Invalidity dossier
US 3328570
Illuminated panel member
Current assignee: General Electric Co
Added 9/23/2026, 3:52:35 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US3328570 — "Illuminated Panel Member"
Patent number: US3328570A
Title: Illuminated panel member
Inventor: Charles A Balchunas
Original/current assignee (per source listing): General Electric Co
Application number: US446819A
Priority/filing date: 1965-04-09
Publication (grant) date: 1967-06-27
Legal status listed: Expired – Lifetime (anticipated expiration listed 1984-06-27)
Source: https://patents.google.com/patent/US3328570/en
Purpose. The invention relates to illuminating means, and more particularly to illuminating means for a panel member of an indicator device — for example an edge-lighted clock or timer dial face whose surfaces are visible to an observer.
Plain-language scope. Light from a source is carried through a bifurcated light transmitting means into a light transmitting panel member (glass or plastic). A plurality of grooves on a surface of the panel member intercept the transmitted rays and reflect and scatter them through the panel surfaces. Because light intensity falls off with distance according to the inverse-square law, the reflecting/scattering area provided by the grooves per unit area of panel is increased with distance from the source under a predetermined mathematical relationship, so illumination stays uniform over the whole panel.
Two disclosed ways of doing this (FIGS. 5 and 6): forming the grooves progressively closer together (a "quasilogarithmic" relationship), or making them extend increasingly deeper into the panel. Grooves may be parallel, on one or both surfaces, and the excerpt indicates the number of grooves per unit area rises with the square of the distance, per a calculation built on E = I/D².
What the excerpt does not establish. It is a partial excerpt: the text is truncated at the discussion of increasing groove depth ("FIG. 6"), so the specification's remaining description and the full set of claims are not shown — no claim language is quoted here. Also not established: definitive ownership or any reassignments, validity, litigation, or prior-art analysis (the listing of anticipatory references is not reproduced). Dates and assignee data are taken as stated by the source.
Generated 10/1/2026, 9:51:19 PM
Cases on file (0)
Specific litigation cases in our database that name US patent 3328570. The free-form analysis below may also discuss cases beyond this list.
No cases on file mention this patent. Upload a CSV or add a case manually in Admin → Manage litigation cases.
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.