Transistors are the most important aspect of modern technology. As the number of transistors increases, so does the computing power. Knowing this, you may be surprised to learn that electronics didn’t always rely on the transistor. The birth of modern electronics came in 1904 with the invention of the transistor’s predecessor, vacuum tubes. These tubes made broadcast radio more accessible and were key pieces for X-ray technology, microwaves, guided missiles, sonar, radar, and television.
If you’re looking for an in-depth technical explanation of the vacuum tube, look elsewhere. I have little interest in electrical engineering and am far more interested in the stories behind technological innovations. So, rather than boring you with my own misunderstandings of the invention, I’m instead going to confuse you with my slightly better understanding of U.S. patent law. Today’s story involves the battle between two pioneers of technology, complications of U.S. patent law, and one of the best examples of karma you will ever hear about.
To fully understand the lore behind the invention of the vacuum tube, you should know in very simple terms how they work. Like the name suggests, a vacuum tube is a glass tube with the air taken out of it, therefore creating a vacuum inside of it. Electrons pass through the tube from a cathode on one end of the tube to an anode on other end. Since there are no air molecules in the tube, electrons are able to move around freely without significant the interference. This freedom of electrons makes it easier to control electric signals that run through them from the cathode to the anode.
The hero of this story is a British man by the name of John Ambrose Fleming. Fleming was an inventor who worked alongside Thomas Edison for the Edison Electric Light Company. By all historical and contemporary accounts, he was absolutely brilliant. I mean, do you really think Edison was out there hiring idiots? As you may have guessed, his most notable invention was the vacuum diode, which allowed radio signals to be detected by a telephone receiver. But the glory that came with such an invention was short-lived and was soon overshadowed by the villain of our story – inventor Lee De Forest.
Lee De Forest was an expert in radio waves, an electrical engineer, and a self-proclaimed genius. If you only learn one thing about Lee De Forest, it should be this – he was a scumbag and a con artist. De Forest started multiple companies focused on creating wireless radios, telephones, and telegraphs. These companies were notorious for exaggerating their products’ capabilities and relied upon designs for receivers and transmitters that were stolen by De Forest himself. De Forest and his business partner used enthusiasm to capitalize on the public’s lack of understanding of their products, overpromising shareholders returns. De Forest even went so far as to call investors in his company “suckers”.
As I mentioned, Fleming worked alongside Thomas Edison. For decades, scientists had been aware of something known as the Edison Effect, which, according to an article in Wired, is “essentially the transmission of a charged current using a heated conductor”. Fleming had performed experiments on this phenomenon in the 1880s and 90s, but not much had come of it. It wasn’t until the early 1900s, when he returned to these experiments, this time focused on improving the detectors in telegraphs, that he found a revolutionary application of this phenomenon. Fleming realized that by using thermionic emission within a vacuum tube, it got electrons moving, which enabled electric signals to be carried, manipulated, and amplified. In 1904, Fleming filed a patent for the device known as the thermionic valve, aka a diode vacuum tube. When electric charges were sent through the tube, the movement of electrons could be switched on and off. This was a revolutionary invention at the time, as it was the first device to convert alternating current to direct current.
Enter Lee De Forest – he couldn’t let a revolutionary invention relating to radio waves get past him without getting in on the action. Using the same theories and technology as Fleming, De Forest created a suspiciously similar device – the triode vacuum tube. Instead of just using an anode and cathode, De Forest added a third electrode, a control grid that further enabled the manipulation of electron flows from the cathode to anode. The triode quickly superseded the diode, and became a commercial success.Noticing the obvious similarities in their inventions, Fleming took De Forest to court over patent infringement. The scientific community sided with Fleming, but the courts sided with De Forest – allowing him to retain full legal rights to “his” invention.
You know what they say though, karma is a bitch.
Although De Forest won his legal disputes against Fleming, General Electric filed suit against him claiming that his Audion tube infringed on one of their preexisting patents. The case DeForest Radio Co. v. Gen. Electric. Co. was a long one, and was characterized by appeals and delays. At one point the case was delayed by the onset of WW1, as the lawyers were required to litigate cases related to the war instead. Decisions were made in district courts, appealed, reversed, appealed again, reversed again, in a seemingly never-ending cycle of lawsuits. Eventually, the case was brought in front of the Supreme Court. A 1925 article in the New York Times wrote “A twelve year battle for the basic patent rights to the modern vacuum tube… was concluded today with the award of the patent to the General Electric company…The type of tube involved in the litigation was invented in 1912 by Dr. Irving Langmuir, assistant director at the GE research laboratory and has been the center of long controversy”. Despite his prior legal victory over Fleming, this lawsuit decimated De Forest and left him emotionally, reputationally, and financially ruined.
John Ambrose Fleming was later knighted, received a Medal of Honor, and is still well respected within the scientific community for his many contributions. De Forest on the other hand; got divorced four times, was indicted on charges of mail fraud, lost nearly everything when his company folded due to embezzlement by his employees, and faced accusations of patent infringement. He spent much of his money defending his inventions in court, and died a poor, disgraced, and lonely man.
STORY WILL BE UPDATED THROUGHOUT 04/04/2024
John Ambrose Fleming invents the vacuum tube, beginning Electronics : History of Information. (n.d.). https://www.historyofinformation.com/detail.php?id=561
Kathy Loves Physics & History. (2018, June 9). History of Radio: How Lee de Forest, a con artist, created radio [Video]. YouTube. https://www.youtube.com/watch?v=xV1I_tQtkEI
Long, T. (2009, November 16). Nov. 16, 1904: Vacuum Tube Heralds Birth of Modern Electronics. WIRED. https://www.wired.com/2009/11/1116fleming-thermionic-valve-vacuum-tube/
McFadden, C. (2017, November 26). Who was Sir John Ambrose Fleming? All About the Father of Electronics. Interesting Engineering. https://interestingengineering.com/culture/who-was-sir-john-ambrose-fleming-all-about-the-father-of-electronics
Misreading the Supreme Court: a puzzling chapter in the history of radio. (2021, May 3). Mercurians. https://mercurians.org/antenna-newsletter/misreading-the-supreme-court-a-puzzling-chapter-in-the-history-of-radio/
Ucl. (2015, July 24). JA Fleming – Discoveries from the Archive. | UCL UCL Culture Blog. https://blogs.ucl.ac.uk/museums/2015/07/24/ja-fleming-discoveries-from-the-archive/
VACUUM TUBE PATENT AWARDED TO LANGMUIR; Research expert wins long battle for invention which made radio practical. (1925, October 21). TimesMachine. https://timesmachine.nytimes.com/timesmachine/1925/10/21/99364752.html?pageNumber=36
English, T. (2020, April 8). Lee de Forest, who successfully invented the Audion but failed at everything else. Interesting Engineering. https://interestingengineering.com/science/lee-de-forest-who-successfully-invented-the-audion-but-failed-at-everything-else
**Post was edited by ChatGPT 3.5**