The multiplane augmented reality (AR) head-up display (HUD) is important in improving
driving safety and comfort. In this paper, we propose an AR-HUD with
switchable display modes based on polymer dispersed liquid crystal
(PDLC) and lens holographic optical elements (HOEs), which can provide
two display modes: the dual-virtual-image mode and the
virtual-real-image mode. The dual-virtual-image mode can produce two
virtual images at different depths, which can provide a better sense
of reality integration for the driver to improve driving safety and
comfort. The virtual-real-image mode can produce one far virtual image
and one near real image at different depths, and it provides a larger
eye box (EB) for both driver and passengers in the car and a higher
image contrast. The two display modes can be switched by an
electronically controlled scattering module consisting of a pair of
PDLC films. The proposed AR-HUD system is compact and equipped with
multiplane display and mode-switching functions, and is expected to be
applied in the future.