US Patent 11635584 Optical imaging system

An optical imaging system includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a positive refractive power, a fifth lens having a negative refractive power, and a sixth lens having a negative refractive power. The first to sixth lenses are sequentially disposed from an object side to an imaging plane. An Abbe number of the second lens is 21 or less.