Headlamp assemblies utilize a solid optical body made of glass or another
heat resistant, light transmissive material. The solid optical body has an axially
positioned cavity therethrough which receives a bulb that injects light through
a cylindrical wall of the cavity into the optical body. In order to reflect light
from the bulb, the optical body has a rear surface which is coated with a reflecting
material, such as aluminize or a dichroic material. In accordance with one embodiment
of the invention in which a plastic lens is used, the optical body is made of glass
with a dichroic coating configured so that the infrared component of light from
the bulb is transmitted through the dichroic coating and emitted through the rear
of the optical body. This reduces transmission of heat from the bulb to the plastic
lens so that the lens can be positioned closer to the optical body, which decreases
the fore/aft extent of the headlamp assemblies. In another embodiment of the invention
the dichroic coating is tuned not to reflect yellow wavelength light.