What is an Auto-Dimming Rear View Mirror? How does the dimming rearview reflector work? What are the symptoms of malfunctioning auto-dimming rearview lenses?
What is an Auto Dinning Rearview mirror?
The rear view mirror is located on the windshield at the top. The mirror’s function is to show the view behind your vehicle, and to allow you to see cars around you as you change lanes. Rear view mirrors are an integral part of safety for you and other vehicles.
Most newer model vehicles use auto-dimming rear-view mirrors. These mirrors have the ability of dimming the light reflected from the surface. This mirror reduces the glare caused by vehicles behind it, which can help to decrease driver fatigue. These mirrors are more useful in heavy traffic at nights. This feature can be found in both the exterior and interior mirrors.
How does an auto-dimming rear view mirror work?
If you look back at history, it is obvious that auto-dimming lenses were first invented in the 1950s. But, commercial applications of auto-dimming mirrors began after 1980. Gentex is a well-respected manufacturer and supplier of auto-dimming lenses.
Modern vehicles use auto-dimming rearview lenses that have the following components:
Ambient Sensor: It detects ambient light. It sends an alert to the controller when it begins to get dark.
It has a Brightness Sensor Measures the intensity of the light that falls on the mirror and sends it to the control unit.
Control Unit The operation of both sensors is monitored and a decision made to reduce the glare.
The auto-darkening reflector uses electrochromatism principles and has a sandwich construction. It consists of a glass and a mirror. In each glass and mirror, there are two conductive layers. These conductive layers can be used to store ions, electrolyte or electrochromatic materials.
After the control unit has instructed to lower the glare of light, the system applies an electric voltage of around 3 volts on the conductive layers. This causes ions flow from the ion store layer to the electrochromatic and blackens the mirror. This is the decrease in light reflection from the mirror.
Why use rear view mirrors that automatically dim?
Driving at night can be difficult for drivers because of the bright rear-facing light. It also reduces driver visibility. The driver’s eyes are subject to severe strain if they are exposed to this light for long periods. Scientific studies show that prolonged exposure to this type of light almost doubles the driver’s reaction time and increases the chance of an accident. In order to prevent such accidents, auto-dimming lights were added to vehicles. These mirrors are rapidly gaining popularity in the automotive industry.
- – It reduces glare from vehicle lights and increases night vision distance.
- Safety is increased by better visibility
- – Reduces driver fatigue and eye strain.
What are the Signs and Symptoms of an Auto-Dinning Rearview Mirror Problem?
The rear view mirror is meant to last for the lifetime of your vehicle. However, sometimes it may fail. These are the most common signs of a defective rear view mirror:
Rearview Mirror Doesn’t Dim Automatically
Behind the mirror are many sensors. If the auto dimming feature does not work, it is possible that the sensors are dirty. Clean them using a soft cloth. Check that there are no obstructions to the light from the sensors. After cleaning them and inspecting them thoroughly, shine a flashlight at them to check if the mirror dims. If the mirror doesn’t dim, the sensor may be defective and should be replaced.
Color Change
Over time, the color of your rear view mirror can fade due to sun damage and other debris. If this happens, you can clean the mirror with a soft cloth to avoid scratching the surface. You may also see discoloration below the mirror’s surface. If the discoloration does not change, it could be beyond repair and may need to be replaced.
In rare cases, the rearview mirror could fall off and break. It should be replaced promptly if it is damaged. Your vehicle may not pass inspection if it does not have an interior rear view mirror. However, this could compromise your driving safety. Inspection can only be done on vehicles with an outside rear view mirror that is the driver’s side (left).
