PURPOSE: To eliminate a ghost based upon the distortion of a transmitted image signal by differentiating the transmitted signal and varying its amplitude with an amplifier and then adding the output to the original transmitted signal.

CONSTITUTION: A work station 104 outputs digital image signal data. An image signal processing circuit 105 converts the digital image signal data into an analog image signal and transmits the signal by a transmission cable 106. The transmission output waveform is distorted while containing a reflected wave. A differentiation circuit 101 generates the differentiated signal of the signal and an amplifying circuit 102 amplifies it. An adder 103 adds the transmission output signal and the output signal of the amplifying circuit 102 and inputs the composite signal to a liquid crystal display device 107. The gain of the amplifying circuit 102 is adjusted so that the influence of the distortion of the signal waveform generated by the transmission is canceled when sampled and held, thereby removing the ghost.