Vehicle-mounted displaying device employing TV program displaying method

A vehicle-mounted device is configured to execute a predetermined function as a foreground process and a TV function as a background process. The vehicle-mounted device is provided with a displaying device. An image corresponding to the predetermined function is displayed on the displaying device when the predetermined function is executed. The device further includes a TV program switching system, a small image generating system that generates a small image when the program switching system is operated to switch the TV programs. The small image is superimposed on the image corresponding to the predetermined function. The device further includes a display control system that displays the small image on the displaying devices such that the small image is superimposed on the image corresponding to the predetermined function, the display control system extinguishing the small image at a predetermined timing.