Patent ID: 8487953

Claim:
An image signal converting apparatus used in a lighting apparatus that includes a red-light imager modulating a red component light according to a red image signal, a green-light imager modulating a green component light according to a green image signal, and a blue-light imager modulating a blue component light according to a blue image signal, in the lighting apparatus, a fourth color component light being simultaneously superimposed on any of the red component light, the green component light, and the blue component light, by a controlling unit, wherein the controlling unit configured to control a superimposition amount of the fourth color component light based on a specific image signal having lower signal strength among two specific image signals corresponds to specific color component lights having hues adjacent to a hue corresponding to the fourth color component light, a color reproduction parameter determined so that the light amount of the fourth color component light increases along with an increase in saturation of an image and a luminance parameter determined so that the light amount of the fourth color component light decreases along with an increase in saturation of an image, wherein the controlling unit controls a reduction amount of the two specific image signals based on the superimposition amount.