High Intensity Discharge Headlamps (HID) - Experience for More Than 3-1/2 Years of Commercial Application of Litronic Headlamps

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. The high acceptance of this new headlamp technology in the market proves the superior concept in safer and more comfortable night-time driving, in Europe as well as in the USA.