Abstract: A signal processor apparatus is adaptable to electronic endoscopes having different lengths without the need for changing the operation timing when sampling a video signal. A sampling pulse generator incorporating a phase varying means is disposed in the operating portion or the connecting portion (setup board) of an electronic endoscope. A sampling pulse having the timing corresponding to the length of the electronic endoscope is formed by varying the phase of the sampling pulse by the phase varying means. The sampling pulse generator may be disposed together with a sample-and-hold circuit, a driving circuit of a CCD and the like. Since it is possible to sample and hold the video signal by using the sampling pulse which is correspondent with the length of the electronic endoscope, effective picture signal processing by the processor apparatus is enabled.