Patent ID: 7880978
Filing Date: 2011-02-01
Classification: G02B

Abstract:
1. A high performance fixed focal length optical imaging system operable to receive radiation from an object space and deliver the received radiation through the optical system so as to form an image at an image surface in an image space, said optical system comprising: a first positively powered lens group and a second positively powered lens group arranged in that order from object space to the image space of the optical system and aligned on a common optical axis wherein; the first positively powered lens group comprising a plurality of optical elements wherein at least one of the plurality of optical elements is stationary and at least one of the plurality of optical elements has an aspheric optical surface; and the second positively powered lens group comprising at least one optical element and being operable to move axially along the common optical axis for focusing the imaging system, wherein at least one optical element of the second lens group has an aspheric optical surface.