Infrared IR Sensors

The History of Infrared Light

• Infrared light has always been present from light from the sun and stars.


• More than 300 years ago Isaac Newton discovered that white light is actually a combination of different colors of light. Newton used two sets of prisms to separate the colors then combine them back together into white light to prove his theory.


• In 1800 Frederick Herschel, had a theory that different colors of light also contained different temperatures. He tested his theory on different color light rays passing through a prism and found his theory was true. During his experiment, he also tested temperature outside of the visible light and found there was a high temperature below the red light ray. The result was the discovery of invisible light we now call infrared light.

Uses for Infrared Sensors

• Similar to visible light, infrared light reflects, refracts, and can be absorbed.


• Consumer electronics such as televisions and DVD players use a remote control that relies on infrared light. The remote has an infrared LED that uses a light wavelength of 980 nm to send a signal to an infrared sensor on the television or DVD player. Current IR remotes use a binary code system (0's and 1's) to communicate with the electronic device.


• The Nintendo Wii uses an infrared sensor in the Wii remote. The Nintendo light bar has 5 infrared LEDs which provide feedback to the sensor. The Wii uses the IR data to position the pointer position on the screen wirelessly.


• Infrared light with an infrared received is commonly used with line-following robots. By using an LED light directed towards the ground in front of the robot with an infrared receiver, the robot processor is able to detect the difference between a dark surface and a reflective light surface. A robot is then programmed to make adjustments in its steering to keep following the reflective light line.


• Infrared cameras can take images and video recording imagry from the infrared light that humans cannot normally see.


• Since humans cannot see infrared light, infrared video cameras are used in security systems to record video at night. Infrared light sources that people cannot see provide the light needed for the cameras.