An auto-dimming rearview mirror uses a sensor that detects the amount of light hitting the mirror's surface. This sensor is typically located on the front side of the mirror, facing the windshield. When the sensor detects bright light from headlights behind the car, it sends a signal to an electronic control unit (ECU).
The ECU then sends a command to the mirror to dim, reducing the amount of light reflected back to the driver's eyes. This dimming process is achieved through a combination of electrochromic gel and an electro-optical device that sits behind the mirror's surface. The electrochromic gel contains tiny particles that darken or lighten in response to a small electrical charge..
The electro-optical device, known as a photodiode, detects the amount of light hitting the mirror's surface and sends a signal back to the ECU. The ECU adjusts the electrical charge to the electrochromic gel accordingly, ensuring the right amount of dimming to reduce glare while still allowing the driver to see behind the car.
AdChoices