Tabletop displays serve as shared displays and co-located workspaces for multiple people. People often place physical objects such as mockup models on the table as an intuitive communication tool for tabletop displays. However, current tabletop displays have limitations in terms of image presentation: The display area is limited to horizontal surfaces, and the view-dependent appearance of the shared images is not provided. The goal of this paper is to solve these limitations by combining

more »

... ded vertical mid-air images and horizontal image projection to enhance visual presentation. For this purpose, our optical design employed a plate-shaped imaging optics as a tabletop surface and diffusion control film as a projection screen. The proposed system, "HoVerTable," provides both vertical and horizontal images to two users facing one another. In this paper, we describe the details of our optical design. A user study confirmed that providing text captions dependent on users' viewpoints is effective for text annotation in a shared tabletop environment. With HoVerTable, users can enjoy interactive applications such as a mixed reality showcase.