Figure 1: See-through additive light field displays with holographic optical elements (HOEs). We propose a novel compressive light field display that uses HOE layers. Each layer diffuses a projection beam from a projector and functions as an additive layer. This prototype consists of two HOE layers, two projectors, and corresponding relaying optics. The images on the right demonstrate the display results of our prototype, and its high levels of transparency, brightness, and image fidelity.
Abstract
We propose a see-through additive light field display as a novel type of compressive light field display. We utilize holographic optical elements (HOEs) as transparent additive layers. The HOE layers are almost free from diffraction unlike spatial light modulator layers, which makes this additive light field display more advantageous when modifying the number of layers, thickness, and pixel density compared with conventional compressive displays. Meanwhile, the additive light field display maintains advantages of compressive light field displays. The proposed additive light field display shows bright and full-color volumetric images in high definition. In addition, users can view real-world scenes beyond the displays. Hence, we expect that our method can contribute to the realization of augmented reality. Here, we describe implementation of a prototype additive light field display with two additive layers, evaluate the performance of transparent HOE layers, describe several results of display experiments, discuss the diffraction effect of spatial light modulators, and analyze the ability of the additive light field display to express uncorrelated light fields.