Patent ID: 6147808
Filing Date: 2000-11-14
Classification: G02B

Abstract:
An image-forming optical system having a positive refracting power as a whole for forming an object image, said image-forming optical system comprising:a first prism and a second prism, each of said first prism and second prism being formed from a medium having a refractive index (n) larger than 1.3 (n>1.3), said second prism being placed at a position on an image side of said first prism, in an optical path exiting said first prism and intersecting a plane where said object image is formed,wherein an intermediate image is not formed,said first prism having three optical surfaces said three optical surfaces comprising:a first surface through which a light beam from an object enters said first prism;a second surface that reflects the light beam entering through said first surface in said first prism;said first surface further reflecting the light beam reflected by said second surface in said first prism; anda third surface through which the light beam reflected by said first surface exits from said first prism;wherein at least one of said first surface and said second surface has a curved surface having a power;said curved surface having a rotationally asymmetric surface configuration that corrects aberrations due to decentration;said second prism having at least one reflecting surface, said reflecting surface having a rotationally asymmetric surface configuration having a power and correcting aberrations due to decentration.