A
rear-view mirror is a
mirrorA mirror is an object that reflects light or sound in a way that preserves much of its original quality prior to its contact with the mirror. Some mirrors also filter out some wavelengths, while preserving other wavelengths in the reflection...
in
automobileAn automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
s and other vehicles, designed to allow the driver to see rearward through the vehicle's backlight (rear windscreen).
In cars, the rear-view mirror is usually affixed to the top of the windscreen on a
swivelA swivel is a connection that allows the connected object, such as a gun or chair, to rotate horizontally and/or vertically. A common design for a swivel is a cylindrical rod that can turn freely within a support structure. The rod is usually prevented from slipping out by a nut, washer or...
mount allowing it to be freely rotated. In the past, some cars had the rear-view mirror mounted on top of the
dashboardA dashboard is a control panel placed in front of the driver of an automobile, housing instrumentation and controls for operation of the vehicle....
. Rear-view mirrors are designed to break away to minimize injury to occupants who may be thrown against it in a
collisionA traffic collision, also known as a traffic accident, motor vehicle collision, motor vehicle accident, car accident, automobile accident, Road Traffic Collision or car crash, occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris, or other stationary obstruction,...
.
For motorcycles and bicycles, the rear-view mirrors are usually mounted to the handlebars, and there are usually two of them, so they are variously referred to as "rear-view mirrors", "side-view mirrors", "side mirrors", or simply "mirrors".
History
The rear-view mirror's earliest known use and mention is by
Dorothy LevittDorothy Elizabeth Levitt, was a motorina and sporting motoriste of the early 20th century. On 4 July 1903 she was reported as the first woman ever to compete in a motor race...
in her 1906 book
The Woman and the Car which noted that women should "carry a little hand-mirror in a convenient place when driving" so they may "hold the mirror aloft from time to time in order to see behind while driving in traffic", thereby inventing the rear view mirror before it was introduced by manufacturers in 1914.
The earliest known rear-view mirror mounted on a motor vehicle appeared in
Ray HarrounRay Harroun was an American racecar driver, born in Spartansburg, Pennsylvania.-Early driving:As noted in the Columbia Car webpages, Harroun participated in the original setting of the record from Chicago to New York in 1903, and the re-taking of that record in 1904...
's Marmon racecar at the inaugural
Indianapolis 500The Indianapolis 500-Mile Race, also known as the Indianapolis 500, the 500 Miles at Indianapolis, the Indy 500 or The 500, is an American automobile race, held annually, typically on the last weekend in May at the Indianapolis Motor Speedway in Speedway, Indiana...
race in 1911. Although Harroun's is the first known use of such a mirror on a motor vehicle, Harroun himself claimed he got the idea from seeing a mirror used for the same purpose on a horse-drawn vehicle in 1904.
Elmer BergerElmer C.A. Berger was an inventor in the early 1900s credited for invention of the rear-view mirror, although racing enthusiast Ray Harroun experimented with one as early as 1911 while driving in the Indianapolis 500. He is now buried in Hollywood Forever, a park in Hollywood, California, in the...
is usually credited with inventing the rear-view mirror, though in fact he was the first to develop it for incorporation into production streetgoing automobiles.
Augmentations and alternatives
Rear-view mirrors are usually augmented with side-view mirrors on the driver's and/or passenger's side of the vehicle.
Recently,
rear-view video camerasA backup camera is a special type of video camera that is produced specifically for the purpose of being attached to the rear of a vehicle to aid in backing up. Backup cameras are alternatively known as 'reversing cameras' or 'rear view cameras'....
have been built into many new model cars, such as the
Mazda Hakaze ConceptThe Mazda Hakaze Concept, is a concept car that was revealed in early February 2007. Its major design elements come from a new design language developed by Mazda called Nagare, developed by Laurens van den Acker, Mazda Global Design Director. It translates to "flow"...
. This was partially in response to the rear-view mirrors' inability to show the road directly behind the car, due to the rear deck or trunk obscuring as much as 3–5 metres (10–15 feet) of road behind the car. For example, as many as 50 times a year, small children are killed by SUVs in America because the driver cannot see them in their rear-view mirrors. These camera systems are usually mounted to the bumper or lower parts of the car allowing for better rear visibility.
AftermarketThe automotive aftermarket is the secondary market of the automotive industry, concerned with the manufacturing, remanufacturing, distribution, retailing, and installation of all vehicle parts, chemicals, tools, equipment and accessories for light and heavy vehicles, after the sale of the...
secondary rear-view mirrors are available. They attach to the main rear-view mirror and are independently adjustable to view the back seat. This is useful to parents to monitor their children in the backseat.
Dimming
A
prismIn geometry, a prism is a polyhedron with an n-sided polygonal base, a translated copy , and n other faces joining corresponding sides of the two bases. All cross-sections parallel to the base faces are the same. Prisms are named for their base, so a prism with a pentagonal base is called a...
atic rear-view mirror — sometimes called a "day/night mirror" — can be tilted to reduce the brightness and
glareGlare is difficulty seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night. Because of this, some cars include mirrors with automatic anti-glare functions....
of lights, mostly for headlights shining directly on the eye level at night. This type of mirror is made of a piece of glass that is wedge-shaped in cross section—its front and rear surfaces are not parallel.
On manual tilt versions, a tab is used to adjust the mirror between "day" and "night" positions. In the day view position, the front surface is tilted and the reflective back side gives a strong reflection. When the mirror is moved to the night view position, its reflectorized rear surface is tilted out of line with the driver's view. This view is actually a reflection off the non-reflectorized front surface. Since the non-reflectorized front surface allows most of the light to go through, only a small amount of light is reflected into the driver's eyes.
Automatic dimming
In the 1950s, American inventor
Jacob RabinowJacob Rabinow was an engineer who led a truly prolific career as an inventor. He earned a total of 230 U.S. patents on a variety of mechanical, optical and electrical devices....
developed a light-sensitive automatic mechanism for the wedge-type day/night mirror. Several Chrysler Corporation cars offered these automatic mirrors as optional equipment as early as 1959, but few customers ordered them for their cars and the item was soon withdrawn from the option lists. Several automakers began offering rear-view mirrors with automatic dimming again in 1983, and it was in the late 1980s that they began to catch on in popularity.
Current systems usually use photo sensors mounted in the actual rear-view mirror to detect light and dim the mirror by means of
electrochromismElectrochromism is the phenomenon displayed by some materials of reversibly changing color when a burst of charge is applied. Various types of materials and structures can be used to construct electrochromic devices, depending on the specific applications....
. This electrochromic feature has been also incorporated into
side-view mirrorsA wing mirror is a mirror found on the exterior of motor vehicles for the purposes of helping the driver see areas behind and to the sides of the vehicle, outside of the driver's peripheral vision .Although almost all modern cars mount their side mirrors on the doors, normally at the "A" pillar,...
allowing them to dim and reduce glare as well.
Motorcycles
Depending on the type of motorcycle, the motorcycle may or may not have rear-view mirrors. Street-legal motorcycles are generally required to have rear-view mirrors. Motorcycles for off-road use only normally do not have rear-view mirrors. Rear-view mirrors come in various shapes and designs, and have various methods of mounting the mirrors to the motorcycle, most commonly to the
handlebarsMotorcycle handlebar refers to the steering mechanism for motorcycles. Handlebars often support part of the rider's weight, and provide a mounting place for controls such as brake, throttle, clutch, horn, light switch, and rear view mirrors....
. Rear-view mirrors can also be attached to the rider's
motorcycle helmetA motorcycle helmet is a type of protective headgear used by motorcycle riders. The primary goal of a motorcycle helmet is motorcycle safety - to protect the rider's head during impact, thus preventing or reducing head injury or saving the rider's life...
.
Bicycles
Some
bicycleA bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....
s are equipped with rear-view mirrors mounted to the handlebars. Cyclists may also choose to mount rear-view mirrors to a helmet or the frame of a pair of eyeglasses, or the basket of the bicycle.
The idea behind the bicycle mirror is rider safety. The bicycle mirror alleviates the problem of having to rotate your head and look over your shoulder, thus taking your concentration off of the roadway in front of you.
Computers
In an effort to prevent
identity theftIdentity theft is a form of stealing another person's identity in which someone pretends to be someone else by assuming that person's identity, typically in order to access resources or obtain credit and other benefits in that person's name...
, some computer users make use of rear-view mirrors to discourage others from looking over the user's shoulder and seeing sensitive information. These are especially prevalent on
automated teller machineAn automated teller machine or automatic teller machine, also known as a Cashpoint , cash machine or sometimes a hole in the wall in British English, is a computerised telecommunications device that provides the clients of a financial institution with access to financial transactions in a public...
s.
See also
- Blind spot (automobile)
A blind spot in a vehicle is an area around the vehicle that cannot be directly observed by the driver while at the controls, under existing circumstances...
- Driver visibility
In transport, driver visibility is the maximum distance at which the driver of a vehicle can see and identify prominent objects around the vehicle. Visibility is primarily determined by weather conditions and by a vehicle's design. The parts of a vehicle that influence visibility include the...
- Wing mirror
A wing mirror is a mirror found on the exterior of motor vehicles for the purposes of helping the driver see areas behind and to the sides of the vehicle, outside of the driver's peripheral vision .Although almost all modern cars mount their side mirrors on the doors, normally at the "A" pillar,...