White LED spectrum?

[Paul Conners]

Would like to find white SMD LEDs suitable for use as backlight for LCD
monitors where the CCFL lamps have burned out. So need is for consistency
between units and... well, "whiteness". ;-)

Or other parameters I should be considering?

Any recommendations (ie, LEDs you think would be good for this)?

(And yes, I can Google and have.)

Thanks,
Dave

 

[N_Cook]

Would like to find white SMD LEDs suitable for use as backlight for LCD
monitors where the CCFL lamps have burned out. So need is for consistency
between units and... well, "whiteness". ;-)

Or other parameters I should be considering?

Any recommendations (ie, LEDs you think would be good for this)?

(And yes, I can Google and have.)

Thanks,
Dave

I take it you will replace the 2mm or so diameter CCFL with a line of LEDs .
The tube is uniform illumination along its length, how will you avoid
stripiness of illumination?
It is very sophisticated dispersion sheets backing the display to make sure
no graduation of illumination across the width of those sheets.

 

[William Sommerwerck]

"White" LEDs are actually blue LEDs with a phosphor that glows yellow under
blue light. The eyes sees blue + yellow = white.

Their spectrum is anything but continuous -- or even peaked at the right
points -- so it's highly unlikely to work.

 

[Rich Webb]

"White" LEDs are actually blue LEDs with a phosphor that glows yellow under
blue light. The eyes sees blue + yellow = white.

Their spectrum is anything but continuous -- or even peaked at the right
points -- so it's highly unlikely to work.

Most white LEDs are phosphor-based but hardy as bi-chromatic as you make
them sound. The little Cree in my pocket flashlight has the typical
broad peak around 450 nm and valley around 485 but it's quite continuous
down to 650, tailing off at about 670. Very different from the narrow,
discrete lines from a CCFL.

 

[Loonie]

While we're at it I'd like a digital "film back" for my Nikon 35 mm
camera.

Three cheers for that. I am looking for one for my Canon A1 and for my
Zeiss Ikon. Is there any movement towards these backs?

TIA

 

[DaveC]

"White" LEDs are actually blue LEDs with a phosphor that glows yellow under

blue light. The eyes sees blue + yellow = white.

Their spectrum is anything but continuous -- or even peaked at the right
points -- so it's highly unlikely to work.

I appreciate your simple and obviously knowledgable answer. It will help me
in my search for the right decision.

Dave

 

[DaveC]

Most white LEDs are phosphor-based but hardy as bi-chromatic as you make

them sound. The little Cree in my pocket flashlight has the typical
broad peak around 450 nm and valley around 485 but it's quite continuous
down to 650, tailing off at about 670. Very different from the narrow,
discrete lines from a CCFL.

[Rich Webb]

Thanks, Rich.

I think the "striping" issue and potential variance between samples will make
for a less-than-satisfying result.

Thanks,
Dave

 

[DaveC]

I really have no help for the question asked, but I think people

interested in the subject may have an answer to one of my questions.

And I have one word for you: HIJACK.

If you don't have an answer to the OP's question, fine. If you have a
question, START YOUR OWN THREAD.