Term ended no later than Apr 5, 2026 · Medium confidence
20-year base term ended Apr 5, 2026
Held by Cadence Design Systems, Inc.
Filed Jun 24, 2009 as application 12/491,106 · Granted May 3, 2011
Base term, 20 years from filing
Today
Ended no later than Apr 5, 2026
2006
2026
Clock starts
Apr 5, 2006
Apr 5, 2006
Ended no later than
Apr 5, 2026
Apr 5, 2026
Granted
May 3, 2011
May 3, 2011
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.
3 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.
4
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.
This patent's term is its 20-year base term, with no adjustment for prosecution delay. A terminal disclaimer is on file with no resolved reference, so no cap is applied and none is guessed. All three maintenance fees were paid, so no fee lapse ended it. Confidence: Medium. from the record
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 Apr 5, 2006, when application 11/278,794, the earliest non-provisional in its chain, was filed (this one was filed Jun 24, 2009) | Apr 5, 2026 | 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 | 3 of 3 maintenance fees paid | term ended | High confidence |
| Computed term end | The steps above, in order | no later than Apr 5, 2026 | Medium confidence |
This family
| US 7,577,558 | Term ended Nov 2026 | Nov 2026 |
| US 8,145,469 | In force Jun 2027 | Jun 2027 |
| US 7,937,258 | this patent no later than Apr 2026 | no later than Apr 2026 |
| US 8,594,991 | Term ended Apr 2026 | Apr 2026 |
The applications whose file history this site holds. The family may have others.
Assignments
Assignment documents as recorded at the USPTO, oldest first, with the reel and frame each was recorded at. A recorded assignment is a filed document, not a statement of current ownership, and the absence of a later one is not evidence that the last one still stands.
| Recorded | Assignor | Assignee | Conveyance |
|---|---|---|---|
| Mar 1, 2012 Reel 27789, frame 450 | Quickturn Design Systems, Inc. | Cadence Design Systems, Inc. | Assignment of Assignor's Interest |
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.
Free plan: 3 watched companies. Pro: unlimited.
Alerts on its grants, lapses and transfers.
What's changing
Note
A terminal disclaimer is on file and its reference is not resolved. No cap is applied and none is guessed
Open question
A terminal disclaimer is on file (approved) and its reference document is not resolved. A disclaimer would cap the term earlier than Apr 5, 2026. We will not guess the cap.
Citations
0
later US patents cite this one
That is below the median of utility patents granted in 2011 in our data, the only group it is compared against.
How we rank
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
This computed term ends no later than the date shown; an unresolved terminal disclaimer may end it earlier. Related patents and pending applications may cover overlapping subject matter.