To realize a simplified image display apparatus that prevents electrical connection between an external monitor and a receiving device when an electric signal generated by the receiving device is transmitted to the external monitor. The simplified image display apparatus includes a photocoupler 23 formed of a light emitting unit 21 electrically connected only to an input terminal 10 and a light receiving unit 22 that receives light output from the light emitting unit 21, a demodulator 24 that demodulates a received radio signal, a switching unit 25 that outputs either one of electric signals from the photocoupler 23 and from the demodulator 24, and a data generator 26 that applies predetermined signal processing to the electric signal input from the switching unit 25 to generate image data, and outputs the image data to a display unit 9 and an output terminal 11.