12 patents currently held
330 more in force are now held by other companies
Held is read from USPTO's recorded assignments; a transfer never recorded there does not appear.
7 more records may belong here and await a decision; they are not counted.
The next term ends in Feb 2027. from the record
Of the 330 now held by other companies, 328 name Maxell Ltd. as their current owner, and 2 more name another party. Each row says which.
Free plan: 3 watched companies. Pro: unlimited.
Alerts on its grants, lapses and transfers.
7
Ending by 2030
Feb 2027
Next term end
12
Patent families
When these terms end
Held patents by the year their term ends
notable patents
fee due within 90 days
all others
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
Notable: the highest-ranked patents in this portfolio by citations and family size. Fee due within 90 days: a maintenance fee is due within 90 days of when this page was computed and not yet paid.
Notable patents
Ranked by citations and family size, against patents of the same kind granted the same year. How we rank
Notable
Ends Jul 2027 · High confidence
Also notable
Ends May 2028 · High confidence
Also notable
Ends Jun 2031 · High confidence
Information Read Device and Read Signal Processing Circuit
US 7,483,478
The most cited patent in this portfolio, cited by 56 later US patents, top 25% of utility patents granted in 2009 in our data. Protection runs to 2027.
Optical Disk Apparatus with an Improved Track Jump Performance
US 7,760,592
Renewed at every maintenance window since the 2010 grant; no more fees are due before its term ends in 2028.
Disk-Shaped Recording Medium and Recording/Reproducing Device for Disk-Shaped Recording Medium
US 8,976,639
Granted 2015 and renewed at every maintenance window due so far. Protection runs to 2031.
Formerly held, still cited
Notable
Ends Feb 2029 · High confidence
Cited by 82 later US patents, top 10% of utility patents granted in 2014 in our data, and renewed at 3 of 3 maintenance windows. Protection runs to 2029.
now held by Maxell, Ltd.
Also notable
Ends Feb 2031 · High confidence
Cited by 71 later US patents, top 10% of utility patents granted in 2013 in our data, and renewed at 3 of 3 maintenance windows. Protection runs to 2031.
now held by Maxell, Ltd.
Also notable
Ends Oct 2028 · High confidence
Cited by 60 later US patents, top 10% of utility patents granted in 2012 in our data, and renewed at 3 of 3 maintenance windows. Protection runs to 2028.
now held by Maxell, Ltd.
Fee deadlines
Maintenance fees fall due 3.5, 7.5 and 11.5 years after grant. A missed fee ends a patent at the end of the six month grace period that follows, not on the due date.
- 1 fee due Dec 30, 2026The maintenance fee for Channel Bitword Processor, PRML Decoder, and Optical Information Recording/Reproducing Device (US 9,070,412) comes due Dec 30, 2026. Unpaid by Jun 30, 2027, it lapses early.
- 2 fees due May 17 to 24, 2027 · next May 17
Recent changes
- 7 terms have ended since Aug 17, 2026
What they patent
The 5 largest of its 12 families, grouped by real patent family and labeled by the earliest filing in each. No technology classification is inferred from titles.
| Disk-Shaped Recording Medium and Recording/Reproducing Device for Disk-Shaped Recording Medium | 1 in force | to Jun 2031 |
| Optical Disk Recording/Reproducing Apparatus and Alternation Process Method Thereof | 1 in force | to Nov 2028 |
| Multilayer Optical Disc | 1 in force | to May 2028 |
| Optical Disk Apparatus with an Improved Track Jump Performance | 1 in force | to May 2028 |
| Information Read Device and Read Signal Processing Circuit | 1 in force | to Jul 2027 |
Patents held now
Soonest term end first.
| Patent | Title | Status | Expires | Confidence |
|---|---|---|---|---|
| US RE43,105 | Tracking Error Detection Method and Optical Disc Reproduction Apparatus Using the Same In force · Low confidence | In force | Low confidence | |
| US 7,483,478 | Information Read Device and Read Signal Processing Circuit In force · High confidence | In force | High confidence | |
| US 7,649,713 | Thin-Film Magnetic Head with Heating Element and Heatsink In force · High confidence | In force | High confidence | |
| US 7,760,592 | Optical Disk Apparatus with an Improved Track Jump Performance In force · High confidence | In force | High confidence | |
| US 8,233,374 | Multilayer Optical Disc In force · High confidence | In force | High confidence | |
| US 7,817,515 | Optical Disk Recording/Reproducing Apparatus and Alternation Process Method Thereof In force · High confidence | In force | High confidence | |
| US 8,085,641 | Reproduced Signal Evaluation Method and Write Adjustment Method In force · High confidence | In force | High confidence | |
| US 8,976,639 | Disk-Shaped Recording Medium and Recording/Reproducing Device for Disk-Shaped Recording Medium In force · High confidence | In force | High confidence | |
| US 8,514,681 | Recording Medium, Address Generating and Detection Method, and Reproduction and Recording Apparatus In force · High confidence | In force | High confidence | |
| US 9,189,324 | Data Archive System, Data Recording/Reproducing Apparatus and Data Library Apparatus In force · High confidence | In force | High confidence |
Also on record, not counted in the 12: 330 patents in force now held by others · 1,482 patents ended · 200 applications abandoned. List them
Sources and methods
Compiled from USPTO application file histories, grants and recorded assignments, with the company's own names reviewed by hand. How this record was built
Portfolio grouped automatically from ownership conveyances to the names matched to this company, usually every name that begins with its own, so it counts patents an affiliate holds; each list row names the holder of record. Security interests are excluded and ambiguous records are not reviewed by hand.
Fee due within 90 days marks a patent with a maintenance fee due within 90 days of the date this page was computed and not yet recorded paid, so it can end earlier than the bar shows. A fee left unpaid ends the patent at the close of the six month grace period that follows its due date, not on the due date itself. It is not a prediction that the fee will be missed.
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.