Display system with single/dual image modes

A display system, comprising:

• (a) an input line selector for selecting two of n input lines as a first input line and a second input line, where n is an integer equal to or greater than 3;
• (b) a first detector for detecting a synchronizing signal of a first video input sent through the first input line;
• the first detector outputting a first detection signal when the synchronizing signal of the first video input is detected;
• (c) a second detector for detecting a synchronizing signal of a second video input sent through the second input line;
• the second detector outputting a second detection signal when the synchronizing signal of the second video input is detected;
• (d) a switch for automatically selecting one of a single image mode and a dual image mode;
• the switch automatically selecting the single image mode when receiving one of the first detection signal outputted from the first detector and the second detection signal outputted from the second detector, thereby producing a first output signal;
• the first output signal corresponding to the one of the first video input and the second video input received by the switch;
• the switch automatically selecting the dual image mode when receiving both of the first detection signal outputted from the first detector and the second detection signal outputted from the second detector, thereby producing a second output signal;
• the second output signal corresponding to the both of the first video input and the second video input received by the switch;
• and
• (e) a display device for displaying an image according to the first output signal on a screen in the single image mode and two images according to the second output signal on the screen in the dual image mode.