Term ends Mar 12, 2033 · High confidence
20-year base term ends Jul 14, 2031
Held by Dualitas Ltd.
Filed Jul 24, 2017 as application 15/658,052 · Granted Feb 23, 2021
Base term plus 607 days of patent term adjustment (USPTO delay)
Today
2011
2033
Clock starts
Jul 14, 2011
Jul 14, 2011
Term ends
Mar 12, 2033
Mar 12, 2033
Granted
Feb 23, 2021
Feb 23, 2021
base term
patent term adjustment
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
607
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
None
Terminal disclaimer
No disclaimer on this record.
1 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 runs 607 days past its 20-year base term on prosecution delay. 1 of 3 maintenance fees is paid so far. Confidence: High. 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 Jul 14, 2011, when application PCT/GB2011/051328, the earliest non-provisional in its chain, was filed (this one was filed Jul 24, 2017) | Jul 14, 2031 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +607 days, USPTO patent term adjustment record | Mar 12, 2033 | 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 | 1 of 3 maintenance fees paid | In force | High confidence |
| Computed term end | The steps above, in order | Mar 12, 2033 | High confidence |
This family
| US 9,715,215 | In force May 2033 | May 2033 |
| US 10,928,776 | this patent Mar 2033 | Mar 2033 |
| US 11,635,621 | In force no later than Oct 2031 | no later than Oct 2031 |
3 of 4 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 |
|---|---|---|---|
| Dec 14, 2017 Reel 44396, frame 110 | Christmas, Jamieson; Masiyano, Dackson | Two Trees Photonics Limited | Assignment of Assignor's Interest |
| Jan 26, 2021 Reel 55028, frame 193 | Two Trees Photonics Ltd. | Dualitas Ltd. | 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.
What's changing
Mar 2033
Term ends Mar 12, 2033. Maintenance fees still fall due before then
Note
The 607 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
5
later US patents cite this one
That is above the median of utility patents granted in 2021 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.