Samsung patents image sensor using nanoposts to split light for pixels

1. An image sensor comprising: a sensor substrate comprising a first pixel and a fourth pixel configured to detect green light, a second pixel configured to detect blue light, and a third pixel configured to detect red light; and a color separation lens array spaced apart from the sensor substrate in a first direction, the color separation lens array being configured to separate incident light based on wavelengths and condense the separated incident light onto the first pixel, the second pixel, the third pixel, and the fourth pixel, wherein the color separation lens array comprises a plurality of nanoposts and a peripheral material on side surfaces of the plurality of nanoposts, wherein a region of the color separation lens array comprises a first pixel corresponding region, a second pixel corresponding region, a third pixel corresponding region, and a fourth pixel corresponding region facing the first pixel, the second pixel, the third pixel, and the fourth pixel, respectively, and the plurality of nanoposts are provided in the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region, and the fourth pixel corresponding region, wherein the plurality of nanoposts comprise a plurality of main posts each having a refractive index greater than a refractive index of the peripheral material and a plurality of sub-posts each having a refractive index less than the refractive index of the peripheral material, and wherein in respective cross-sections of the first pixel corresponding region, the second pixel corresponding region, the third pixel corresponding region, and the fourth pixel corresponding region which are perpendicular to the first direction, ratios of a sum of respective areas of the plurality of sub-posts to a sum of respective areas of the plurality of main posts are a first fill factor, a second fill factor, a third fill factor, and a fourth fill factor, respectively, the second fill factor being largest among the first fill factor, the second fill factor, the third fill factor, and the fourth fill factor.