Patent ID: 8269799

Claim:
An image signal processor comprising: a controller configured to generate a red output signal, a green output signal, a blue output signal and a fourth color output signal in accordance with image input signals including a red input signal corresponding to a red light component, a green input signal corresponding to a green light component and a blue input signal corresponding to a blue light component, and configured to output the red output signal, the green output signal, the blue output signal and the fourth color output signal, a red imager configured to modulate the red light component, a green imager configured to modulate the green light component, a blue imager configured to modulate the blue light component, a polarization switching element configured to adjust polarization state of a fourth color light component enables to reproduce a color outside the range of a color reproducible by the red light component, the green light component and the blue light component, and a combining unit configured to combine the light components emitted from the red imager, the green imager and the blue imager, wherein a superimposed light component, which is one of the red light component, the green light component, and the blue light component, enters the polarization switching element with the fourth color light component, the polarization switching element transmits the superimposed light component and the fourth color light component, while changing the polarization direction between the superimposed light component and the fourth color light component, the superimposed light component and the fourth color light component emitted from the polarization switching element enters an imager corresponding to the superimposed light component, the controller generates the fourth color output signal on the basis of a reference signal, among the image input signals, that corresponds to a color different from a complementary color of a color reproduced by the fourth color light component, and on the basis of a color reproduction parameter α for controlling a light amount of the fourth color light component, and the color reproduction parameter α is determined that the light amount of the fourth color light component is increased along with an increase in color saturation of an image.