Crosstalk reduction method in a glasses-free AR 3D HUD

We previously developed an augmented reality (AR) 3D head-up display (HUD) system[1] for vehicles that can match a 3D arrow object with roads in the real world at a distance from 3.7 m to 70 m. Current autostereoscopic[2] (glasses-free) 3D displays[3] suffer from the 3D crosstalk problem, in which optical phenomena such as light bleeding incompletely separate stereo images[4]. As a result, accurate AR graphics are not irradiated to both eyes, and the user does not perceive a 3D stereoscopic effect. There are two existing methods for reducing crosstalk as user experience post-processing, blurring the image or lowering the brightness; both reduce image quality. In contrast, we solve the problem without reducing image quality or HUD brightness by covering the 3D crosstalk area with a newly generated image (a crosstalk concealer) that depends on the distance of the arrow object, outdoor luminance, and brightness of the HUD. The width of the crosstalk concealer is determined by the change in disparity according to the distance of the object in the HUD virtual screen. The opacity of the crosstalk concealer is adjusted according to the external brightness and HUD brightness. The environmental conditions considered in this study include the external light-source brightness, HUD brightness, arrow object distance, and the arrow object size, and the system was optimized to maintain HUD brightness and clarity while eliminating crosstalk.