List of prolific inventors

Inventors with 200 or more worldwide utility patents are shown in the following table. While in many cases this is the number of utility patents granted by the United States Patent and Trademark Office, it may include utility patents granted by other countries, as noted by the source references for an inventor.

Inventor		Patents	Country	Patent Years	Years	Patents / Year	Majority assignment
Shunpei Yamazaki	[5]	5795	Japan	1972-2021	50	116	Semiconductor Energy Laboratory
Kia Silverbrook	[6]	4747	Australia	1994-2018	25	190	Silverbrook Research
Kangguo Cheng	[7]	2332	USA	2004-2021	18	130	IBM
Lowell L. Wood, Jr.	[8]	1964	USA	1977-2020	44	45	Intellectual Ventures
Roderick A. Hyde	[9]	1876	USA	2001-2020	20	94	Intellectual Ventures
Jun Koyama	[10]	1422	Japan	1991-2021	31	46	Semiconductor Energy Laboratory
Gurtej Sandhu	[11]	1364	India	1991-2021	31	44	Micron
Paul Lapstun	[12]	1296	Australia	2000-2021	22	59	Silverbrook Research
Clarence T. Tegreene	[13]	1230	USA	2000-2020	21	59	Intellectual Ventures
Shou-Shan Fan	[14]	1173	China	2006-2021	16	73	Hon Hai
Leonard Forbes	[15]	1108	Canada	1991-2019	29	38	Micron
Edward K. Y. Jung	[16]	1100	USA	1996-2020	25	44	Intellectual Ventures
Thomas Edison	[17]	1084	USA	1869-1931	63	17	Thomas Edison
Rick Allen Hamilton II	[18]	1013	USA	1999-2021	23	44	IBM
Donald E. Weder	[19]	1000	USA	1978-2017	40	25	Weder Family Trust
George Albert Lyon	[20]	993	Canada	1901-1965	65	15	Lyon George Albert
Alexander Reznicek	[21]	983	USA	2006-2021	16	61	IBM
Jordin T. Kare	[22]	978	USA	1992-2020	29	34	Intellectual Ventures
Jay S. Walker	[23]	968	USA	1998-2020	23	42	Walker Digital
Michael J. Sullivan	[24]	965	USA	1989-2021	33	29	Acushnet Holdings
John F. O'Connor	[25]	949	USA	1901-1935	35	27	William H. Miner
Melvin De Groote	[26]	925	USA	1924-1966	43	22	Petrolite
Nathan Myhrvold	[27]	895	USA	1994-2020	27	33	Intellectual Ventures
Francis H. Richards	[28]	894	USA	1899-1930	32	28	Francis H. Richards
Mark Malamud	[29]	880	USA	1997-2020	24	37	Intellectual Ventures
Ahmadreza Rofougaran	[30]	876	Iran	2002-2021	20	44	Broadcom
Robert W. Lord	[31]	858	USA	2003-2020	18	48	Intellectual Ventures
Royce A. Levien	[32]	850	USA	1997-2020	24	35	Intellectual Ventures
William H. Eby	[33]	836	USA	1994-2020	27	31	Monsanto
Muriel Y. Ishikawa	[34]	833	USA	2002-2020	19	44	Intellectual Ventures
Jason K. Resch	[35]	808	USA	2009-2021	13	62	IBM
Michael K. Gschwind	[36]	788	USA	2001-2021	21	38	IBM
Warren Farnworth	[37]	773	USA	1990-2020	31	25	Micron
Salman Akram	[38]	769	Nigeria	1995-2020	26	30	Micron
Jeyhan Karaoguz	[39]	754	USA	1996-2021	26	29	Broadcom
Carleton Ellis	[40]	753	USA	1902-1946	45	17	Ellis Foster Co
Clifford A. Pickover	[41]	740	USA	1992-2021	30	25	IBM
Ali Khakifirooz	[42]	736	Iran	2011-2021	11	67	IBM
Hideo Ando	[43]	729	Japan	1983-2017	35	21	Toshiba
George Spector	[44]	722	USA	1975-1998	24	30	George Spector
Austin L. Gurney	[45]	716	USA	1999-2020	22	33	Genentech
John M. Santosuosso	[46]	713	USA	2001-2021	21	34	IBM
Devendra K. Sadana	[47]	705	India	1983-2021	39	18	IBM
Bruce B. Doris	[48]	703	USA	1995-2021	27	26	IBM
Tetsujiro Kondo	[49]	699	Japan	1987-2020	34	21	Sony
Elihu Thomson	[50]	696	UK	1899-1935	37	19	GE
Ruilong Xie	[51]	692	Singapore	2013-2021	9	77	IBM
Chih-Chao Yang	[52]	690	Taiwan	2003-2021	19	36	IBM
Sarbajit K. Rakshit	[53]	673	India	2013-2021	9	75	IBM
Eric C. Leuthardt	[54]	660	USA	2006-2020	15	44	Intellectual Ventures
William I. Wood	[55]	653	USA	1981-2016	36	18	Genentech
Simon R. Walmsley	[56]	651	Australia	1995-2015	21	31	Silverbrook Research
Edward J. Nowak	[57]	633	USA	1979-2021	43	15	IBM
Audrey D. Goddard	[58]	626	USA	1997-2021	25	25	Genentech
Kie Y. Ahn	[59]	614	USA	1976-2018	43	14	Micron
Irwin Gerszberg	[60]	611	USA	1994-2021	28	22	AT&T
Esmael H. Dinan	[61]	608	Iran	2006-2021	16	38	Ofinno
Gregory J. Boss	[62]	607	USA	2008-2021	14	43	IBM
Jerome H. Lemelson	[63]	606	USA	1953-2009	57	11	Jerome Lemelson
Tadahiro Ohmi	[64]	597	Japan	1981-2018	38	16	Tadahiro Ohmi
Béla Barényi	[65]	595	Austria	1939-1979	41	15	Daimler
Paul S. Henry	[66]	588	USA	1978-2021	44	13	AT&T
Paul J. Godowski	[67]	579	USA	1994-2014	21	28	Genentech
Lisa Seacat DeLuca	[68]	573	USA	2009-2021	13	44	IBM
Artur Fischer	[69]	570	Germany	1951-2006	56	10	Artur Fischer
Jeffrey P. Gambino	[70]	570	USA	1992-2021	30	19	IBM
Victoria Y. H. Wood	[71]	564	USA	2009-2020	12	47	Intellectual Ventures
Anthony K. Stamper	[72]	559	USA	1998-2021	24	23	IBM
Kai-Li Jiang	[73]	557	China	2006-2021	16	35	Hon Hai
Louis L. Hsu	[74]	551	Taiwan	1988-2016	29	19	IBM
Ronald S. Cok	[75]	548	USA	1986-2021	36	15	Kodak
Robert S. Langer	[76]	546	USA	1983-2021	39	14	MIT
Edwin H. Land	[77]	535	USA	1933-1990	58	9	Polaroid
Belgacem Haba	[78]	531	Algeria	1991-2021	31	17	Tessera
Henri Dreyfus	[79]	524	Switzerland	1916-1945	30	17	Henri Dreyfus
Frederick A. Ware	[80]	519	USA	1981-2021	41	13	Rambus
Stuart C. Salter	[81]	515	USA	2009-2021	13	40	Ford
Clyde C. Farmer	[82]	513	USA	1905-1960	56	9	Westinghouse Air Brake
Heinz Focke	[83]	512	Germany	1965-2013	49	10	Focke & Co.
Mark I. Gardner	[84]	511	USA	1994-2010	17	30	AMD
Ravi K. Arimilli	[85]	508	India	1992-2019	28	18	IBM
Farhad Barzegar	[86]	504	Iran	1988-2021	34	15	AT&T
Louis H. Morin	[87]	503	USA	1924-1969	46	11	Louis H. Morin
Tobin A. King	[88]	501	Australia	2000-2018	19	26	Silverbrook Research
Tenko Yamashita	[89]	498	USA	2005-2021	17	29	IBM
Stephen E. Terry	[90]	492	USA	2003-2020	18	27	InterDigital
Pouya Hashemi	[91]	492	USA	2013-2021	9	55	IBM
James M. Hart	[92]	487	USA	1988-2019	32	15	General Motors
Lawrence A. Clevenger	[93]	483	USA	1996-2021	26	19	IBM
Jack A. Mandelman	[94]	481	USA	1987-2014	28	17	IBM
Muhammad A. Kazmi	[95]	480	Sweden	2010-2021	12	40	Ericsson
Brian M. O'Connell	[96]	477	USA	2009-2020	12	40	IBM
Thomas M. Willis III	[97]	476	USA	2006-2021	16	30	AT&T
John L. Melanson	[98]	476	USA	1978-2021	44	11	Cirrus Logic
Valentina Salapura	[99]	462	Bosnia and Herzegovina	2004-2021	18	26	IBM
Akira Nakazawa	[100]	461	Australia	1980-2020	41	11	Silverbrook Research
Eberhard Ammermann	[101]	451	Germany	1979-2015	37	12	BASF
Vincent J. Zimmer	[102]	451	USA	1999-2021	23	20	Intel
Brent A. Anderson	[103]	450	USA	2001-2021	21	21	IBM
Thomas E. Murray	[104]	449	USA	1891-1940	50	9	Thomas E. Murray
Hongyong Zhang	[105]	440	Japan	1993-2016	24	18	Semiconductor Energy Laboratory
Scott H. Wittkopp	[106]	435	USA	2001-2020	20	22	General Motors
Xuemin (Sherman) Chen	[107]	428	China	1997-2021	25	17	Broadcom
Robert Bennett	[108]	420	USA	2002-2021	20	21	AT&T
John Hays Hammond, Jr.	[109]	417	USA	1912-1967	56	7	John Hays Hammond, Jr.
Hossein Eslambolchi	[110]	416	USA	1993-2019	27	15	AT&T
Donald J. Barnickel	[111]	416	USA	2000-2021	22	19	AT&T
Cary L. Bates	[112]	414	USA	1994-2020	27	15	IBM
Michael (S.) Tsirkin	[113]	413	Israel	2012-2021	10	41	Red Hat
Wilhelm Brandes	[114]	411	Germany	1976-2010	35	12	Bayer
Gary W. Grube	[115]	407	USA	1991-2021	31	13	IBM
Bengt Lindoff	[116]	405	Sweden	2000-2021	22	18	Ericsson
Stanford R. Ovshinsky	[117]	400	USA	1952-2012	61	7	Energy Conversion Devices
Assaf Natanzon	[118]	395	Israel	2007-2021	15	26	EMC
Paul Marinier	[119]	393	Canada	2004-2021	18	22	InterDigital
Jeffrey E. Stahmann	[120]	389	USA	1994-2021	28	14	Cardiac Pacemakers
Josef Theurer	[121]	388	Austria	1958-2016	59	7	Plasser & Theurer
David V. Horak	[122]	388	USA	1992-2020	29	13	IBM
Paul W. Dent	[123]	386	USA	1984-2020	37	10	Ericsson
Timothy J. Slegel	[124]	385	USA	1993-2021	29	13	IBM
Wael W. Diab	[125]	384	USA	2003-2020	18	21	Broadcom
Dean L. Kamen	[126]	381	USA	1979-2021	43	9	DEKA
Greg R. Dhuse	[127]	380	USA	2011-2021	11	35	IBM
George P. Liang	[128]	379	China	1983-2018	36	11	Florida Turbine Technologies
James E. Bostick	[129]	379	USA	1993-2021	29	13	IBM
Hans-Joachim Santel	[130]	377	Germany	1986-2013	28	13	Bayer
Elizabeth A. Sweeney	[131]	376	USA	2010-2020	11	34	Intellectual Ventures
Gisela Lorenz	[132]	374	Germany	1990-2015	26	14	BASF
William Daniel Hillis	[133]	372	USA	1986-2021	36	10	Intellectual Ventures
Philip D. Nguyen	[134]	368	USA	1992-2021	30	12	Halliburton
Garry R. Jackson	[135]	367	Australia	2001-2016	16	23	Silverbrook Research
Carl J. Radens	[136]	364	USA	1994-2020	27	13	IBM
Norman M. Berry	[137]	364	Australia	2006-2021	16	23	Silverbrook Research
John M. Ganci	[138]	362	USA	2009-2021	13	28	IBM
George Westinghouse	[139]	361	USA	1873-1918	46	8	George Westinghouse
Hanson S. Gifford III	[140]	361	USA	1986-2021	36	10	Medtronic
Patrick J. O'Sullivan	[141]	360	Ireland	2008-2021	14	26	IBM
Mark W. Kroll	[142]	356	USA	1987-2020	34	10	Pacesetter
Wesley B. Legette	[143]	355	USA	2011-2021	11	32	IBM
Ajith K. Kumar	[144]	351	India	1984-2020	37	9	GE
Keith R. Walker	[145]	351	Saudi Arabia	2003-2021	19	18	IBM
Robert R. Schmidt	[146]	350	Germany	1971-2005	35	10	Bayer
Siddharth S. Oroskar	[147]	346	India	2010-2021	12	29	Sprint
Andrew D. Baptist	[148]	344	USA	2012-2021	10	34	IBM
Daniel J. Winarski	[149]	343	USA	1982-2021	40	9	IBM
Steven L. Teig	[150]	343	USA	1995-2021	27	13	Cadence Design Systems
Paul K. Dellock	[151]	342	USA	2002-2021	20	17	Ford
Kulvir S. Bhogal	[152]	337	USA	2003-2021	19	18	IBM
Jennifer L. Hillman	[153]	332	USA	1997-2014	18	18	Incyte
Chung-Lung (Kevin) Shum	[154]	332	USA	2001-2021	21	16	IBM
Jasinder P. Singh	[155]	330	USA	2010-2021	12	28	Sprint
Bor Z. Jang	[156]	329	Taiwan	1996-2021	26	13	Nanotek Instruments
Andrew J. Ouderkirk	[157]	328	USA	1989-2021	33	10	3M
Liang Liu	[158]	322	China	2005-2020	16	20	Hon Hai
Cyprian E. Uzoh	[159]	320	Nigeria	1998-2021	24	13	Invensas
Frank J. Viola	[160]	319	USA	1981-2021	41	8	Covidien
Victor S. Moore	[161]	315	USA	1982-2020	39	8	IBM
Stefan Parkvall	[162]	314	Sweden	2003-2021	19	17	Ericsson
Victoria Smith	[163]	308	USA	2006-2017	12	26	Genentech
Paul R. Bastide	[164]	308	USA	2013-2021	9	34	IBM
Aruna Zhamu	[165]	307	USA	2009-2021	13	24	Nanotek Instruments
Ramachandra Divakaruni	[166]	303	India	2000-2020	21	14	IBM
Christopher B. Locke	[167]	302	UK	2010-2021	12	25	KCI
Sandeep R. Patil	[168]	301	India	2008-2021	14	22	IBM
Robert G. LeTourneau	[169]	299	USA	1936-1968	33	9	LeTourneau Technologies
Christian P. Jacobi	[170]	299	Germany	1999-2021	23	13	IBM
Dorin Comaniciu	[171]	299	USA	2003-2021	19	16	Siemens
Robert Baldemair	[172]	296	Sweden	2007-2021	15	20	Ericsson
Daniel C. Edelstein	[173]	294	USA	1991-2021	31	9	IBM
William R. Tonti	[174]	292	USA	1994-2020	27	11	IBM
Zine-Eddine Boutaghou	[175]	290	Algeria	1994-2018	25	12	Seagate Technology
Brent Keeth	[176]	290	USA	1994-2020	27	11	Micron
Adam Heller	[177]	289	Romania	1968-2020	53	5	Abbott Laboratories
Madhusudan K. Iyengar	[178]	289	India	2005-2020	16	18	IBM
Jeffrey W. Sleight	[179]	288	USA	1998-2020	23	13	IBM
Hui Zang	[180]	285	USA	2014-2021	8	36	GlobalFoundries
Michael A. Rothman	[181]	281	USA	2001-2020	20	14	Intel
Christopher J. Dawson	[182]	281	USA	2006-2021	16	18	IBM
Zvi Or-Bach	[183]	278	USA	1982-2021	40	7	MonolithIC 3D Inc.
Michael L. Fripp	[184]	274	USA	2004-2021	18	15	Halliburton
Takeshi Chujoh	[185]	273	Japan	1995-2020	26	10	Toshiba
Bran Ferren	[186]	273	USA	1986-2021	36	8	Intellectual Ventures
Craig E. Hampel	[187]	273	USA	1996-2021	26	10	Rambus
Hartley Owen	[188]	267	USA	1976-2010	35	8	Mobil
Rajiv V. Joshi	[189]	267	USA	1986-2021	36	7	IBM
Olga Bandman	[190]	266	Russia	1997-2018	22	12	Incyte
Eran Steinberg	[191]	266	Israel	1996-2020	25	11	FotoNation
Corville O. Allen	[192]	266	Jamaica	2009-2021	13	20	IBM
Sheldon K. Meredith	[193]	265	USA	1996-2021	26	10	AT&T
Diana Pani	[194]	261	Canada	2008-2021	14	19	InterDigital
Yoshihiro Kikuchi	[195]	258	Japan	1994-2018	25	10	Toshiba
Gary D. Cudak	[196]	258	USA	2013-2021	9	29	Lenovo
Martin G. Keen	[197]	257	UK	2016-2021	6	43	IBM
Harry (Tom) Graef	[198]	256	USA	1976-2020	45	6	Diebold Nixdorf
Imad Libbus	[199]	256	USA	2007-2021	15	17	Cardiac Pacemakers
Santokh S. Badesha	[200]	255	India	1983-2020	38	7	Xerox
Matthew B. Trevathan	[201]	253	USA	2005-2020	16	16	IBM
Ilya Volvovski	[202]	250	Russia	2011-2021	11	23	IBM
Johnny M. Shieh	[203]	248	USA	1996-2020	25	10	IBM
Stephen M. Trimberger	[204]	248	USA	1988-2020	33	8	Xilinx
Nobuyuki Taniguchi	[205]	245	Japan	1979-2015	37	7	Minolta
Louis B. Rosenberg	[206]	245	USA	1995-2020	26	9	Immersion
Nathan J. Peterson	[207]	243	USA	2006-2021	16	15	Lenovo
Dale W. Malik	[208]	243	USA	1995-2021	27	9	AT&T
Philip S. Yu	[209]	240	USA	1982-2018	37	6	IBM
Seung H. Kang	[210]	240	USA	2002-2020	19	13	Qualcomm
Choonghyun Lee	[211]	240	USA	2017-2021	5	48	IBM
Xin Miao	[212]	240	USA	2016-2021	6	40	IBM
James R. Kraemer	[213]	239	USA	2008-2020	13	18	IBM
Al Chakra	[214]	238	Lebanon	2010-2021	12	20	IBM
Gerald F. McBrearty	[215]	237	USA	1997-2021	25	9	IBM
Thomas J. Kennedy III	[216]	236	USA	1992-2020	29	8	Callaway
Mark A. Horowitz	[217]	236	USA	1993-2020	28	8	Rambus
Stephen G. Perlman	[218]	235	USA	1989-2021	33	7	Sony
David C. Gibbon	[219]	233	USA	1995-2021	27	9	AT&T
Benzion Landa	[220]	232	Israel	1976-2021	46	5	Savin
Ilyas Mohammed	[221]	232	USA	2003-2021	19	12	Tessera
Iana Siomina	[222]	232	Sweden	2012-2021	10	23	Ericsson
Burkay Donderici	[223]	230	Turkey	2014-2021	8	29	Halliburton
John A. Colgrove	[224]	226	USA	1991-2021	31	7	Pure Storage
James W. Seaman	[225]	225	USA	2005-2020	16	14	IBM
Dureseti Chidambarrao	[226]	225	USA	1995-2020	26	9	IBM
S. Christopher Gladwin	[227]	225	USA	1999-2021	23	10	IBM
Michael A. Guillorn	[228]	223	USA	2003-2020	18	12	IBM
Vijay Narayanan	[229]	222	USA	2004-2021	18	12	IBM
Paul Ian Mackey	[230]	220	Australia	2008-2016	9	24	Silverbrook Research
Maulik K. Shah	[231]	220	USA	2011-2020	10	22	Sprint
Mukta Ghate Farooq	[232]	220	India	1993-2020	28	8	IBM
Aaron K. Baughman	[233]	220	USA	2011-2021	11	20	IBM
Daniel Larsson	[234]	220	Sweden	2012-2021	10	22	Ericsson
Martin Langhammer	[235]	215	Canada	2001-2020	20	11	Altera
Kunal R. Parekh	[236]	215	USA	1996-2021	26	8	Micron
Sebastian T. Ventrone	[237]	214	USA	1989-2020	32	7	IBM
Jed H. Rankin	[238]	214	USA	2000-2020	21	10	IBM
Jonathan J. Hull	[239]	214	USA	1995-2020	26	8	Ricoh
Rajarshi Gupta	[240]	214	India	2004-2020	17	13	Qualcomm
Rhonda L. Childress	[241]	214	USA	2004-2021	18	12	IBM
Bruce B. Pedersen	[242]	213	USA	1992-2020	29	7	Altera
Gregory J. McAvoy	[243]	212	Ireland	2003-2020	18	12	Silverbrook Research
Shuji Nakamura	[244]	211	Japan	1994-2020	27	8	UC Santa Barbara
Sergey Y. Shumarayev	[245]	211	Russia	2001-2021	21	10	Altera
Steven J. Simske	[246]	209	USA	2007-2021	15	14	HP
Arup Bhattacharyya	[247]	207	India	1974-2021	48	4	Micron
David M. Durham	[248]	207	USA	2003-2021	19	11	Intel
Craig M. Trim	[249]	206	USA	2013-2021	9	23	IBM
Hiroshi (You) Yoshioka	[250]	205	Japan	1997-2015	19	11	Toshiba
Patrick B. Usoro	[251]	205	USA	1999-2016	18	11	General Motors
Robert E. Fischell	[252]	205	USA	1963-2020	58	4	Angel Medical Systems
Paul W. Coteus	[253]	205	USA	1992-2020	29	7	IBM
Fredrik Gunnarsson	[254]	205	Sweden	2002-2021	20	10	Ericsson
Michael K. Bugenhagen	[255]	205	USA	2008-2021	14	15	Lumen Technologies
Sadeg M. Faris	[256]	202	Libya	1979-2018	40	5	Reveo

This table is usually updated every Tuesday evening in US Eastern time, and is current as of February 2, 2021.

The columns are defined as follows:

• Inventor: The name of the inventor.
• Patents: The number of utility patents that have been issued. Only utility patents (or the international equivalent) are listed, as a utility patent is a patent for an invention. Not all patents are for inventions. Other patent types include: design patents for the ornamental design of an object; plant patents for plant varieties; and reissue patents, where a correction is made to an already granted patent. This list does not include patent applications (patents pending) as there is no guarantee that a patent application actually describes a novel invention until the patent is granted.
• Country: The country of birth or upbringing of the inventor, where known. If unknown, this is the country of residence identified in the inventor's patent filings.
• Patent Years: The first and last year in which an inventor received a patent issuance.
• Years: The number of years between and including the first and last year in which an inventor received a patent issuance.
• Patents / Year: The average number of patents received per year [Patents column divided by Years column, rounded].
• Majority assignment: The entity that has the most patents assigned from an inventor's portfolio. This is current and not original assignment. It is usually, but not always an indication of which company the inventor worked at for the majority of their patent activity.

As the average number of patents per inventor is around 3, some sources define prolific inventors as five times above the average (in terms of patents), leading to a threshold of 15 patents.[257] However, this table currently has an arbitrary cut-off limit for inclusion of 200 patents. This is purely for practical reasons – there are tens of thousands of inventors with more than 15 patents. The threshold of 200 patents means that some famous prolific inventors such as Nikola Tesla are not included in this list, as Tesla had 111 patents.[258][259]

This table is a sortable list of the most prolific inventors as measured by utility patents granted. It does not include other types of invention, such as inventions that were never applied for nor granted, for which there is no known source. Nor does the table attempt to measure the significance of an inventor and their inventions. The significance of inventions is often not apparent until many decades after the invention has been made. For recent inventors, it is not yet possible to determine their place in history.

The common symbol for inventiveness, the light bulb, is an example. The first incandescent light bulb was invented by British chemist Sir Humphry Davy in 1802. Many subsequent inventors improved Davy's invention prior to the successful commercialization of electric lighting by Thomas Edison in 1880, 78 years later. Electric lighting continued to be developed. Edison's carbon filament light bulb was made obsolete by the tungsten filament light bulb, invented in 1904 by Sándor Just and Franjo Hanaman. It is this that forms the popular conception of a light bulb, though there are other major forms of lighting. The principle of fluorescent lights was known since 1845, and various inventors, including Edison and Nikola Tesla worked on them without commercial success. Various improvements were made by many other inventors, until General Electric introduced "fluorescent lumiline lamps" commercially in 1938, first available to the public at the 1939 World's Fair. LED lamps also have a long history, with the first light-emitting diode (LED) invented in 1927 by Oleg Losev. LEDs were initially of low brightness, and have been used as indicator lamps and seven-segment displays since 1968. It wasn't until the development of high efficiency blue LEDs by Shuji Nakamura in the 1980s that white LEDs for lighting applications became practical. Although higher cost than incandescent light bulbs, LEDs have higher efficiency and longer life and may finally displace light bulbs in general lighting applications. In each case, more than 50 years passed between the initial invention and commercial success in general lighting applications.

Rankings of prolific inventors have been published at various times. However, until the patent records were digitized, these lists were very tedious to prepare, as many thousands of patent records had to be checked manually. Even after digitization, it is still not a simple process. While the USPTO keeps statistics for annual rankings of inventions assigned to companies, it no longer publishes rankings of individual inventors. The last such list was published by the USPTO in 1998.[260] Also, patents predating 1976 have not yet been digitized in the USPTO records. This means that patents before 1976 will not be included in a USPTO search by inventor name, and the number of patents granted before 1976 must be added to current searches.

In January 1936, Popular Science published a list of the "most prolific living inventors to be found in America today".

Thomas Edison was not included in the list, as he died in 1931, five years earlier.

On December 4, 2000, Time Magazine published a list of the "top five inventors".

This list only included U.S. inventors, so omitted Canadian inventor George Albert Lyon, with 993 U.S. patents at the time of publication, Japanese inventor Shunpei Yamazaki, with 745 U.S. patents, and Béla Barényi, with 595 German patents. Also omitted were John F. O'Connor with 949 U.S. patents, and Carleton Ellis, with 753 U.S. patents at the time of publication.

On December 13, 2005, USA Today published a list of "the top 10 living U.S. patent holders":[261]

This research was performed by ipIQ of Chicago (now "The Patent Board"[262]) and 1790 Analytics[263] of New Jersey. This list only considered living inventors, and thus did not include prolific inventors such as Thomas Edison, Melvin De Groote, and Elihu Thomson. This list included design patents, which are not patents for inventions.

On October 15, 2007, Condé Nast Portfolio Magazine published a list[264] of "the world's most prolific inventors alive":

This research was performed by The Patent Board,[262] a Chicago patent research and advisory firm. As with the USA Today list, the Portfolio list only considered living inventors, and thus did not include such prolific inventors as Thomas Edison. This list also included design patents, which are not patents for inventions.

On May 6, 2011, Business Insider published an article titled: "The Ten Greatest Inventors In The Modern Era"[3] containing the following list:

This list included living and dead inventors, and only included granted utility patents (patents for inventions).

Strutpatent.com publishes a list of the "Top 10 Inventors"[265] listing inventors ranked by US patents (of all types) issued since 1990:

This list included only patents granted since 1990, and includes design patents as well as utility patents.

Strutpatent.com publishes weekly, monthly, and annual lists of the top ten categories, inventors and assignees of US patents since 2007. These lists include all patent types, not just patents for inventions (utility patents).

The top ten inventors of US patents for 2007:[266]

The top ten inventors of US patents for 2008:[267]

The top ten inventors of US patents for 2009:[268]

The top ten inventors of US patents for 2010:[269]

The top ten inventors of US patents for 2011:[270]

The top ten inventors of US patents for 2012:[271]

This table omitted Rick Allen Hamilton II. The USPTO database shows Hamilton was an inventor or co-inventor of 128 US patents granted in 2012,[272] which would place Hamilton at 6th rank for 2012.

Differences in patent numbers between the various lists are due to several reasons:

• The lists were created on different dates. As many of the inventors in the lists are still active, the number of patents they hold are increasing.
• While the U.S. Patent and Trademark Office (USPTO) is the primary source for U.S. patent information, only patents issued since 1976 can be electronically searched by the inventor's name at the USPTO website. For some of the listed inventors, such as Thomas Edison, all of their patents predate 1976, so other sources must be used.
• Often entities list the worldwide total number of patents that they hold. This is not the same as the number of inventions, as a patent in one country may be for the same invention as a patent in another country. The set of patents covering a single invention in different countries is a Patent family.
• The Time, USA Today and Portfolio lists show the total number of U.S. patents, including patents for designs (Design patents) as well as patents for inventions (Utility patents).
• The annual lists from strutpatent.com list only those patents issued in the particular year to the inventor, not all of the inventor's patents.

• Timeline of historic inventions
• List of inventors
• List of top United States patent recipients