Small short back focus 2 lens optical imaging lens system

摘要

[Task] to provide a compact short back focus 2 lens optical imaging lens system. A first lens having a A positive refractive index, and a second lens having a negative refractive power, and an infrared filter, is configured with an image sensor, by the following conditions: to satisfy Equation 9], wherein , f ₁ is the focus length of the first lens, the distance f ₂ is the focal length of the second lens, bf is the back focus distance of the imaging lens system, TL is the aperture stop on the optical axis to the image plane. [Equation 9] .BACKGROUND