A screen medium of a rear projection screen is formed on its incidence surface with lenticular lenses, and on its viewing surface with lenticular lenses in light focusing area and with grooves and ridges in no-light focusing areas. Each of the grooves is bordered by the ridges and filled therein a ink...http://www.google.com.tw/patents/US4927233?utm_source=gb-gplus-share專利 US4927233 - Rear projection screen
