Mirrors mounted on the exterior of the vehicle body to provide a view of the areas behind and to the sides of the vehicle.
In modern technology, electronic exterior rearview mirrors-known as Camera Monitor Systems (CMS)-capture real-time footage of the side and rear areas via external cameras and display the images on interior screens, serving as an intelligent vision system that provides an indirect field of view.
Exterior rearview mirrors are devices installed on both sides of a vehicle to monitor traffic conditions behind, alongside, and below the vehicle. The concept dates back to the early 20th century; they were first used in race cars in 1911, and in 1921, Elmer Berger obtained a patent and achieved mass production, marking the official birth of exterior rearview mirrors for consumer vehicles. By providing drivers with an indirect field of view, they serve as a critical component for driving safety; their installation is mandated by regulations in countries worldwide, and there are clear industry standards regarding their field of view.
With technological advancements, electronic rearview mirrors (CMS) have come into use. On July 1, 2023, China implemented the new national standard GB 15084-2022, which defined technical requirements for CMS and authorized their use as a replacement for traditional optical mirrors. CMS operate using a system of cameras and displays, offering advantages such as a wider field of view, reduced susceptibility to weather conditions, and lower wind resistance.