US Patent 7851837 Light-collecting device and solid-state imaging apparatus

A solid-state imaging apparatus includes unit pixels arranged in a two-dimensional array. Each unit pixel includes a light-collector and light-receiver. The light-collector includes light-transmitting films that form a refractive index distribution and multiple zones, each of which has a width equal to or shorter than a wavelength of incident light. For each central unit pixel, a center axis of the light-receiver matches a central axis of the light-collector. For each peripheral unit pixel, a central axis of the light-collector is displaced from the central axis of the light-receiver toward the center of the imaging area. The line width of each light-transmitting film of a central unit pixel is different than the line width of each light-transmitting film of a peripheral unit pixel in a same relative position, and the sum of line widths of the central unit pixel differs from the sum of line widths of the peripheral unit pixel.