图文电视是利用电视机正程扫描显示图像、逆程扫描则被消隐这一原理,将文字、图片等信息,通过数字处理及特殊编码后,插入到逆程信号中随电视信号一同发射,接收端用图文数据信息接收卡截获逆程信号中的附加信息,经解调处理后,便可还原及重现。1972年英国率先播出了这种当时被称做电子杂志的图文电视。进入90年代中期,一种新兴的卫星电视逆程(VBI)信息传输业务,得到快速的推广,它具有覆盖面大、信息传输速度快和实时高效等特点。由西安交大通视数据有限责任公司(下称通视公司)出品的通视Ⅲ型(V型)内置图文数据信息接收卡就是此项技术的延伸产品。图1是通视Ⅲ型图文数 Teletext is to use the TV program to scan the display image, reverse scan is blanked this principle, the text, pictures and other information, through digital processing and special coding, inserted into the reverse signal with the television signal transmitted together , The receiving end uses the teletext data receiving card to intercept the additional information in the reversing signal, after being demodulated, it can be restored and reproduced. In 1972, the United Kingdom was the first to broadcast the teletext, then known as an electronic magazine. Into the mid-90s, a new satellite television reverse (VBI) information transmission business, get rapid promotion, it has a large coverage, information transmission speed and real-time efficient features. The Type V (V) built-in teletext data receiving card produced by Xi’an Jiaotong University’s General Data Co., Ltd. (hereinafter referred to as “Video Company”) is an extension of this technology. Figure 1 is the type of visual III figure