Interactive Holographic Display for Real-Time Drawing and Erasing of 3D Point-Cloud Images With a Fingertip

We demonstrate an interactive holographic display system for real-time drawing and erasing of 3D point-cloud images. This system detects the position of the observer’s fingertip with a motion sensor, which it uses to calculate the complex amplitude distribution for the hologram. Because the calculated distribution is added to or subtracted from the complex amplitude distribution of the previous frame, the calculation time per frame is independent of the number of points comprising the 3D point cloud. Then, the system can quickly update the hologram even when the number of points comprising the 3D point cloud is increased. Because the 3D point-cloud image reconstructed from the calculated hologram is projected at the same position as the observer’s fingertip with almost no latency, the system can draw and erase a 3D point-cloud image through interactions with the observer’s fingertip. We experimentally confirmed that the system successfully draws and erases a 3D point-cloud image.