An autostereoscopic 3D display device may be configured to set the width of a viewing zone to a proper fraction of the interocular distance while at the same time overlapping the viewing zones with each other. Through this, an autostereoscopic 3D display device allowing the input and output of stereo image data may be implemented to reduce the number of image sources as well as reduce 3D crosstalk. In addition, the autostereoscopic 3D display device may apply view data rendering to extend a 3D viewing zone.