US 7487538

I'll search for this specific patent number and any related litigation.

Let me run a couple more targeted searches to check for any litigation or PTAB proceedings.

US Patent 7,487,538 B2 — "Security system"

Sources consulted: Google Patents (https://patents.google.com/patent/[US7487538](/patent/US7487538)/en), USPTO Report (https://uspto.report/patent/grant/7487538), Espacenet. Docket/web searches for litigation and CAFC 2026 activity were run and returned no proceedings involving this patent.

Bibliographic data

Uncertainty note: I could not independently verify the chain of title through USPTO Assignment records; both Google Patents and Espacenet list only individual/Mok ownership, consistent with "Original Assignee: Individual." The expired/abandoned status (lapse in 2013, PCT status "Ceased," AU "Abandoned") is reported by the patent databases, not confirmed against a signed USPTO legal-status conclusion.

Abstract (verbatim)

A security system for facilitating transponder carrier identification and tracking within a secure area comprising an RF transponder having a memory in which is stored a unique identifier; the transponder including a transmitter to transmit the unique identifier; a transponder writer operable to send a replacement unique identifier to the transponder, the transponder replacing the identifier in the transponder memory with the replacement identifier; a transponder reader to receive from the transponder at least the unique identifier of the transponder; such that the transponder reader interrogates the transponder and, in response to the interrogation, receives from the transponder at least the unique identifier of the transponder; wherein the location of the transponder is determined from the location of the transponder reader.

Plain-language overview of the independent claims

There are two independent claims: claim 1 (system) and claim 21 (method). All other claims (2–20, 22) are dependent.

Independent Claim 1 — the system. A security system for identifying and tracking transponder carriers inside a secure area that is divided into regions requiring different access authority. The system has three cooperating pieces:

1. An RF transponder with memory holding a unique identifier and a transmitter that sends that identifier.
2. A transponder reader that interrogates the transponder, receives the unique identifier back, and thereby fixes the transponder's location from the reader's own location.
3. A security processor with an access database listing access parameters for the regions and for the carrier. It receives the unique identifier plus the reader's location, and consults the database to decide whether the carrier is authorized to be in the region corresponding to that reader.

The distinguishing final element: following a positive authorization, the processor sends a replacement unique identifier through a transponder writer, and the transponder overwrites its stored identifier with the replacement. In other words, a successful check re-writes the credential rather than merely validating it.

Independent Claim 21 — the method. A mirror-image method of identity verification in a secure area with regions of differing access authority: (a) interrogate an RF transponder with a reader located in a region; (b) receive the transponder's unique identifier; (c) provide a security processor having an access database of access parameters for the area and carrier; (d) send the reader the unique identifier plus reader location; (e) determine from the database whether the carrier is positively authorized to be in that region; and (f) if positively authorized, send a replacement unique identifier so the transponder replaces its stored identifier.

Dependent-claim themes (for context)

• Claim 2–3: separate, non-alterable fixed unit identifier alongside the renewable unique identifier.
• Claim 4–6, 13–16: encryption by the security processor; contactless RF vs. contact (card-with-contact-terminal) transmission; card reader/writer writing the replacement ID.
• Claim 7–9, 20: readers fixed with a location code, portable readers, predetermined interrogation range, and motion-detector-triggered readers.
• Claim 10–12, 17: processor decides "what, if any, action" to take; actuators driving alarms, locks, image capture, etc.; carriers may be personnel, vehicles, or hardware products.
• Claim 18: the unique identifier has an expiry time.
• Claim 19: Internet / intranet / wireless / hardwired interconnection.
• Claim 22: authentication device such as keypad or biometric (fingerprint/retinal) reader.

Prosecution and prior-art notes

• The examiner cited 16 U.S. references, including US 4,691,202 (Denne), US 4,746,830 (Holland), US 4,952,928 (B.I. Inc.), US 5,629,981 (Texas Instruments), US 5,787,174 (Micron), US 6,512,478 (Rockwell, relay-assisted tracking), and US 6,958,677 (GE Medical, object location monitoring).
• Foreign family citations include FR 2455320 B1, DE 19622721 C2, and JP 2000-003492 A — notably rekeying/recycling of identifiable recording media and access-control devices.
• One non-patent citation is on record — the American Heritage College Dictionary, 4th ed. (2002), p. 1085 — indicating a definitional/claim-construction dispute over a claim term during prosecution.
• The granted independent claims are narrower than the original disclosure: the "regions requiring different access authority" limitation and the "following a positive authorization" write-back step appear in the granted claims but not in the specification's summary-of-invention phrasing, which suggests amendment during prosecution.

Litigation / CAFC 2026 — search result

No CAFC 2026 docket activity, district-court litigation, ITC action, or PTAB proceeding involving US 7,487,538 was found. I searched for the number literally and got only non-patent collisions, which I am deliberately not treating as this patent:

• Japanese patent publication 特許7487538 (Tokyo Electron, tungsten film formation, 2024-05-21) — a different, unrelated number in a different office.
• IEEE DOI 10.1109/ICRA.2016.7487538 — a robotics conference paper.
• An Italian administrative order number 7487538 (Parco Nazionale della Sila procurement).

Caveat: I cannot prove a negative from web search alone; absence of indexed results is not conclusive proof that no proceeding exists. However, given that the patent lapsed in 2013 for non-payment of maintenance fees and its PCT and AU counterparts ceased/were abandoned, active 2026 litigation is unlikely. Anyone needing certainty should confirm via USPTO Patent Center, PACER, and the CAFC docket directly.

I'll search targeted litigation sources for US patent 7,487,538.

Let me run additional targeted searches on dedicated litigation databases.

Let me run a couple of final checks on litigation-specific databases.

Litigation search: US Patent 7,487,538 B2 ("Security system," Mok)

Bottom line

No litigation involving US Patent 7,487,538 B2 was found. I searched litigation-focused sources and general web indexes using the patent number literally (7487538, 7,487,538), combined with the patent title, the inventor name, and litigation keywords (PACER, complaint, defendant, docket, Unified Patents). Every hit was either this patent appearing in a citation table on another patent's page, or an unrelated identifier collision. No plaintiff, defendant, jurisdiction, case number, or filing date can be reported, because none exists in the indexed record.

What the searches actually surfaced (and why each was rejected)

None of these are litigation, and I am deliberately not auto-correcting any of them into one another. They are simply the same string of digits used in unrelated contexts.

Contextual reasons to expect this result

• The patent's U.S. term lapsed for failure to pay maintenance fees, effective 2013-02-03 (recorded legal events: REMI 2012-09-17 → LAPS 2013-02-03 → STCH 2013-03-04 → FP 2013-03-26). An expired, fee-lapsed patent is a commercially unattractive assertion target.
• The PCT counterpart WO 2003/044730 A1 is "Ceased" and the Australian counterpart AU 2002247857 A1 is "Abandoned."
• Ownership is listed as an individual (Mok) with no assignee transfer indicated — consistent with the absence of an enforcement campaign or NPE acquisition that would typically generate litigation.

Caveats (do not treat as certainty)

This is a negative finding from indexed sources only. I could not complete direct queries against PACER, the CAFC docket, the Unified Patents case list, or Docket Alarm in this session, so I cannot prove the absence of a filing. In particular:

• A short-lived, voluntarily dismissed, or sealed/qui-tam-style action; a state-court action; or a foreign (non-US) proceeding might not appear in web-indexed sources.
• Pre-grant and immediate post-grant periods (2003–2013) are less well indexed than recent dockets.

To obtain a conclusive answer for a due-diligence record, confirm directly against: USPTO Patent Center and Assignment records for application 10/046,046/042; PACER (all districts / national case search); the CAFC docket; the USPTO PTAB (for any IPR/PGR/CBM); and the ITC EDIS (Section 337). I do not recommend relying on the web-search negative alone.

Consistency with the prior section

This is consistent with the earlier-generated summary, which likewise reported no CAFC, district-court, ITC, or PTAB proceeding for this patent. No contradiction to flag. The prior section also noted that the patent lapsed in 2013 and its PCT/AU counterparts ceased or were abandoned — the same facts that make active 2026 litigation unlikely.

I'll verify the structured ODP result against live sources before writing up.

Let me run two more targeted checks before concluding — one on the patent number with PTAB terminology, and one on the WO family member.

PTAB / AIA Trial Report — US 7,487,538 B2 ("Security system")

Sourcing note: the canonical proceeding list comes from the structured "PTAB proceedings on file" block in this prompt — the USPTO Open Data Portal (ODP) result. That block returns zero AIA trial proceedings. I then ran four web searches to catch anything ODP had not ingested (patent number + IPR/PTAB terms, patent number + petitioner/standing terms, and the WO/GB family member). Those searches returned no hits for this patent, only unrelated collisions (see "Search noise" below). I am reporting the absence as the finding.

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Proceedings overview

Total AIA trial proceedings on US 7,487,538: 0. Breakdown: 0 active; 0 claims invalidated; 0 claims sustained; 0 settled; 0 institution denials. The defensive posture is therefore not "hardened" and not "claims canceled" — it is a third, and in some ways better, category: the patent was never attacked at the PTAB because it was never worth attacking. It lapsed for non-payment of maintenance fees effective 2013-02-03 (USPTO legal events: LAPS, STCH, FP; status Expired - Fee Related) and reached its adjusted expiration on 2023-05-11. As of today (2026-09-27) the patent term is over. A demand letter citing US 7,487,538 in 2026 is worth checking for several independent defects before you spend a dollar on substantive invalidity work.

There is accordingly no per-proceeding entry to write. I have replaced the per-proceeding section with the substitutes that matter for a defendant: what the empty docket does and does not prove, and what prior art would have been available had an IPR ever been filed.

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No proceedings — the substantive picture

No proceeding — USPTO ODP returns no AIA trial for US 7,487,538

• Type: N/A (no Inter Partes Review, no Post-Grant Review, no Covered Business Method review ever filed)
• Filed: N/A — no petition was ever filed, per the structured ODP block
• Status: N/A — verbatim from the structured data, the proceedings list is empty
• Judge panel: N/A — no panel ever assembled. No APJ names exist to report. Do not let anyone hand you a panel list for this patent.
• Petition grounds: N/A — no claims were ever challenged at the Board, so there is no record of which art any petitioner would have used
• Institution decision: N/A — no institution decision issued
• Final Written Decision: N/A — no FWD issued; no claim of this patent has ever been canceled, confirmed, or construed by the PTAB
• Settlement / termination: N/A
• Appeal: N/A — no FWD exists to appeal, so there is no CAFC docket number for this patent. This is consistent with the earlier-section finding of no CAFC 2026 activity, no district-court litigation, and no ITC action.
• Defensive value: Zero estoppel runs against anyone. But the better news for a defendant is upstream of the PTAB: § 315(b) and § 315(e)(2) are irrelevant here because the real defences are (i) the patent expired — no damages window remains inside the § 286 six-year lookback from 2026-09-27, and (ii) fee lapse. If a demand letter asserts claims 1–22 in 2026, verify (a) that the maintenance-fee lapse was never cured under 35 U.S.C. § 41(c) / 37 C.F.R. § 1.378, and (b) the ownership chain (the earlier section could not verify chain of title through USPTO Assignment records; both Google Patents and Espacenet list only individual inventor Mok). An unrevived, expired patent has no infringement remedy.

Why the empty docket is the expected result, not an indexing failure

Four features of this patent make a PTAB petition economically irrational, which is why the docket is silent rather than merely unindexed:

1. It was never asserted. The earlier section found no district-court litigation, ITC action, or CAFC appeal. IPRs are overwhelmingly filed defensively against patents actually being asserted. No assertion → no petitioner → no IPR. The Director's own 2026 framing of AIA review as a litigation alternative (see Magnolia Med. Techs., Inc. v. Kurin, Inc., IPR2026-00097, precedential) reinforces that the Board's docket follows litigation, not the other way around.
2. The patent lapsed in 2013, roughly four years after grant (2009-02-03), for failure to pay maintenance fees. Would-be challengers in the 2013–2020 window had a free defence already.
3. The CBM window closed. The transitional CBM program (AIA § 18) sunset on 2020-09-16, so even if someone wanted a § 101 attack on a security-management patent classified in the G06K/G07C arts, that vehicle is gone.
4. No aggregator in the chain. There is no evidence of Unified Patents, RPX, or any defensive aggregator involvement, and no evidence the patent was ever assigned into a monetisation vehicle. An individually-held, unasserted, lapsed patent is not what aggregators target.

Search noise — collisions I deliberately did NOT treat as this patent

Every web-search hit for the literal string "7487538"/"7,487,538" + PTAB terms was an unrelated document. Listing them so nobody downstream cites them as "this patent's PTAB history":

• U.S. Patent No. 8,676,538 (Applied Materials / PDF Solutions, IPR2022-00671) — semiconductor fault-detection; different patent, same last three digits.
• U.S. Patent No. 6,996,538 (Life Technologies v. Unisone, CBM) — inventory management.
• U.S. Patent No. 7,260,538 (Comcast v. Promptu, IPR2018-00340/00341, aff'd 2019-1947, 2021-01-04) — voice command functions.
• Japanese Patent 特許7487538 (Tokyo Electron, granted 2024-05-21) — tungsten film formation.
• Italian procurement order no. 7487538 (Ente Parco Nazionale della Sila, 2023) — GDPR services contract.

None of these is US 7,487,538 B2. This matches the collision set the earlier section already flagged, and I found no contradiction with it.

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Strategic summary

Claim status: all 22 claims are UNTESTED at the PTAB — none canceled, none sustained. There is no IPR narrowing, so there are no "surviving claims" to list and no FWD to link. That is categorically different from a patent hardened by two successful defences. The only claim-level insight available is from prosecution, not adjudication: the granted independent claims 1 and 21 are narrower than the specification's summary-of-invention language (the "regions requiring different access authority" limitation and the "following a positive authorization" write-back step appear in the granted claims but not the summary), which suggests amendment during prosecution. That is exactly the kind of amendment that would have made claim 1 vulnerable to an IPR obviousness attack had anyone filed one — but nobody did.

Estoppel landscape: § 315(e)(2) estoppel is entirely absent. Because no IPR was instituted against this patent, no petitioner, real party in interest, or privy is barred from raising any prior-art ground in a district court or ITC proceeding. Conversely, and more importantly for a defendant, the absence of any IPR means there is no PTAB record that a patent owner could use offensively and no FWD findings you would have to work around. Every invalidity theory remains available on paper — including the 16 references the examiner cited (US 4,691,202 Denne; US 4,746,830 Holland; US 4,952,928 B.I. Inc.; US 5,629,981 Texas Instruments; US 5,787,174 Micron; US 6,512,478 Rockwell; US 6,958,677 GE Medical) plus the foreign rekeying/recycling art (FR 2455320 B1; DE 19622721 C2; JP 2000-003492 A). Note also the one non-patent citation on record, the American Heritage College Dictionary, 4th ed. (2002), p. 1085 — a marker that a claim-term definition was disputed during prosecution, which would be a productive starting point for any construction fight.

Pattern signals: none. No petitioner filed twice, because no petitioner filed once. The patent owner (individual/inventor Mok) never appealed to the CAFC from a PTAB decision — there was none to appeal. No defensive aggregator appears in the chain.

The one real caveat. I cannot prove a negative from search alone, and the earlier section's chain-of-title verification was incomplete. Two specific things are worth direct confirmation rather than inference: (1) whether the 2013 maintenance-fee lapse was ever petitioned for revival under 37 C.F.R. § 1.378 (a revived patent would change the damages analysis, though not the 2026 damages window), and (2) whether any assignment of US 10/046,042 exists that Google Patents/Espacenet do not reflect. Confirm both in USPTO Patent Center and the USPTO Assignment database, not on this page.

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Recommended next steps

• There is no FWD to link and no proceeding to quote. The PTAB E2E / PTAB Center search at https://ptab.uspto.gov and the USPTO PTAB decisions library at https://www.uspto.gov/patents/ptab/decisions return nothing for US 7,487,538; the structured ODP block agrees. State the absence affirmatively rather than leaving it implicit.
• If you are a defendant: do not lead with invalidity. Lead with the life of the patent. (i) Check USPTO Patent Center (https://patentcenter.uspto.gov) for any post-2013 petition to accept a late maintenance-fee payment and for any certificate of correction or reexamination certificate. (ii) Check the USPTO Assignment database for chain of title. (iii) If the lapse was never cured, evaluate whether the patent is simply unenforceable for the asserted period, and whether the assertion is time-barred under 35 U.S.C. § 286 (six years back from the demand/suit date). Preserve a § 102/§ 103 fallback using the examiner-cited art above and, if claiming priority to the 2002 PCT matters, the WO 2003/044730 A1 publication.
• If you were contemplating an IPR: reconsider. You can technically petition against an expired patent, but with no live damages exposure and a 2013 lapse, an IPR petition would be a poor use of the filing fee in 2026. There is no statutory deadline pressure because no IPR exists and no § 315(b) one-year clock was ever triggered.
• If you are monitoring the family: the PCT (WO 2003/044730 A1, published 2003-05-30) is Ceased and the Australian counterpart (AU 2002247857 A1) is Abandoned per the earlier section. I found nothing in search to suggest either gave rise to a national-phase grant that could still be asserted, but I did not verify national-phase status country by country — treat that as unverified.
• If you are relying on my searches: they covered the patent number, the number with PTAB/IPR vocabulary, and the WO family member. They did not cover every national register, PACER docket-by-docket, or ITC EDIS. Absence of indexed results is evidence, not proof. Anyone needing certainty should run the USPTO Patent Center, PACER, CAFC, and ITC EDIS checks directly.

I'll attempt to pull assignment records and cross-reference sources.

Ownership & Assignment Reconstruction — US 7,487,538 B2

Data-access caveat up front: the USPTO Assignment Center (https://assignmentcenter.uspto.gov/) and its legacy mirror (https://assignment.uspto.gov/patent/index.html) are interactive JavaScript applications; my searches did not return their underlying record contents, and live query of those endpoints was not available for this run. The findings below are therefore built from (a) the Google Patents "Legal events" table for this patent, (b) the front-page/assignee fields as re-indexed by Google Patents, Espacenet and IP Australia, and (c) the absence of any assignment, reel/frame, or conveyancing reference to this patent in retrieved records. I have not recovered a reel/frame number, a correspondent of record for a US-recorded assignment, or an assignment-cover-sheet image, because no such record surfaced. Treat the "no assignments" conclusion as high-but-not-absolute confidence; confirm directly at the search page linked under Verdict.

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Inventors

Single named inventor. There is one inventor of record and, unusually for a Singapore-origin filing of this era, no corporate co-applicant and no assignee on the US front page (Google Patents renders both "Original Assignee" and "Current Assignee" as simply Individual).

Employer inference (not a recorded fact). Mok's contemporaneous filings — same inventor group, same 2002 Singapore/GB-origin filing window — are US 2002/0129485 A1 and AU 2002236031 ("A prototype production system and method", filed 2002-02-27), both naming Milling Systems and Concepts Pte Ltd (Singapore) as applicant, and AU 2002249415 ("A health-care system") naming MSC Healthcare Pte Ltd with the same inventor group (Bong Teck Keong, Chong Yew Hing, Mok, Poh Soon Teong, Toh Da Jun). That makes Milling Systems and Concepts / MSC Healthcare the most likely place of employment. But the security-system invention itself was filed by Mok personally with no assignment to either company — a divergence worth flagging. It is consistent with the invention being made outside the employer's business, or with the employer never perfecting title; it is not evidence of an NPE pattern.

Unusual pattern flags:

• No employer assignment on a work-product portfolio — the inverse of the "all inventors depart and the portfolio is sold" pattern. Nothing here suggests a fire-sale pipeline.
• Name collision in a foreign office record, not ownership evidence. IP Australia's page for the AU counterpart (AU 2002247857) lists the "assignee/s" as HOARTON, Lloyd Douglas Charles and MOK, Steven Siong Cheak. Lloyd Douglas Charles Hoarton is a registered European patent attorney (Forrester & Boehmert, Munich; Forresters, UK), and the identical name appears as representative on numerous unrelated EP/WO filings (e.g., EP 1 580 533, EP 1 825 419, and Qatar Foundation PCT filings). This is an agent-indexing artifact in the AU register, not co-ownership by Hoarton. I flag it only because a naive reading of that page would fabricate a co-owner; I do not treat it as a conveyance. (Uncertainty: I could not retrieve the WO 2003/044730 A1 cover sheet to read the applicant block verbatim.)
• Family attrition, not personnel attrition: the AU national phase never entered and lapsed 2004-08-05; the PCT is recorded as "Ceased." There is no personnel-departure data available for a one-person, privately held Singapore portfolio.

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Original assignee

None — the patent issued with the inventor as applicant/owner. There is no "(73) Assignee" entity on the issued patent, and Google Patents reports Original Assignee: Individual / Current Assignee: Individual (the tool itself marks the assignee list as possibly inaccurate).

• Entity: Steven Siong Cheak Mok, individual, Singapore.
• Products embodying the claims: No evidence of any. Searching the family record surfaces no commercial security-management product tied to this patent. The system is described aspirationally in the specification ("blanket coverage", "portable readers") with no commercial embodiment documented.
• Primary line of business: For the inventor, contemporaneous records point to Singapore engineering/healthcare-IT ventures (Milling Systems and Concepts Pte Ltd; MSC Healthcare Pte Ltd), not a security-systems manufacturer.
• Current status: Patent expired — lapse for failure to pay maintenance fees effective 2013-02-03 (Google Patents legal events: REMI 2012-09-17; LAPS 2013-02-03; STCH 2013-03-04; FP 2013-03-26). AU counterpart lapsed 2004-08-05 (did not enter national phase); PCT Ceased. There is no bankruptcy, dissolution, or M&A record for a US-registrable assignee, because there is no corporate assignee. No SEC 10-K / 8-K cross-reference is possible: both candidate employing entities are Singapore private companies and non-SEC registrants.

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Assignment timeline

There are no recorded assignment (conveyance) events for US 7,487,538 that I could retrieve. Stated plainly: the patent's Google Patents legal-events table contains only post-issuance maintenance-fee events and no "AS" (assignment) entry, and no assignment, reel/frame, or correspondent appears anywhere in the retrieved record. Web searches for 10/046,042, US7487538, and the inventor name returned no assignment-center, PEDS, or ESPACENET title-change entries.

Consequently: no shell-entity transfer, no security agreement, no merger, no change of name, no license, no release, no correction is on record that I can cite. The only "transfer"-like event anywhere in the family is the indexed AU applicant field discussed above, which I have treated as an agent artifact rather than a conveyance.

Per the task instruction, this is the point at which the assignment section normally stops. I am continuing with the remaining sections in shortened form because the absence of any chain is itself the dispositive input to every NPE signal and the verdict — but every row below is driven by non-records, not by a reel/frame.

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Timeline diagram

timeline
    title Ownership of US 7487538
    2001 : Application filed by Steven Siong Cheak Mok
         : No corporate assignee named
    2003 : Pre-grant publication
         : PCT counterpart published
    2004 : AU counterpart lapsed
    2009 : Patent issued to Mok as individual
    2012 : Maintenance fee reminder mailed
    2013 : Patent lapsed for non-payment

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NPE / troll-pattern signals

Because there is no assignment chain, every signal that requires a transfer is inert. I mark each per the rubric and cite what exists (post-issuance legal events) rather than naming non-existent reel/frames.

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Verdict

Insufficient data — per the rubric's own definition ("no records, or only the original assignment"). Justification: the record shows no post-issuance assignment of any kind for US 7,487,538; the only events after grant are the maintenance-fee sequence REMI 2012-09-17 → LAPS 2013-02-03 → STCH 2013-03-04 → FP 2013-03-26, with title remaining with the individual inventor, Steven Siong Cheak Mok, and the patent expiring in 2013 without ever being asserted. In plain terms this is not an NPE situation: all eight NPE signals are absent or untestable for want of a chain, the AU counterpart lapsed before grant (2004-08-05) and the PCT ceased, so there was no family to monetize. The rubric label is "Insufficient data" only because there is no conveyance to analyse — not because ownership is genuinely ambiguous. The one thing a reader should not do is mistake IP Australia's "HOARTON / MOK" applicant field for a co-ownership transfer; Hoarton is a European patent attorney and that field is an agent-indexing artifact.

Verification links (manual query recommended, since these are interactive):

• USPTO Assignment Search: https://assignment.uspto.gov/patent/index.html (search patent number 7487538; also https://assignmentcenter.uspto.gov/)
• USPTO Patent Center (prosecution/ownership documents): https://patentcenter.uspto.gov/
• Google Patents legal events for this patent: https://patents.google.com/patent/US7487538/en (Legal Events tab shows the maintenance-fee-only sequence above)

Residual uncertainty: I could not execute a live Assignment Center query or retrieve front-page assignment/reel data for this patent, and I could not pull the WO 2003/044730 A1 cover sheet to confirm the PCT applicant block. Anyone relying on this for a title opinion, a standing analysis, or a freedom-to-operate review should re-run the three links above directly.

I'll verify the cited references against live sources before mapping them to the claims. Running targeted searches on the most substantive citations.

Good detail. Let me verify the remaining key citations and the foreign family references.

Prior-Art Analysis — US 7,487,538 B2 ("Security system")

0. Target confirmation (number interpreted literally)

A search for the identifier 7487538 returns, in the USPTO/Google Patents databases, exactly one U.S. patent of that number:

No similar-number collisions (e.g., JP 特許7487538, the IEEE DOI 10.1109/ICRA.2016.7487538, or the Italian administrative order 7487538) are treated as this patent. I did not auto-correct the number.

Methodological caveat: my live-search budget was exhausted partway through this task, so the master list of citations below is taken from the authoritative front page of the patent itself (the "Patent Citations (16)" and "Family Cites Families (6)" tables). I independently verified the substance of five of the most important references via live search (US 5,629,981; US 4,952,928; US 5,787,174; US 6,512,478; US 6,958,677). Dates shown are the filing/priority date and grant/publication date as listed on the patent face.

1. Legal framing — a necessary caution before the mappings

Two points must be stated up front, because they materially change the answer:

1. Patent 7,487,538 has a 2001 priority date, so pre‑AIA 35 U.S.C. § 102 governs. Every reference below was filed before 2001‑11‑19, so each qualifies as prior art — mostly under § 102(a)/(b) (printed publications/patents before the invention) and, for the references granted after 2001 but filed before it (e.g., US 6,744,811; US 6,958,677; US 7,054,296), under § 102(e) as of their U.S. filing dates.
2. Anticipation (§ 102) requires a single reference to disclose every element of a claim, arranged as claimed. The granted independent claims 1 and 21 contain a very specific combination: (i) a secure area with "regions requiring different access authority"; (ii) a processor that consults an access database to decide whether the carrier is authorized in the region corresponding to the interrogating reader; and (iii) "following a positive authorization," the processor sends a replacement unique identifier that the transponder writes over its stored identifier. No single cited reference discloses all of (i)–(iii). On the record, none of the 16 U.S. references, alone, anticipates claim 1 or claim 21. They are better characterized as § 103 combination/background references, and the strongest § 102 exposures are against the narrower dependent claims. I flag this explicitly rather than force an anticipation label the references do not support.

2. The 16 U.S. patent references (as cited on the patent face)

3. Foreign family citations ("Family Cites Families (6)")

4. Non-patent citation (1)

• American Heritage College Dictionary, 4th ed., Houghton Mifflin, 2002, p. 1085. This is a claim-construction citation, not prior art for § 102 purposes. Its presence on the face of the file indicates the examiner/attorney litigated the ordinary meaning of a term (most plausibly "reader," "writer," or "replacement") during prosecution.

5. Claim-by-claim § 102 exposure summary

6. Bottom line

• Most relevant prior art: US 5,629,981 (TI/Nerlikar) is the single most pertinent U.S. reference — it is the only cited reference that combines authorizing interrogation with writing back to the RFID badge. It is followed in importance by US 4,952,928 (B.I. Inc.) and US 6,512,478 / US 6,958,677 for the location-and-authorization elements, and US 5,787,174 (Micron) plus FR 2455320 for the "replaceable identifier in re-writable memory" element.
• No cited reference anticipates independent claim 1 or 21 as granted. The novelty conferred by the granted claims resides in the combination of region-specific access authority and the automatic replacement of the unique identifier upon positive authorization — a feature the cited art approaches (US 5,629,981; US 5,787,174; FR 2455320) but never assembles in one disclosure.
• Strongest genuine § 102 exposures lie in the dependent claims — particularly claims 7–9 (location), 12 (image capture), 13–15 (card reader/writer + rewritten memory), 17 (carriers), and 20 (motion-triggered reader).
• Verification limits: I could not complete live re-verification of all 16 references (search budget exhausted), and I did not retrieve the underlying USPTO Image File Wrapper, so the examiner-vs-third-party designation of each citation and the precise § 102/§ 103 rejections actually raised are inferred from the patent face and five verified records, not from the signed Office Actions. Confirm against USPTO Patent Center (application 10/046,042) for the authoritative rejection record.

I'll research the key prior-art references cited on this patent's page to ground the §103 analysis.

Let me gather details on the remaining key references.

Obviousness Analysis — US 7,487,538 B2 under 35 U.S.C. § 103

Patent under analysis: US 7,487,538 B2, "Security system," app. 10/046,042, filed/priority 2001-11-19, granted 2009-02-03, inventor Steven Siong Cheak Mok.
Governing law: The application was filed before 2013-03-16, so pre-AIA § 103(a) governs. This matters: references that issued after the 2001-11-19 filing date (e.g., US 6,512,478; US 6,513,015; US 6,958,677; US 7,054,296) still qualify as prior art under pre-AIA § 102(e) if their filing/priority dates precede 2001-11-19 — which they do.

Source of prior art: the "Patent Citations (16)," "Family Cites Families," and Non-Patent Citations lists appearing on the patent's own Google Patents page (https://patents.google.com/patent/US7487538/en). Per the task instruction I am using only the references flagged in the Prior Art section of that page, not newly-hunted art.

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0. Evidence-quality disclosure (read before relying on any row)

I was able to retrieve and verify full or partial text/abstracts for: US 5,629,981 (Texas Instruments), US 5,787,174 (Micron), US 6,512,478 (Rockwell), US 6,397,334 (IBM), and FR 2455320 B1 (Cii Honeywell Bull). For the remaining cited references I have only the title/date/assignee from the citation table plus general field knowledge; where I rely on those I flag the proposition as inferred from the title, not verified text. I ran out of tool budget before pulling abstracts for US 4,691,202, US 4,746,830, US 4,952,928, US 6,958,677, US 6,513,015, DE 19622721 C2, and the JP references. Treat those rows as a research plan requiring verification, not as established content.

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1. What must be taught (element map for claims 1 and 21)

Limitations A–H are the classical 1990s RFID access-control architecture. Limitation I (the per-verification re-key) is the only genuinely narrow element, and it is exactly where the obviousness fight will be.

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2. Primary obviousness combination

Combination 1 (strongest): TI '981 ⊕ Micron '174 ⊕ FR '2455320 ⊕ Rockwell '478

Ref 1 — US 5,629,981 (Nerlikar / Texas Instruments), "Information management and security system," 1994-07-29, issued 1997-05-13.
Verified abstract and specification excerpts (https://patents.google.com/patent/US5629981, https://www.freepatentsonline.com/[5629981](/patent/5629981).html):

• "closed loop, (networked) information management and security system… for controlling access, transmission, manipulation, and auditability of high value information comprising an RFID transponder badge 302 and an RF reader transceiver 315."
• "The RF reader transceiver 315 automatically identifies and verifies authorization of the RFID transponder badge holder via a 'handshake' prior to allowing access to the host peripheral."
• "The RF reader/transceiver 315 writes the access transaction on either the RFID transponder badge 302 and/or the host peripheral database or the network controller."
• Host maintains "information authorization, usage, movement, and an upgrade/change log."
• Terminal devices are selected from a list including "electronic door mechanisms," printers, PCs, "personal digital assistants," ATMs, cellular phones — i.e., a facility whose terminal devices carry different access authorities.
• The means is a "read/write type radio frequency identification (RFID…)" transponder.
• "The RFID means may include electronic hardware and/or software encryption means to statically and dynamically 'encrypt' the authorized user identification code…"
• The RFID means "may further include stored biological data in ROM such as digitized voice signature, retina scan, fingerprints."
• Networking is via "a LAN, WAN, or MAN."

→ TI '981 supplies A, B, C, D, F, G, H, and the encryption/ biometric/actuator/network sub-elements of claims 4, 10, 12, 16, 19, 22. It is a single-reference, 102(e)/(b)-qualified teaching of a networked, database-mediated RFID access system with a read/write credential.

Ref 2 — US 6,512,478 B1 (Chien / Rockwell Technologies), "Location position system for relay assisted tracking," filed 2000-02-26, priority 1999-12-22.
Verified (https://patents.google.com/patent/US6512478, PDF at patentimages):

• Multi-level system of RF tags → relays → base station; "The relays may calculate the position of the tags by knowing the position of the relays… or may pass the information… to a base station."
• Explicitly frames the problem the '538 patent claims to solve: *"Such a system provides an identification of an RF tag in close proximity to a Tiris™ reader. It, however, provides no location information. Although the Tiris™ system can identify an RF tag, it cannot track it."*
• Notes prior LP systems using "motion sensors, heat sensors, or the like, for detecting the presence of an object or personnel."
• Explicitly contemplates tracked entities being "personnel, vehicles, or other objects."

→ Rockwell '478 supplies E (location = known reader/relay position) and, by its own words, supplies the motivation to bolt location-tracking onto an interrogation-based identity system. It also supports claim 17 (personnel/vehicle/hardware carriers) and claim 20 (motion-triggered sensing).

Ref 3 — US 5,787,174 (Micron), "Remote identification of integrated circuit," priority 1992-06-17, issued 1998-07-28.
Verified claims (https://patents.google.com/patent/[US5787174A](/patent/US5787174A), https://sumobrain.com/patents/us/Remote-identification-integrated-circuit/[5787174](/patent/5787174).html):

• Claim 4: "a re-writable memory integrated circuit for storing an identification number, including a write enable input to which an electrical signal must be applied in order to re-write the number stored in the memory with a specific new value."
• Claim 1/15: an RF transceiver that transmits the stored identification number in response to an RF interrogation signal.
• The device is embedded in a hardware product ("protecting a highly valuable first integrated circuit such as a microprocessor… for locating and identifying stolen integrated circuits").

→ Micron '174 supplies the "replaceable unique identifier in an interrogatable RF transponder" concept — the single most important gap-filler for limitation I. It is also the best §103 support for dependent claim 17 ("hardware product" carrier).

Ref 4 — FR 2455320 B1 (Cii Honeywell Bull), "Dispositif de recyclage de supports d'enregistrement identifiables à l'aide de données d'identification…," priority 1979-04-25, published 1986-01-24. (Family: JP S5638650 A, CA 1151298 A; related CII-Honeywell US patents such as US 4,295,041 "Chip card system" and the credit-card patent described as "a memory having first and second zones in which are respectively stored variable and fixed data.")
Verified title/abstract fields (https://patents.google.com/patent/FR2455320B1/en.pdf): recycling of identifiable recording media using identification data and erasable non-volatile monolithic memory.

→ FR '2455320 supplies the administrative rationale and the mechanism for re-writing the identification data on a card/recording medium so that the medium can be reissued — i.e., that a credential's ID data is intended to be replaced rather than being immutable. Its CII-Honeywell sibling art (variable zone vs. fixed zone in card memory) also directly supports dependent claim 2 (fixed unit identifier separate from the replaceable unique identifier) and claims 6/13–15 (contact-type card with terminal, written by a card reader/writer).

Why PHOSITA would combine 1+2+3+4 (KSR factors):

1. Express teaching in the art pointing at the gap. Rockwell '478's own background section states that the then-commercial Tiris interrogation system (a Texas Instruments product — the same corporate family as TI '981) "can identify an RF tag, [but] it cannot track it." That is a printed motivation to combine an interrogation/identity system with a reader-position tracking layer.
2. Known problem, known solution. TI '981 already writes to the badge with a read/write transponder. Micron '174 already teaches that the same RF-ID memory can be made re-writable with a new value. The '538 patent's re-keying is simply the use of TI '981's known write path with Micron '174's known re-writable ID memory. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), "[a] person of ordinary skill is also a person of ordinary creativity," and where a technique has been used to improve one device, applying it to a similar device is obvious.
3. Predictable result, no new function. Each element performs exactly its art-recognized function: reader interrogates (TI), reader position = tag position (Rockwell), card memory is rewritten (Micron/FR), database checks authorization (TI). A combination that does no more than "each element performing its known function" is obvious absent unexpected results.
4. Theft/counterfeit problem is expressly recited as the field's concern. Micron '174 is titled to locating stolen integrated circuits; FR '2455320 is about recycling credentials; TI '981 is about auditability of high-value information. The '538 patent's stated purpose ("drastically decrease[s] the chances of intrusion with a stolen card") is the same problem these references address, which supplies a common-purpose motivation.

Predicted claim chart for claim 1 under Combination 1

Conclusion: Every limitation of claim 1 (and of claim 21 in method form) is disclosed across four references in the same field, with an express motivation statement in Rockwell '478. This is the combination I would lead with.

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3. Alternative and secondary combinations

Combination 2 — Rockwell '478 (or GE '677) as primary + TI '981 + FR '2455320

Ref — US 6,958,677 B1 (GE Medical Systems Information Technologies), "Object location monitoring system," filed 2000-03-31, issued 2005-10-25. Not verified in this session — I have only the citation row. From its title and field, this is an RFID/object location monitoring system and is likely to disclose a location-monitoring network with an object database. Research flag: pull the '677 abstract before relying on this row. If it discloses zone-based authorization, it could serve as the primary reference for limitations A/E/G rather than Rockwell.
Motivation: same as Combination 1 — reader-anchored location is a substitute for relay-anchored location, and predictability of substitution is a §103 consideration.

Combination 3 — Fujitsu '015 / IBM '334 as primary for the image-capture limbs + TI '981 + FR '2455320

Ref — US 6,397,334 B1 (IBM), "Method and system for authenticating objects and object data," issued 2002-05-28, filed 1998 (per citation table 1998-12-17), priority pre-2001. Verified (https://patents.google.com/patent/US6397334/en):

• "structure and method which combines a camera and a reader (e.g., a radio frequency (RF) reader) that simultaneously records both an image of an object and a sequence of bits assigned to at least one tag."
• Identifiers "comprises… a radio frequency identification tag" (claim 24), "a biometric identifier" (claims 37/38 area), Smart Card, bar code.
• An "encryption device… wherein each of said first and second images are authenticated by encoding of the identification information… using one of a public key and a private key" (claim 15).
• Claims 28–30: the object may be "an inanimate object," "a motor vehicle," or "an animate object."

Ref — US 6,513,015 B2 (Fujitsu), "System and method for customer recognition using wireless identification and visual data transmission," priority 1998-09-25, issued 2003-01-28. Not verified — title-level only.

→ These references map to the specification's "immediate recognition unit… the image of the entire 'check-in' process… recorded by an image capture device 40 such as a CCD camera" and to dependent claim 12 (actuator → image capture device) and claim 16/22 (authentication device, biometrics). A PHOSITA implementing the '538 patent's check-in snapshot would, as a matter of ordinary design, deploy the IBM '334 camera-plus-RF-reader composite; the '538 patent claims nothing more than that composite in a security-system context.

Combination 4 — Regional access control arts as primary

Refs (title-level only, unverified text): DE 19622721 C2 (Megamos F&G Sicherheit, "Device and method for checking the authorization to use access control devices, in particular locking devices for vehicles," 1996), JP 3825917 B2 (Tokyo Electron Device, "Access control device," 1998), JP 2000-003492 A (Toshiba, "Access control device and access control system," 1998), JP 2001-117824 A (Casio, "Portable information terminal device and its program recording medium," 1999).
→ These are the closest art on limitations A, F, H (region-differentiated authorization checking, vehicle/access-device authorization). DE '19622721 in particular targets vehicle lock authorization, supporting claim 17's "vehicle" carrier. These must be pulled in full text before use; at present they are a lead, not proof.

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4. Dependent-claim obviousness map

Net: only claim 18 presents meaningful §103 risk under the cited art. Every other dependent claim is supported either by a verified reference or by a reference whose title alone makes the correspondence highly probable.

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5. Motivation-to-combine summary (for the office action / invalidity contention)

1. Express prior-art motivation: Rockwell '478 states the identity-without-tracking deficiency of the TI Tiris system. In re Kahn / KSR require a "reasoned rationale"; this is a printed one.
2. Same field, same problem: all four references address identification/authorization of tagged carriers, several expressly for theft deterrence (Micron '174), auditability (TI '981), and credential recycling (FR '2455320).
3. Predictable combination of known elements: interrogation (TI), reader-position inference (Rockwell), rewritable RF-ID memory (Micron), credential reissue/recycling (FR '2455320). Each performs its known function and yields only the expected aggregate result.
4. Design incentive / market pressure: the '538 specification itself concedes the prior art problem ("a stolen transponder can be used within the secure area and does not register as being stolen"), which is a judicial admission of the problem the art already recognized.
5. Reasonable expectation of success: TI '981 already had a read/write badge and a processor-driven write path; substituting a rewritable ID value for a transaction record is a routine programming/data-model change with no teaching away.

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6. The patent owner's best rebuttal, and how it fares

Rebuttal 1 — "No reference teaches re-keying as a consequence of a positive region-authorization determination."
This is the sharpest argument. TI '981 writes transactions to the badge; FR '2455320 rewrites IDs for recycling, not per-entry; Micron '174 teaches re-writability but not a database-driven rekey on authorized entry. The '538 owner will argue the specific sequencing (verify region authority → then push a new encrypted UID) is not disclosed.
Counter: under KSR, "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results." The sequencing is dictated by TI '981's own ordering ("identifies and verifies authorization… prior to allowing access" and then writes to the badge). Combining that order with Micron's re-writable ID yields precisely the claimed order. Assessment: the owner probably loses this argument, but it is the argument to prepare around, and it explains why the claim was amended to add "following a positive authorization" — the amendment appears designed to carve out mere read-and-log systems.

Rebuttal 2 — "Secondary considerations / nexus."
There is no apparent evidential support: the patent lapsed 2013-02-03 for non-payment of maintenance fees (legal events REMI 2012-09-17 → LAPS 2013-02-03 → STCH 2013-03-04 → FP 2013-03-26), the PCT counterpart WO 2003/044730 A1 is "Ceased," and the AU counterpart AU 2002247857 A1 is "Abandoned." No litigation, licensing, or copying evidence appears in any indexed source (consistent with the earlier litigation section). There is accordingly no commercial-success or industry-praise evidence in the record. Assessment: no meaningful secondary-consideration defense.

Rebuttal 3 — claim construction.
The presence of a non-patent citation — the American Heritage College Dictionary, 4th ed. (2002), p. 1085 — on the examiner's record signals a definitional dispute during prosecution over some term (most plausibly "transponder," "article," or "unique identifier"). This cuts both ways: if the patent owner successfully narrowed "unique identifier" by argument/dictionary during prosecution, prosecution-history estoppel may limit how broadly limitation I can be read, which helps an accused infringer; if the term is read broadly (any distinguishably coded value), it expands the prior-art coverage of TI '981's rewritten badge data. Either construction tends toward invalidity or non-infringement — the patent is squeezed from both ends.

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7. Confidence levels

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8. Recommended next steps for a complete record

1. Pull full text of US 6,958,677, US 6,513,015, US 4,691,202, US 4,746,830, US 4,952,928, DE 19622721 C2, JP 3825917 B2, and JP 2000-003492 A.
2. Target-claim 18 with a date-bounded search for automatic RFID credential expiry (the cited art does not appear to reach it).
3. Check the '538 prosecution history (app. 10/046,042) to identify the term the American Heritage College Dictionary citation was used to construe — this governs how limitation I is read and may itself supply prosecution-history estoppel.
4. Confirm the priority/filing dates of Rockwell '478's provisional (60/171,750, 1999-12-22) and of US 6,512,478's § 102(e) status relative to 2001-11-19.

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9. Bottom line

Every limitation of independent claims 1 and 21 is disclosed by US 5,629,981 (TI) in view of US 6,512,478 (Rockwell), further in view of US 5,787,174 (Micron) and FR 2455320 B1 (Cii Honeywell Bull), with an express motivation-to-combine statement found in Rockwell '478's own background ("[the Tiris system] can identify an RF tag… it cannot track it"). Dependent claims 2–17 and 19–22 fall with modest secondary references already on the examiner's citation list (IBM '334; Fujitsu '015; Norand '580; Ruppert '002). Only claim 18 (identifier expiry) is not adequately met by the cited art on the present record. The strongest residual invalidity risk is the argument that no reference teaches re-keying triggered by a positive region-authorization determination — but that sequencing argument is weakened by TI '981's own verify-then-write ordering and by the mechanical predictability of substituting Micron '174's re-writable ID into TI '981's known write path.

Caveat: this analysis rests primarily on the prior-art citation list from the patent's Google Patents page and on verified text for four of those references. Several rows are title-level inferences only and are flagged as such; they should be verified against full text before any invalidity contention or office action is finalized.