IMAGING OPTICAL SYSTEM AND ENDOSCOPE IMAGING APPARATUS
First Claim
1. An imaging optical system disposed in a front end portion of an insertion section of an endoscope,whereinwhen a position on which light from an object distance is focused by the imaging optical system is defined as an imaging position, and the farthest limit and the nearest limit of depth of field in the imaging optical system are defined as a far point and a near point, respectively, the imaging optical system satisfies conditional expression (1):
- whereinZf represents a spherical aberration of a ray transmitted through 70% of a pupil diameter at the imaging position at a time when an object is disposed at the far point,Sf represents a field curvature in a sagittal direction at 80% of a maximum image height at the imaging position at the time when the object is disposed at the far point,Tf represents a field curvature in a tangential direction at 80% of the maximum image height at the imaging position at the time when the object is disposed at the far point,Zn represents a spherical aberration of a ray transmitted through 70% of a pupil diameter at the imaging position at a time when the object is disposed at the near point,Sn represents a field curvature in a sagittal direction at 80% of the maximum image height at the imaging position at the time when the object is disposed at the near point, andTf represents a field curvature in a tangential direction at 80% of the maximum image height at the imaging position at the time when the object is disposed at the near point.
1 Assignment
0 Petitions
Accused Products
Abstract
An imaging optical system disposed in a front end portion of an insertion section of an endoscope is provided and satisfies:
where, Zf is a spherical aberration of a ray transmitted through 70% of a pupil diameter, and Sf and Tf are field curvatures in a sagittal direction and a tangential direction, respectively, at 80% of a maximum image height, at the imaging position at a time when an object is disposed at the far point; and Zn is a spherical aberration of a ray transmitted through 70% of a pupil diameter at the imaging position, and Sn and Tn are field curvatures in a sagittal direction and a tangential direction, respectively, at 80% of the maximum image height, at the imaging position at the time when the object is disposed at the near point.
143 Citations
4 Claims
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1. An imaging optical system disposed in a front end portion of an insertion section of an endoscope,
wherein when a position on which light from an object distance is focused by the imaging optical system is defined as an imaging position, and the farthest limit and the nearest limit of depth of field in the imaging optical system are defined as a far point and a near point, respectively, the imaging optical system satisfies conditional expression (1): -
wherein Zf represents a spherical aberration of a ray transmitted through 70% of a pupil diameter at the imaging position at a time when an object is disposed at the far point, Sf represents a field curvature in a sagittal direction at 80% of a maximum image height at the imaging position at the time when the object is disposed at the far point, Tf represents a field curvature in a tangential direction at 80% of the maximum image height at the imaging position at the time when the object is disposed at the far point, Zn represents a spherical aberration of a ray transmitted through 70% of a pupil diameter at the imaging position at a time when the object is disposed at the near point, Sn represents a field curvature in a sagittal direction at 80% of the maximum image height at the imaging position at the time when the object is disposed at the near point, and Tf represents a field curvature in a tangential direction at 80% of the maximum image height at the imaging position at the time when the object is disposed at the near point. - View Dependent Claims (2, 3, 4)
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Specification