Vehicle-mounted display system

Left and right frame elements are provided in such a manner as to be movable in a horizontal direction. The left frame element has a shape of the left half of a circular ring and the right frame element has a shape of the right half of the circular ring. The frame elements are horizontally positioned away from each other such that the left frame element surrounds the left side of a speedometer image displayed on a display and the right frame element surrounds the right side of a tachometer image displayed on the display. Two frame interpolation part images are arranged and displayed on the display in a form that the two frame interpolation part images couple upper edges of the left and right frame elements to each other and couple lower edges of them to each other, respectively.