Infrared LED intensity

Question

I'm trying to make a stationary remote control that doesn't have to move. Basically I need to use a high intensity IR LED (I think). I'm assuming if the LED is not facing the TV etc. it will bounce around the room more effectively if its more intense. However, I'm a little worried after reading the datasheet for SFH 4550. It says:

"Depending on the mode of operation, these devices emit highly concentrated non visible infrared light which can be hazardous to the human eye"

Do I actually need to be worried about eye damage? Is there a way to avoid it causing damage (a filter over the LED?)

Answer 1

You could insist that users wear IR protective goggles.

If you don't really need that narrow angle (6°) that the SH4550 offers, you could also use a different LED that has a broader angle. The intensity also drops with the square of the distance from the LED.

Here are some detailed safety guidelines for IR LEDs. Remote signals are brief and pulsed, so the allowable power level for your application may be higher than for an IR illuminator.

Answer 2

Consider thinking totally differently. Focusing things make no sense if you're pointing it towards a wall, which makes quite a diffuse reflection.

It is much easier to increase sensitivity of the receiver, than to increase the output of the emitter.

A standard IR receiver such as http://www.vishay.com/docs/82491/tsop382.pdf works well with IR signal bouncing off from two walls, emitted by a standard 60degree IR led, driven from 10mA.