Minimum achievable height of a single-module LED low-beam projection headlamp

Area of Science:

• Automotive Engineering
• Optical Engineering
• Solid-state Lighting

Background:

• LED headlamp technology has advanced, but miniaturization efforts face challenges in maintaining performance and aesthetics.
• Current LED headlamp height is typically 40-60 mm, with recent innovations in total internal reflection modules not reducing overall housing size.
• Conventional single-module LED low-beam headlamps offer cost and compactness advantages, but their minimum achievable height remains an open question.

Purpose of the Study:

• To analytically determine the minimum achievable height for a single-module LED low-beam projection headlamp.
• To establish a general design framework for compact LED headlamp development.

Main Methods:

• Analytical investigation of optical properties using geometrical optics and photometrical luminance transfer.
• Utilized the ratio of focal distances (m) of elliptical reflectors as a key design variable.
• Confirmed and extended analytical findings through numerical simulation using ray-tracing software.

Main Results:

• Identified a suitable range for the focal distance ratio (m) as 0.15-0.17 to meet low-beam regulations.
• Determined the best achievable height for a single-module LED low-beam headlamp is approximately 46 mm when m is around 0.15.
• The precise minimum height is dependent on specific LED properties and module geometry.

Conclusions:

• A minimum achievable height of 46 mm for single-module LED low-beam headlamps is feasible.
• The study provides a validated analytical framework for designing compact and compliant LED automotive lighting.
• This research contributes to advancing automotive headlamp design by defining limits for miniaturization.