| 摘要 |
PROBLEM TO BE SOLVED: To widen the angle of field, and to allow an image plane to be placed near the image capturing area over the whole angle of field. SOLUTION: A capsule endoscope 10 is provided with an image-capturing optical system 20 for capturing an image of the object surface 12 of a concave semispherical surface. The image-capturing optical system 20 satisfies -5≤ΔZr/ΔZp≤5 whereΔZr represents the difference between the position of the real image plane with respect to the light flux of 2ωmax and the position of the real image plane with respect to the light flux ofωmax when the maximum half angle of field is denoted byωmax, andΔZp represents the difference between the position of the paraxial image plane when the plane passing through the intersection point P1 of the object surface 12 and the principal ray of 2ωmax and perpendicular to the optical axis XP is defined as a virtual object surface 24 and the position of the paraxial image plane when the plane passing through the intersection point P2 of the object 12 and the principal ray ofωmax and perpendicular to the optical axis Xp is defined as a virtual object surface 25. COPYRIGHT: (C)2011,JPO&INPIT |
