Multichannel television sound stereo and surround sound encoder suitable for use with video signals encoded in plural formats

US 6,445,422 Lapsed on the fee record

Overview Sources & methods

Lapsed Sep 3, 2014 on the fee record · From the USPTO record

Computed 20-year base term

Third maintenance fee unpaid; grace period ended.

Named at grant Cable Electronics, Inc. · find this owner

Filed Jul 25, 2001 as application 09/915,148 · Granted Sep 3, 2002

Base term, 20 years from filing

Today

Lapsed Sep 3, 2014

1997 2026

Clock starts
Aug 25, 1997

No longer in force
Sep 3, 2014

Granted
Sep 3, 2002

Term would have run to
Aug 25, 2017

base term after the term ends fee events Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know

None

Term adjustment

No prosecution delay on this record.

Unresolved

Terminal disclaimer

On file, reference document not resolved, so the date above is an upper bound. We do not guess the cap.

2 of 3

Maintenance fees paid

Three maintenance fees fall due, at 3.5, 7.5 and 11.5 years from grant. This counts the ones the record shows paid.

How we calculated this date

One row per rule, each showing its own input and what it did to the date. A step we could not verify says so instead of resolving itself.

Step	Input	Date after this step	Confidence
Base term, 20 years from filing	Clock starts Aug 25, 1997, when the earliest non-provisional application in its chain was filed (this one was filed Jul 25, 2001)	Aug 25, 2017	High confidence
Continuity chain	Every parent in the chain resolved	no change	High confidence
Patent term adjustment	None on file	no change	High confidence
Terminal disclaimer cap	Disclaimer on file (approved), reference document not resolved	no cap applied, and none guessed	Medium confidence
Patent term extension	None on file	no change	High confidence
Fee events	2 of 3 maintenance fees paid	lapsed Sep 3, 2014	High confidence
Computed term end	The steps above, in order	Sep 3, 2014	From the USPTO record

Sources

Google Patents · The patent document at USPTO · Assignment records at USPTO

USPTO account required: This application in Patent Center · USPTO's maintenance fee lookup

Maintenance fee events come from USPTO's own fee records. Its fee lookup asks for the patent number and the application number.

Not on this page: the patent's family, its recorded assignments and its citation count. USPTO's assignment records, linked above, list every recorded assignment.

Every date shows its work: the base term, any term adjustment or extension, any disclaimer cap, and the maintenance fee record, each with a confidence tier. How this record was built

Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.

Multichannel television sound stereo and surround sound encoder suitable for use with video signals encoded in plural formats

Lapsed Sep 3, 2014 on the fee record · From the USPTO record

20-year base term ended Aug 25, 2017

How we calculated this date

Sources