| 摘要 |
PROBLEM TO BE SOLVED: To provide an eccentric optical system, an image projection device, and an image imaging device which are compact and simple in structure and capable of projecting or imaging an image with high resolution.SOLUTION: An eccentric optical system 1 has a first optical element 10 having at least three optical surfaces that are eccentric with one another including a first surface 11, a second surface 12; and a third surface 13, and an inner refractive index equal to or larger than 1, and rotation non-symmetrical with at least one optical surface; and a second optical element 20 arranged on the side of the surface 12 and having at least two optical surfaces that are eccentric to each other including a recess-shaped second surface 22 on the first surface 21 and the outside, an inner refractive index equal to 1 or larger, and rotation-non symmetry with at least one optical surface. The first optical element and the second optical element are spaced apart from each other in a passage area of a light flux, and satisfies the following formula: 0<D/f≤0.3 provided that Dis the maximum value of a distance measured in a direction parallel to a central principal ray between the surface 12 and the surface 21 in the passage region of a light flux on a cross section including the central principal ray Lc, and f is a focal length of the eccentric optical system 1.SELECTED DRAWING: Figure 1 |
