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Isamu Akasaki, inventor of first efficient blue LED, has died (japantimes.co.jp)
409 points by _Microft 16 days ago | hide | past | favorite | 119 comments

I distinctively remember buying my first blue LED in what must have been the mid-90s. I simply walked into an electronic parts store and bought a single spare LED. I don't think I had ever seen a blue LED in action before, it was completely new to me, so I was very curious.

It was of the very common standard shape and size LEDs were during that time, and its case was colorless but cloudy, not clear. A good thing, because that meant the LED would emit its light along the entire casing, not just straight forward, making it much easier to look at. It also wasn't much brighter than other LEDs, that came later.

When I applied power and saw it shining in that beautiful blue color, I was positively amazed. This was so much cooler and so much more beautiful than the red, green, and yellow LEDs I had been using before. I distinctively remember just leaving it attached to power, sitting on my desk, just for something nice to look at.

I totally get that. I did exactly the same. Cost £8 at the time if I remember as well which is a hell of a lot of money for an LED. It was just so different to the yellow, red and green ones. I was buying a bit of the future.

But roll on to today and the things are mostly a nuisance In my life. I’ve got one shining at me off my monitor now. If I scoot myself up in my chair a bit it doesn’t annoy me as much. I may stick some tape over it.

Still, RIP Mr Akasaki. Your contribution to the world is a net good one. Without it we probably wouldn’t have white leds :)

I remember there was a phase in the late 90s when all of the premium gear had blue LEDs. I remember a Cambridge Audio amp rack and CD player a flat mate had.

Now of course they are used on all of the most tacky direct from China stuff.

Yep, I have one computer with black electrical tape over the blue LEDs, and another where I added a resistor in between the motherboard and the light.

Very similar story here. I was in undergrad back then and worked in a part-time job with the high energy physics dept (we built front-end detector electronics for particle detectors at CERN, Fermilan, SNO, etc).

One of the guys on our team had great relations with the major electronics distributors and always had well stocked lab. One day, mid 90’s, we saw he got a sample of few of these brand new Blue LED’s.

My coworker and I snuck into his lab after he left and wired one of them up.

It’s hard to describe what it was like to see this bright deep blue compared to only the red, yellow, and green LED’s that existed until that point. It was so cool to look at.

incidentally you can get leds with clear, clouded, or colored+clouded encasings. Only with the latter can you tell what color they are when they're off.

One time I had some red leds in clear encasing in a parallel configuration and they inexplicably would not light up... it turned out one of the leds was actually infrared and it was invisibly on and sucking up all of the voltage

> A good thing, because that meant the LED would emit its light along the entire casing, not just straight forward, making it much easier to look at.

In a pinch, if you don’t want your 5 or 7mm LEDs to be so focussed: carefully take a set of side-cutters and cut the tip off the LED.

Could probably just use a lower grit sandpaper to rough up the tip.

At a past job we used LEDs for lighting for machine vision and that's precisely what we did to make them more diffuse.

Save that for lapping CPUs/GPUs and whip out the Dremel.

Oh man, that takes me back.

I used to love looking into my father's spare electronics cabinet when I was a kid, full of chips and resistors and capacitors. I vividly remember the LED drawer, with a hundred red, green, yellow LEDs he used in almost all of his projects, and just one or two of those opaque, white LEDs which I knew shone blue light, and I've never seen him use, as if they were a rare and prized possession.

I get it now, as the blue LED technology is so much more recent than any other LED technology. They must have been much more expensive than the other ones.

Oh, I remember when blue LEDs became readily available (late 90s for me) and I would mod all my stuff to blue.

Had this MS ergo keyboard, with the LEDs in the middle hump, came with green. So, I replaced with these 2.5 hi-blues and I was blinded by my own Numlock-Beam. Had to cross a resistor over there to take the edge off.

Anyway, I think HN should get a black-bar because the blue LED is so cool.

I found myself taping over some blue LEDs because they were so bright at night!

I have a laptop charger with one that I taped over with kapton tape: the orange kapton is almost the exact opposite of the blue LED so you're left with a dim white indicator, no blinding brightness.

I hate them with a passion for this reason but on second thought maybe I can't really blame it on the LEDs themselves. People seem to give them too much forward voltage and don't always use diffusing packaging, which would have made them much more pleasant to look at.

Then again, I rarely see such problems with products with red or amber LEDs.

I have a synthesizer with blue LEDs that's particularly obnoxious. It's probably feeding them 5V and there's of course no diffusion at all. I've taped all of them over with a layer of duck tape and they're still too bright.

Allegedly blue LEDs are supposed to be really disruptive to sleep (not just due to brightness but due to wavelength. Body interprets blue as daylight and red dusk or something)

Well, you're right sort off. Blue light is related to the production of melatonin, which is used regulate our sleep cycle.

Blue light (aka shorter waveforms) blocks the melatonin production, most likely a genetic factor as the blue wavelength is related to the sun's day cycle.

So as to keep one more alert during daylight hours, and ready to exert energy?

It's long, but if you're into it this podcast (episodes 2-5) go into some lengthy research and discussion into it: https://www.youtube.com/playlist?list=PLPNW_gerXa4NjSNbZhpSD...

Yes, it's why SAD therapy lights are blue-ish.

I used to have the all transparent plastic Harmon Cardon speakers (iSub?) but I had to get rid of it because the power lights were so bright. And since it was transparent you couldn't cover them up.

I actually bought a little sheet of circle neutral density filters sticker things to cover a ton of these LEDs in my world.

Still do this all the time

Yeah, I feel sorry for this man's family and loved ones, but I wish he'd never invented the damn things. Blue light scatters in air more than non-blue, and it's just garish to look at.

You wouldn’t have white LED lighting or any of the mixed colours that include blue (eg cyan or purple) without his contribution.

Don’t blame the inventor for the bad applications of companies. Just like you wouldn’t blame Alexander Graham Bell for telemarketer spam.

Worst one for me is on an older pair of Sony's flagship NC headphones. Putting them on at night is like flying a plane with landing lights on, and of course it shines right in the face of my partner.

I did the same thing to my Dell laptop in college when purple LEDs first became available. And a year or so prior to that (when my google results were still fruitless), I swapped blue LEDs in like you, and got a purple-ish result by putting some pink paper between the LED and the numlock icon (or whichever it was). I was fascinated to find that the paper faded to white after a few weeks as a result.

These days I like yellow, but am lazy and just put kapton tape over the white LEDs on my desktop...

Panasonic initially picked a teal LED for its notebook because it was really, really expensive back in nineties. Few percents of the laptop cost was that single power LED.

The legend is that they secured an exclusivity agreement with Nichia for that colour for some years, but the reality is much likelly be it just being expensive, and hard to source.

Do blue LEDs on home electronics bother anyone else at night time as much as it does me? They appear so much brighter to me than other colors

I have a drawer full of black electrical tape and small round dot stickers almost entirely due to blue leds. Though it's convenient on everything. The electrical tape blocks it out entirely, for the most part. The round stickers let through some light so is great for dimming it down a bit or just use multiple to block it completely.

I think they're so widespread now largely because they were so expensive when they first started becoming common that they were used in expensive equipment, and became a way of making things look higher end.

I’ve found that for many of them (particularly the smaller ones) I can color them in with a black pen in a way that dims them ~95%, that way they’re not overbearing but I can still see whatever status they were trying to tell me.

Ballpoints or other fine-tips tend to follow the shape of the recess and it does a pretty tidy job.

I've got a laptop charger with a blue led. It's awful, I have to remember to unplug it at night, even in the other room. I've forgotten before and woke up to use the washroom only to find the whole living room lit up from the little led and I'd feel instantly wide awake.

Contrast that with a USB charger I picked up in an emergency, unaware it had a red led that was on constantly as long as the cord was receiving power, fucking terrible design and I've thankfully replaced it, but it didn't bother me too badly when I had to use it in my room at night. I could still sleep and everything.

Yes, I was getting annoyed by an access point I bought that had blue status lights but amazingly it has a setting that turns them off either always or during specified hours. I'm floored that every device doesn't allow you to disable them.

I remember a Digikey catalogue c.2002? where it seemed like blue LEDs were the star of the show. Page after page of this new wonder. And then the following decade-long flood of blue-LED-festooned consumer products, where every new bit of kit needed to visually proclaim how new-fangled it was by blasting out that particularly shrill wavelength of visible light.

So cool, but so annoying.

Yes, I have LightDims (https://www.lightdims.com/) on nearly everything.

> Do blue LEDs on home electronics bother anyone else at night time as much as it does me?

Don't have home electronics in your bedroom is my advice.

Easier said than done unfortunately.

For example: it's hard to get through summer without a fan or air conditioner in your bedroom by me. A surprising number of those come with always on lights and it's not always clear until you plug them in.

Beyond that there's just "not everyone has the luxury of a single purpose room." Especially now, lots of people need to setup their home office in their bedroom. I have a vacuum with an always on indicator light, and the only good place to put it is a bedroom. Some people have studios and their entire apartment is their "bedroom."

All in: you're right, it's best to keep your electronics out of the bedroom, but that's not always practical and way to many things have unnecessary status lights.

I just black tape everything in my bedroom. I don't need to see a light to know the fan is on.

Having grown up in a small house and spent quite a lot of time in a friends house which is a lot bigger (I'm still young, so this was very much post video games for example), I think the mental separation of having multiple rooms in a house (rather than everything being done in my bedroom) is probably worth another 5 or 10 percent on exams for me at least. The idea of having a "games room" for example is utterly unthinkable to me still, for example.

I have a guitar pedal that uses blue and red LEDs to indicate mode. Part of my bedtime ritual is to stomp it to the red mode.

I have an electric kettle that holds water in a vessel with transparent sides. When the kettle is turned on and heating water it illuminates the water with blue LEDs.

It doesn't bother me at night time as the light goes on only when it is in use. But the fact that it has lights at all is bothering.

My kettle's thermostat only releases the power switch, but doesn't actually cut the power, so if something is blocking the switch from going to the "off"(up) position - like a large plate or something similar - it boils off all the water and then starts burning itself.

Happen once and I only noticed because the light was on and I couldn't hear the water boiling because it wasn't there anymore.

A deaf person wouldn't be able to hear the kettle going through its phases.

Disability-first design has a way of blending in for people who aren't yet disabled.

Haha! I have this one too. I’ve always wondered, wouldn’t red represent the fact it’s being heated better? Anyway, I have to admit it looks cool unfortunately

That's the feature that sold me on electric kettles!

The one in my humidifier bothered me so much I opened the dang thing and was pleasantly surprised to find the LED on its own tiny board which I then disconnected.

There has to be another way of showing an appliance is receiving power which is both visible at night and in broad daylight. The super-bright LED is overkill in anything but the brightest lighting scenario, and makes any room immediately ugly and unpleasant after 6pm.

I have a hard drive enclosure in the bedroom that was too bright to my taste. So much so that I opened it to remove it (which, incidentally, was really easy, it was plugged in the board via a connector, I didn't even need to cut wires or anything)

While blue LEDs are wonderful to have, I don’t get why anyone would add them to a product as an indicator.

They are annoying and typically insanely bright. Also, just because something has bluetooth, does mean that a blue LED is legally required.

When Mr. Akasaki's invention started making waves, blue LEDs were still more expensive. So a blue LED was a signifier of quality. They became more affordable, so everyone started putting them everywhere. And made them bright so you would notice.

Probably an analog is curving a 42" screen designed to be viewed on a couch across a living room.

Overbright indicators of any kind on electronics bother me. The brightest are indeed usually blue, but green and red are also offenders.

Yes! I cover them all up with electrical tape or LightDims

The effect that some people's work eventually has on everyone's life can be just amazing.

In this case it enabled LED lighting for everyone. Transistors (Bardeen, Shockley), lasers or artificial fertilizer (Haber, Bosch) also come into mind.

Agreed. Also, Norman Borlaug (the Green Revolution which prevented, or at least postponed, the famine we'd have been living in for 40 years now, thus saving a billion lives) and Stanislav Petrov (who refused to raise the alarm in 01983 that would have started a global thermonuclear war, thus saving three billion lives).

My personal favorite here is John B. Goodenough for lithium-ion battery chemistry.

What an amazing name!

Also for major contributions to the development of RAM.

Not bad. Or shall we say, good enough?

640K ought to be good enough

The Hall–Héroult process for electrolytic aluminum refining is pretty impactful. Many polymer synthesis processes are also very impactful day to day, starting with Bakelite (less relevant now).

Blue LEDs have enabled incredible power savings by making LEDs viable for lighting rooms and screens.

Peter Mansfield also comes to mind (MRI).

A more important question is, how well were they compensated? Most of the value are not captured by the original inventors.

To be fair, to a certain degree that's part of the deal in academia. Tenure is like an reverse insurance, everyone gets a salary, even if only few will be able to make significant contributions. And that's okay, because a lot of luck is involved in individual success in academia.

Company's gross went from 200 million USD to 800 million USD.

He got $180.

After a lawsuit, they settled for around 8 million.

Got a Nobel prize too.

Regarding the lawsuit, I believe you’re thinking of Nakamura.


Similar story around AIDS-denier Kary Mullis, who invented PCR. I think his employer sold the patent for >$1B. 1993 Nobel in chemistry.

I remember reading about him in Omni magazine.

What do you mean by original inventor?

I remember back in 1990 there were no efficient blue LEDs. We were desperately looking for a solid state blue light source to get some chemical to fluoresce and the source had to be small and efficient. The initial SiC diodes which I think came out in 1992-1994 were not powerful enough. Huge progress has been made since then.

I remember in ~2000, I went with my wife to buy some LEDs. The price of red, orange, yellow and green was $0.1 each, so we bought 10 of each.

We were very surprised that they also had blue LEDs, so we asked the price and it was $2 each. After some deliberation we only bought only 2 of them.

I'm still surprised when I see a cheap toy or device with a blue or white LED.

I agree, fond memories. Today you can get all the popular colors for less than a penny each.


I remember reading the story of the development and breakthrough of the blue semiconductor laser in Scientific American (in print). Looked it up[0], it was Sept '97.

Quite fascinating, it was a holy grail of sorts in that it would lead to higher resolution applications (Blu-ray) as well as round out the RGB to be able to make the range of visible colors. One thing I remember about the article was that it's hard to say 'blue' with a Japanese accent and it comes out 'true baroo'.

Shortly after there were lots of expensive blue LEDs being added to lots of high-end items, including audiophile equipment that two of my family members made (separate brands: one tube, one solid-state).

[0] https://www.scientificamerican.com/article/true-blue/

That article mentions blue laser. Is that the same as blue LED?

I'm no expert but I think they're closely related. There are gas lasers and semiconductor lasers. I think a semiconductor laser without any amplification/mirrors is essentially an LED. The blue LED used Gallium Nitride (GaN) which also used in blue lasers.

Just as important, or even more-so, this allowed efficient controllable multicolor and white LED lights, since we already had red and green LEDs.

It allowed white LEDs in another, more important, way.

There was a quantum leap required to go from Green to Blue. That same technical insight led to UV leds, which means florescent white light LEDs in various temperatures.

IIRC, the company he worked for when he discovered / invented the blue LED was - shall we say - not particularly inclined to give him his dues.

I believe you might be thinking about Shuji Nakamura (and his then-employer Nichia), one of the other two who shared the prize. Akasaki and Amano were mostly associated with Nagoya University, and Akasaki later with Meijo.

You are correct, didn't recall correctly.

Japan, in general, does not like to highlight individuals; instead, focusing on the team.

My boss wrote a book about color management, featuring the devices we made, and they made him remove his name. He did 100% of the work.

It's true. But still there are plenty of examples of people in Japan taking credit vs the company. Hideo Kojima, Tetsuya Mizuguchi, Yu Suzuki, to name a few.

Also, they take all the credit even though they also had teams, often who did all the real creative work.

They also rarely share the rewards. Yu Suzuki had 6 expensive sports cars (Ferrari, etc...) while his teams worked 80hr weeks and got paid $30k-$40k salaries.

Well, do inventors at Apple ever get any recognition? I only hear about their product designer Jony Ive.

Usually Apple does not invent anything, they design using what other people have invented.

Apple does not focus on research as much as in development. They put billions into factories that mass produce what has been already proven to work.

Multi touch for example was not invented by Apple, Apple bought a company that invented most of the technology and brought it into telephones.

They did not invented Gorilla glass or accelerometers or small hard drives(like in the old ipod). They approached inventors and offered using their technologies in the millions or tens of millions of units.

I would assume that dues are about money, not recognition.

Most likely, but they are very related and I was thinking about both.

You can find their names on their patents or on their Linkedins.

They used to, with the original Macintosh.

You are talking about Shuji Nakamura.

Anecdotally, Nakamura seems to get most of the credit in American academia

Probably because he's in American academia?

I think my first blue LED was in the power button of the Playstation 2. Something that made it seem exceptionally futuristic at the time.

Then came the fad of the bright blue, "plugged in but turned off" indicator on consumer electronics that had to be taped over if you wanted to sleep in the same room as the device.

The PS2 got it right-- its power button was a red/green bicolor LED (red on standby; green when powered on).

The blue LED was on the eject button, and was only lit while the console was powered on (and a disc was loaded, IIRC).

This fad has unfortunately not fully died yet!

Agreed. One of my monitors can attest to that. Black duct tape, to match the monitor design :-))

My Sony amp from '99 had one which they actually enhanced with some acrylic to make it appear even larger. Yes I bought it specifically because it had that blue LED.

Yes! One of my first hobby electronics projects as a kid was adding a blue LED to an RC car just for the cool factor.

A joke I first saw on Twitter:

  LED status key
  Green - online
  Red   - error
  Amber - busy
  Blue  - modern
(Source: https://twitter.com/deviantollam/status/1345143016307113985 )

This is the error I get when clicking that Twitter link: https://i.imgur.com/B4ackBV.png..............I_HATE_TWITTER/...

Reloading the page fixes it.. I've had this issue for probably about a year with Twitter.

Blue = Bluetooth.

At this point a blue LED is a little early 2000 electronics.

So he's who I can blame! Just kidding, but in reality I do cover up any and every blue LED that comes in my house. No thank you every electronics manufacturer in existence!

Well, if you look a bit past the immediate effect of having blue LEDs, I doubt you cover any and every LCD screen/touch screen that comes into your house. Since you know, those use LEDs (including blue ones) as backlighting :-D

Similar story for LED lamps, I'm reasonably sure those are derived from blue LEDs.

Where would we we in a world without Zinc!?

wakes up in a cold sweat

Noooo come back zinc!

For anyone wondering (like I was): Why A Blue LED Is Worth A Nobel Prize (2014) https://www.popsci.com/article/technology/why-blue-led-worth...

I remember when upgrading Nokia 3310’s to Blue LEDs was a thing in Chinatown. People’s phones glowed like something out of the world back then.

"I gotta get me a blue LED or something because that blue light ... is bad ass."


I always have trouble with the official story of the blue LED, because I had a 1985 Volkswagen Golf that had a blue LED for the high-beam indicator. It might not have been as bright as today's blue LEDs, but it was bright enough to be useful.

It wasn't an LED, but was made to look like the LEDs next to it:


Could have been electroflorescent, like the timex backlights?

How do you know it was an led?

I remember reading the article about blue LED's finally being invented, then about a year later I saw my city (Lyon) started using them downtown to light the street markers. I as impressed at the adoption speed

The purple made by mixing blue LEDs with red LEDs (it's a very distinct purple) is my favorite color (after black, of course).

This man made it possible for LED purple to be everywhere.

Do you have an image of this? I am having a hard time imaging it..

I'm not sure if it doesn't photograph well or if modern displays aren't good at reproducing it, but I have never seen a photograph that does the color justice.

Perhaps that's why I like it: it's novel when one is used to looking at screens all day.

I remember when I saw my first blue LED. It immediately felt like I was in the future, and I remember how bright it was lighting up the entire room in the dark.

Dang covid has killed a lot of brilliant humans. So many obituaries here are from covid

Please read carefully and comment after. He passed away from Pneumonia. There is no mention of COVID anywhere in this article or online.

This makes me want to work on fundamental technology that will change the world.

Would be interesting to see how many deaths are attributed to 'pneumonia' of late in Japan.

Now's a good time to read up on blue light, macular degeneration, blue blockers, and F.lux.

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