Double-screen simultaneous viewing circuit of a wide-television

摘要

A double-screen simultaneous viewing circuit for simultaneously displaying two pictures on the main screen of a extra-wide television is provided. The two pictures each have a 4-to-3 aspect ratio and are displayed on left and right subscreens of the main screen. The viewing circuit includes first and second analog-to-digital converters for respectively converting first and second video signals of the two pictures into digital signals. The first and second video signals are respectively converted according to first and second clock signals which have equal frequencies and which are respectively synchronized with synchronizing signals of the first and second video signals. The digital video signals are stored in first and second memories based on the first and second clock signals, and the digital video signals are read from the first and second memories based on a third clock signal. The third clock signal is synchronized with the synchronizing signals of the first video signal and has a frequency twice as high as the frequency of the first clock signal. The digital video signals are converted into first and second analog signals by first and second digital-to-analog converters based on the third clock signal, and a switch alternately outputs the first and second analog signals according to an horizontal synchronizing signal of the first video signal. Subsequently, the analog signals are respectively displayed on the left and right subscreen as the two pictures.