What were the earliest commercial uses for the initial red and infrared LEDs developed in the 1960s?

Answer

Indicator lights signaling power on or system status.

Due to high cost and low brightness compared to incandescent bulbs, the first LEDs were restricted to niche applications like small indicator lights.

What were the earliest commercial uses for the initial red and infrared LEDs developed in the 1960s?

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History of LED Lights - How do they Work? - YouTube

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