Invalidity dossier
US 5473396
Display apparatus and method of making the same
Current assignee: Panasonic Holdings Corp
Added 9/23/2026, 7:54:51 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 5,473,396 A
Title: Display apparatus and method of making the same
Assignee: Original assignee Matsushita Electric Industrial Co., Ltd. (current assignee listed as Panasonic Holdings Corp).
Inventors: Michio Okajima; Takao Tohda
Dates: Priority/filing date 1993-09-08; publication (grant) date 1995-12-05; anticipated expiration 2013-09-08. Legal status listed as "Expired – Fee Related."
Purpose: The invention addresses shortcomings of existing large-screen approaches — CRTs (heavy, deep, costly at large sizes), plasma displays (low efficiency, high power), EL color displays (no high-efficiency red/blue phosphors), and liquid-crystal and projection systems (low aperture, low light-condensing efficiency, high backlight power, reduced viewing angle). Its stated object is a display that is lightweight, compact, low in power consumption, high in display quality at large picture size, and low in manufacturing cost.
Plain-language scope: The apparatus has three core elements: (1) a face-type UV light source emitting a UV image from its light-emitting face (e.g., a UV-emitting CRT with a UV-emitting fluorescent face, or an EL device with UV-emitting pixel regions); (2) a projection lens system that enlarges and projects the UV image; and (3) a fluorescent screen that emits visible light when excited by the projected UV rays. The result is a direct-view system where UV rays from the source are enlarged onto a large fluorescent screen, converting UV directly into a visible-light image. Preferred variants add a light shield/mask between screen and lens, or a UV-deflection lens array in its place, so that UV rays excite the correct visible-light-emitting fluorescent material dots without color distortion. The excerpt also mentions FIGS. 1–6 and a method of manufacturing the fluorescent screen, but their details are not provided here.
Source: https://patents.google.com/patent/US5473396/en
Not established by this excerpt: the specific claims, the fluorescent-screen manufacturing steps and materials, detailed figure contents, and any omitted description text.
Generated 10/1/2026, 9:41:43 PM
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Litigation summary
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Proceedings on file (0)
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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
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Obviousness
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Extensions
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Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.