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 postprocessing, 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.
Although head-up displays (HUDs) have already been installed in some commercial vehicles, their application to augmented reality (AR) is limited owing to the resulting narrow field of view (FoV) and fixed virtual-image distance. The matching of depth between AR information and real objects across wide FoVs is a key feature of AR HUDs to provide a safe driving experience. Meanwhile, current approaches based on the integration of two-plane virtual images and computer-generated holography suffer from problems such as partial depth control and high computational complexity, respectively, which makes them unsuitable for application in fast-moving vehicles. To bridge this gap, here, we propose a light-field-based 3D display technology with eye-tracking. We begin by matching the HUD optics with the light-field display view formation. First, we design mirrors to deliver high-quality virtual images with an FoV of 10 × 5° for a total eyebox size of 140 × 120 mm and compensate for the curved windshield shape. Next, we define the procedure to translate the driver eye position, obtained via eye-tracking, to the plane of the light-field display views. We further implement a lenticular-lens design and the corresponding sub-pixel-allocation-based rendering, for which we construct a simplified model to substitute for the freeform mirror optics. Finally, we present a prototyped device that affords the desired image quality, 3D image depth up to 100 m, and crosstalk level of <1.5%. Our findings indicate that such 3D HUDs can form the mainstream technology for AR HUDs.
The eye-box expansion method using the merging of waveguide and HOE (holographic optical element) is presented. Using the waveguide with the refractive index of 1.7, the wide FoV (field of view) that is up to 60° is achieved. Full color and wide FoV are obtained using 2 waveguides. Projection optical system based on Scheimpflug principle is proposed and designed to compensate large-scale off-axis HOE aberrations. In order to enhance image quality, the projection system is precisely simulated and the grating pitch and alignment are calculated to increase the eye-box and uniformity.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.