Rear-lamp lenses

Rear-lamp lenses and reflectors have demanding needs of a different kind to reflect light in different colors. This has led to the use of multiple-color injection-molding machines for making PMMA lenses, with a strict control on colors used [10,28]. Reflectors for rear lamps are generally made of ABS (pure or blend), or PP in cases where they must be made more cheaply [28]. However, other materials like ASA, PEI, and glass-reinforced plastics can also be used [10,28]. A list of plastics used to make lenses or reflectors in different car models is given in Table 30.5. 

Adjust the illuminant to be in line with the telescope and bring the border line approximately to the reticle. While viewing the rear prism face by means of the auxiliary lens, rotate the lamp bracket to the right until only the extreme left side of the prism appears to be illuminated. If this rotation is carried too far, vertical interference lines will appear in the back face. These are generally irregular and rather faint. The best adjustment for contrast and illumination seems to be the point just before these fringes become distinct. 

Complex reflectors within new vehicle headlamp assemblies typically must withstand temperatures of up to 400°F. Appropriate thermoplastic materials must be selected not only for the lamp backcan and lens, but also for the electronic/electrical connectors. Variations on filled polyester, poly(imides), bulk molding compound (a sheet molding compound [SMC] analogue), and nylon/poly(phenylene oxide) alloys are typically utilized in these applications. Poly(carbonate) (PC) or impact-modified PC is typically used in the lens applications where high heat is required. Acrylic plastics can and are most typically utilized in lens apphcations that do not require high heat, such as rear stop mount designs. 

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