We've done CFL's , what about LED's ?

[Bruce]

Twenty years ago, I would not have believed how far fluorescent lights would progress by 2009. It will be the same with LEDs.

[Huge]

I assume you mean know-nothing politicians and innumerates like Hansen? Because just about everyone else here who dislikes CFL's has actually tried them, in my case a number of them. At least one person has done some measurements on light output, also.

[Dave Plowman (News)]

You're assuming we've reached the end point for the development of fluorescents?

[The Natural Philosopher]

The basi effiencies aren't a lot better than they were the first time someone filled a tube with mercury vapour and lit it.

[The Medway Handyman]

Why don't you contradict that assertion with some facts? Instead of acting like a tosser?

[Bruce]

What do you mean, "like" a tosser?

The man's a professional!

[Bruce]

No, not at all. After all, there is *plenty* of room for improvement.

I was just pointing out the huge technological change we have seen in fluorescents, and I believe we will see similar, or even faster changes with LEDs. The drive to reduce carbon emissions will see to that.

[Bruce]

True, but the quality of light they produce has dramatically improved.

[Dave Plowman (News)]

By that yardstick LEDs have dropped in efficiency, then.

[The Natural Philosopher]

Oh..I thought we were on an efficiency dribve.

If you want a broad clean spectrum, try an incandescent. Black body trumps Fraunhofer every time..;-)

[The Natural Philosopher]

Probably have. I think the correct solution will PROBABLY be some form of OLED material deposited inside a glass bulb.

[dennis]

TVs produce red, green and blue with bits missing.. nobody sees a problem there. In fact LED TVs exist and do the same and people don't have a problem with them either. It makes the claims that the bits missing cause a problem a bit weak.

[dennis]

Don't be silly, just print them on the wall paper. There is no need for brass candle sticks with bulbs on the ends.

[Dave Plowman (News)]

You jest, I presume? Or perhaps you think all TVs produce identical pictures?

Do they? I've never seen one. Perhaps there's a good reason why...

No - it makes your argument nonsense.

As I said 'white light' as we know it does not comprise of three spikes of red green and blue.

[PCPaul]

There are colour balance issues, but generally TVs do produce an adequate colour gamut with only RGB phosphors.

However producing a picture to view and producing ambient light to live by is two different things...

Because they are either very new, or very specialised. Most of the huge animated billboards you see in Times Square, Picadilly Circus etc. are done with RGB cells made with LEDs.

TVs are just coming on the market now with LED backlights instead of CCFLs. Supposed to be much thinner, less power hungry and brighter.

Look up 'metamers'. The human brain does perceive spikes of RGB as an almost complete visible spectrum.

But like I said above, for healthy day to day background lighting, it's not the same thing. Incandescent lights have one very skewed spectrum, fluorescents have another and LEDs will have a third. one of them are anywhere near natural daylight. The LEDs probably have the best chance of getting closest to it - although your average consumer LED bulb almost certainly won't put a high priority on that, just like VHS didn't put a hgh priority on pixel-perfect reproduction. 'Good enough' and cheap was the requirement..

[Dave Plowman (News)]

But those phosphors don't produce narrow band light in the same way as LEDs can.

Accuracy is hardly going to be an issue with those. But many of the smaller ones are DLP anyway.

I'm not denying that it might be possible to make LEDs with a decent spectrum - but *am* querying how efficient they are. That they may be used for an LCD TV doesn't answer this - despite what the TV set maker may claim.

It might perceive it as that when viewed on a white surface - but non continuous light does strange things to colours it is lighting - the reason most dislike it.

Well, one of the biggest complains about non filament lighting is the quality of that light, so you're rather on your own with this. Normal tungsten does have a red shift to the spectrum - but not that different from daylight at some times of the day.

[Alang]

I've just scrapped off a toaster but before I binned it I took the display out. The backlight was a piece of plastic the thickness of a piece of paper about 4 x 2 cms. I was amazed at how far they have come in the last ten years. The last LCD displays I installed (1996)had a couple of white LEDs behind them

[D.M. Procida]

I must really be behnd the times as far as toasters are concerned. It never occurred to me that a toaster might feature a display.

Daniele

[Alang]

Just under 4 years old and used quite heavily. Chinese with LCD display with the power levels and defrost settings displayed. I haven't seen another. 4 slice long slot toasters seem to be getting quite rare.

[Jules]

There's a huge gulf between noticing the missing bits in a moving picture vs. doing the same for a stationary room light source, though.