Patent ID: 7245443

Claim:
A panoramic attachment optical system, which is attached to an entrance side of an image-formation lens having positive power or an exit side of a projection lens having positive power to form a full 360°-direction image on a an image plane or project an image located on an image plane in a full 360° direction, wherein said panoramic attachment optical system comprises a transparent medium that is rotationally symmetric about a center axis and includes at least two internal reflecting surfaces and at least two refracting surfaces, wherein a light beam enters said transparent medium via an entrance-side refracting surface in order of travel of a light ray in the case of an image-formation optical system, and oppositely to the order of travel of a light ray in the case of a projection optical system, and reflects successively at said internal reflecting surfaces to leave said transparent medium via an exit-side refracting surface, forming an image at a position of said image plane off said center axis via said image-formation lens or said projections lens, said internal reflecting surfaces and said refracting surfaces are each of shape rotationally symmetric about said center axis, and a light beam coming from far away forms an image at least one time in a section including said center axis, and at least one time in a plane that is orthogonal to said section and includes a center light ray of said light beam as well.