Invalidity dossier
US 5190370
Added 9/23/2026, 4:00:23 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US5190370A
Title: High aspect ratio lighting element
Patent number: US5190370A
Application number: US07/748,030
Filing / priority date: 1991-08-21 (both listed as the same date)
Publication (grant) date: 1993-03-02
Inventor(s): Richard A. Miller; Kenneth A. Aho; Sanford Cobb, Jr.
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee (per source): 3M Co; the source notes listed assignees may be inaccurate and that it performed no legal analysis
Legal status: Expired – Lifetime; anticipated expiration 2011-08-21
Purpose / plain-language scope (from the supplied excerpt):
The patent concerns a "high aspect ratio lighting element." Available indexing terms repeatedly reference light, extractor, prisms, prism, extraction, and illumination, indicating a light-guide style element in which prisms serve as an extractor to direct light outward. Classification data place the disclosure in light-guide and lighting-device categories, including planar/plate-like light guides, coupling-in and coupling-out means, linear indentations or grooves (e.g., arc-shaped or meandering grooves) extending over the full length or width of the guide, tapered/wedge-shaped light guides, reflecting elements, hollow light guides, and vehicle-exterior signalling devices (e.g., brake lamps, direction indicators, reversing lights). The excerpt further lists optical effects, dispersion, manufacturing processes, "mining," and polycarbonate as materials/terms of interest.
Source: https://patents.google.com/patent/[US5190370](/patent/US5190370)/en
What this excerpt does not establish:
The supplied text contains no claims, abstract, or description body, so the actual claimed scope, the precise extractor/prism geometry, dimensions, aspect-ratio values, and any stated objects or advantages are not established here. Also not established: embodiments, examples, or figures; cited prior art or references; examination history; and family-member content beyond the listed EP, KR, and JP priority filings. The classification entries, keyword counts, and assignee listing are source-provided metadata, not legal conclusions.
Generated 10/1/2026, 9:51:14 PM
Cases on file (0)
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Litigation summary
Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.
Proceedings on file (0)
All PTAB activity →AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.
No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.