress → store with time/date+ID → FIFO rotation → alarm transfer → decode/encode ID & time/date pipeline. It is the strongest single-reference threat to Claim A, and its recitation of a plurality of cameras/recording receivers is relevant to Claim B.
• Caveat / contradiction flag: because it is the same inventor’s own earlier application, it may be § 102(e) art (and/or subject to a double-patenting / obviousness-type relationship rather than pure anticipation). Whether it anticipates versus merely renders obvious depends on whether it discloses the particular claim features (e.g., “locked to the external sync” and vertical-blanking re-injection as claimed) — which I cannot finalize without the ’546 claim text.

2. Other art worth pulling (not fully verified in this pass)

• Forward citations (references citing ’546, useful for the field’s state of the art but not § 102 prior art against ’546): e.g., US 9,697,428 (System and method for managing a surveillance system, AT&T IP) and US 7,843,336 (Self-contained wireless security sensor collective system, Honeywell) both list 7502546 (Elberbaum, 2009-03-10) in their references-cited tables (https://patents.justia.com/patent/[9697428](/patent/9697428)). These are later documents and are not anticipatory art for ’546.
• False-positive warning (as in the prior summary): many “7502546” hits are the A549 cell-culture ATCC lot number 7502546 in biotech publications (e.g., US 2014/0194439 A1, WO 2011/085126, US 9,073,858 B2). These are unrelated to this patent and must not be treated as citations of ’546.

3. Bottom line

• Highest-risk § 102 references against ’546: (1) US 2002/0141731 A1 (Elberbaum, filed 2001-03-27) — the closest, due to its compression + time/date+ID storage + FIFO + alarm-transfer teaching; (2) US 5,267,039 and (3) US 4,943,864 — the same inventor’s earlier Elbex patents, which together disclose the ID-code inject/extract and externally-synchronized-transmission-line architecture recited in the apparatus claim; with (4) US 4,603,352 and (5) US 5,335,014 supplying the external-sync-over-video-line + comparator transfer.
• Anticipation caveat: each of these references is strong on one cluster of the ’546 disclosure (either the ID/sync transmission architecture or the digital recording pipeline), but I have not confirmed that any single one discloses all elements of any given ’546 claim — and I could not verify that because the ’546 claim set is not in the available record. A reference can only anticipate under § 102 if it discloses every claim limitation; otherwise it is at most a § 103 combination reference.

What to verify next (required before relying on this)

1. Pull the front-page "References Cited" list (applicant + examiner) from the ’546 PDF/PatentCenter — my set above is the spec-embedded citations only.
2. Pull the verbatim claim set to convert the provisional A/B/C mapping into actual claim numbers.
3. Confirm the filing/issue dates I flagged as unverified for US 4,603,352, US 4,943,864 (filing), US 4,989,085, US 5,335,014, and the publication date of US 2002/0141731 A1.
4. Confirm whether US 4,989,085 is in fact the Sensormatic-litigated patent (prior summary asserted this; I could not re-verify).

Identifiers were taken literally from the record and not auto-corrected (e.g., “7502546,” “4,989,085,” “09/818,243”). Where the search results were silent, I have marked dates as unverified rather than supplying them from memory.

I'll gather the cited prior-art references and try to pin down the actual claim language before running the §103 analysis.

Obviousness Analysis — US 7,502,546 B2 under 35 U.S.C. § 103

Current date: April 26, 2026 (as instructed for this task)
Patent: US 7,502,546 B2, Method and apparatus for digitally recording and synchronously retrieving a plurality of video signals; app. US 10/696,497; filed 2003‑10‑29; granted 2009‑03‑10; inventor David Elberbaum; assignee Elbex Video Ltd.
Source of record: https://patents.google.com/patent/US7502546/en

0. Threshold caveats (read before relying on anything below)

1. The claim set is still not in front of me. The authoritative text I hold is the Google Patents bibliographic + description rendering, which is truncated mid‑sentence in the detailed description ("…sequentially selecting m…") and contains no claims. My earlier sections flagged this; it remains true. Everything below is therefore an analysis of the three independent claim concepts reconstructed from the patent's own "Summary of the Invention," which in this document tracks the claim structure almost verbatim. Do not attribute my paraphrase to the patent as claim language.
2. Prior‑art identifiers are reproduced literally. The '546 specification cites U.S. Pat. No. 4,603,352. Note that a different document I retrieved (US 5,274,450) refers to a "U.S. Pat. No. 4,608,352" for what appears to be the same Elbex external‑sync camera feature. Per the strict no‑auto‑correction rule, I am not harmonizing these. Flagging it as a discrepancy in the record, not correcting it.
3. Internal anomaly in the '546: the specification refers to "the video output circuit 47 … of the digital recorder 30 of FIG. 16," but the patent has only FIGS. 1–14. Noted as a drafting artifact; irrelevant to § 103 but relevant to § 112 if anyone ever litigates this.
4. Same‑inventor/same‑assignee problem. Nearly every material reference is by David Elberbaum and assigned to Elbex Video Ltd. — i.e., the inventor's own earlier work. That does not immunize it from § 103: an inventor's own patents and printed publications that predate the critical date are prior art under pre‑AIA § 102(a)/(b), and they may be combined under § 103. The § 103(c) "commonly owned" safe harbor reaches only art that is prior art solely under § 102(e)/(f)/(g), and only for subject matter "developed by another person." I apply that distinction explicitly below.

1. The prior‑art set actually available on this record

2. The critical date matters, and it strongly favors the obviousness case

The '546 was filed 2003‑10‑29 and claims no earlier priority. That means its own Background section, its incorporated references, and the 2002‑10‑03 publication of Ser. No. 09/818,243 all sit before the critical date. Notably, the '546's Background admits a great deal:

• it admits DVRs existed that record a single camera in real time by locking to the camera's own sync;
• it admits DVRs existed that "convert the recorded output signals into composite video signal";
• it admits the multiplexer/frame‑switcher, split‑screen (Quad/9/16), time‑lapse and real‑time modes, external‑sync injection on the video line, and code‑in‑VBI recording were all known.

At the critical date, therefore, the remaining delta between the admitted art and the '546's independent claims is small: compress + time/date‑index into a circular buffer, tag alarm records, then on playback decompress, lock to an external sync, and re‑inject ID/time‑date/alarm codes into the vertical blanking interval.

3. Reconstructed independent claim 1 — the single‑camera, externally synchronized DVR method

Claim concept (reconstructed): detect/register an ID code on an input video signal → compress → store compressed video with time and date → fill the memory to capacity and then run endless FIFO rotation (newest overwrites oldest) → code alarm‑period recordings with alarm codes → select/retrieve by ID code, time/date, or alarm code → decompress → lock to the external sync → re‑inject ID, time/date and alarm code during the vertical blanking period.

Combination 1 (strongest): '731 publication (the applicant's own pre‑critical‑date blueprint of the external‑sync + sequencing DVR + code‑select architecture) + '864/'085 (code generation, injection, extraction, per‑code memory retrieval) + '352/'039 (external sync injection on the video line and memory‑based re‑synchronization) + a known circular‑buffer DVR with alarm write‑protection (Ely‑type record). Every element is accounted for, and the motivations are the applicant's own stated problem.

4. Reconstructed independent claim 2 — the multi‑DVR receiving/display method

Claim concept: generate selection commands on the basis of ID codes, recording time/date, and alarm codes; feed them to the plurality of DVRs to display an individually selected signal or combine multiple selected signals into a split‑screen display.

• '731 publication discloses the multi‑source version directly: a plurality of transmitters 2 / DVRs, a code select circuit 39, a monitor 60.
• '085 discloses a selecting/switching device and a controlling device that generates codes addressed to a specific camera and a memory of per‑camera data — i.e., a selection command based on an extracted code.
• '014 discloses the complementary half: feeding an identification‑code signal and the external sync to the transmitters over the line so the addressed device acts.
• '598,321 discloses selective routing of information signals with per‑device ID code addressing.
• Split‑screen assembly (Quad/9/16/PIP) is admitted by the '546 to be "a well known circuit." Combining a plurality of now externally synchronized composite outputs into a known split‑screen assembler is a predictable combination whose only requirement — mutual sync — is supplied by '352.

Combination 2: '731 + '085 + '014 + '598,321 + admitted‑known Quad/split‑screen circuit. The claimed advance ("it is possible to combine efficiently the output signals") is the result of applying known sync to known switchers — a classic KSR "obvious to try / predictable result."

5. Reconstructed independent claim 3 — the apparatus claim

Claim concept: input circuit receiving analog or digital camera video carrying an allotted ID code + external‑sync receive‑and‑transfer stage synchronizing both the recorder's internal sync generator and the camera + recording stage storing the video with ID code and time/date and playing it back + encode/decode stage extracting the incoming ID and re‑encoding/injecting ID + time/date into the played‑back signal during vertical blanking.

• Input circuit w/ ID code: '864, '085, '598,321.
• External‑sync receive‑and‑transfer to both the recorder and the camera, propagating in the reverse direction on the video line: '352 and, more pointedly, '579,060 (P1 injection + clipping so it "will not cause any receiving error") and '014 (sync + ID sent over the line to the transmitters). The '546's FIG. 12 comparator 70B "separating an external sync signal fed through the video out line" is the same comparator‑against‑reference circuit taught in '352/'085 material.
• Recording stage storing with ID + time/date and playing back: '039 (memory store/retrieve), '731 (DVR 30 with code select), '685 (digital recording on finite‑capacity media).
• Encode/decode re‑injection during VBLANK: '864 + '085.

Combination 3: '352 + '864 + '085 + '039 + '731. Literally every block in the '546's FIG. 1/12/13 has a counterpart in these five documents, four of which the applicant expressly incorporated by reference into the very specification being examined. Express incorporation is powerful, admissible evidence that the applicant regarded these teachings as combinable with one another and with the new recorder.

6. The alarm‑preservation dependent concept

Claim concept (reconstructed): duplicate the alarm‑coded recordings into an exclusive memory device (or a memory portion excluded from routine FIFO recording), or onto a removable/swappable medium (HDD, DVD, CD), protecting them from routine erasure.

• Ely‑type record: "a control circuit that responds to alarm commands to protect pre‑ and post‑alarm data"; "selective retrieval of alarm data … without interrupting ongoing storage of live video." This is the same idea — alarm data carved out of the overwrite path. (Patent number unverified on this record.)
• '546's own '685: removable/swappable media and permanent archiving of digital recordings is the entire subject of that Elberbaum patent.
• '019,905 claim 10 (alarm → real‑time mode) shows alarm‑responsive recording control in the same field.
• Motivation: preserving evidence is the stated, self‑evident purpose; a POSITA would either (a) reserve a memory region, or (b) copy to removable media — two predictable alternatives.

Combination 4: Ely‑type record + '685 (or ordinary removable‑media backup practice) + '019,905.

7. Motivation to combine — the KSR analysis

Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), the motivations here are unusually strong:

1. Same field of endeavor. Every reference is CCTV information‑transmission, camera identification coding, camera synchronization, or video recording/playback. There is no field‑crossing problem.
2. Same inventor and same assignee. Elberbaum/Elbex authored essentially the entire pre‑2003 solution space for externally synchronized, identification‑coded CCTV — and the '546 builds directly on it.
3. Express incorporation by reference. The '546 itself incorporates '352, '039, '864, '085 and '014 as the building blocks of its own disclosure. A reference that the specification incorporates for the very purpose at issue is about as combinable as prior art gets.
4. The '731 publication is a near‑blueprint. The applicant's own pre‑critical‑date published application already shows external sync generator + sequencing switch + digital video recorder + code select circuit (time/date and code) + monitor. The '546's independent claims are the systematization of that disclosure with routine DVR features layered on top.
5. The '546 concedes the conventionality of the pieces it relies on: "hard disk management software, such as used with personal computer (PC)"; compression formats (JPEG/MJPEG/Wavelet/MPEG‑1/2/4) described as "well known"; the split‑screen circuit described as "well known"; the TBC as "well known."
6. Predictable results / finite number of identified solutions. Given the known problem ("[i]n systems employing a plurality of digital video recorders each connected to a single camera it is not possible to combine efficiently the output signals … because the digital video recorders are not externally synchronized"), the known solutions were (a) externally synchronize the recorders, (b) code the signals, (c) buffer/re‑clock the outputs. All three were in the art, and the '546 uses all three — a classic "combination of familiar elements according to known methods … yield[ing] no more than predictable results."
7. Design incentive / market pressure. Quad/9/16 split‑screen displays were a mainstream CCTV product category; there was explicit design incentive to make DVR outputs combine in them.

8. The best non‑obviousness arguments, and why they likely fail

(a) "Digital video recorders ignore the vertical blanking period." The '546's Background states that DVRs "ignore the vertical blanking period and instead … employ a complex control software for indexing the files." Applicant could argue this teaches away from VBI code injection in a digital recorder.
Rebuttal: (i) Teaching away requires the prior art to criticize, discredit or discourage the solution; a statement that known DVRs discard VBI is a statement of fact about those DVRs, not a discouragement from re‑inserting a code at the recorder's output stage — which is exactly what '864/'085 already teach. (ii) The applicant's own '731 publication (102(b)) shows the external‑sync + coded digital architecture and thereby undercuts the claim that the path was discredited. (iii) The '546 admits DVRs that output composite video existed, so re‑injecting a code into that composite output is a small step.

(b) "VGA outputs are complex and costly to combine." This is a statement about a different output format. The '546 solves the problem by using composite outputs and known split‑screen circuits; the admitted existence of composite‑output DVRs dissolves the argument.

(c) "The alarm‑preservation feature is a safety‑critical improvement, not a mere duplication." Even so, the motivation (evidentiary preservation) is self‑evident and the mechanism (exclude from overwrite, or copy out) was known.

(d) Objective indicia (secondary considerations). I found no evidence on this record of nexus‑bearing secondary considerations: no unexpected results, no licensing program tied to the '546, no industry praise, no copying evidence, and no litigation establishing commercial success attributable to the claimed combination. Given the patent's expired‑fee‑related status and adjusted expiration of 2026‑10‑28, there is no evident enforcement history (consistent with the litigation sections of this analysis). Absent such evidence, the KSR factors control.

9. Explicit combination recipes (summary chart)

Net conclusion: On the reconstructed claim concepts, US 7,502,546 is highly vulnerable to a § 103 challenge built almost entirely from the applicant's own earlier patents and published application, several of which the '546 expressly incorporates by reference. The delta over the admitted art is (i) routine compression, (ii) routine time/date indexing, (iii) a routine FIFO HDD buffer, (iv) alarm tagging/protection, and (v) re‑injection of the already‑known codes into VBLANK on playback — each a predictable use of a known technique for its known purpose, and each with a clear motivation in the applicant's own stated problem.

10. Confidence, weight, and residual risk

Because the claim set is unavailable to me, treat this as a strong prima facie obviousness case on reconstructed claims, not as a final invalidity opinion. If the actual claims contain narrower limitations that I have guessed broadly — e.g., a specific requirement that the decompression be clocked from the externally supplied sync while the compression is clocked from the camera sync, or a specific recitation of the reverse‑direction propagation of external sync on the video output line — those limitations should be re‑run against '352, '579,060 and '014, which are the references most likely to still disclose them.

To close the loop

1. Pull the verbatim claims from USPTO PatentCenter (application 10/696,497) or the granted‑patent PDF, and the "References Cited" table on the Google Patents page (I could not retrieve that table; the authoritative full text I hold is the bibliographic + description rendering).
2. Confirm Ely's patent number and fetch its claims to firm up the ring‑buffer/alarm‑protection mapping.
3. Confirm whether any Elbex family member sharing this disclosure was ever the subject of a terminal disclaimer — that would raise an obviousness‑type double‑patenting exposure independent of § 103.
4. Verify whether US 2002/0141731's prosecution establishes it as the same application as Ser. No. 09/818,243 (it does by all appearances).