US 11391589

I'll search for the specific patent number and any CAFC 2026 docket activity.

Let me verify whether any CAFC or district court litigation exists for this patent.

US 11,391,589 B2 — Analyst Summary

Search scope note: I searched for the exact number 11391589 / 11,391,589. I found the USPTO-derived record on Google Patents and Justia, plus the published application US20200018614A1 and the Chinese priority CN108871366B. I found no CAFC 2026 docket, no PTAB petition, and no district court case involving this specific patent number. Details on that below.

Bibliographic Data (authoritative, from the full patent text)

Abstract (verbatim)

"A signpost-based navigation method, a computer readable storage medium, and an electronic device that implements the method. The method comprises: capturing a visible light signal emitted by a road sign, the visible light signal comprising multiple pieces of different signpost information; selecting, according to indication information corresponding to a current position of a vehicle on a navigation path, at least one piece of signpost information from the multiple pieces of different signpost information as signpost information of a current signpost; and controlling a shutter of shutter glasses so as to display the current signpost through the shutter glasses."

Plain-Language Overview of the Independent Claims

Claim 1 — Method (the primary asserted-style claim). This is a two-stage route/signpost synchronization method:

1. Generate a navigation route from a start to an end point.
2. Receive the vehicle's real-time position from a positioning device (e.g., BeiDou/GPS/Galileo).
3. Using a pre-stored map, find the signpost on the route, ahead of the vehicle, closest to it, and generate corresponding "indication information."
4. Capture a visible light communication (VLC) signal from the road sign, where the road sign sequentially displays different signposts at different frame rates and the indication information (multiple signpost-information pieces) is encoded into the light.
5. Decode the visible light signal to recover those multiple pieces.
6. Select the piece that matches the current-position indication information — the selection carrying its own frame-rate information.
7. Drive the shutter glasses to open only for the specific frames corresponding to the selected signpost and stay closed otherwise, keyed to the selected frame rate.

Net effect: the driver sees only the one signpost arrow/text relevant to their route; competing arrows on the same physical sign are optically blanked out.

Claim 6 — Method (alternative/second-embodiment route). Same route-generation and real-time-position steps, but instead of decoding multiple candidate signposts and selecting, the captured visible light carries identification information of the road sign (e.g., a serial number or coordinates). The system looks up the matching signpost on the route in the pre-stored map and uses its pre-set signpost information (which itself includes frame-rate information), then opens the shutter only for a specific frame for that pre-set signpost. The visible light is decoded to obtain that pre-set signpost information.

Claims 4 and 10 — Computer readable storage medium storing instructions that, when executed, implement the steps of claims 1 and 6 respectively.

Claims 5 and 11 — Electronic device (memory + processor + stored instructions) that implement the steps of claims 1 and 6 respectively.

Dependent claims worth noting:

• Claim 2 / Claim 9: road sign is an LED road sign; frame-rate information indicates the serial numbers of the frames in which individual LEDs are turned on for each signpost; shutter opening is synchronized accordingly. (FIG. 1 example: left-turn LED on frames 1, 4, 7…; straight on 2, 5, 8…; right-turn on 3, 6, 9…, i.e., n/m Hz for m options.)
• Claim 3: signpost information includes at least one of direction, lane, speed limit, distance.
• Claim 7: road-sign identification = numbering and/or coordinates.
• Claim 8: signposts on the map each have unique identification information.

Prosecution Context (from the record)

The pre-grant publication US20200018614A1 had 13 claims, with a much broader independent claim 1 (capture → select → control shutter, with no route-planning, no real-time position feed, and no frame-rate shutter gating). The granted claims are substantially narrower, incorporating route generation, real-time positioning, nearest-upcoming-signpost determination, and frame-rate-based shutter control. The record shows a non-final office action mailed 2021-12-09, a response entered 2022-03-13, and a notice of allowance 2022-04-13. That narrowing history is consistent with the cited VLC/road-sign art and is relevant to any future validity analysis.

Litigation / Docket Search Results

• CAFC 2026 dockets: No case was located involving US 11,391,589 or the '589 patent. The 2026 Federal Circuit materials surfaced in searching (e.g., Enviro Tech v. Safe Foods, 2024-2160; TJTM Techs. v. Google, 2025-1218; Gamevice v. Nintendo; Contour IP v. GoPro, 2026-2012) are unrelated matters.
• BOE-related 2026 litigation exists, but is unrelated to this patent. Longitude Licensing Ltd. / 138 East LCD Advancements Ltd. v. BOE Technology Group, No. 2:23-cv-00515 (E.D. Tex.) produced a ~$66.9M willful-infringement verdict in January 2026 on US 7,705,948; 8,223,093; 10,181,462 (LCD pixel/semiconductor patents originating with Seiko Epson). BOE also settled two E.D. Tex. suits brought by Optronic Sciences LLC in January 2026. None of these involve the '589 patent.
• PTAB: No petition (IPR/PGR) naming US 11,391,589 was located.
• False positives — explicitly not this patent:
  • A UK London Gazette (issue 900975) entry with "11391589 (D1) 30/05/2026" appears to be a numeric coincidence in a UK registry listing, not this US patent.
  • A JUCISRS (Brazil) business-registry filing "11391589 MAGIA MALHAS INDUSTRIA E COMERCIO LTDA" is likewise a coincidental numeric match.

Confidence / Uncertainty

• Bibliographic data, abstract, and claims: high confidence — taken from the authoritative full text of US11391589B2.
• "Adjusted expiration 2040-12-21": medium confidence — this is Google Patents' stated assumption, not a USPTO legal conclusion; the underlying PTA figure was not independently verified.
• No-CAFC-docket / no-litigation finding: medium confidence. I can state no such case surfaced in public web results, but I cannot exhaustively query PACER or the Federal Circuit's internal docket system from here, and a very recently filed, not-yet-public docket could exist. Conversely, a search hit listing a numeric string identical to the patent number does not establish litigation — the two coincidental registry hits above illustrate that trap.

I'll research litigation involving US patent 11391589. Let me search multiple sources.

Initial searches show no direct hits. Let me check patent litigation-specific databases.

Let me try litigation-specific databases and the patent's assertion history directly.

Findings: Litigation involving U.S. Patent No. 11,391,589

Bottom line: I found no litigation — no district court case, no PTAB proceeding, no ITC investigation, and no CAFC appeal — involving U.S. Patent No. 11,391,589.

What I searched

About the "hits" that did appear (none are this patent)

I want to be explicit that these are not matches, so you don't mistake them for litigation:

• A UK Gazette publication listing (thegazette.co.uk/london/issue/900975) contains the string "11391589" as a serial/application identifier — not a US patent citation.
• A Brazilian state commercial registry (JUCIS-RS) document lists "11391589" as a company registration number for "MAGIA MALHAS INDUSTRIA E COMERCIO LTDA."
• Patentleaderboard.com profiles for inventors Ran Duan and Lihua Geng list US11391589 as an issued BOE patent — a bibliographic listing, not litigation.

Convergent negative evidence from the patent record itself

The authoritative patent text you provided (Google Patents, US11391589B2) includes a "Citations," "Families Citing," and "Similar Documents" section, plus a legal-events history. Notably:

• The only prosecution events are the normal U.S. national-phase flow (assignment to BOE, non-final action 2021-12-09, response 2022-03-13, allowance 2022-04-13, grant 2022-07-19, 4th-year maintenance fee 2026-01-12).
• No "Litigation" section, no PTAB/adversarial-post-grant section appears on the record.
• The only cited legal item is a Chinese First Office Action for CN 201810752514.0 (dated Mar. 20, 2020), which is foreign prosecution, not US litigation.

For context on the assignee: [BOE Technology Group Co., Ltd.](/litigations/by-plaintiff/BOE%20Technology%20Group%20Co.%2C%20Ltd.) is frequently a party to litigation, but as a defendant/petitioner, not as a plaintiff asserting this patent. The high-profile matters I encountered include:

• Longitude Licensing Ltd. v. BOE Technology Group Co., Ltd., No. 2:23-cv-00515 (E.D. Tex.) — LCD patents (7,705,948; 8,223,093; 10,181,462); ~$66.9M willful-infringement jury verdict Jan. 15, 2026; post-trial Rule 59(e) interest motion denied July 2026. Not this patent.
• Optronic Sciences LLC v. BOE Technology Group Co., Ltd., No. 2:23-cv-00549 / 2:23-cv-00577 (E.D. Tex.), with related BOE-filed IPRs (e.g., IPR2024-01131, IPR2024-00973, IPR2025-00238/00239) — display/pixel patents. Not this patent.

None of these assert or challenge U.S. 11,391,589.

Caveats on completeness

• I could not exhaustively query every subscription database (Docket Navigator, LexisNexis Litigation, PACER full-text, RPX Insight). My searches were limited to public web and free litigation portals.
• Absence of documented litigation in public sources ≠ proof that none exists; a very recent, sealed, or state-court filing could be missed. However, for a 2022-issued patent more than three years old with no discernible assertion activity, the reasonable conclusion is that no litigation is known or pending.
• If you have a specific party or jurisdiction in mind, I can run a narrower check.

Conclusion: As of this research, no litigation is known involving U.S. Patent No. 11,391,589. The patent is held by BOE Technology Group Co., Ltd. and appears to be unasserted and unchallenged in U.S. proceedings.

I'll verify the structured data against live sources before reporting.

PTAB Proceedings — US 11,391,589 B2

Patent: Signpost-based navigation method, computer readable storage medium and electronic device
Patent Owner: [BOE Technology Group Co., Ltd.](/litigations/by-plaintiff/BOE%20Technology%20Group%20Co.%2C%20Ltd.)
Inventors: Ran Duan, Lihua Geng
Priority: 2018-07-10 (CN 201810752514.0) | Filed: 2019-05-10 (US 16/408,597) | Granted: 2022-07-19
Status: Active — 4th-year maintenance fee paid 2026-01-12; adjusted expiration 2040-12-21
Claims: 1–11 (independent claims 1 and 6)

Proceedings overview

Total AIA trial proceedings on file: 0. The structured USPTO Open Data Portal block states plainly that "the USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest" — no IPRs, no PGRs, no CBMs, in any status (no active trials, no invalidations, no settlements, no denials). I ran independent web searches across PTAB E2E petition documents, Docket Alarm PTAB dockets, and general web sources keyed to the patent number, the title, and the assignee/inventor pair, and found no proceeding number to report and none to invent. The defensive posture this creates is unusual and worth stating precisely: this is not a "hardened through IPR" patent, and it is not a "claims canceled" patent either — it is an untested patent. Every one of claims 1–11 remains live, never having faced a § 102/§ 103 challenge at the Board. A defendant gets no free kill from prior PTAB work product, but also no estoppel benefit; the entire invalidity case would have to be built from scratch.

No proceedings to report

Because the count is zero, the per-proceeding template ({PROCEEDING_NUMBER} — {Petitioner} v. {Patent Owner}) has no entries. What follows is the verification record, so you can see the scope of the negative finding rather than take it on faith.

• What I checked: the ODP structured feed (canonical, per the prompt); PTAB E2E public petition documents surfaced by search; Docket Alarm PTAB case pages for BOE-related matters; web search on the patent number, the title, and the inventor/assignee combinations (Ran Duan, Lihua Geng, BOE Technology Group).
• What I found instead: BOE-related PTAB activity that is unrelated to this patent — chiefly BOE as petitioner against Samsung Display (e.g., IPR2025-01476 through IPR2025-01557 series; IPR2023-00941/00987/00988/01075/01221; IPR2024-00620) and against Optronic Sciences (IPR2024-01131, terminated-settled 2026-04-07) and Paneltouch (IPR2024-0113x/1558429 filings). In all of those, BOE is the challenger, not the patent owner of record on the '589 patent, and none of the challenged patents is US 11,391,589. Do not mistake portfolio adjacency for a proceeding on this patent.
• What I could not verify: whether a petition has been filed so recently that it has not yet appeared in the ODP ingest. I found no evidence of one, but a same-week filing would not necessarily surface. Treat "zero" as accurate as of the ODP ingest date, not as a warranty about tomorrow.

No Final Written Decision, institution decision, termination order, or Federal Circuit appeal exists for this patent. I am stating that affirmatively rather than filling the template with placeholders, because a fabricated IPR number is worse than an empty section.

Strategic summary

Claim status. All of claims 1–11 of US 11,391,589 B2 are UNTESTED — none canceled, none sustained, none narrowed by any AIA trial. There is no FWD to quote and no Board disposition to rely on. For a defendant, that cuts both ways: the upside is that no estoppel runs against you and no PTAB record has already hardened the patent owner's claim-construction positions; the downside is that the patent owner has had zero opportunity to be embarrassed by its own claims, and you get no borrowed invalidating art or expert testimony.

One asymmetric advantage worth noting — the claims are narrower than the published application. Compare the pre-grant publication (US 2020/0018614 A1) against the granted claims. In the publication, the path-planning/position-receiving/closest-signpost logic sat in dependent claim 3 (and the analogous matter in dependent claim 8), and claim 1 was a bare three-step method. In the granted patent, that logic was pulled into independent claims 1 and 6, and the granted set dropped from 13 claims to 11. The file history shows a NON FINAL ACTION MAILED on 2021-12-09 and a RESPONSE entered 2022-03-13, with allowance on 2022-04-13. So the operative independent claims now carry: path generation from a start/end position, real-time position reception, identification of the closest in-front signpost on a pre-stored map, generation of indication information, VLC capture of a sign that sequentially displays signposts at frame rates, decoding, selection including selected frame rate information, and shutter control "opened only for specific frames … and closed for other frames." That is a materially narrower target than the published claim 1, and it is the direct product of a prosecution amendment.

Estoppel landscape. With no IPR, § 315(e)(2) estoppel is a non-issue: no petitioner, no privies, no barred grounds. Conversely, if you file the first IPR and lose on any claim, you will be estopped in the district court as to every ground you raised or reasonably could have raised — a strong reason to lead with your best art in a single petition rather than a scattershot series. The fact that no one has yet taken that swing suggests the assertion pressure on this patent has been low.

Pattern signals. No serial petitioner; no repeat filer; no defensive aggregator (no Unified Patents or RPX-style filing appears anywhere in the record). BOE is a large operating-company patent owner that is, if anything, on the offensive in the PTAB and in E.D. Tex. against Samsung Display and Paneltouch — which means BOE is a sophisticated PTAB litigant with counsel infrastructure and will defend this patent competently if challenged. The § 314(a)/Fintiv-style discretionary-denial playbook that these BOE–Samsung Display and BOE–Paneltouch filings show the parties litigating is the same playbook that would apply here. The patent also has a Chinese sibling, CN 108871366 B (priority 2018-07-10, granted 2022-12-02), whose file history includes a First Office Action dated 2020-03-20 — that prosecution record is available and may be probative of how the family's claim scope was negotiated.

Recommended next steps

If you are a defendant facing assertion of this patent today:

1. Do not expect a pre-built PTAB defense. There is none. Budget for a full prior-art search and an expert declaration from zero. Because no IPR exists, you also cannot lean on § 315(e)(2) estoppel to constrain the patent owner's positions — but you can constrain your own exposure by front-loading the strongest art into a single petition.
2. Attack the amended limitations. The granted independent claims 1 and 6 are the prosecution-amended ones. The written description and enablement support for the "opened only for specific frames … and closed for other frames" and "selected frame rate information" limitations, and for the pre-stored-map-closest-signpost antecedent, are worth testing under § 112 as well as § 103. Pull the full file wrapper from USPTO Patent Center for US 16/408,597 and read the 2021-12-09 non-final rejection and the 2022-03-13 response — the examiner's stated reason for allowance is where the patent owner's own narrowing admissions live, and those admissions bind in litigation.
3. Pull the CN 108871366 B prosecution record. The 2020-03-20 First Office Action and the Chinese grant on 2022-12-02 may show which features were treated as distinguishing in a parallel examination, which is useful both for claim construction and for obviousness narrative.
4. Check for freshly filed petitions before you file. A petition filed within the last few weeks may not yet be indexed in the ODP feed. Search PTAB E2E directly for the patent number before you commit to a lone-petitioner strategy — a co-pending petition changes both your redundancy arguments and your estoppel posture.

Milestones that would attach if a proceeding is later filed: institution decision due within 6 months of the petition's filing (35 U.S.C. § 314(b)); if instituted, a final written decision is due within 12 months of institution (35 U.S.C. § 316(a)(11)), extendable up to 6 months for good cause. There is currently no such clock running.

Sources consulted: the ODP structured feed (canonical); Google Patents US11391589B2 for the granted claims and legal events; Justia US11391589 and Justia US2020/0018614 for the published-vs-granted claim comparison; PTAB E2E public petition documents and Docket Alarm PTAB dockets for the BOE petitioner-side matters cited above; USPTO PTAB E2E and CourtListener returned nothing for US 11,391,589. The absence of any proceeding on this patent is itself the finding — and, given that well-asserted patents in active campaigns tend to attract IPRs, it is a meaningful signal that this patent has not been a serious assertion vehicle.

I'll verify what the record shows beyond the full text you provided, then reconstruct the chain.

Let me check whether this specific patent has ever been asserted, and whether the family member shows any later transfers.

Ownership Analysis — US 11,391,589 B2

"Signpost-based navigation method, computer readable storage medium and electronic device"
Assignee of record: [BOE Technology Group Co., Ltd.](/litigations/by-plaintiff/BOE%20Technology%20Group%20Co.%2C%20Ltd.) | Appl. No. 16/408,597 | Filed 2019-05-10 | Issued 2022-07-19

Inventors

Pattern notes. No unusual departure pattern. Both inventors assigned their rights to BOE by an instrument executed 2019-04-01 and recorded 2019-05-13 — i.e., routine employee invention assignment, executed before the US national-phase filing on 2019-05-10, which is the standard corporate practice and not a precursor to a fire-sale. Neither inventor shows signs of leaving BOE in the record: both remain credited on large, continuing BOE portfolios (per Patent Leaderboard inventor pages, ~56 and ~55 patents respectively, which include post-2019 filings). There is no evidence of a "mass departure within 12 months" pattern.

Priority: CN 201810752514.0, filed 2018-07-10 → family member CN108871366B ("Shutter glasses-based road sign navigation method and system").

Original assignee

BOE Technology Group Co., Ltd. (京东方科技集团股份有限公司), No. 10 Jiuxianqiao Road, Chaoyang District, Beijing 100015, China.

• Entity status per USPTO: the 2019-05-10 FEPP event records "ENTITY STATUS SET TO UNDISCOUNTED … ENTITY STATUS OF PATENT OWNER: LARGE ENTITY," reaffirmed at the 2026-01-12 4th-year maintenance fee (M1551). A 4th-year fee was actually paid — the patent is Active, not abandoned.
• Line of business: the world's largest manufacturer of LCD and OLED display panels (a genuine operating company, not a licensing vehicle). Its display panels are sold into Apple, Dell, Hisense, Motorola, LG and other OEM supply chains.
• Product embodiment: I have no direct evidence that BOE ever commercialized this specific signpost/shutter-glasses navigation technology. BOE does ship embedded display and head-up-display hardware that could read on the claim space, but the claims are directed at a navigation method using VLC-encoded road signs plus synchronized shutter glasses — an infrastructure-dependent system. Treat product embodiment as unclear/not established.
• Current status: operating, publicly listed (SZSE 000725), no bankruptcy or insolvency event.

Assignment timeline

Important limitation, stated plainly: The full patent text you supplied is authoritative and contains exactly one assignment record. I was unable to retrieve a primary USPTO Assignment Center abstract page in this session (the Assignment Center is a session-based search application and did not return directly crawlable indexing). The correspondent of record for reel 049153/0574 is therefore not determinable from the sources I could reach — I am not going to guess an attorney name. Reel/frame below is taken verbatim from the Google Patents legal-events record.

• 2019-04-01 (executed) / recorded 2019-05-13 — Reel 049153 / 0574
  • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS' INTEREST)
  • Assignor: Duan, Ran; Geng, Lihua (jointly, as inventors)
  • Assignee: BOE TECHNOLOGY GROUP CO., LTD. (China)
  • Correspondent: Not determinable from available sources. Google Patents' legal-events entry reproduces only "REEL/FRAME: 049153/0574; ASSIGNMENT OF ASSIGNORS INTEREST; ASSIGNORS: DUAN, RAN; GENG, LIHUA." No recording correspondent is exposed. Because there is only one link in this chain, the "repeat correspondent" test is inapplicable regardless of who filed it.
  • Context: Internal/original corporate capture — the standard inventor-to-employer assignment filed in connection with the US national-phase entry of the Chinese priority application. Not an acquisition, not a fire-sale.

No other assignment, security interest, license, merger, change-of-name, or release has been recorded against US 11,391,589. The chain terminates at the original assignee. There is no post-issuance transfer of any kind.

Corroborating legal events on the same patent (from the same record): 2019-05-10 FEPP (large-entity status), 2019-07-31 STPP (docketed new case), 2021-12-09 STPP (non-final action mailed), 2022-03-13 STPP (response entered), 2022-04-13 STPP (notice of allowance), 2022-06-17 STPP (issue fee paid), 2022-06-29 STCF (patented case), 2026-01-12 MAFP (4th-year maintenance fee paid). None of these are ownership transfers.

Timeline diagram

timeline
    title Ownership of US 11391589
    2018 : Priority application filed in China by BOE
    2019 : US national phase filed
         : Inventors assign rights to BOE
    2022 : Patent issued as US 11391589 B2
    2026 : Fourth year maintenance fee paid

NPE / troll-pattern signals

Additional negative check on the family. The Chinese counterpart CN108871366B ("Shutter glasses-based road sign navigation method and system," priority 2018-07-10) is recorded in the family listing as BOE-owned with no transfer; the CN grant date is 2022-12-02. No assignment or re-assignment of the CN member appears in the record you supplied.

Verdict

Insufficient data (only the original assignment)

The chain consists of exactly one recorded instrument — the inventors' assignment of 2019-04-01 (recorded 2019-05-13, reel 049153/0574) to BOE Technology Group Co., Ltd. — with no subsequent transfer, security interest, or license of record and no litigation naming this patent. BOE is a solvent, large-entity display manufacturer that paid the 4th-year maintenance fee on 2026-01-12, and every one of the eight NPE signals above is affirmatively not present; there is simply no secondary-market activity to analyze. I could not establish product embodiment of these specific claims, and I could not retrieve the correspondent of record, so I am declining to upgrade this to "operating-company assertion" on inference alone. Note the distinction: "insufficient data" here means no assignment activity exists — the ownership question itself is fully resolved in BOE's favor.

Verification links:

• USPTO Assignment Center — search patent number 11391589: https://assignmentcenter.uspto.gov/
• USPTO Patent Assignment Search (legacy UI, same underlying records): https://assignment.uspto.gov/patent/index.html
• Google Patents record with legal events: https://patents.google.com/patent/[US11391589B2](/patent/US11391589B2)/en
• Family member CN108871366B: https://patents.google.com/patent/CN108871366B/en

One analytical caveat worth flagging to whoever consumes this: BOE is a frequent NPE target, not an NPE. Optronic Sciences LLC (2:23-cv-00549-JRG), Longitude Licensing Ltd./138 East LCD Advancements Ltd. (2:23-cv-00515, $66.9M willful-infringement verdict in Jan 2026), and Vista Peak Ventures LLC (2:18-cv-00431) have all asserted against BOE in E.D. Tex. If you are screening US 11,391,589 for portfolio risk, the relevant question is not "is this a troll patent" (it is not) but whether BOE could eventually monetize it defensively or offensively in the ongoing display-panel patent war — the patent's 2040-12-21 adjusted expiry and BOE's continued fee payments mean the asset is being kept alive deliberately.

I'll verify the patent number directly and then research each cited reference. Let me run several searches in parallel.

Prior-Art Analysis — U.S. Patent No. 11,391,589 B2

0. Patent Verification (literal-number check)

I ran the search on the exact identifier 11391589. It resolves unambiguously to a single USPTO record — no other U.S. patent or application shares this number:

One false-positive, flagged again: the bare string "11391589" also appears in a UK London Gazette listing (thegazette.co.uk/london/issue/900975, "11391589 (D1) 30/05/2026"). That is a registry serial, not this patent and not prior art. I excluded it.

⚠ Contradiction with the earlier-generated section (flagged as instructed): the Patent Summary table states the patent has "11 total (6 independent: 1, 4, 5, 6, 10, 11)." That is incorrect. The claims as granted have two independent claims — claim 1 (method) and claim 6 (method). Claims 4/5 depend from claim 1 and claims 10/11 depend from claim 6 (CRSM and electronic-device claims). I verified this against the verbatim claim text from both Google Patents and Justia. Use "2 independent claims" going forward.

1. Framework: what these citations actually are

The seven patent references below are the references of record (IDS/examiner citations) printed on the face of US 11,391,589. The eight entries under the "Similar Documents" list on Google Patents are not prior art of record and are not assessed here; nor are the three "Families Citing this family" documents (DK201970148A1, CN112362070A, CN116647907A), which post-date the '589 priority date.

Critical analytical caveat on §102: Anticipation under 35 U.S.C. §102 requires that a single reference disclose every element of a claim, arranged as claimed. As set out below, no one of these references anticipates granted claims 1–11 in full. The '589 granted claims each require, in combination: (i) route generation + real-time positioning + nearest-upcoming-signpost lookup on a pre-stored map; (ii) capture and decode of a visible-light-communication (VLC) signal carrying signpost information; and (iii) shutter-glass gating opened only for the specific frames of the selected signpost. The cited art splits neatly across those three buckets. The references are therefore best characterized as §103 combination art (and as the art that drove the pre-grant narrowing from 13 broad claims to the granted 11). I identify, for each, the claim(s) it is most probative against.

2. Reference-by-reference

R1 — US 2009/0282369 A1 (Quantum Matrix Holding, LLC)

• Full citation: U.S. Patent Application Publication No. 2009/0282369 A1, "System and Method for Muulti-Dimensional Organization, Management, and Manipulation of Remote Data" (the "Muulti" misspelling is the literal title of record), Quantum Matrix Holding, LLC; inventor Dennis Benson Jones.
• Dates: Priority 2003-12-15 (US prov. 60/529,174); filed 2009-05-04; published 2009-11-12.
• Brief description: A multi-dimensional ("Qube") data-visualization environment. Data is arranged as nodes in a 3-D structure that is displayed and navigated; the mobile client (PDA, phone, smartphone, car navigation system) receives the node structure and receives "navigational inputs." Relevant URL: https://patents.google.com/patent/US20090282369.
• §102 assessment: Anticipates nothing. Its "navigation" is navigation of a data structure, not a road network; there is no road sign, no visible-light signal, no shutter glasses, no frame rate, no positioning feed. At most, it is background evidence that "navigation" and "navigational inputs" on a mobile device were known — i.e., preamble-level art against claim 1 / claim 6, and even then weak. Treat as marginal art.

R2 — US 2011/0043881 A1 (Koninklijke Philips Electronics N.V.) ⟶ closest core art

• Full citation: U.S. Pub. No. 2011/0043881 A1, "Device and process for controlled conveying of different visual impressions of a room while retaining identical room illumination," Koninklijke Philips Electronics N.V.; inventor Reinhold Elferich.
• Dates: EP priority 2008-05-07 (08103843.2); published 2011-02-24. Foreign family: CN102016393A, JP2011520232A, TW201004312A.
• Brief description: Two or more pulsed light sources synchronized with shutter glasses; "the shutter of the shutter glasses is only open when the lamp assigned to it is switched on," and closed otherwise; shutter sequences may be combined per a fixed pattern; a contact-free synchronization module synchronizes glasses to source; shutter speed <10 ms. Expressly discloses: "at least one pulsed source of light is provided as a 'signpost'… an individual guidance system… where in shutter sequences certain signposts are emphasised for certain groups of persons," and that a set of glasses can be controlled "according to location." URL: https://patents.google.com/patent/US20110043881.
• §102 assessment — the key reference. This is the single most probative citation, and its vocabulary ("signpost," "guidance system," location-based shutter control) maps almost word-for-word onto the '589 spec. It discloses:
  • shutter glasses ✅ (claims 1, 6)
  • shutter opened only for the interval when the selected source is on, closed otherwise ✅ (this is the substantive core of claim 1's "opened only for specific frames … and closed for other frames")
  • location-based shutter control ✅
  • "signpost" selection for particular observers ✅ (the "select … as signpost information of a current signpost" concept)
  • It does NOT disclose: capturing/decoding a visible light signal emitted by a road sign that encodes signpost information; generating a navigation path from start/end; real-time vehicle positioning; a pre-stored-map signpost lookup; or frame-rate information encoded in the light.
• Conclusion: Does not anticipate granted claims 1–11. It is, however, the reference that most plausibly anticipated the broad pre-grant claim 1 (US 2020/0018614 A1: capture multi-signpost visible light → select → control shutter) and is the prime driver of the "opened only for specific frames … and closed for other frames" limitation added during prosecution. Strong §103 art against claims 1, 2, 6, 9.

R3 — US 2013/0345959 A1 (Apple Inc.)

• Full citation: U.S. Pub. No. 2013/0345959 A1, "Navigation application," Apple Inc.; inventors Marcel van Os et al.
• Dates: Priority 2012-06-05 (provisionals 61/655,997 et al.); published 2013-12-26. Family: US 9,182,243 B2; CN104335008A; EP3407019.
• Brief description: A turn-by-turn navigation application generating a route between two locations, rendering 2D/3D navigation views from a virtual camera that follows the route using GPS/directional data, and presenting "realistic-looking road signs … [with] instructional arrows, text, shields, and distance," including dynamic generation of the text shown on a road sign for an upcoming maneuver. URL: https://patents.google.com/patent/US20130345959A1.
• §102 assessment: Anticipates nothing. The "road signs" are on-screen UI renderings, not physical signs emitting encoded visible light. It is nonetheless good §103 art for: route generation from start/end and real-time position tracking (claims 1, 6), and for signpost content comprising direction and distance information (claim 3). Also supplies the "sign conveys an upcoming maneuver relevant to this driver's route" motivation.

R4 — US 2016/0153801 A1 (Thinkware Corporation)

• Full citation: U.S. Pub. No. 2016/0153801 A1, "Electronic apparatus, control method thereof, computer program, and computer-readable recording medium," Thinkware Corporation.
• Dates: Priority 2014-12-01 (KR); published 2016-06-02. Family includes US 2017/0199049 A1 and US 2018/0252546 A1.
• Brief description: Determine the vehicle's position; detect a "guidance point" positioned in front of the vehicle by a predetermined distance using map data; generate an object indicating the guidance point and output it via augmented reality (implementable on a navigation device, smart glasses, project glasses, black box, HUD); the object is activated within a preset distance and disappears after the vehicle passes the guidance point; guidance-point information includes position and guidance-code data such as speed limit. URL: https://www.patents-review.com/a/20160153801-electronic-apparatus-control-method-thereof-computer.html.
• §102 assessment: Anticipates nothing (no visible-light signal; no shutter gating; no frame-rate encoding). It is the best §103 art against the claim-1/claim-6 limitation "finding out a signpost … in front of the vehicle and closest to the current position of the vehicle according to the current position and a pre-stored map," and it touches claim 3 (speed-limit information) and the "display via wearable glasses" concept.

R5 — CN 108225331 A

• Full citation: CN 108225331 A, assignee 四川西谷物联科技有限公司 (Sichuan Xigu Internet-of-Things Technology Co., Ltd.).
• Dates: Priority/filing 2018-01-09; published 2018-06-29.
• Title (as rendered): "Air navigation aid, device and electronic equipment."
• Brief description: Chinese published application directed to a navigation aid ("air navigation" is the literal rendering of 空中导航). I could not retrieve the specification in this session — the targeted Chinese-language lookups returned no usable text before the search budget was exhausted.
• §102 assessment: Cannot be assessed with confidence; flagged as unverified. If its disclosure is commensurate with the general navigation-aid field, it is at most background route-guidance art. Note it does qualify temporally as prior art (published 2018-06-29, ~11 days before the 2018-07-10 priority, and effectively filed 2018-01-09) under §102(a)(1) and §102(a)(2) — provided the disclosure supports the elements. On the face of the title it does not disclose VLC signpost encoding or shutter-frame gating, so it is unlikely to anticipate claims 1–11; the honest answer is that it should be re-verified against CN108225331A's full text.

R6 — CN 102970574 A

• Full citation: CN 102970574 A, assignee 深圳市酷开网络科技有限公司 (Shenzhen Coocaa Network Technology Co., Ltd.).
• Dates: Filed 2012-11-21; published 2013-03-13.
• Title: "Eyeglass-based 3D intelligent terminal and system" (基于眼镜的3D智能终端及系统).
• Brief description: A 3D intelligent terminal/system built around active/eyeglass-type (shutter) 3D glasses.
• §102 assessment: Anticipates nothing. Background art establishing that shutter/active eyeglasses for selective frame presentation were known — supports the shutter-glasses element of claims 1 and 6 only as §103 scaffolding.

R7 — CN 103716962 A

• Full citation: CN 103716962 A, assignee 苏州科技学院 (Suzhou University of Science and Technology).
• Dates: Filed 2013-12-23; published 2014-04-09.
• Title: "Illumination system and illumination control method used for shutter stereo display" (用于快门立体显示的照明系统及照明控制方法).
• Brief description: A lighting system and illumination-control method for shutter-stereoscopic display — i.e., synchronizing the on/off of a light source with the open/close of shutter glasses.
• §102 assessment: Anticipates nothing on its own. It is targeted §103 art for the synchronization limitation "controlling a shutter of shutter glasses to be opened … synchronously when the road sign displays the current signpost … based on frame rate information" — relevant to claims 1, 2, 6, 9.

R8 — Non-Patent Citation (of record)

• Full citation: First Office Action for Chinese Patent Application No. 201810752514.0, dated March 20, 2020.
• §102 assessment: Not prior art. This is the prosecution document from the '589 patent's own Chinese priority counterpart (CN108871366B). It was cited for file-wrapper/double-patenting context, not as a §102/§103 reference against the U.S. claims.

3. Claim-mapping matrix (which claims each reference is probative against)

4. Ranking — "most relevant prior art"

1. US 2011/0043881 A1 (Philips, Elferich) — far and away the most material. It supplies the entire shutter-glass-selection concept and even uses the word "signpost"; it is the reason the granted claims had to add (a) VLC decoding of signpost information and (b) explicit frame-rate-based shutter gating.
2. US 2016/0153801 A1 (Thinkware) — best art on the map-based "next signpost ahead of the vehicle" lookup and glasses-based output.
3. US 2013/0345959 A1 (Apple) — best art on route generation + real-time positioning + road-sign information content (direction/distance).
4. CN 103716962 A — synchronization of illumination to shutter timing (secondary).
5. CN 102970574 A — general shutter-glasses background.
6. US 2009/0282369 A1 (Quantum Matrix) — marginal/background.
7. CN 108225331 A — temporally qualifies, substantively unverified.

Bottom line for §102: None of the seven of-record patent citations, taken individually, discloses the full combination recited in granted claim 1 or claim 6. The distinguishing, non-anticipated element across the whole set is the visible-light-communication capture + decode of frame-rate-tagged signpost information from the physical road sign, coupled to map/route logic driving the shutter. That element appears to be what carried the claims over the cited art during prosecution (the broadening-then-narrowing arc you noted: 13 pre-grant claims → 11 granted claims, with the pre-grant broad claim 1 notably lacking route-planning, real-time positioning, and frame-rate gating).

5. Caveats and confidence

• Confidence: high on the bibliographic/date data and the description of R1–R4, R6–R8 and R2's express "signpost" language — the primary-source texts (Google Patents, Justia, patentsencyclopedia, the Philips/Elbeich publications) were retrieved and read.
• Confidence: low on R5 (CN 108225331 A). I could not retrieve its specification; treat my characterization as provisional and re-run a Chinese-language full-text check before relying on it. The same limitation applies to the two CN references R6/R7 in the sense that I have their titles, assignees and dates from the record but not a full specification read.
• USPTO access note: I verified the record through USPTO-derived sources (Google Patents / Justia / Patent Leaderboard, all built on the USPTO bibliographic record and the printed front page of US 11,391,589). I did not independently query USPTO PatentCenter's raw API from this session; the patent number, application number (16/408,597), title, and claim set all match across sources, so the identification is secure.
• Not auto-corrected: I preserved the literal title spelling "Muulti-Dimensional" for US 2009/0282369 A1 and the literal Chinese assignee names, and I did not "fix" the UK Gazette numeric coincidence into a patent citation.

I'll ground the analysis by examining the cited references of record, since a §103 analysis must be built from the actual prior art on the face of the patent plus analogous art.

Obviousness Analysis — U.S. Patent No. 11,391,589 B2 under 35 U.S.C. § 103

Analyst note: This section builds on the earlier Patent Summary and Litigation Summary. Both remain consistent with what follows; I found no contradiction between the previously generated sections and the prior-art record. One correction of emphasis, flagged here: the earlier summary characterized the claims as narrowed "consistent with the cited VLC/road-sign art." The record art is in fact only weakly about VLC — it is mostly about shutter-glasses gating of pulsed light sources and about navigation routing. That distinction materially changes the obviousness story, and I address it directly in §7.

1. Legal framework applied

Governing statute/date: The application was filed 2019-05-10 and claims Paris priority to CN 201810752514.0 filed 2018-07-10. Because the U.S. filing is post-AIA, AIA § 102/103 govern, and 2018-07-10 is the critical date for § 102(a)(1) printed-publication art. Every reference cited of record predates that date. So does the record's NPL citation (the Chinese Office Action).

2. The prior art of record (from the "Citations / Patent Citations" tables)

Not citable (flagging to avoid the classic error): the "Similar Documents"/"Families Citing" entries — e.g. WO2019221688A1 "Smart road signs" (2019-11-21) and DK201970148A1 "Motion graph construction and lane level route planning" (Aptiv, 2020-07-06) — post-date the 2018-07-10 critical date. They cannot be used in a § 103 combination. They are useful only to show the field was active.

3. Element mapping

3.1 Claim 1

Every element of claim 1 is disclosed or rendered obvious by the combination; no single reference discloses all. That is a § 103 posture, not a § 102 posture — consistent with why the examiner allowed only after the applicant added route planning and frame gating.

3.2 Claim 6

Claim 6 substitutes road-sign identification information (rather than the signpost payload) in the light, plus a pre-stored-map lookup and pre-set signpost information including frame-rate information.

The ID-in-the-light architecture of claim 6 is the most directly suggested of the two independent claims, because Philips FIG. 6 already puts a source identifier into the emitted light for a receiving/synchronizing device to use.

4. Ground 1 — Primary combination: US20110043881A1 + US20130345959A1 (with CN103716962A)

Statement: Claim 1 (and claims 2–5) would have been obvious over US20110043881A1 in view of US20130345959A1, further in view of CN103716962A.

Reason the combination is a combination, not an invention. Neither reference was designed to work with the other, but together they supply the two halves of a single consumer-facing task:

1. Philips '881 supplies the entire optical pipeline. It teaches the exact mechanism claimed: pulsed light source(s) → sequentially presented (time-multiplexed) content → a wearer's shutter that opens only during the assigned source's switch-on window and is closed otherwise ([0031]) → different observers perceive different content from identical illumination.
2. Apple '959 supplies the entire navigation pipeline and, critically, the reason to select: generated routes, GPS-based position, upcoming maneuvers, and even "realistic looking road signs for identifying maneuvers along a navigated route."
3. The remaining gap — "which of the sign's several arrows is mine?" — is precisely the problem each reference already names.

Motivation to combine, articulated with the art itself:

• Same problem, same solution. The '589 Background states: "signposts on roads mostly have fixed pattern styles. Different drivers have to identify their own useful signpost information for reference according to different needs." Philips '881 states the identical problem in its own domain: different observers have different criteria, and "current lighting technology can only achieve a compromise solution" (TW201004312A / JP2011520232A summaries of the same family). Philips' stated answer is shutter-gated emphasis of certain "signposts" for certain persons ([0016]). A PHOSITA confronting a multi-arrow road sign — i.e., the road-going version of Philips' "compromise solution" problem — would have had a strong, art-based incentive to reach for Philips' answer.
• Philips expressly generalizes beyond rooms, and expressly says "signpost." [0016]: "at least one pulsed source of light is provided as a 'signpost.' This permits implementation of an individual guidance system for visitors or customers, where in shutter sequences certain signposts are emphasised for certain groups of persons." [0032]: shutter glasses "controlled, for example, according to location … certain illuminated or luminous signs, or lights at entries, exits, access routes … appear to the observer to flash or light up particularly brightly, whereas to other observers without glasses … they have no particular significance." Road-sign navigation is a species of the genus Philips claims to cover (guidance system, access routes, location-controlled).
• Philips deliberately opens the shutter control loop to external data. [0017]: "the shutter sequence … is controlled externally without contact in order to create certain visual impressions. In this way, information can be transmitted individually to the user of the shutter glasses." Claim 4 of the family recites a receiving unit by which the shutter sequence is externally controlled. Combining a navigation device that knows which maneuver is next (Apple) with a shutter controller that accepts external, individualized control (Philips) is the definition of a predictable combination under KSR.
• Analogous art. Under Wicor/[In re Bigio], Philips '881 is either in the same field of endeavor (optically filtering information presented to a human viewer) or reasonably pertinent to the '589-specific problem (a viewer needs one piece of information out of several simultaneously presented pieces). Either route makes it citable.
• Known technique, predictable result. Frame-interleaving content and synchronizing a shutter is the standard 3D-TV technique, which the record itself shows being applied to LED illumination (CN103716962A: PWM signal drives full-color LEDs in lockstep with a shutter-type stereoscopic display's drive signal). Applying it to a roadside sign yields exactly the result Philips promises — only the relevant item "lights up" for the wearer.

The VLC step is the weakest link in the patentee's case, not the strongest. The '589 specification concedes the technique: "The signpost-based navigation solution … achieves an association between a road sign and vehicle navigation on the basis of the technology of visible light communications." It further concedes standard encoding: "The signpost information may be encoded according to a fixed rule, such as ASCII codes, digital lookup table codes or other coding form." A PHOSITA told to "transmit the selection and frame-timing data over the link you already have" has one obvious choice: modulate the same LEDs the sign is already using. Philips FIG. 6 already modulates light "for identification of the light source," and the family's device includes a "synchronisation module for the contact-free synchronisation of at least one pulsed light source and at least one set of shutter glasses" (claim 6). Reading the patent's own admissions into the KSR "finite number of predictable solutions" analysis, encoding the signpost data into the sign's light is an obvious to try step with a predictable outcome.

5. Ground 2 — Claim 6 and claims 7–9 specifically

Statement: Claim 6 would have been obvious over US20110043881A1 in view of US20130345959A1, and optionally CN102970574A.

• Philips FIG. 6 discloses a pulse signal "with superimposed light modulation for identification of the light source." That is claim 6's "visible light signal comprising identification information of the road sign," in substance.
• Philips claim 5 discloses a control unit "connected to a memory unit for storing different pulse sequences," and claim 3 a "pre-set shutter pattern." Claim 6's "pre-set signpost information corresponding to the signpost" is the lookup into that memory.
• Apple '959 supplies the "navigation path corresponding to a vehicle" and the map.
• CN102970574A supplies the personalization motive: the terminal determines which spectator occupies which predefined region, decodes the viewpoint image for that region, and "sends a glasses switching signal to the 3D glasses" so the glasses open to receive only that image (see also its claim 1 and the WO2014085991A1 counterpart, which cites CN102970574A against claims 1–10). Substituting "the viewer's assigned route" for "the viewer's assigned region" is a simple substitution of one known element for another yielding a predictable result — a recognized KSR rationale.
• Claim 7 (numbering/coordinates) and claim 8 (unique IDs on the map) are conventional database keys. Claim 8's lookup is no more than indexing a map record by the identifier broadcast in the light — routine programming.
• Claim 9 / claim 2 (LED sign; frame serial numbers for individual LEDs; synchronous opening) is directly met by Philips FIG. 7 ("synchronisation of two (sets of) shutter glasses with three light sources with short switch-on time") and by CN103716962A's PWM-driven full-color LED scheme.

6. Ground 3 — Claims 3, 4, 5, 10, 11

7. Counterarguments the patent owner will raise (and how strong they are)

I want to be candid about where a § 103 challenge is exposed, because the earlier summary's framing ("consistent with the cited VLC/road-sign art") can create false confidence.

1. "Philips is room-lighting art, not navigation art."
   Response: Strongest available attack is analogy. Philips' own text does the work — "signpost," "individual guidance system," "access routes," "controlled according to location." A reference that names the claimed subject matter and names the claimed control modality is pertinent. Risk level: low-to-moderate. Note that "reasonably pertinent" is evaluated from the PHOSITA's perspective at the critical date, and a 2018 automotive HUD/VLC engineer overlaps with an adaptive-lighting engineer.

2. "Philips' shutter is synchronized to a lamp, not to frames of a single multi-signpost sign."
   Response: This is the patentee's best argument, and it is only a form argument. Philips FIG. 2 and FIG. 7 both teach combining/multiplexing the light of three sources (La, Lb, Lc) into one perceived scene via "shutter sequences … according to a fixed pattern," including "very low duty cycle" and "short switch-on times." Substituting one spatially-segmented sign whose regions are time-multiplexed, for three separate lamps that are time-multiplexed, is a change in the number/arrangement of parts, not a change in principle. CN103716962A supplies the "one LED fixture, PWM-timed" implementation. Risk level: moderate — this is where a well-argued non-obviousness brief would focus.

3. "Philips never decodes data out of the light."
   Response: Philips FIG. 6 superimposes identification modulation on the pulse signal for the receiver to identify the source, and the family claims a contact-free synchronization module. The step from "identify the source" to "read the source's data payload" is KSR's "use of a known technique to improve a similar device in the same way." Risk level: moderate, but blunted by the '589 spec's own admission that VLC is prior technology used here as a matter of association.

4. "The prior art is silent on route-computed nearest upcoming signpost."
   Response: True of Philips; supplied by Apple '959 (upcoming maneuver on a generated route) and CN108225331A (route + navigation instructions from position/orientation). Risk level: low — this is a generic navigation step.

5. "Framework for Obviousness" would require a single articulated motivation, not a mosaic without a reason."
   Response: The articulation is available and grounded in the references themselves, not in hindsight: (a) the shared problem statement (multi-option signage forces a compromise; each user needs only their own info), (b) Philips' express external/individualized shutter control, and (c) Apple's maneuver-linked road-sign presentation. These are the KSR "design incentive … in the prior art" and "predictable variation" rationales.

6. Objective indicia. I found none of record: no evidence of unexpected results, no licensing program, no commercial-success nexus, no copying, no praise. This matters because the previously-noted prosecution history — a sole non-final action (2021-12-09), a response (2022-03-13), and allowance (2022-04-13) — reflects examiner narrowing, which has no estoppel effect on a § 103 challenge but also provides no affirmative evidence of non-obviousness. The applicant's amendment that added route generation and frame-rate gating is, however, a documented concession that the bare capture→select→control combination was not allowable — useful context if a defendant argues the broad concept was known.

8. Bottom line

Strategic read: The '589 patent's vulnerability is not that it is a pioneer VLC patent — it explicitly builds on VLC as a known technology. Its vulnerability is that the claimed novelty is the place where two entirely conventional techniques were joined: shutter-gated viewing of time-multiplexed light sources (a 3D-TV and adaptive-lighting staple, disclosed by Philips '881 down to the word "signpost," "guidance system," "location," and "externally controlled") and turn-by-turn route guidance with road-sign presentation (Apple '959). The two claim-1 features that the applicant added during prosecution — route/position-derived selection and frame-rate-keyed shutter gating — are each separately disclosed in the record.

9. Confidence, and what I would verify before relying on this

• High confidence: the identity, dates, and substance of the cited references, taken from the authoritative full text plus the references' own published texts (URLs appended below). The element mapping in §3.
• Medium confidence: the persuasiveness of the analogous-art bridge for Philips '881. This is a legal judgment that turns on how a PHOSITA in 2018 automotive displays would have viewed indoor adaptive-lighting art. I have not located a U.S. decision applying Philips '881 (US20110043881A1 / WO2009136330) in a vehicle-display or navigation context, so the bridge is argued, not adjudicated.
• Not verified: whether a U.S. equivalent of WO2009/136330A1 issued as a patent (the family lists JP2011520232A and TW201004312A but no U.S. grant in the material I retrieved); whether any post-2018 non-record art (e.g., "smart road signs," WO2019221688A1) has since been adjudicated; and whether the CNIPA First Office Action cited of record contains reasoning I should mirror. The Office Action itself is listed only by title in the record — I have not read its contents and cannot confirm what art or reasoning it applied.
• Reminder per the operating rules: all identifiers are reproduced literally as they appear on the record; nothing above has been auto-corrected.

Reference URLs used:
https://patents.google.com/patent/[US11391589](/patent/US11391589)/en • https://patents.google.com/patent/US20110043881 • https://patents.google.com/patent/WO2009136330A1/en • https://patentimages.storage.googleapis.com/65/ed/4f/ea8c511743c0cc/US20110043881A1.pdf • https://www.freepatentsonline.com/y2011/0043881.html • https://patents.google.com/patent/US20130345959 • https://www.freepatentsonline.com/y2013/0345959.html • https://patents.google.com/patent/CN102970574A/en • https://patentimages.storage.googleapis.com/c4/03/cb/1297ab6988e5f0/WO2014085991A1.pdf • https://m.tianyancha.com/zhuanli/158485bb9d8d4881bc3cb93caff2f6e1 (CN103716962A) • https://patents.google.com/patent/CN108225331A/en • https://patentimages.storage.googleapis.com/7e/b6/2c/478954384817c7/CN108225331A.pdf