How Organic Diodes Make Light Using Special Molecules
Eastman Kodak's 1982 patent on creating light-emitting diodes (OLEDs) using organic materials, specifically a layer of porphyrinic compounds to help inject electrical charges.
Original patent title: “Organic electroluminescent cell”
Eastman Kodak's 1982 patent on creating light-emitting diodes (OLEDs) using organic materials, specifically a layer of porphyrinic compounds to help inject electrical charges. Granted to Eastman Kodak Co in 1982 with 6 claims and 1,031 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
This patent describes how to build a light-emitting device, like a tiny light bulb, using organic materials. It details an 'electroluminescent cell' with a light-producing layer sandwiched between two electrical contacts (an anode and a cathode). The key innovation is adding a special 'hole-injecting zone' made of a porphyrinic compound, like phthalocyanine, right next to the anode. This layer helps electrical 'holes' (think of them as positive charges) move more easily into the light-emitting layer, making the device work better.
The gap
What does this patent NOT cover?
- Electroluminescent cells that do not use organic materials for the light-emitting zone.
- Devices where the hole-injecting zone is not made of a porphyrinic compound.
- Cells that lack a distinct hole-injecting zone between the luminescent zone and the anode.
- Electroluminescent cells where the binder material has a breakdown field strength below 10^5 volt/cm.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The crucial insight was realizing that a specific class of organic molecules, porphyrinic compounds, could act as an efficient 'bridge' to inject positive charge carriers (holes) into the organic light-emitting layer, significantly improving device performance and efficiency.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Modern OLED displays in smartphones
OLED televisions
Flexible OLED screens
Why it matters
The bigger picture
This patent is a foundational piece for modern organic light-emitting diode (OLED) technology. OLEDs are now ubiquitous in high-end smartphone screens, televisions, and flexible displays. The principles laid out by Ching W. Tang here enabled the development of efficient, thin, and flexible displays that revolutionized consumer electronics.
Filed
July 17, 1980
Granted
October 26, 1982
Market context
Who's building on this
Companies in this space
The foundational work in this patent has been built upon by countless companies in the display and lighting industries. Major players like Samsung Display, LG Display, and Universal Display Corporation (UDC) are heavily involved in developing and manufacturing OLED technology, leveraging advancements in organic materials and device architecture.
Market impact
This patent laid the groundwork for the entire OLED industry. It established the core architecture for efficient organic light-emitting devices, enabling the creation of vibrant, thin, and energy-efficient displays that have become a standard in premium consumer electronics, driving significant market growth and innovation in display technology.
Claim 1 — Plain English
What this patent covers
This patent describes how to build a light-emitting device, like a tiny light bulb, using organic materials. It details an 'electroluminescent cell' with a light-producing layer sandwiched between two electrical contacts (an anode and a cathode). The key innovation is adding a special 'hole-injecting zone' made of a porphyrinic compound, like phthalocyanine, right next to the anode. This layer helps electrical 'holes' (think of them as positive charges) move more easily into the light-emitting layer, making the device work better.
The clever bit
The crucial insight was realizing that a specific class of organic molecules, porphyrinic compounds, could act as an efficient 'bridge' to inject positive charge carriers (holes) into the organic light-emitting layer, significantly improving device performance and efficiency.
What it does not cover
- Electroluminescent cells that do not use organic materials for the light-emitting zone.
- Devices where the hole-injecting zone is not made of a porphyrinic compound.
- Cells that lack a distinct hole-injecting zone between the luminescent zone and the anode.
- Electroluminescent cells where the binder material has a breakdown field strength below 10^5 volt/cm.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Moderate
Citation count
40/40
Highly cited
Claim breadth
4/20
Moderate scope
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$63K – $202K
Midpoint $126K · expired or expiring · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
6 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Tang, C. W. (1982). How Organic Diodes Make Light Using Special Molecules (U.S. Patent No. 4,356,429). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/4356429/oled-organic-light-emitting-diode
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US4356429"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4965188 · 1990
How to Make Many Copies of a DNA Piece with Heat
This patent describes the Polymerase Chain Reaction (PCR) method, a technique to make millions of copies of a specific DNA segment using a heat-resistant enzyme and repeated temperature changes.
Cetus Corp
US 4235871 · 1980
How to Encapsulate Active Materials in Lipid Bubbles Efficiently
This patent describes a method for trapping biologically active substances inside tiny, multi-layered fat bubbles called liposomes, using a specific water-in-oil emulsion and gel-forming process to improve how much material gets captured.
Individual
Semantically similar
You might also find these interesting
US 4683195 · 1987
US 8697359 · 2014
US 7657849 · 2010
US 4733665 · 1988
US 4965188 · 1990
US 4235871 · 1980
US 4405829 · 1983
US 4575330 · 1986
US 4683202 · 1987
US 4376110 · 1983
US 3953566 · 1976
US 5121329 · 1992
US 7479949 · 2009
US 5347632 · 1994
US 5521184 · 1996
US 4528643 · 1985
US 10452978 · 2019
US 3906166 · 1975
US 4703008 · 1987
US 4727064 · 1988
US 6285999 · 2001
US 7469381 · 2008
US 4665913 · 1987
US 5210015 · 1993
US 5960411 · 1999
US 5471515 · 1995
US 4816567 · 1989
US 4063220 · 1977
US 4522811 · 1985
US 3778614 · 1973
US 7669123 · 2010
US 7653883 · 2010
US 4200770 · 1980
US 9548050 · 2017
US RE47218 · 2019
US 5825352 · 1998
US 4558302 · 1985
US 7527791 · 2009
US 11204787 · 2021
US 10878335 · 2020
US 3691140 · 1972
US 5487069 · 1996
US 5325765 · 1994
US RE49155 · 2022
US 7957762 · 2011
US 3803463 · 1974
US 8675084 · 2014
US 5273995 · 1993
US 6323846 · 2001
US 4195637 · 1980
US 8887212 · 2014
US 4009052 · 1977
US 4237224 · 1980
US 4683194 · 1987
US 10909459 · 2021
US 4356429 · 1982
US 5961804 · 1999
US 5272135 · 1993
US 10133995 · 2018
US 4736866 · 1988
US 8606792 · 2013
US 10102356 · 2018
US 3789832 · 1974
US 4723129 · 1988
US 8372396 · 2013
US 9280591 · 2016
US 3672155 · 1972
US 6090382 · 2000
US 9349016 · 2016
US 7158878 · 2007
US 9332078 · 2016
US 8171128 · 2012
US 8990235 · 2015
US 3761682 · 1973
US 7782297 · 2010
US 11436484 · 2022
US 10147076 · 2018
US 9202233 · 2015
US 5075216 · 1991
US 4681893 · 1987
US 7434177 · 2008
US 6054297 · 2000
US 8285656 · 2012
US 6267958 · 2001
US 9544394 · 2017
US 8423408 · 2013
US 5176995 · 1993
US 6682736 · 2004
US 5585089 · 1996
US 6590928 · 2003
US 7930393 · 2011
US 9939279 · 2018
US 6233389 · 2001
US 4131919 · 1978
US 5774670 · 1998
US 2297691 · 1942
US 3819587 · 1974
US RE46310 · 2017
US 4259444 · 1981
US 9083770 · 2015
US 6370526 · 2002
US 8898564 · 2014
US 3659285 · 1972
US 8125456 · 2012
US 8600430 · 2013
US 8214768 · 2012
US 5563422 · 1996
US 6523026 · 2003
US 5726435 · 1998
US 8429565 · 2013
US 5303388 · 1994
US 4166152 · 1979
US 6884879 · 2005
US 10275117 · 2019
US 10373050 · 2019
US 4267420 · 1981
US 3946398 · 1976
US 11377237 · 2022
US 11858662 · 2024
US 8291344 · 2012
US 11905044 · 2024
US 4231938 · 1980
US 8410274 · 2013
US 8914392 · 2014
US 8423911 · 2013
US 11706521 · 2023
US 5639476 · 1997
US 4669140 · 1987
US 7812826 · 2010
US 10002199 · 2018
US 8074172 · 2011
US 4490728 · 1984
US 10127595 · 2018
US 5305919 · 1994
US 9268820 · 2016
US 8399514 · 2013
US 7387788 · 2008
US 11840398 · 2023
US 10050760 · 2018
US 11809700 · 2023
US RE45701 · 2015
US 8831529 · 2014
US 8448084 · 2013
US 10184000 · 2019
US 10472419 · 2019
US 10564770 · 2020
US 8732039 · 2014
US 6355623 · 2002
US 10013058 · 2018
US 8521818 · 2013
US 10169761 · 2019
US 8688813 · 2014
US 5199424 · 1993
US 9845355 · 2017
US 4356270 · 1982
US 4687200 · 1987
US 9405582 · 2016
US 11615208 · 2023
US 8701014 · 2014
US 7355593 · 2008
US 10466883 · 2019
US 7136875 · 2006
US 10318574 · 2019
US 9965247 · 2018
US 9672117 · 2017
US 5397703 · 1995
US 3713148 · 1973
US 8700540 · 2014
US 9492534 · 2016
US 3655201 · 1972
US 4302518 · 1981
US 4173796 · 1979
US 8216583 · 2012
US 3693535 · 1972
US 7509588 · 2009
US 2708656 · 1955
US 10402750 · 2019
US 9607103 · 2017
US 11685554 · 2023
US RE48170 · 2020
US 11062228 · 2021
US 8580275 · 2013
US 7222127 · 2007
US 2130523 · 1938
US 9479807 · 2016
US 10832138 · 2020
US 8592397 · 2013
US 7111231 · 2006
US 9677869 · 2017
US 3826068 · 1974
US 10019297 · 2018
US 3819921 · 1974
US 11921980 · 2024
US 12008152 · 2024
US 6195698 · 2001
US 12431234 · 2025
US 7070775 · 2006
US 10192220 · 2019
US RE45905 · 2016
US 6567533 · 2003
US 9538220 · 2017
US 6424946 · 2002
US 8775328 · 2014
US 10223653 · 2019
US 3668658 · 1972
US 11492143 · 2022
US 10217092 · 2019
US 11623768 · 2023
US 9535948 · 2017
US 11958662 · 2024
US 11608181 · 2023
US 11651227 · 2023
US 7672870 · 2010
US RE40324 · 2008
US 2981877 · 1961
US 8825660 · 2014
US 10198731 · 2019
US 3220960 · 1965
US 3492131 · 1970
US 9760393 · 2017
US 8983975 · 2015
US 9516045 · 2016
US 9330167 · 2016
US 7169901 · 2007
US 6458360 · 2002
US RE39497 · 2007
US 11708181 · 2023
US 9430664 · 2016
US 6816710 · 2004
US 12497890 · 2025
US 8112476 · 2012
US 2569347 · 1951
US 2524035 · 1950
US 3387286 · 1968
US 3005282 · 1961
US 9881277 · 2018
US RE48900 · 2022
US 11593558 · 2023
US RE50567 · 2025
US RE50510 · 2025
US 10106579 · 2018
US 12365678 · 2025
US 3792322 · 1974
US 9483121 · 2016
US 2929922 · 1960
US 5191573 · 1993
US 8822430 · 2014
US 3142599 · 1964
US D504889 · 2005
US RE50301 · 2025
US 10303266 · 2019
US 5838906 · 1998
US 9874914 · 2018
US 9477524 · 2016
US 12200123 · 2025
US 11023780 · 2021
US 11544573 · 2023
US 10402375 · 2019
US 3867571 · 1975
US 3359678 · 1967
US 9811430 · 2017
US 2543181 · 1951
US 10289962 · 2019
US 7530026 · 2009
US 8176439 · 2012
US 9998475 · 2018
US 11919658 · 2024
US RE48750 · 2021
US 12043450 · 2024
US RE50045 · 2024
US D670286 · 2012
US 10185946 · 2019
US 4031893 · 1977
US RE49995 · 2024
US 4063048 · 1977
US RE49912 · 2024
US 10025401 · 2018
US 11932418 · 2024
US RE45254 · 2014
US 12442345 · 2025
US 9602875 · 2017
US 9602605 · 2017
US 8769558 · 2014
US 5973252 · 1999
US 7740842 · 2010
US 3541541 · 1970
US 11853535 · 2023
US 5595721 · 1997
US 12354567 · 2025
US 5559942 · 1996
US 12321234 · 2025
US 12310123 · 2025
US 2717437 · 1955
US 12299012 · 2025
US RE48492 · 2021
US 3733309 · 1973
US 12145678 · 2024
US 9154532 · 2015
US 12244567 · 2025
US 3322485 · 1967
US 12217035 · 2025
US 12211234 · 2025
US 5002952 · 1991
US 12453456 · 2025
US RE49538 · 2023
US 3789409 · 1974
US 3585356 · 1971
US 11878818 · 2024
US RE49480 · 2023
US 5920316 · 1999
US 12112345 · 2024
US 7296016 · 2007
US 7596761 · 2009
US 12101428 · 2024
US 10157378 · 2018
US 8972477 · 2015
US 2026082 · 1935
US 5574018 · 1996
US 4147780 · 1979
US 12277890 · 2025
US 8060616 · 2011
US RE49280 · 2022
US 12255678 · 2025
US 9216996 · 2015
US 3057356 · 1962
US 3671542 · 1972
US RE50690 · 2025
US 11449194 · 2022
US 2266401 · 1941
US 3927193 · 1975
US 9075783 · 2015
US 7343566 · 2008
US 11521601 · 2022
US 6883201 · 2005
US 8957079 · 2015
US 12100000 · 2024
US RE45559 · 2015
US 11429864 · 2022
US 11170293 · 2021
US 3711262 · 1973
US 11794927 · 2023
US 4136359 · 1979
US RE48965 · 2022
US 7801772 · 2010
US 10108619 · 2018
US 7877330 · 2011
US 11124318 · 2021
US RE48925 · 2022
US 9934408 · 2018
US 11501192 · 2022
US 4756529 · 1988
US 9154561 · 2015
US 9276922 · 2016
US 8069204 · 2011
US 6302230 · 2001
US 5754176 · 1998
US 11645473 · 2023
US 9699159 · 2017
US 11059609 · 2021
US 4357215 · 1982
US RE47420 · 2019
US RE49412 · 2023
US 3489148 · 1970
US 11814186 · 2023
US 9830146 · 2017
US RE48596 · 2021
US 12060178 · 2024
US 2780765 · 1957
US 11753188 · 2023
US 4549302 · 1985
US 10212148 · 2019
US 12266789 · 2025
US 11488063 · 2022
US RE38800 · 2005
US 12233456 · 2025
US 11975868 · 2024
US 10928980 · 2021
US 10525078 · 2020
US RE48406 · 2021
US 9021535 · 2015
US 12464567 · 2025
US 5110802 · 1992
US 10543427 · 2020
US 8843528 · 2014
US 10204358 · 2019
US RE48232 · 2020
US 6901559 · 2005
US 1948384 · 1934
US 10732795 · 2020
US 2292387 · 1942
US 3293513 · 1966
US RE47935 · 2020
US 10579225 · 2020
US 8710041 · 2014
US 9098533 · 2015
US 11609640 · 2023
US 223898 · 1880
US 9398340 · 2016
US 2230654 · 1941
US 2682235 · 1954
US 8356005 · 2013
US 4492385 · 1985
US 3997676 · 1976
US 3614954 · 1971
US 12031028 · 2024
US 9723108 · 2017
US 10210146 · 2019
US 9075661 · 2015
US 9037656 · 2015
US 2742437 · 1956
US 3102230 · 1963
US RE48399 · 2021
US 10140638 · 2018
US 12189012 · 2025
US 8204793 · 2012
US 10108910 · 2018
US 2487400 · 1949
US 3388314 · 1968
US 3723796 · 1973
US 10427804 · 2019
US 10311112 · 2019
US 2988237 · 1961
US 9888087 · 2018
US 3678182 · 1972
US 12332345 · 2025
US 3498798 · 1970
US 2168726 · 1939
US 3138743 · 1964
US 4531203 · 1985
US 9949013 · 2018
US 8702514 · 2014
US 10853731 · 2020
US 10521248 · 2019
US 12398901 · 2025
US D618677 · 2010
US 12387890 · 2025
US 7530029 · 2009
US 8249948 · 2012
US 10357559 · 2019
US 3191596 · 1965
US 11827373 · 2023
US 1102653 · 1914
US 2911759 · 1959
US 9741006 · 2017
US 12288901 · 2025
US 821393 · 1906
US 2541851 · 1951
US 2708722 · 1955
US 10138293 · 2018
US RE45786 · 2015
US 12486789 · 2025
US 11188196 · 2021
US 9661085 · 2017
US 10626109 · 2020
US 6824780 · 2004
US 2929804 · 1960
US 8496208 · 2013
US 3501586 · 1970
US 10210529 · 2019
US 5443036 · 1995
US 12123456 · 2024
US 2741146 · 1956
US 12343456 · 2025
US 7503526 · 2009
US RE47150 · 2018
US 9264471 · 2016
US 7993644 · 2011
US 10981678 · 2021
US 12012230 · 2024
US 9792375 · 2017
US 447918 · 1891
US 12222345 · 2025
US RE48183 · 2020
US 11945698 · 2024
US 3789410 · 1974
US 9210222 · 2015
US 9606820 · 2017
US 10664744 · 2020
US 4810490 · 1989
US 8307004 · 2012
US 7836050 · 2010
US 10266282 · 2019
US 8862582 · 2014
US 6339142 · 2002
US 9721254 · 2017
US 8606929 · 2013
US 5181252 · 1993
US 10751416 · 2020
US 12178901 · 2024
US 9744181 · 2017
US RE44685 · 2013
US 3987163 · 1976
US 12409012 · 2025
US 9073647 · 2015
US 10176475 · 2019
US 2495429 · 1950
US 11724824 · 2023
US 10350488 · 2019
US 2620061 · 1952
US 7225154 · 2007
US 2744122 · 1956
US 10003680 · 2018
US 10565497 · 2020
US 3120606 · 1964
US 11513606 · 2022
US 7297334 · 2007
US 3778335 · 1973
US 9011851 · 2015
US 12073418 · 2024
US 7807153 · 2010
US 8735372 · 2014
US 8372398 · 2013
US 12508901 · 2025
US 7750134 · 2010
US 7404202 · 2008
US 3351836 · 1967
US 3349949 · 1967
US 2514269 · 1950
US 12420123 · 2025
US 11511890 · 2022
US 12156789 · 2024
US 1342885 · 1920
US 8429011 · 2013
US 174465 · 1876
US 2988008 · 1961
US 10800552 · 2020
US 2390636 · 1945
US 2768109 · 1956
US 2820187 · 1958
US 10618678 · 2020
US 1203495 · 1916
US 3552770 · 1971
US 3043625 · 1962
US 6903756 · 2005
US RE46915 · 2018
US 1964911 · 1934
US 3378274 · 1968
US 12086666 · 2024
US 8889135 · 2014
US RE46907 · 2018
US 1661058 · 1928
US 2089171 · 1937
US RE46290 · 2017
US 2776139 · 1957
US 2012680 · 1935
US RE45965 · 2016
US 3079728 · 1963
US 12475678 · 2025
US 12167890 · 2024
US 2817025 · 1957
US 3167440 · 1965
US 1994488 · 1935
US 2415012 · 1947
US RE42346 · 2011
US 1956350 · 1934
US 808897 · 1906
US 3055113 · 1962
US 1113371 · 1914
US 2982547 · 1961
US 2370990 · 1945
US 3023824 · 1962
US 8689253 · 2014
US 1480914 · 1924
US 1781541 · 1930
US 2442141 · 1948
US 8495220 · 2013
US 12134567 · 2024
US 2189285 · 1940
US 200521 · 1878
US 2960558 · 1960
US 9398104 · 2016
US 10152712 · 2018
US 10402038 · 2019
US 7528115 · 2009
US 8062633 · 2011
US 10318876 · 2019
US RE48450 · 2021
US 10241750 · 2019
US 400664 · 1889
US 1242872 · 1917
US 2519859 · 1950
US 2799449 · 1957
US 2187888 · 1940
US 11993444 · 2024
US 7596798 · 2009
US 1612267 · 1926
US 1505592 · 1924
US 2546078 · 1951
US 723325 · 1903
US 2956114 · 1960
US 1760820 · 1930
US 2133235 · 1938
US 6266060 · 2001
US RE36574 · 2000
US 1219881 · 1917
US 468226 · 1892
US 2058761 · 1936
US 3503060 · 1970
US 8577894 · 2013
US 613809 · 1898
US 2331117 · 1943
US RE39833 · 2007
US 9605068 · 2017
US 1351086 · 1920
US 12376789 · 2025
US 1773079 · 1930
US 3454279 · 1969
US 608845 · 1898
US 9402913 · 2016
US 349611 · 1886
US 1469997 · 1923
US 11715014 · 2023
US 1264128 · 1918
US 1647 · 1840
US 2118318 · 1938
US 775134 · 1904
US RE46627 · 2017
US 2485039 · 1949
US 1057423 · 1913
US 454622 · 1891
US RE48036 · 2020
US 2196914 · 1940
US 9919813 · 2018
US 6793929 · 2004
US RE48592 · 2021
US 5639606 · 1997
US 7685160 · 2010
US 20150206070
US 2880132 · 1959
US 5891653 · 1999
US 207559 · 1878
US 2713176 · 1955
US 644077 · 1900
US 31128 · 1861
US 1721815 · 1929
US 2824789 · 1958
US 3475623 · 1969
US 10028963 · 2018
US 10456769 · 2019
US 10113167 · 2018
US 9824092 · 2017
US 11267584 · 2022
US 3633 · 1844
US 9811783 · 2017
US 2046343 · 1936
US 10163106 · 2018
US 4302536 · 1981
US 8278036 · 2012
US 586193 · 1897
US 78317 · 1868
US 36836 · 1862
US 1906844 · 1933
US 22186 · 1858
US 6531124 · 2003
US 1967861 · 1934
US 10362429 · 2019
US 9965705 · 2018
US 10702600 · 2020
US 4677614 · 1987
US 5903495 · 1999
US 4914603 · 1990
US 942699 · 1909
US 2485586 · 1949
US 2702035 · 1955
US 743801 · 1903
US 375962 · 1888
US 9839649 · 2017
US 7663607 · 2010
US 6362826 · 2002
US 5401560 · 1995
US 10824959 · 2020
US 7664715 · 2010
US 3333846 · 1967
US 3735375 · 1973
US 382280 · 1888
US RE46892 · 2018
US 5013088 · 1991
US 10155945 · 2018
US 8046721 · 2011
US 11727263 · 2023
US 1462456 · 1923
US 37305 · 1863
US 9467413 · 2016
US 139121 · 1873
US 879532 · 1908
US 157124 · 1874
US 558393 · 1896
US 8080 · 1851
US 889823 · 1908
US 11295225 · 2022
US 10607134 · 2020
US 7512773 · 2009
US 5946647 · 1999
US 6281 · 1849
US 1788434 · 1931
US 1647147 · 1927
US 4750 · 1846
US 10400035 · 2019
US 1125476 · 1915
US 11361763 · 2022
US 5876725 · 1999
US 5920821 · 1999
US 10559047 · 2020
US 1032557 · 1912
US 9266948 · 2016
US 3321037 · 1967
US 483166 · 1892
US 5440632 · 1995
US 1304 · 1839
US 1475024 · 1923
US 1115674 · 1914
US 387571 · 1888
US 319082 · 1885
US 2186907 · 1940
US 5455030 · 1995
US 5346778 · 1994
US 5561631 · 1996
US 4660166 · 1987
US 5579517 · 1996
US 388116 · 1888
US 1242065 · 1917
US 355139 · 1886
US 259054 · 1882
US 6476836 · 2002
US 10540437 · 2020
US 10410117 · 2019
US 7865399 · 2011
US 19783 · 1858
US 1049667 · 1913
US 1721530 · 1929
US 1066809 · 1913
US 388850 · 1888
US RE45784 · 2015
US 1394450 · 1921
US 5657390 · 1997
US 5682513 · 1997
US 10423875 · 2019
US 7844915 · 2010
US 4081538 · 1978
US 4064521 · 1977
US 7543038 · 2009
US 98304 · 1869
US 88929 · 1869
US 7577616 · 2009
US 10282665 · 2019
US 7352772 · 2008
US 1537326 · 1925
US 6630507 · 2003
US 4558176 · 1985
US 8311950 · 2012
US 9182882 · 2015
US 6033785 · 2000
US 6122658 · 2000
US 7812828 · 2010
US 9379564 · 2016
US 1001260 · 1911
US 5579430 · 1996
US 6665308 · 2003
US 6828755 · 2004
US 10599957 · 2020
US 8683378 · 2014
US 5774660 · 1998
US 8615514 · 2013
US 9361579 · 2016
US 9481728 · 2016
US 11429762 · 2022
US 5673322 · 1997
US 7233978 · 2007
US 6073184 · 2000
US 8619056 · 2013
US 5966126 · 1999
US 589168 · 1897
US 10276149 · 2019
US 10962473 · 2021
US 8493330 · 2013
US 549160 · 1895
US 6178160 · 2001
US 90646 · 1869
US 8044672 · 2011
US 7904576 · 2011
US 11145922 · 2021
US 310966 · 1885
US 8133298 · 2012
US 9959544 · 2018
US 9571603 · 2017
US 6990497 · 2006
US 9368994 · 2016
US 271363 · 1883
US 966677 · 1910
US 116842 · 1871
US 293545 · 1884
US 815350 · 1906
US 6732183 · 2004
US 8037168 · 2011
US 8914752 · 2014
US 8168877 · 2012
US 8587547 · 2013
US 11417435 · 2022
US 10593988 · 2020
US 10566652 · 2020
US 9328156 · 2016
US 8219158 · 2012
US 10186887 · 2019
US 11176462 · 2021
US 10740671 · 2020
US 11239459 · 2022
US 9685235 · 2017
US 12423586 · 2025
US 1141798 · 1915
US 12326604 · 2025
US 11606373 · 2023
US 11235681 · 2022
US 12085565 · 2024
US 12327854 · 2025
US 9256834 · 2016
US 7833668 · 2010
US 8310051 · 2012
US 10956815 · 2021
US 8882665 · 2014
US 8387464 · 2013
US 8956321 · 2015
US 12518214 · 2026
US 12443890 · 2025
US 12353827 · 2025
US 12350368 · 2025
US 10314897 · 2019
US 11942620 · 2024
US 11648507 · 2023
US 10248907 · 2019
US 11126171 · 2021
US 12163952 · 2024
US 9397374 · 2016
US 11842324 · 2023
US 6552634 · 2003
US 11593031 · 2023
US 11507851 · 2022
US 12307349 · 2025
US 12299406 · 2025
US 10019188 · 2018
US 9293619 · 2016
US 12277178 · 2025
US 10307129 · 2019
US 9411722 · 2016
US 12181722 · 2024
US 11728052 · 2023
US 10522884 · 2019
US 12574477 · 2026
US 12438891 · 2025
US 12168044 · 2024
US 11900293 · 2024
US 9949801 · 2018
US 11836577 · 2023
US 8303250 · 2012
US 11741188 · 2023
US 11704899 · 2023
US 8049150 · 2011
US 12073952 · 2024
US 12416013 · 2025
US 8130043 · 2012
US 11922469 · 2024
US 10692210 · 2020
US 12414825 · 2025
US 12121527 · 2024
US 10700376 · 2020
US 12505360 · 2025
US 7614852 · 2009
US 10950878 · 2021
US 8636880 · 2014
US 20160166668
US 20160168227
US 20220161815
US 9412678 · 2016
US 10514610 · 2019
US 9141832 · 2015
US 8932024 · 2015
US 12252707 · 2025
US 9854998 · 2018
US 11137298 · 2021
US 9884123 · 2018
US 9925149 · 2018
US 10818403 · 2020
US 11542303 · 2023
US 8156057 · 2012
US 20180127759
US 8912428 · 2014
US 20230162023
US 20220012637
US 9181624 · 2015
US 8269555 · 2012
US 11786761 · 2023
US 20230412513
US 9055681 · 2015
US 7824959 · 2010
US 20240406210
US 20110132770
US 10468695 · 2019
US 11095127 · 2021
US 20110120221
US 20210174903
US 20160291760
US 9985438 · 2018
US 20200281484
US 20220383078
US 10914745 · 2021
US 9168838 · 2015
US 20120091953
US 20240082373
US 20210123152
US 20240186800
US 20210117042
US 20250190949
US 20250027216
US 20230195095
US 20210280268
US 20230383290
US 20230297446
US 20240296359
US 20210205465
US 20250172879
US 20260003141
US 20200371093
US 20250363357
US 20230187025
US 20220304938
US 20190160160
US 20260080696
More to explore
More in Consumer Electronics
US 7657849 · 2010 · Apple Inc
How the iPhone's Slide-to-Unlock Gesture Works
US 7479949 · 2009 · Apple Inc
How Touchscreens Understand Your Finger Swipes and Scrolls
US 4528643 · 1985 · FPDC Inc
How Stores Make Custom Products On-Demand with Remote Approval
US 7469381 · 2008 · Apple Inc
How Touchscreens Show and Snap Back When You Scroll Past an Edge
New to patents?
Common Questions
Frequently Asked Questions
What does How Organic Diodes Make Light Using Special Molecules cover?
Eastman Kodak's 1982 patent on creating light-emitting diodes (OLEDs) using organic materials, specifically a layer of porphyrinic compounds to help inject electrical charges.
Who owns patent US 4356429?
Eastman Kodak Co owns this patent, granted in 1982.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 4356429 cited by?
This patent has been cited by 1031 later patents that build on its ideas.
What problem does this patent solve?
This patent is a foundational piece for modern organic light-emitting diode (OLED) technology. OLEDs are now ubiquitous in high-end smartphone screens, televisions, and flexible displays. The principles laid out by Ching W. Tang here enabled the development of efficient, thin, and flexible displays that revolutionized consumer electronics.
What does this patent NOT cover?
Electroluminescent cells that do not use organic materials for the light-emitting zone.
Same assignee
More from Eastman Kodak Co
Patent monitoring