Blue Tinted IRLEDs.
Anyone know why some IRLEDs have a blue tinted encapsulation instead of
water clear? TIA. |
Blue Tinted IRLEDs.
On Wed, 16 Jul 2008 17:56:02 +0100, "ian field"
wrote: Anyone know why some IRLEDs have a blue tinted encapsulation instead of water clear? 1) It's benign? 2) It's cheaper? 3) For ident/differentiation? 4) Mechanical filtering? I've seen infra-red leds with almost-black encapsulation. RL |
Blue Tinted IRLEDs.
"legg" wrote in message ... On Wed, 16 Jul 2008 17:56:02 +0100, "ian field" wrote: Anyone know why some IRLEDs have a blue tinted encapsulation instead of water clear? 1) It's benign? 2) It's cheaper? 3) For ident/differentiation? 4) Mechanical filtering? I've seen infra-red leds with almost-black encapsulation. RL The almost black types are ubiquitous in consumer electronics as the integrated IR receiver modules, I was wondering why sometimes blue when blue is at the other end of the spectrum from IR? |
Blue Tinted IRLEDs.
"ian field" wrote in message ... The almost black types are ubiquitous in consumer electronics as the integrated IR receiver modules, I was wondering why sometimes blue when blue is at the other end of the spectrum from IR? As long as it's transparent to IR at (usually) 850-950nM is fine. The PhotoDiodes used in remote receivers are 'black' to block out ambient light shorter wavelength than about 850nM. ** Posted from http://www.teranews.com ** |
Blue Tinted IRLEDs.
On Wed, 16 Jul 2008 21:03:31 +0100, "ian field"
wrote: "legg" wrote in message .. . On Wed, 16 Jul 2008 17:56:02 +0100, "ian field" wrote: Anyone know why some IRLEDs have a blue tinted encapsulation instead of water clear? 1) It's benign? 2) It's cheaper? 3) For ident/differentiation? 4) Mechanical filtering? I've seen infra-red leds with almost-black encapsulation. RL The almost black types are ubiquitous in consumer electronics as the integrated IR receiver modules, I was wondering why sometimes blue when blue is at the other end of the spectrum from IR? Apparently the visible coloration doesn't always relate to near-visible or IR transmission. Googling.... a Peacock Blue filter is a black absorber under IR light, while the Congo Blue is transparent, though one looks a 'lighter' blue than the other. It turns out that the 'water clear' and darker tinted polycarbonates, are grades that tend to be more stable with temperature - it's a reliability issue, if not actually one of flammability. (polyetherimides and polyethersulphones are probably too pricey here) RL |
All times are GMT +1. The time now is 03:19 PM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter