Term ends Oct 10, 2028 · Medium confidence
20-year base term ends Mar 4, 2028
Why Medium: A parent in the chain could not be resolved.
Held by Ennostar Corporation
Filed Jun 16, 2011 as application 13/161,835 · Granted Mar 31, 2015
Base term plus 220 days of patent term adjustment (USPTO delay)
Today
2008
2028
Clock starts
Mar 4, 2008
Mar 4, 2008
Term ends
Oct 10, 2028
Oct 10, 2028
Granted
Mar 31, 2015
Mar 31, 2015
base term
patent term adjustment
fee events
Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
220
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
None
Terminal disclaimer
No disclaimer on this record.
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.
12
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 runs 220 days past its 20-year base term on prosecution delay. 2 of 3 maintenance fees are paid so far. 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 Mar 4, 2008, when the earliest non-provisional application in its chain was filed (this one was filed Jun 16, 2011); a parent in its chain could not be resolved (the next row) | Mar 4, 2028 | High confidence |
| Continuity chain | A parent in the chain could not be resolved | dated from this application's own claim | Medium confidence |
| Patent term adjustment | +220 days, USPTO patent term adjustment record | Oct 10, 2028 | High confidence |
| Terminal disclaimer cap | None on record | no cap applied | High confidence |
| Patent term extension | None on file | no change | High confidence |
| Fee events | 2 of 3 maintenance fees paid | In force | High confidence |
| Computed term end | The steps above, in order | Oct 10, 2028 | Medium confidence |
This family
| US 7,355,210 | Term ended Sep 2025 | Sep 2025 |
| US 7,385,226 | Term ended Mar 2025 | Mar 2025 |
| US 8,097,897 | Term ended Apr 2026 | Apr 2026 |
| US 8,188,505 | In force Sep 2030 | Sep 2030 |
| US 9,508,902 | Term ended Sep 2026 | Sep 2026 |
| US 8,872,204 | In force May 2029 | May 2029 |
| US 8,994,052 | this patent Oct 2028 | Oct 2028 |
| US 9,461,202 | Term ended Dec 2025 | Dec 2025 |
8 of 12 applications in this family shown, earliest filings first. 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 |
|---|---|---|---|
| Jun 16, 2011 Reel 26458, frame 616 | Shen, Chien-fu; Chen, Chao-hsing; Huang, Chien-fu; Chen, Shih-i; Yao, Chiu-lin; Hsu, Chia-liang; Ou, Chen | Epistar Corporation | Assignment of Assignor's Interest |
| Apr 22, 2026 Reel 75513, frame 783 | Epistar Corporation | Ennostar Corporation | Change of Name |
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
Oct 2028
Term ends Oct 10, 2028.
Note
The 220 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
1
later US patent cites this one
That is below the median of utility patents granted in 2015 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
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.
In force means the term is running and no lapse is on record. It is not a finding that the patent is valid.