Rearview mirror has a vision of the problem, that is, mirrors can be reflected to the range. The industry has three elements of the horizon, that is, the distance between the driver's eye and the rearview mirror; the size of the rearview mirror and the radius of curvature of the rearview mirror. These three elements have a certain relationship between the rearview mirror when the distance and size of the same mirror, the smaller the radius of curvature of the mirror, the mirror reflects the greater the horizon. The radius of curvature of the mirror
The same, the greater the size of the mirror, mirror the greater the visual field.
However, things have a dual nature, although the curvature of the mirror radius of the smaller field of view the greater the scope, but at the same time the mirror reflects the greater degree of deformation of the object, which some like "haha mirror", often cause the driver's illusion. From the perspective of traffic safety, there is a problem of image distortion.
Industry standards, the plane mirror distortion rate of not more than 3%, convex mirror distortion rate of not more than 7%, the request can not reflect the deformation of the physical image (the new regulations have been canceled on the distortion requirements). Therefore, the radius of curvature of the mirror there is a limit, the industry standard provides the curvature of the outer mirror R radius of not less than 1200mm, the curvature of the inner mirror for the infinite radius (plane mirror). In addition, the deviation range of the radius of curvature is specified (see GB15084).
The rearview mirror also has a reflectivity indicator. The greater the reflectivity, the sharper the image of the mirror. The size of the reflectivity is related to the inner surface reflective film material. Automotive rearview mirror reflective film generally silver and aluminum as the material, their minimum reflectivity of 80%. High reflectivity in some occasions there will be side effects, such as night driving in the back of the car headlamps under the irradiation, the reflection of the rearview mirror will make the driver a sense of dazzling, affecting traffic safety. Therefore, the general use of prism mirrors, although the mirror is flat, but its cross-sectional shape is prismatic, it uses the prismatic surface reflectivity and reflect the reflectivity is not the same characteristics, to achieve no glare requirements.
Daylight with a reflectivity of 80% of the silver or aluminum inside the reflective film, the night with the reflectivity of only about 4% of the surface glass. To this end, only a little bit of the night position of the rearview mirror rotation angle on the line. There is an automatic rear-view mirror with Auto-Dimming. Its electronic photodetector automatically discerns the natural light and imposes a light source. Adjusts the liquid crystal material in the mirror for a few seconds. Become colored to adjust the reflectivity of the rearview mirror, thus solving the dazzling problem.