Endoscope optical system
AssigneeOlympus Corporation
InventorTsutomu Igarashi
Life of this patent
Estimating the term…
Abstract
An endoscope observation optical system capable of improving the observation resolution of a mucous membrane of a living body is provided. The endoscope includes an observation optical system compatible with both standard visible-light observation and blood-vessel-enhancement observation, whose main component of a displayed image is an absorption peak of hemoglobin present in a waveband lower than 480 nm, wherein some longitudinal chromatic aberration remains in the endoscope observation optical system due to undercorrection at a wavelength of 415 nm, and wherein the focal position during blood-vessel-enhancement observation is set closer to a near point than the focal position during standard visible-light observation.
Claims2
An endoscope comprising:
- an observation optical system compatible with both standard visible-light observation and blood-vessel-enhancement observation whose main component of a displayed image is an absorption peak of hemoglobin present in a waveband lower than 480 nm,
- wherein the endoscope observation optical system satisfying Formula (1) below for the focal position during standard visible-light observation:
- −0.25<Δ[415]/f<−0.02 (1)
- where Δ[415] represents the longitudinal chromatic aberration of light having a wavelength of 415 nm (when light having a wavelength of 546 nm is used as a reference), and f represents the focal length of the entire observation optical system for light having a wavelength of 546 nm.
Dependencies are inferred from the claim text.