Can an LED TV transmit infra red?

OU812

Just wondering if an LED TV would be capable of transmitting IR alongside regular programming?

The TV is basically hundreds of bulbs and should theoretically be able to transmit a sequence outside of the normal visual range, right?

Dempsey

The led's in a tv would be manufactured with only the visible spectrum engineered for. I imagine some of them would be able to produce infrared of the shortest wavelength possible, i.e around 800nm. Only a manufacturing defect would see longer wavelengths being produced.

brightspark

OU812 wrote: »

Just wondering if an LED TV would be capable of transmitting IR alongside regular programming?

The TV is basically hundreds of bulbs and should theoretically be able to transmit a sequence outside of the normal visual range, right?

Bulbs? None in any TV I've seen! (Usually found in garden centres, handy if you need tulips)

Seriously I'm sure LEDs emit some infra red due to heat, but the output from an individual LED is restricted to the spectrum for which it is designed.

ZENER

I'm curious why you'd want to do this ? There are a couple of points you need to consider, firstly LCD panels pass the light from a backlight through polarised crystals which produces different colours seen by the viewer. There are no discreet LEDs making up the display. OLED, of course is a different matter.

Backlights can be either CCFL tubes or LEDs. CCFL tubes can produce light and radiation outside the human visual range, in the past old remote control TVs used to show unusual behaviour when a fluorescent light was turned on including reduced range of the handheld remote control due to ambient IR flooding the sensor of the TV.

LED backlights are a different story. Most domestic and computer applications employ Blue LEDS with a yellow addition. These are smaller and cheaper to produce. High end screens use RG and B LEDS allowing better control over the colour temperature of the display. I'm not sure how much IR these can produce but I imagine the RGB version stands a better chance.

I'm guessing you want to emit a specific amount or duration of IR so therefore need control not possible by relying on the IR generated by heat alone ?

Ken

Led grow lamps do or you can just buy the LEDs as electronic components.

ozmo

OU812 wrote: »

Just wondering if an LED TV would be capable of transmitting IR alongside regular programming?

BBC used to transmit computer programs during the credits of some shows.

You would stick a light sensor to a flickering square on the screen and it would blink the bits to your computer. Not IR - this was a flashing square...

This was about mid 80's I think.