Invalidity dossier
US 5838403
Liquid crystal display system with internally reflecting waveguide for backlighting and non-Lambertian diffusing
Current assignee: Luminit LLC
Added 9/23/2026, 6:45:41 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 5,838,403 A
Title: "Liquid crystal display system with internally reflecting waveguide for backlighting and non-Lambertian diffusing"
Patent number / application: US 5,838,403 A (application US 08/601,133)
Original assignee: Physical Optics Corp. The supplied text also lists current assignees "Luminit LLC" and "United California Bank," but states the listed assignees may be inaccurate and that no legal analysis was performed. Inventors: Joanna L. Jannson, Tomasz P. Jannson, and Jeremy M. Lerner.
Key dates (as listed; priority date is expressly an assumption, not a legal conclusion):
- Priority date / filing date: 1996-02-14
- Publication (grant) date: 1998-11-17
- Anticipated expiration: 2016-02-14
- Legal status: "Expired - Lifetime"
Purpose and plain-language scope: The invention concerns a liquid crystal display (LCD) system backlight. The source's prior-art keywords—"light," "backlight," "input end," "top surface," "facet"—indicate an internally reflecting waveguide that receives light at an input end, transports it, and couples light out through facets to backlight the display. The abstract-level indexing terms list "liquid crystal," "illumination," "optical effect," "distribution," "light shaping," "flux," "design," "coupling," "diffusing," "ground glass," and "non-Lambertian," indicating the system shapes light output directionally rather than in a purely Lambertian distribution. Corresponding international filings are listed (WO 1997/030373 A1, EP 0880723 B1, CA 2245833 C, JP 2000-504855 A, DE 69728754 T2), and related US cases US 6,072,551 A and US 6,130,730 A are noted under priority.
Not established by this excerpt: The excerpt omits the claims, detailed description, and drawings, so exact claim scope, claim limitations, and terminology definitions (e.g., how "non-Lambertian" is defined) cannot be verified. The excerpt likewise does not establish claim count, validity, enforceability, or freedom to operate. Consistent with instructions, no litigation, ownership-transfer analysis, validity, or prior-art review is undertaken here.
Generated 10/1/2026, 9:42:37 PM
Cases on file (0)
Specific litigation cases in our database that name US patent 5838403. 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.