Patent ID: 7573499

Claim:
An endoscope apparatus, comprising: an endoscope having an image pickup element having a sensitivity, which can be changed by multiplying generated charges by supplied pulse-type signals; a light source portion for irradiating light to an object; an aperture portion for adjusting an amount of light to be irradiated to the object; a driver portion for adjusting and supplying the pulse-type signals to the image pickup element in order to change the sensitivity of the image pickup element; a metering portion for generating an intensity signal based on a signal output from the image pickup element; a sensitivity control portion for, based on the intensity signal of the metering portion, supplying to the driver portion a sensitivity control signal for generating the pulse-type signals for controlling a charge multiplication factor of the image pickup element; an aperture control portion for controlling the aperture portion based on the intensity signal of the metering portion; and a dimming/switching portion for selectively operating sensitivity control of the image pickup element by the sensitivity control portion and the aperture portion by the aperture control portion in accordance with intensity of the intensity signals, wherein, in a state where the sensitivity control of the image pickup element by the sensitivity control portion is operated, when the intensity of the intensity signal is equal to or greater than a predetermined value and a sensitivity multiplication factor is the predetermined minimum value, the dimming/switching portion fixes the sensitivity multiplication factor to the predetermined minimum value and operates only the control of the aperture portion by the aperture control portion, and in a state where the control of the aperture portion by the aperture control portion is operated, when the intensity of the intensity signal is smaller than the predetermined value and the aperture portion is at a full-open position, the dimming/switching portion fixes the aperture portion at the full-open position and operates only the sensitivity control of the image pickup element by the sensitivity control portion.