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The 'windshield' (also known as the 'windscreen') of an aircraft, automobile, bus, motorcycle, or tram is the front window. Modern windshields are generally made of laminated safety glass, which consists of two (typically) curved sheets of glass with a plastic layer laminated between them for safety, and are glued into the window frame.
Motorcycle windscreens are often made of high-impact acrylic plastic. As the name implies, their main function is to shield the driver from the wind, though they do not do so as totally as those of a car.

Contents

Usage

Safety

Other aspects

Terminology

Stone chip and crack damage

See also

Usage

In daily use, windshields mainly protect the vehicle's occupants from wind, temperature extremes, and flying debris such as dust, insects, and rocks, as well as providing an aerodynamically formed window towards the front. UV Coating may be applied to screen out harmful ultraviolet light.

Safety

Early windscreens were made of ordinary window glass, but that could lead to serious injuries in the event of a crash. They were replaced with windshields made of toughened glass and were fitted in the frame using a rubber or neoprene seal. The hardened glass shattered into many mostly harmless fragments when the windscreen broke. These windshields, however, could shatter from a simple stone chip. Especially in police cars this was seen as a problem and it led to the development of the laminated glass windows most cars use. However, there have been some concern over the risk of decapitation and some cars instead use a windscreen of lexan.
The modern, glued-in screens contribute to the vehicle's rigidity, but the main forcing in innovating the windshield has historically been the need to prevent injury from sharp glass fragments. Modern windshields, now almost universally required in all nations, do not fragment, but tend to stay in one piece even if broken, except if pierced locally by a strong force. Properly installed automobile windshields are also essential to safety; along with the roof of the car, they provide protection in the case of a roll-over accident in the vehicle.

Other aspects

In many places, laws restrict the use of heavily tinted glass in vehicle windshields; generally, laws specify the maximum level of tint permitted. Some vehicles have noticeably more tint in the uppermost part of the windshield of motor vehicles that blocks glare from the sun.
In aircraft windscreens, a current is applied through a conducting layer of tin(IV) oxide to generate heat to prevent icing. A similar system for automobile windshields, introduced on Ford vehicles as "Quickclear" in Europe ("InstaClear" in North America) in the 1980s, uses very thin heating wires or conductive-film layer embedded between the two laminations.
Using thermal glass has one downside: it prevents some navigation systems from functioning correctly, as the embedded metal jams the satellite signal. This can be resolved by using an external antenna for the navigation system.

Terminology

The term ''windshield'' is used generally throughout North America, although ''windscreen'' is often used for motorcycles and similar vehicles. The term ''windscreen'' is the usual term in the UK and Australia/New Zealand for all vehicles. In Japanese English, it is called "front glass".
In the USA, ''windscreen'' refers to the mesh or foam screen placed over a microphone to minimize wind noise, while a ''windshield'' refers to the front window of a car. In the UK, the meaning of these terms is reversed.
Today’s windshields are a safety device just like seat belts and air bags. The installation of the auto glass is done with an automotive grade urethane designed specifically for automobiles. The adhesive creates a molecular bond between the glass and the vehicle. If the adhesive bond fails at any point on the glass it can reduce the effectiveness of the air bag and substantially compromise the structural integrity of the roof. (Raymond Clough)

Auto windscreens less than 20 cm (8 inches) in height are sometimes known as 'aeroscreens' since they only deflect the wind. The twin aeroscreen setup (often called Brooklands) was popular among older sports and modern cars in vintage style.
A ''wiperless windshield'' is a windshield that uses a mechanism other than wipers to remove snow and rain from the windshield. The concept car Acura TL features a wiperless windshield using a series of jet nozzles in the cowl to blow pressurized air onto the windshield.

Stone chip and crack damage

Many types of stone damage can be successfully repaired. Bullseyes, cracks, starbreaks or a combination of all three, can be repaired without removing the screen, eliminating the risk of leaking or bonding problems sometimes associated with replacement.

See also

★ Windshield/windscreen wiper