高中英语 Unit 3 The world of science Section Ⅰ Starting out Understanding ideas教案 外研版必修第三册-外研版高一第三册英语教案VIP专享

Unit 3 The world of science电视机是怎么来的呢？哪些人对它的发展做出了贡献呢？让我们通过下文一探究竟。The invention of television was a gradual process(过程)．The television was not invented by a single person.Before it appeared, people from all over the world had experimented on it for many times.At the dawn of television history, there were two competing( 相 互 矛 盾 的 ) experimental approaches that led to the breakthroughs that made the technology possible.Early inventors attempted to either build a mechanical television system based on the technology of Paul Nipkow’s rotating disks(旋转磁盘) or they tried to build an electronic television system using a cathode ray(阴极射线) tube developed independently in 1897 by German inventor Karl Braun.German inventor Paul Nipkow developed a rotating disc technology to send pictures over wire in 1884 called the Nipkow disk.Nipkow is famous for discovering television’s scanning(扫描) principle，in which the light strength of small parts of an image(形象) is successively analyzed(分析) and sent.In the 1920’s, John Logie Baird came up with the idea of using lines of a special metal to send images for television by reflected light rather than backlit silhouettes. Baird based his technology on Paul Nipkow’s scanning disc idea and other latest developments in electronics.Russian inventor Vladimir Zworykin invented an improved cathode ray tube in 1929. At the time, the tube was badly needed for television and Zworykin was one of the first to test a television system with all the features of modern picture tubes.In 1927, American inventor Philo Farnsworth became the first inventor to send a television image consisting of 60 level lines. The image sent was dollar sign.Farnswo...