Most of head-up displays (HUDs) in the automotive sector make use of LCDs that are illuminated by LEDs for image generation. Because of the losses due to polarization, absorption of the color filter and low reflectivity of the combiner element, the efficiency is low and does not allow for daylight and sunlight readability of the displayed information. Therefore, modern requirements of automotive HUDs (also avionics ones) involve full color display technology with high brightness. Such technology would allow for differentiating the displayed information and enhancing brightness and contrast in the viewing zone of the driver. During the last few years, there have been tremendous advances in the development of pico-projectors. In particular, laser-scanner pico-projector that is based on the flying-spot principle proved to be efficient and compact technologies for image generation. In the following article, we discuss the requirements of integrating such novel image sources to HUDs and the state-of-the-art of the key properties (e.g. image quality namely speckle and resolution) and components (e.g. green laser diode).
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