30-view Projection 3D Display

摘要

A 30-view auto-stereoscopic display using angle-magnifying screen is proposed. Small incident angle of Lamp-scanning from exit pupil of projection lens is magnified into large field of view on the observing side. The lamp-scanning is realized by the vibration of Galvano-mirror that synchronizing with the frame rate of the DMD and reflecting the laser illuminator to the scanning angles. To achieve 15-view, a 3-chip DLP projector with frame rate of 720 Hz is used. From one cycle of vibration of Galvano-mirror, steps of 0, 2, 4, 6, 8 10, 12, 14 are reflected on going-path and steps of 13, 11, 9, 7, 5, 3, 1 are reflected on returning path. A frame is divided into two half parts of odd lines and even lines for two views. For each view, 48 half frames per second are provided. A projection lens with aperture-relay module is used to double the lens aperture and separating the frame into two half parts of even and odd lines. After going through the Philips prism, three panels, the scanning 15 spots are doubled to 30 spots and emerge from the exit pupil of the projection lens. The exit 30 light spots from the projection lens are projected to 30 viewing zones by the angle-magnifying screen. A cabinet of rear projection with two folded mirrors is used because a projection lens of long throw distance is required.