Patent ID: 8885032

Claim:
An endoscope apparatus comprising: an illumination section that irradiates at least one illuminating light having a predetermined wavelength band to a subject; an image pickup section that picks up an image of return light from the subject based on the irradiation by the illumination section; an image signal processing section that generates an image signal based on an image pickup signal from the image pickup section; a light-adjusting section that, based on a first luminance value based on a signal with a first wavelength band that is a narrow band and a second luminance value based on a signal with a second wavelength band that is a narrow band between a wavelength band providing a maximal value and a wavelength band providing a minimal value in a light absorption characteristic of hemoglobin in a body tissue of the subject in a red band in a visible range, the second wavelength band being within the red band in the visible range, providing an absorption coefficient lower than that of the signal of the first wavelength band in the light absorption characteristic of hemoglobin and providing a suppressed scattering characteristic of the body tissue, and a third luminance value based on a signal with a third wavelength band that is a narrow band, the third wavelength band being a wavelength band outside the red band, and providing an absorption coefficient higher than that of the signal with the first wavelength band in the absorption characteristic, performs processing for addition by adding a weight coefficient larger than a weight coefficient to be added to the third luminance value to the first luminance value and the second luminance value to calculate a light adjustment reference signal for adjusting a light amount in the illumination section and outputs the light adjustment reference signal; and an illumination control section that controls an amount of light irradiated by the illumination section based on the light adjustment reference signal outputted from the light-adjusting section.