Optical system, image projection apparatus, and imaging apparatus

Abstract

The present disclosure is directed to an optical system internally having an intermediate imaging position MI that is conjugate with both of a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, the optical system including: a first positive lens group GP1 including a plurality of lens elements and positioned on the magnification side with respect to the intermediate imaging position; a second positive lens group GP2 including a plurality of lens elements and positioned between the first positive lens group GP1 and the intermediate imaging position M1; and a negative lens group GN including a plurality of lens elements and positioned on the reduction side with respect to the intermediate imaging position MI, wherein, during focusing, the first positive lens group GP1 and the negative lens group GN move in an optical axis direction, and the second positive lens group GP2 is stationary.

Dependencies are inferred from the claim text.