Imaging and Non-imaging Illumination of a DLP for High-Resolution Headlamps

摘要

Matrix-LED systems offer different functionalities to increase road safety, e.g. glare-free high beam and markinglight. Shortly after their introduction, efforts have been made to increase the amount of pixels. One of theresults is the EVIYOS LED consisting of 1024 individually controllable pixels, which practically set the stagefor pixel light systems. Current efforts to implement high-resolution pixel light systems are focused towards theexploration of an efficient light source in combination with the use of spatial light modulators.One approach to implement high-resolution pixel light systems is the use of LED arrays as a light source toilluminate a DLP. Unlike video projectors which require a homogeneous illumination of the DLP in order toobtain a homogeneous projection, headlamps require an inhomogeneous light distribution with high illuminancein the center. In order to receive a high system efficiency preforming the desired illuminance onto the activearea of the modulator is advantageous. To further increase the systems efficiency an imaging illumination of theDLP, where the images of the emission surfaces of the LEDs are superposed onto the active area of the DLP, isworthwhile.In this paper, concepts for imaging and non-imaging illumination strategies of a DLP for high resolution headlampswill be introduced. For both illumination strategies the most promising concept will be selected to setup an optical system to illuminate a DLP. The paper concludes with a comparative analysis of the imaging andnon-imaging optical system with regards to the system architecture and system efficiency.