Arear-view mirror(orrearview mirror) is a, usuallyflat,mirror inautomobilesand other vehicles, designed to allow the driver to see rearward through the vehicle's rear window (rearwindshield).
In cars, the rear-view mirror is usually affixed to the top of thewindshieldon a double-swivelmount allowing it to be adjusted to suit the height and viewing angle of any driver and to swing harmlessly out of the way if impacted by a vehicle occupant in acollision.
The rear-view mirror is augmented by one or moreside-view mirrors,which serve as the only rear-vision mirrors ontrucks,motorcyclesandbicycles.
History
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Early use of fixed mirrors was described as early as 1906, with a trade magazine noting mirrors for showing what is coming behind were now popular on closed bodied automobiles, and were likely to be widely adopted in a short time.[1]The same year, a Mr. Bilal Ghanty fromFrancepatented a "Warning mirror for automobiles".[2]The Argus Dash Mirror, adjustable to any position to see the road behind, appeared in 1908.[3][4]Earliest known rear-view mirror mounted on a racing vehicle appeared onRay Harroun'sMarmonrace car at the inauguralIndianapolis 500race in 1911.[5]Harroun himself claimed he got the idea from seeing a mirror used for a similar purpose on ahorse-drawn vehiclein 1904.[6]Harroun also claimed that the mirror vibrated constantly due to the rough brick surface, and it was rendered largely useless.[7]
Elmer Bergeris usually credited with inventing the rear-view mirror, though in fact he was the first to patent it (1921) and develop it for incorporation into production street going automobiles by his Berger and Company.[citation needed]
Augmentations and alternatives
editRecently,rear-view video camerashave been built into many new model cars, 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 meters (10–15 feet) of road behind the car. As many as 50 small children are killed bySUVsevery year in the USA because the driver cannot see them in their rear-view mirrors.[8]Camera systems are usually mounted to the rear bumper or lower parts of the car, allowing for better rear visibility.[citation needed]
Aftermarketsecondary 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 enable adults to monitor children in the back seat.[citation needed]
Anti-glare
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  In the "day" position, the driver sees the road behind by reflection on the (rear) metal surface. In the "night" position, the driver sees the dimmer reflection on the (front) glass coating. The light is attenuated in the second mode, which partially compensates thepupillary response. |
Aprismaticrear-viewmirror—sometimes called a "day/night mirror" —can betiltedto reduce the brightness andglareof lights, mostly for high-beamheadlightsof vehicles behind which would otherwise be reflected directly into the driver's eyes 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 reflecting rear surface is tilted out of line with the driver's view. This view is actually a reflection of the low-reflection front surface; only a much-reduced amount of light is reflected in the driver's eyes.
"Manual tilt" day/night mirrors first began appearing in the 1930s and became standard equipment on most passenger cars and trucks by the early 1970s.
Automatic dimming
editIn the 1940s, American inventorJacob Rabinowdeveloped a light-sensitive automatic mechanism for the wedge-type day/night mirror.[9]SeveralChrysler Corporationcars 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.[citation needed]Several automakers[vague]began offering rear-view mirrors with automatic dimming again in 1983,[citation needed]and it was in the late 1980s that they began to catch on in popularity.[citation needed]
Current systems usually usephotosensorsmounted in the rear-view mirror to detect light and dim the mirror by means ofelectrochromism.This electrochromic feature has also been incorporated intoside-view mirrorsallowing them to dim and reduce glare as well.
Suspending objects
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Objects are sometimes hung from the rear-view mirror, includingcross necklaces,prayer beads,good luck charms,decorations likefuzzy dice,and air fresheners likeLittle Trees.[10][11]In some jurisdictions such hanging is illegal on the basis that it impairs the driver's forward view and so compromises safety.[12]Black Lives Matterprotesters have cited this as an example of the minor violations used as grounds fortraffic stopsdisproportionately targeting black drivers.[12][13]
Trucks and buses
editOn trucks and buses, the load often blocks rearward vision out the backlight. In the U.S. virtually all trucks and buses have a side view mirror on each side, often mounted on the doors and viewed out the side windows, which are used for rear vision. These mirrors leave a large unviewable ( "blind" ) area behind the vehicle, which tapers down as the distance increases. This is a safety issue which the driver must compensate for, often with a person guiding the truck back in congested areas, or by backing in a curve.[14]"Spot mirrors", aconvex mirrorwhich provides a distorted image of the entire side of the vehicle, are commonly mounted on at least the right side of a vehicle. In the U.S. mirrors are considered "safety equipment", and are not included in width restrictions.[15][16]
Motorcycles
editDepending on thetype of motorcycle,the motorcycle may or may not have rear-view mirrors.Street-legalmotorcycles 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 thehandlebars.Rear-view mirrors can also be attached to the rider'smotorcycle helmet.The Reevu MSX1 helmet uses an internal periscope that allows the user rear vision.[17][18][19]
Bicycles
editSomebicyclesare equipped with a rear-view mirror mounted on ahandlebar.Rear-view mirrors may also be fitted to thebicycle frame,on ahelmet,on thearmor the frame of a pair ofeyeglasses.This allows what is behind to be checked continuously without turning round. Rear-view mirrors almost never come with a new bicycle and require an additional purchase.
Aircraft
editBy 1956, theCivil Aeronautics Administrationhad approved a rear-view mirror for light aircraft.[20]They also predicted periscopes in larger aircraft.[20]Fighter aircraft usually have one or more rear-view mirrors mounted on the front canopy frame to watch out for chasing aircraft.[citation needed]
See also
editReferences
edit- ^The Automobile (weekly), Thursday, 27 December 1906, p. 910
- ^"Brevet d'invention: dispositif de miroir avertisseur pour automobiles".Institut national de la propriété intellectuelle.8 January 1907.Archivedfrom the original on 1 October 2017.Retrieved15 October2017.
- ^Cycle & Automobile Trade Journal, 1 December 1908, p249
- ^"All female team create award-winning concept car".Volvo.Archived fromthe originalon 30 August 2006.Retrieved14 December2006.
- ^Ward's Auto World: Rearview MirrorArchived26 April 2005 at theWayback Machine
- ^Davidson, DonaldThe Talk of Gasoline Alley(radio program). Accessed via WIBC (FM), 28 May 2006
- ^The Talk of Gasoline Alley.5 May 2010.WFNI.
- ^Tatiana Morales (22 October 2002)."Kids And SUVs: Preventing Accidents - The Early Show".CBS News. Archived fromthe originalon 7 March 2005.Retrieved2 December2011.
- ^Rabinow, Jacob(18 May 1990).Inventing for Fun and Profit.San Francisco, CA: San Francisco Press.ISBN978-0-911302-64-6.
- ^Griffin, Alaine (10 August 2010)."Supreme Court Rules On Cross Hanging From Rearview Mirror".Hartford Courant.Retrieved24 March2022.
- ^Jain, Geetike (1 October 2020)."What cab drivers around the world hang on their rear-view mirrors".Condé Nast Traveller India.Archivedfrom the original on 20 January 2021.Retrieved13 August2021.
- ^abBaker, Mike; Bogel-Burroughs, Nicholas (17 April 2021)."How a Common Air Freshener Can Result in a High-Stakes Traffic Stop".The New York Times.Archivedfrom the original on 17 April 2021.Retrieved13 August2021.
- ^"Minneapolis police to curb stops for minor traffic violators".Associated Press.13 August 2021.Archivedfrom the original on 13 August 2021.Retrieved13 August2021.
- ^"CDL Commercial Drivers License Study Guide"(PDF).Illinois Secretary of State. pp.23–24.Archived(PDF)from the original on 1 September 2013.Retrieved4 June2013.
- ^"Standard No. 111; Rearview mirrors".Federal Motor Vehicle Safety Standards. U.S. Department of Transportation. 12 April 2013.Archivedfrom the original on 22 May 2013.Retrieved4 June2013.
- ^"Federal Size and Weight Regulations".U.S. Department of Transportation. 20 June 2012.Archivedfrom the original on 5 June 2013.Retrieved4 June2013.
- ^"Motorbike helmet that lets you see road behind".Daily Mirror.18 September 2010.
- ^"World's First Rear Vision" in "a Helmet Taking off in 2014".
- ^"Reevu Helmets: Everything You Need to Know".9 May 2015.
- ^ab"Periscopes for Aircraft"Archived8 July 2014 at theWayback MachinePopular Mechanics,June 1956, p. 142.
