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Since the very first series introduction of a HID Litronic headlamp in 1991 by Bosch, almost all vehicles have been equipped with the projector headlamp technology, utilizing the D1 and later-on the D2S discharge bulbs. These bulbs need some additional measure to provide for good contrast and thus for good control of the glare values. With a projector headlamp this measure is accomplished via the system-inherent shield, yielding an excellent control of the cut-off line both for ECE and SAE beam patterns. In this paper, newly developed headlamps of the projection- and reflection-type from Bosch and Mercedes-Benz will be presented. Due to the ongoing development of the discharge bulbs the D2R bulb is now available. This bulb which has been specifically designed for reflection type headlamps incorporates accurately adjusted shielding stripes on the outer glass jacket of the bulb.

A new electronic headlamp system Litronic (light and electronic) was developed by Bosch and was launched in a first series project by BMW in autumn 1991. The 2nd generation Litronic or Xenon headlamps have been available since mid of 1994 in the new BMW 7 series. The unsurpassed light output of the newly developed high intensity discharge lamp for automotive use results in a significantly improved light pattern produced by a specially adapted low beam projector headlamp. Better visibility and visual guidance will essentially enhance driver's safety and comfort without dazzling other traffic. This paper presents the development of the integrated electronic HID headlamp and discusses light pattern, electronics and headlamp design. Furthermore the application of this headlamp to the car and the specific automotive reqirements as well as the experience from more than 3-1/2 years of original equipment are discussed.