Saturday, October 18, 2014

US 3,819,974: Gallium nitride metal-semiconductor junction light emitting diode

US 3,819,974, with a claim to a light emitting diode comprising gallium nitride and magnesium doped gallium nitride, issued on June 25, 1974.

One notes that the "description of preferred embodiment" in US '974 is written in the present tense, not in the past tense.

Wally Rhines has a post in EE Times titled "Nobels Should Celebrate Invention and Optimization."

A comment to the Rhines post by Rick Merritt correctly distinguishes between innovation [what the Nichia people did] and invention [what Maruska, Rhines, Stevenson did].

See also a post in Physics Today Wall Street Journal op-ed disputes physics Nobel achievement’s provenance . The Wall Street Journal post How America Lighted the Way for a Japanese Nobel

See also Nobel Shocker: RCA Had the First Blue LED in 1972

Newsworks has a story on an experiment done on Maruska's initial device, which includes the text

After hearing of the Nobel announcement, and the omission of Maruska, Gross wanted to see if the prototype blue LED still worked. (...)

First thing they do is check the power source, a 22.5 volt battery attached to the back.

"Son of a gun, it actually has some poop," Allen says after plugging it into a volt meter.

"How much voltage are we talking here?" says Gross.

"20 volts," replies Allen.

"That's not bad," Gross says. (...)

"We got it, it is lighting faintly. We've got blue, it is glowing, that is definitely blue. It is beautiful!" says Gross.

A voice crackles with joy over the phone: "After all these years?"

These guys are over the moon. This little blue light, this artifact from the tale end of the golden age of American technology still fires.

The Nobel may have overlooked this contribution, but the foundation for the light bulbs of the future was laid in America.

Separately, a discussion by Paul Maruska appears at

which includes mention of how RCA failed to followup on Maruska's work.

In passing, one notes that blue LED story illustrates a number of aspects of patent strategy. That LED's could be used as a (white) light source was predicted in a 1963 in a Reader's Digest article, is mentioned in the 1974 patent, but did not "change the way we live" (an innovation) for more than thirty years later.

Different elements of patent strategy are illustrated in the story of Richard K. Lyon. Both Lyon and Maruska left Exxon Corporate Research Laboratory in the year 1986.

**See also


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