Patent ID: 7623167

Claim:
A wavelength proportion detection apparatus comprising: a color filter which transmits light from an object irradiated with light from a light source; an image-pickup element which outputs an image-pickup signal by converting light in a visible wavelength region and light in an infrared wavelength region transmitted through the color filter into an electrical signal; an extractor which extracts a color-difference signal from the image-pickup signal; and a detector which detects, on the basis of the extracted color-difference signal, the proportion of a wavelength component in a first infrared wavelength region and the proportion of a wavelength component in a second infrared wavelength region in the light from the light source, the first infrared wavelength region being a region in which the transmittance of the color filter for a red wavelength component is higher than the transmittances of the color filter for blue and green wavelength components, and the second infrared wavelength region being a region in which the difference between the transmittance of the color filter for the red wavelength component and the transmittances of the color filter for the blue and green wavelength components is smaller than that in the first infrared wavelength region.