Four cameras provide a 360 degree view of an area using a four sided pyramid shaped element. The four sides of the pyramid shaped element are reflective and reflect images from four different directions. Each camera is positioned to receive a reflected image from one of the reflective sides of the pyramids....http://www.google.com.tw/patents/US5990934?utm_source=gb-gplus-share專利 US5990934 - Method and system for panoramic viewing
