Patent ID: 7842909

Claim:
A CMOS imager comprising: a photosite array; and a microlens array comprising first microlenses and second microlenses, the first and second microlenses being alternately distributed according to a constant pitch, the second microlenses each having a circular edge, wherein: each first microlens is surrounded by four adjacent second microlenses and has an active surface with rounded edges including four positive rounded edges with positive curve and four negative rounded edges with negative curve, the four positive rounded edges of the first microlens being four arcs of a circle having a first radius that is larger than a second radius of the circular edge of each second microlens, and the four negative rounded edges of the first microlens being defined by respective arcs of the circular edges of the four adjacent second microlens that surround the first microlens, and the second microlenses have active surfaces with surface areas that are substantially equal to surface areas of the active surfaces of the first microlenses.