Aardvark Daily

Please visit the sponsor!

Happy Birthday LEDs

Yesterday was an important day in the electronics history timeline.

It was 50 years ago that the first LED was switched on and its feeble red light changed forever the field of display and indicator technology.

I don't actually recall the first time I played with a single LED emitter but...

My first solid memory was of a tiny single digit numeric display device. The seven segments were not just a single LED but multiple very small LEDs that made up separate points of light. From memory it was about $30 worth of -- and that was a *lot* of coin way-back then -- for something barely 6mm high.

And of course -- the only colour available was red.

I do remember buying a green LED when they first came out and marveling that now there were *two* colours of indicators I could use in my designs. Shortly afterwards we got yellow and orange -- woohoo.

Way back then however, blue and white LEDs were unheard of -- stuff of dreams.

These days of course you can get LEDs in any colour you like and white ones are some of the most efficient light emitters on the planet.

Multi-colour LEDs contain red, green and blue emitters that, by mixing the amount of each, are capable of producing virtually any colour in the rainbow. Far more versatile than any other form of illumination.

I suspect it won't be too long (although longer than some predict) before LEDs become the most popular form of indoor lighting -- but for the time being they still have price/performance issues and some of the cheap/affordable Chinese-made product is awfully unreliable.

What I did spot were some very nice looking LED lighting panels on Dave Jones' EEVBlog the other day. At A$200 a pop they're certainly not cheap -- but look to be a great alternative to fluros, especially if the price drops a bit.

Perhaps the most significant effect the LED has had so far on lighting is the humble torch/flashlight. LED units are lighter, smaller, brighter and run for much longer than the old bulb-based ones. What's more, they're now so cheap I can't imagine why anyone wouldn't have one.

Let's not forget the effect that LED technology has had on lasers either.

As a young lad, I recall reading all about lasers and the wonderful things you could do with a beam of coherent light. Of course a gas or ruby laser was well beyond the means of a boy who's income was solely derived from mowing the lawns once a week -- but these days you can pick up a 5mW laser pointer at the $2 shop. That, is progress!

So where to now for LEDs?

Well OLEDs have been predicted as "the next big thing" for many years now - but so far they're still not delivering on that promise.

In theory, they have numerous advantages over the LEDs we presently know and love -- however, their operational life (especially colours such as blue) leave a lot to be desired -- yet I suspect, given how often we trade in our phones and other devices, that will soon be a non-problem.

The really cool thing about OLEDs is that they can be printed onto all sorts of substrates -- even flexible ones. How long before we see business cards that are composed totally of a set of printed OLED pixels controlled by a tiny embedded processor and programmed through a NFC setup. This way, you only need buy the blank cards, design your graphics on your PC and then transfer the final result to the card itself. Change your phone-number or email address -- no worry, just reprogram the cards you've still got in your wallet and you're good to go -- PLUS you can have some cool animation (ugh!).

Just what the world needs -- animated business cards - right?

So happy birthday LED -- boy, I really didn't realise you were already 50 years old. Where has time gone?

Please visit the sponsor!

Have your say on this...

PERMALINK to this column

Oh, and don't forget today's sci/tech news headlines

Rank This Aardvark Page

Change Font