The composite colour television system mainly used in the USA and Japan. It was defined by the NTSC (US National Television Systems Committee). It has 525 lines, interlaced at 60 Hz.

• 这个综合性彩色电视系统主要在美国和日本使用。它由NTSC（美国国家电视系统委员会）界定。它包括525条线路，并以60赫兹的频率相交。