Patent US 4,821,116

This invention concerns an endoscope using a line transfer type solid pickup element which is provided with a means to control the light incident upon the light receiving plane of the solid pickup element and accumulates the optical image from the subject during the incident period and reads the accumulated signal charges during the non-incident period. The means to control the incident light consists of the method to switch ON and OFF the light source driving voltage, method to switch ON and OFF the applied voltage of the liquid crystal filter provided in the optical path, method to provide a rotary filter with shielding regions in front of the light source and method to use a strobo light source. Furthermore, in order to display in color, the combination with the R, G and B color filters is used.