Patent ID: 7570284

Claim:
A white balance adjustment circuit comprising: a first gain adjuster that adjusts a signal level of a second analog image-capturing signal based on a color temperature of a subject, the second image-capturing signal being provided by an image-capturing element which captures an image of a subject through a spectroscopic element and outputs a first analog image-capturing signal corresponding to a first color, the second analog image-capturing signal corresponding to a second color and a third analog image-capturing signal corresponding to a third color; a second gain adjuster that adjusts a signal level of the third analog image-capturing signal based on the color temperature of the subject, the third analog image-capturing signal being provided by the image-capturing element; an A/D converter that performs A/D conversion of: the first analog image-capturing signal to output a first digital image-capturing signal, the second analog image-capturing signal adjusted by the first gain adjuster to output a second digital image-capturing signal, and the third analog image-capturing signal adjusted by the second gain adjuster to output a third digital image-capturing signal; and a white balance adjuster that adjusts a signal ratio among the first digital image-capturing signal, the second digital image-capturing signal having been adjusted by the first gain adjuster, and the third digital image-capturing signal having been adjusted by the second gain adjuster to achieve a predetermined ratio, wherein the white balance adjuster multiplies each of the first, the second and the third digital image-capturing signals by an adjustment coefficient larger than 1.