Abstract: An image sensor, including a substrate having a first surface, and a second surface opposite to the first surface; a first focus pixel; a first merged pixel; a second merged pixel; a first color filter; a second color filter; a third color filter; a grid pattern separating the first to third color filters, but not overlapped by the first to third color filters; a first micro-lens disposed on the first color filter; and a second micro-lens disposed on the second and third color filters, wherein a first-third unit pixel, the first focus pixel, and a second-third unit pixel are continuously arranged along the first direction, and wherein a width of the grid pattern between the first color filter and the second color filter is greater than a width of the grid pattern between the second color filter and the third color filter.