Invalidity dossier
US 4128332
Illuminator
Current assignee: Xerox Corp
Added 9/23/2026, 5:53:47 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 — US 4,128,332 ("Illuminator")
Bibliographic data (from source): US Patent 4,128,332 A; application US05/656,559; inventor Stephen H. Rowe; original assignee and current assignee Xerox Corp; prior art date 1975-03-24; filing date 1976-02-09; publication/grant date 1978-12-05; anticipated expiration 1996-02-09; status listed as "Expired - Lifetime."
Purpose. The invention "relates to illuminators particularly although not exclusively for use in office copiers." The described arrangement "provides an efficient 'strip' light particularly suitable for illuminating a document in a copier."
Plain-language scope. An illuminator has a transparent dielectric channel (illustrated as a glass rod 10) carrying light from source means along the channel by total internal reflection. Surface means remote from the source sit in intimate contact with the channel's outer surface and deflect light out toward the object. Two coating types are disclosed: a diffuse white-paint layer (Nextel, or Velvet White) that scatters light out, and a transparent surface layer of refractive index greater than the conduit's, which lets light escape through it. The layer's contour or thickness can be varied along the rod to control illumination, e.g. for even distribution or greater intensity at a document's extreme edges. Sources may be held stationary while a portion of the rod scans; the rod may be at least partly flexible. A variant uses one source and a flat mirror terminating the rod, and a spiral-rod version serves as a laser pumping device. Supporting or clamping means should have a lower refractive index than the channel to avoid light leakage.
What the excerpt does not establish. The supplied text gives only an abstract-style summary and partial description; it does not include the full claims, the complete description, or the drawings' details, so the precise claim scope cannot be verified. The text states no litigation, ownership transfers, validity determinations, or prior art, and none are asserted here. Legal status shown is characterized in the source itself as an assumption, not a legal conclusion.
Generated 10/1/2026, 9:43:12 PM
Cases on file (0)
Specific litigation cases in our database that name US patent 4128332. 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.