Patent ID: 7230225

Claim:
An image sensor unit comprising a first photodiode array for photoelectrically converting light of a first color from a source image into a first color output signal a second photodiode array for photoelectrically converting light of a second color from a source image into a second color output signal a third photodiode array for photoelectrically converting light of a third color from a source image into a third color output signal, wherein the first, second, and third color output signals are digitized into respective first, second, and third color pixel data each having a first number of bits per pixel a fourth photodiode array for photoelectrically converting light from the source image into a monochrome output signal, wherein the monochrome output signal is digitized into monochrome pixel data having a second number of bits per pixel greater than the first number of bits per pixel a color signal correction unit to combine the monochrome pixel data with the first, second, and third color pixel data to provide first, second, and third enhanced color image signals having improved gradation compared to the first, second, and third color output signals.