Automotive forward lamp assemblies have been modified over the years to decrease the overall mass of the assemblies in order to increase the safety and the gas mileage of automobiles. Most conventional automotive forward lamp assemblies require a large amount of mass concentration at the front of the vehicle. For example, a typical headlamp and fog lamp assembly will comprise a housing with a reflector, at least one filament bulb, a plurality of electrical wires and a lens. This construction results in a large mass concentration located at the front of the vehicle. In the event of a vehicular accident, a large mass concentration at the front of the vehicle is undesirable because it can result in increased damage and increased injuries. This is especially problematic in the event an automobile collides with a pedestrian.
In an effort to reduce the mass of automotive front lighting systems, designers have begun using thermoplastic materials to construct the reflector for headlamp and fog lamp assemblies. Thermoplastic reflectors have the advantage of having less mass than other types of reflectors. Thus, thermoplastic reflectors reduce the overall weight of the lamp assembly. Unfortunately, thermoplastic materials have the drawback of creating manufacturing defects in the form of sinks. As used herein, the term “sink” is used to describe a manufacturing defect located on the reflector that forms a pit in the reflector (i.e. an indentation, a recess and/or a concave surface). A sink causes a large amount of glare to be emitted from the lamp assembly because the defect reflects light in such a manner that a large amount of light is concentrated over a small angle when light reflects from the sink. Concentration of light over a small angle can result in unwanted glare or bright spots in the beam pattern. Thus, sinks are detrimental to the optical performance of an automotive lamp assembly because they cause the lamp assembly to emit a large amount of glare. Sinks occur frequently in the manufacturing of headlamp reflectors because of the thick sections required to form the reflector. For example, a sink normally forms around the socket hole of the reflector. While this is an example of a normal location of a sink, sinks of all shapes and sizes are also prone to appear in other portions of the reflector. In order to use thermoplastic reflectors to manufacture headlamp assemblies, designers of headlamp assemblies are faced with overcoming the glare problems associated with sinks.
Accordingly, it is desirable to have an automotive forward lamp assembly that would allow for the use of a thermoplastic reflector without having the large amount of glare resulting from a sink in the thermoplastic reflector. Specifically, it is desirable to develop a design feature that can eliminate the optical problems caused by sinks on thermoplastic reflectors.