PURPOSE: To provide a picture signal converter capable of automatically changing the view angle size.

CONSTITUTION: When signals in the non-interlace system from a PC display signal generation part 15 which forms a computer picture are selected by a control signal TCS from a microcomputer 31, the program to generate the picture data having the view angle size reduced is automatically executed in a PC signal processing part 13 based on the control signal TCS. Picture data having the view angle size reduced is converted into signals in the non-interlace system by the PC display signal generation part 15. Signals in the interlace system are generated from these signals in the non-interlace system to display the computer picture on a television device 22 connected to a video terminal 21. Since the computer picture has the view angle size reduced, all the computer picture is displayed on the screen of the television device 22 even in the case of the use of the overscan type television device 22.