Abstract: A signal processing device which makes an adjustment of a displayed picture easy. When a game button 31 of a television is pressed, a picture and a sound from a game unit are selected from among a plurality of inputs, an indicator 10 lights up and a predetermined sound is outputted to confirm for the user that the picture and the sound of the game unit have been selected. When the game button 31 is rotated, preset types of adjustment of the displayed picture, for example, a change to the aspect ratio or a change to the position in which the picture is displayed on a CRT, are carried out.

Abstract: A device having a display device employing a cathode-ray tube and an electron beam includes an on-screen display memory for storing data used to display white on an entire screen of the cathode-ray tube, a circuit for supplying signals used to display white on the entire screen of the said display device employing the electron beam based on the data stored in the on-screen display memory, and a controller for outputting a signal indicative of a command for displaying white on the entire screen from the on-screen display memory in accordance with a de-energizing operation. The signals used to display white on an entire screen of the cathode-ray tube are output to the display device employing the electron beam after the device having the display device is de-energized. Displayed contents are erased by removing a residual high voltage in the display device employing the electron beam.