Invalidity dossier
US 7742528
Variable length encoding method and variable length decoding method
Current assignee: Godo Kaisha IP Bridge 1
Added 9/23/2026, 8:03:44 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 — US7742528B2
Title: Variable length encoding method and variable length decoding method
Patent number / application: US7742528B2; application US10/481,277; published as US20040184544A1.
Inventors: Satoshi Kondo, Shinya Kadono, Makoto Hagai, Kiyofumi Abe. Originally assigned to Panasonic Corp (assignment recorded to Matsushita Electric Industrial Co., Ltd. in 2003, later name change to Panasonic Corporation); the source lists the current assignee as Godo Kaisha IP Bridge 1.
Key dates (as stated in the source): priority date 2002-04-26; filing date 2003-04-16; publication of the granted patent 2010-06-22; legal status "Expired - Lifetime," with adjusted expiration 2026-04-04.
Purpose and plain-language scope: The patent concerns variable length encoding and decoding, i.e., converting video data into, and back from, a compressed code. From the excerpt, the disclosed subject matter appears directed to adaptive coding in video compression—specifically adaptive entropy coding, including context adaptive binary arithmetic coding (CABAC) and adaptive variable length coding (AVLC)—with prior-art keywords "probability," "coefficient," "switching," and "probability table" suggesting probability-table-based switching. The classification data places the invention in video coding (H04N19/00, H04N19/10, H04N19/13), variable length coding (H03M7/40), and arithmetic coding (H03M7/4006), with the coded unit being transform coefficients, blocks/macroblocks, or pixels. The excerpt does not reproduce any claims, so the metes and bounds of the claimed scope cannot be verified from this text alone.
What the excerpt does not establish: No claim language, written description, or embodiments are included. The legal status statements are expressly assumptions, not legal conclusions. Inventorship, assignee accuracy, and the listed expiry date are likewise unverified here. The excerpt also mentions family litigation data and numerous later-filed continuations (e.g., US8098736, US7970059, US8005146, US8284841, US8804838, US9191666, US9497467, US9521415, US9794567, US10349054, US10356412) but provides no details about them; those are outside this overview's scope.
Source: https://patents.google.com/patent/[US7742528](/patent/US7742528)/en
Generated 10/1/2026, 9:41:37 PM
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Litigation summary
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Proceedings on file (0)
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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
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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.