Abstract: An image pickup apparatus such as a video camera including a pickup tube, a diaphragm mechanism and an electrochromic filter plate which are disposed along the optical path of incident image light on the pickup tube. When an illuminance of an object to be photographed is lower than a predetermined illuminance, only the diaphragm mechanism is used to suitably control an exposure of the pickup tube. However, when the illuminance of the object exceeds the predetermined illuminance level, the diaphragm mechanism is operated to keep its aperture size at a predetermined aperture size which is larger than an original minimum aperture size corresponding to a pinhole state. At the same time, the electrochromic filter plate continuously changes its light transmissivity in response to an aperture control signal, thereby controlling the exposure of the pickup tube.

Abstract: An improvement in an all solid type electrochromic display element comprising a first electrode, a first oxidation-reduction reaction film layer, an insulating film layer, a second oxidation-reduction reaction film layer and a second electrode laminated in this order. The improvement is characterized in that only one of the first and second oxidation-reduction film layers is patterned.