CPC technology class · H03

H03L - Automatic Control

Automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses. 6,701 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

Compiled by PlainPatent · May 15, 2026

6,701
US patents granted: #5/10
in H03: 7.0%
H03 class share: -20%
5-yr velocity

The verdict

According to USPTO PatentsView, Automatic Control ranks #215 of 670 CPC technology areas - 6,701 US patents granted since 2015, with recorded grant volume down 20% over five years.

#215
of 670 CPC technology areas: 6,701
US patents granted, 2015–2025: Seiko Epson
leading assignee (302): -20%
grant velocity, last 5 yrs

How H03L's grant cadence moved

Between 2020–2024, H03L recorded 2,742 grants versus 3,422 in 2015–2019 (-20% equal-window velocity). Across complete years, output peaked in 2019 at 787 grants and bottomed in 2024 at 402 (+96% peak-over-trough). Lead assignee Seiko Epson Corporation holds 4.5% of the class ; the top three share 10.5%.

Leaderboard read

H03L concentration, lead at 4.5%

Seiko Epson Corporation leads this historical grant record at 4.5% of H03L - foreign corporation assignees hold 55% of class grants (1,949 of 3,529). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share: 4.5%
Top three share: 10.5%
Lead over #2: 33

Where H03L sits inside H03

Among 10 subclasses in H03 (Electronic Circuitry), H03L ranks #5 and holds 7.0% of the parent class's 95,387 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

H03K 30,872 H03M 21,338 H03F 14,014 H03H 11,825 H03G 5,213 H03B 3,110 H03D 1,165 H03J 659

Rising assignees active in H03L

Company-wide grant multiples (2022–2024 vs 2019–2021) among assignees with ≥5 patents in this subclass. Growth is company-wide; class patent counts are subclass-specific.

#1 Changxin Memory Technologies, Inc. 63x 17 → 1,066 company-wide · 16 in H03L
#2 Shaheen Innovations Holding Limted 19x 2 → 38 company-wide · 11 in H03L
#3 Kioxia Corporation 11x 180 → 2,031 company-wide · 20 in H03L
#4 Shaoxing Yuanfang Semiconductor Co., Ltd. 11x 0 → 11 company-wide · 11 in H03L
#5 Stathera IP Holdings Inc. 8.00x 0 → 8 company-wide · 5 in H03L

H03L grants by year, peak 2019 (787)

US utility-patent grants per year in H03L, 2015–2025 - recent five years are down 20% versus 2015–2019.

Seiko Epson

302
Texas Instruments…

269
Sk hynix

133
Rambus

121
Silicon Laboratories

104
Realtek Semiconductor

89
Nxp B V

82
Renesas

75
Mediatek

74
Xilinx

69
Stmicroelectronics…

52
Altera

51

What this shows Seiko Epson is the most active filer in H03L, holding 302 of the 6,701 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

View data table

Top patent holders in CPC subclass H03L
Rank	Company	Patents in H03L
#1	Seiko Epson Corporation	302
#2	Texas Instruments Incorporated	269
#3	SK hynix Inc.	133
#4	Rambus Inc.	121
#5	Silicon Laboratories Inc.	104
#6	Realtek Semiconductor Corp.	89
#7	NXP B.V.	82
#8	Renesas Electronics Corporation	75
#9	Mediatek Inc.	74
#10	Xilinx, Inc.	69
#11	STMicroelectronics International N.V.	52
#12	Altera Corporation	51
#13	NXP USA, Inc.	49
#14	Analog Devices, Inc.	45
#15	Inphi Corporation	40
#16	Nihon Dempa Kogyo Co., Ltd.	40
#17	Skyworks Solutions, Inc.	39
#18	Kandou Labs SA	39
#19	Socionext Inc.	37
#20	Ciena Corporation	36

Footprint here vs. claim strategy

Each dot is a leading H03L assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 H03L assignees by class footprint. Bubble size = patents in H03L. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near H03L's 6,701-grant footprint

Nationwide nearest neighbors for H03L (#215 of 670 by volume ; lead share 4.5%) - not the H03 parent-class siblings above.

Nearest by grant volume

B60G 6,732 B81B 6,733 B63B 6,790 A47C 6,586

Nearest by lead-assignee share

C08H 4.5% G08G 4.5% G09B 4.6% H04K 4.6%

Questions about H03L

Which company holds the most patents in H03L?

Seiko Epson Corporation leads H03L with 302 patents (4.5% of the subclass). By PatentsView assignee type, foreign corporations account for 55% of class grants.

Which H03L assignees grew fastest recently?

Among assignees with ≥5 grants in H03L, Changxin Memory Technologies, Inc. shows the highest company-wide grant multiple (63x: 17 grants in 2019–2021 → 1,066 in 2022–2024) while holding 16 patents in this subclass. Growth is company-wide, not class-only.

How does H03L compare inside parent class H03?

Inside H03 (Electronic Circuitry), H03L ranks #5 of 10 subclasses by grant volume and holds 7.0% of the parent class total. The largest sibling is H03K (30,872 grants).

What to do with this data

H03L in context - here's where to go next.

Seiko Epson Corporation leads H03L with 302 grants in this class. See full portfolio
H03L ranks #215 of 670 by grant volume among all tracked CPC technology areas. See the ranking
Inside parent class H03, the largest sibling subclass is H03K with 30,872 grants. Explore H03K

Figures reflect USPTO PatentsView grant data through 2026-05-15; pending applications not yet granted are not counted.

Methodology - H03L figures are USPTO PatentsView granted-utility totals for this subclass (6,701 grants in the tracked window).

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.