Optical element and optical system having the same
AssigneeCanon Kabushiki Kaisha
InventorsKeisuke Araki, Sadahiko Tsuji, Tsunefumi Tanaka, Kenichi Kimura, Norihiro Nanba, Hiroshi Saruwatari, Michiharu Aratani, Takeshi Akiyama
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Abstract
An optical element includes an incidence surface, one or more reflecting surfaces reflecting light from the incident surface, an emergence surface, and off-axial curved surfaces causing the light to emerge from the emergence surface. At least one of the incidence surface, the emergence surface and the one or more reflecting surfaces is a surface having diffracting action. The surface having the diffracting action is a curved surface.
Claims34
An optical element of transparent optical material, said optical element comprising:
- an incidence surface on which a light beam is incident;
- one or more reflecting surfaces reflecting the light beam incident on said incidence surface, said one or more reflecting surfaces having an off-axial curved surface;
- and
- an emergence surface from which the light beam reflected by said one or more reflecting surfaces emerges,
- wherein at least one of said incidence surface, said emergence surface and said one or more reflecting surfaces is a surface having rotation-asymmetrical diffracting action, and
- said surface having the rotation-asymmetrical diffracting action being a rotation-symmetrical curved surface.
An optical element of transparent optical material, said optical element comprising:
- an incidence surface on which light is incident;
- one or more reflecting surfaces reflecting light from said incident surface, said one or more reflecting surfaces having an off-axial curved surface;
- and
- an emergence surface from which the light reflected by said one or more reflecting surfaces emerges,
- at least one of said incidence surface, said emergence surface and said one or more reflecting surfaces being a surface having a rotation-asymmetrical diffraction action, said rotation-asymmetrical diffraction-action surface having rotation-asymmetrical stripes for diffracting the light incident thereon,
- said surface having the rotation-asymmetrical diffracting action being a rotation-symmetrical curved surface.
Dependencies are inferred from the claim text.