Imaging optical system and imaging device

Abstract

To provide an imaging optical system capable of scanning an object with a simple mechanism without moving the object and an imaging element.SOLUTION: An imaging optical system 10 according to the present disclosure is used for obtaining a spectral image of an object S by guiding light L for imaging the object S into an imaging element 31, the system comprising: a first diaphragm 11 positioned on an objective lens 70 side; a scanning part 12 positioned on an imaging element 31 side relative to an image forming position of the light L having passed through the first diaphragm 11; a light condensing part 13 condensing the light L having passed through the scanning part 12; a second diaphragm 14 positioned on the imaging element 31 side relative to the light condensing part 13; and a slit 15 disposed on a position at which the light L passes through the second diaphragm 14 and is condensed by the light condensing part 13. The slit 15 causes only the light L corresponding to a predetermined region of the object S out of the light L having passed through the scanning part 12 to pass. The scanning part 12 changes the predetermined region to scan the object S while keeping constant an optical path length between the image forming position and the light condensing part 13.SELECTED DRAWING: Figure 1

Claims

[Claim 1] An imaging optical system used to guide light for imaging an object to an image sensor and to obtain a spectral image of the object, The first aperture is located on the objective lens side, A scanning unit located on the image sensor side of the image formation position by the light that has passed through the first aperture, A light-collecting unit that collects the light that has passed through the scanning unit, A second aperture located closer to the image sensor than the light-gathering section, A slit is positioned so that the light passes through the second aperture and is focused by the light-gathering section, Equipped with, The slit allows only the light corresponding to a predetermined area of ​​the object to pass through the scanning unit. The scanning unit scans the object by changing the predetermined area while maintaining a constant optical path length between the imaging position and the light-gathering unit. Imaging optical system. [Claim 2] The imaging optical system according to claim 1, The scanning unit has a first mirror and a second mirror that move in the same direction and by the same distance from each other along the short-side direction of the slit during scanning of the object. Imaging optical system. [Claim 3] The imaging optical system according to claim 2, The scanning unit includes a third mirror that reflects the light reflected by the first mirror back to the second mirror, and a fourth mirror that reflects the light reflected by the second mirror back to the light-gathering unit. Imaging optical system. [Claim 4] An imaging optical system according to any one of claims 1 to 3, The first aperture is positioned in an open state with an aperture value of 4 or less. Imaging optical system. [Claim 5] An imaging optical system according to any one of claims 1 to 3, The second aperture has an F-number of 11 or more and 16 or less. Imaging optical system. [Claim 6] An imaging optical system according to any one of claims 1 to 3, The width of the slit in the shorter direction of the slit is within the range of 80 μm to 120 μm. Imaging optical system. [Claim 7] An imaging optical system according to any one of claims 1 to 3, The system further comprises a spectroscopic element that spectrally separates the light that has passed through the slit into multiple wavelength regions defined by a hyperspectrum. Imaging optical system. [Claim 8] An imaging apparatus comprising the imaging optical system according to any one of claims 1 to 3, the objective lens, and the image sensor. [Claim 9] The imaging apparatus according to claim 8, The imaging device includes a rigid endoscope. Imaging device.

Images